--- /dev/null
+/*
+ * Copyright (C) 2008
+ * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
+ *
+ * Copyright (C) 2005-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/clk.h>
+#include <linux/vmalloc.h>
+#include <linux/string.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+
+#include <mach/ipu.h>
+
+#include "ipu_intern.h"
+
+#define FS_VF_IN_VALID 0x00000002
+#define FS_ENC_IN_VALID        0x00000001
+
+/*
+ * There can be only one, we could allocate it dynamically, but then we'd have
+ * to add an extra parameter to some functions, and use something as ugly as
+ *     struct ipu *ipu = to_ipu(to_idmac(ichan->dma_chan.device));
+ * in the ISR
+ */
+static struct ipu ipu_data;
+
+#define to_ipu(id) container_of(id, struct ipu, idmac)
+
+static u32 __idmac_read_icreg(struct ipu *ipu, unsigned long reg)
+{
+       return __raw_readl(ipu->reg_ic + reg);
+}
+
+#define idmac_read_icreg(ipu, reg) __idmac_read_icreg(ipu, reg - IC_CONF)
+
+static void __idmac_write_icreg(struct ipu *ipu, u32 value, unsigned long reg)
+{
+       __raw_writel(value, ipu->reg_ic + reg);
+}
+
+#define idmac_write_icreg(ipu, v, reg) __idmac_write_icreg(ipu, v, reg - IC_CONF)
+
+static u32 idmac_read_ipureg(struct ipu *ipu, unsigned long reg)
+{
+       return __raw_readl(ipu->reg_ipu + reg);
+}
+
+static void idmac_write_ipureg(struct ipu *ipu, u32 value, unsigned long reg)
+{
+       __raw_writel(value, ipu->reg_ipu + reg);
+}
+
+/*****************************************************************************
+ * IPU / IC common functions
+ */
+static void dump_idmac_reg(struct ipu *ipu)
+{
+       dev_dbg(ipu->dev, "IDMAC_CONF 0x%x, IC_CONF 0x%x, IDMAC_CHA_EN 0x%x, "
+               "IDMAC_CHA_PRI 0x%x, IDMAC_CHA_BUSY 0x%x\n",
+               idmac_read_icreg(ipu, IDMAC_CONF),
+               idmac_read_icreg(ipu, IC_CONF),
+               idmac_read_icreg(ipu, IDMAC_CHA_EN),
+               idmac_read_icreg(ipu, IDMAC_CHA_PRI),
+               idmac_read_icreg(ipu, IDMAC_CHA_BUSY));
+       dev_dbg(ipu->dev, "BUF0_RDY 0x%x, BUF1_RDY 0x%x, CUR_BUF 0x%x, "
+               "DB_MODE 0x%x, TASKS_STAT 0x%x\n",
+               idmac_read_ipureg(ipu, IPU_CHA_BUF0_RDY),
+               idmac_read_ipureg(ipu, IPU_CHA_BUF1_RDY),
+               idmac_read_ipureg(ipu, IPU_CHA_CUR_BUF),
+               idmac_read_ipureg(ipu, IPU_CHA_DB_MODE_SEL),
+               idmac_read_ipureg(ipu, IPU_TASKS_STAT));
+}
+
+static uint32_t bytes_per_pixel(enum pixel_fmt fmt)
+{
+       switch (fmt) {
+       case IPU_PIX_FMT_GENERIC:       /* generic data */
+       case IPU_PIX_FMT_RGB332:
+       case IPU_PIX_FMT_YUV420P:
+       case IPU_PIX_FMT_YUV422P:
+       default:
+               return 1;
+       case IPU_PIX_FMT_RGB565:
+       case IPU_PIX_FMT_YUYV:
+       case IPU_PIX_FMT_UYVY:
+               return 2;
+       case IPU_PIX_FMT_BGR24:
+       case IPU_PIX_FMT_RGB24:
+               return 3;
+       case IPU_PIX_FMT_GENERIC_32:    /* generic data */
+       case IPU_PIX_FMT_BGR32:
+       case IPU_PIX_FMT_RGB32:
+       case IPU_PIX_FMT_ABGR32:
+               return 4;
+       }
+}
+
+/* Enable / disable direct write to memory by the Camera Sensor Interface */
+static void ipu_ic_enable_task(struct ipu *ipu, enum ipu_channel channel)
+{
+       uint32_t ic_conf, mask;
+
+       switch (channel) {
+       case IDMAC_IC_0:
+               mask = IC_CONF_PRPENC_EN;
+               break;
+       case IDMAC_IC_7:
+               mask = IC_CONF_RWS_EN | IC_CONF_PRPENC_EN;
+               break;
+       default:
+               return;
+       }
+       ic_conf = idmac_read_icreg(ipu, IC_CONF) | mask;
+       idmac_write_icreg(ipu, ic_conf, IC_CONF);
+}
+
+static void ipu_ic_disable_task(struct ipu *ipu, enum ipu_channel channel)
+{
+       uint32_t ic_conf, mask;
+
+       switch (channel) {
+       case IDMAC_IC_0:
+               mask = IC_CONF_PRPENC_EN;
+               break;
+       case IDMAC_IC_7:
+               mask = IC_CONF_RWS_EN | IC_CONF_PRPENC_EN;
+               break;
+       default:
+               return;
+       }
+       ic_conf = idmac_read_icreg(ipu, IC_CONF) & ~mask;
+       idmac_write_icreg(ipu, ic_conf, IC_CONF);
+}
+
+static uint32_t ipu_channel_status(struct ipu *ipu, enum ipu_channel channel)
+{
+       uint32_t stat = TASK_STAT_IDLE;
+       uint32_t task_stat_reg = idmac_read_ipureg(ipu, IPU_TASKS_STAT);
+
+       switch (channel) {
+       case IDMAC_IC_7:
+               stat = (task_stat_reg & TSTAT_CSI2MEM_MASK) >>
+                       TSTAT_CSI2MEM_OFFSET;
+               break;
+       case IDMAC_IC_0:
+       case IDMAC_SDC_0:
+       case IDMAC_SDC_1:
+       default:
+               break;
+       }
+       return stat;
+}
+
+struct chan_param_mem_planar {
+       /* Word 0 */
+       u32     xv:10;
+       u32     yv:10;
+       u32     xb:12;
+
+       u32     yb:12;
+       u32     res1:2;
+       u32     nsb:1;
+       u32     lnpb:6;
+       u32     ubo_l:11;
+
+       u32     ubo_h:15;
+       u32     vbo_l:17;
+
+       u32     vbo_h:9;
+       u32     res2:3;
+       u32     fw:12;
+       u32     fh_l:8;
+
+       u32     fh_h:4;
+       u32     res3:28;
+
+       /* Word 1 */
+       u32     eba0;
+
+       u32     eba1;
+
+       u32     bpp:3;
+       u32     sl:14;
+       u32     pfs:3;
+       u32     bam:3;
+       u32     res4:2;
+       u32     npb:6;
+       u32     res5:1;
+
+       u32     sat:2;
+       u32     res6:30;
+} __attribute__ ((packed));
+
+struct chan_param_mem_interleaved {
+       /* Word 0 */
+       u32     xv:10;
+       u32     yv:10;
+       u32     xb:12;
+
+       u32     yb:12;
+       u32     sce:1;
+       u32     res1:1;
+       u32     nsb:1;
+       u32     lnpb:6;
+       u32     sx:10;
+       u32     sy_l:1;
+
+       u32     sy_h:9;
+       u32     ns:10;
+       u32     sm:10;
+       u32     sdx_l:3;
+
+       u32     sdx_h:2;
+       u32     sdy:5;
+       u32     sdrx:1;
+       u32     sdry:1;
+       u32     sdr1:1;
+       u32     res2:2;
+       u32     fw:12;
+       u32     fh_l:8;
+
+       u32     fh_h:4;
+       u32     res3:28;
+
+       /* Word 1 */
+       u32     eba0;
+
+       u32     eba1;
+
+       u32     bpp:3;
+       u32     sl:14;
+       u32     pfs:3;
+       u32     bam:3;
+       u32     res4:2;
+       u32     npb:6;
+       u32     res5:1;
+
+       u32     sat:2;
+       u32     scc:1;
+       u32     ofs0:5;
+       u32     ofs1:5;
+       u32     ofs2:5;
+       u32     ofs3:5;
+       u32     wid0:3;
+       u32     wid1:3;
+       u32     wid2:3;
+
+       u32     wid3:3;
+       u32     dec_sel:1;
+       u32     res6:28;
+} __attribute__ ((packed));
+
+union chan_param_mem {
+       struct chan_param_mem_planar            pp;
+       struct chan_param_mem_interleaved       ip;
+};
+
+static void ipu_ch_param_set_plane_offset(union chan_param_mem *params,
+                                         u32 u_offset, u32 v_offset)
+{
+       params->pp.ubo_l = u_offset & 0x7ff;
+       params->pp.ubo_h = u_offset >> 11;
+       params->pp.vbo_l = v_offset & 0x1ffff;
+       params->pp.vbo_h = v_offset >> 17;
+}
+
+static void ipu_ch_param_set_size(union chan_param_mem *params,
+                                 uint32_t pixel_fmt, uint16_t width,
+                                 uint16_t height, uint16_t stride)
+{
+       u32 u_offset;
+       u32 v_offset;
+
+       params->pp.fw           = width - 1;
+       params->pp.fh_l         = height - 1;
+       params->pp.fh_h         = (height - 1) >> 8;
+       params->pp.sl           = stride - 1;
+
+       switch (pixel_fmt) {
+       case IPU_PIX_FMT_GENERIC:
+               /*Represents 8-bit Generic data */
+               params->pp.bpp  = 3;
+               params->pp.pfs  = 7;
+               params->pp.npb  = 31;
+               params->pp.sat  = 2;            /* SAT = use 32-bit access */
+               break;
+       case IPU_PIX_FMT_GENERIC_32:
+               /*Represents 32-bit Generic data */
+               params->pp.bpp  = 0;
+               params->pp.pfs  = 7;
+               params->pp.npb  = 7;
+               params->pp.sat  = 2;            /* SAT = use 32-bit access */
+               break;
+       case IPU_PIX_FMT_RGB565:
+               params->ip.bpp  = 2;
+               params->ip.pfs  = 4;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               params->ip.ofs0 = 0;            /* Red bit offset */
+               params->ip.ofs1 = 5;            /* Green bit offset */
+               params->ip.ofs2 = 11;           /* Blue bit offset */
+               params->ip.ofs3 = 16;           /* Alpha bit offset */
+               params->ip.wid0 = 4;            /* Red bit width - 1 */
+               params->ip.wid1 = 5;            /* Green bit width - 1 */
+               params->ip.wid2 = 4;            /* Blue bit width - 1 */
+               break;
+       case IPU_PIX_FMT_BGR24:
+               params->ip.bpp  = 1;            /* 24 BPP & RGB PFS */
+               params->ip.pfs  = 4;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               params->ip.ofs0 = 0;            /* Red bit offset */
+               params->ip.ofs1 = 8;            /* Green bit offset */
+               params->ip.ofs2 = 16;           /* Blue bit offset */
+               params->ip.ofs3 = 24;           /* Alpha bit offset */
+               params->ip.wid0 = 7;            /* Red bit width - 1 */
+               params->ip.wid1 = 7;            /* Green bit width - 1 */
+               params->ip.wid2 = 7;            /* Blue bit width - 1 */
+               break;
+       case IPU_PIX_FMT_RGB24:
+               params->ip.bpp  = 1;            /* 24 BPP & RGB PFS */
+               params->ip.pfs  = 4;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               params->ip.ofs0 = 16;           /* Red bit offset */
+               params->ip.ofs1 = 8;            /* Green bit offset */
+               params->ip.ofs2 = 0;            /* Blue bit offset */
+               params->ip.ofs3 = 24;           /* Alpha bit offset */
+               params->ip.wid0 = 7;            /* Red bit width - 1 */
+               params->ip.wid1 = 7;            /* Green bit width - 1 */
+               params->ip.wid2 = 7;            /* Blue bit width - 1 */
+               break;
+       case IPU_PIX_FMT_BGRA32:
+       case IPU_PIX_FMT_BGR32:
+               params->ip.bpp  = 0;
+               params->ip.pfs  = 4;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               params->ip.ofs0 = 8;            /* Red bit offset */
+               params->ip.ofs1 = 16;           /* Green bit offset */
+               params->ip.ofs2 = 24;           /* Blue bit offset */
+               params->ip.ofs3 = 0;            /* Alpha bit offset */
+               params->ip.wid0 = 7;            /* Red bit width - 1 */
+               params->ip.wid1 = 7;            /* Green bit width - 1 */
+               params->ip.wid2 = 7;            /* Blue bit width - 1 */
+               params->ip.wid3 = 7;            /* Alpha bit width - 1 */
+               break;
+       case IPU_PIX_FMT_RGBA32:
+       case IPU_PIX_FMT_RGB32:
+               params->ip.bpp  = 0;
+               params->ip.pfs  = 4;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               params->ip.ofs0 = 24;           /* Red bit offset */
+               params->ip.ofs1 = 16;           /* Green bit offset */
+               params->ip.ofs2 = 8;            /* Blue bit offset */
+               params->ip.ofs3 = 0;            /* Alpha bit offset */
+               params->ip.wid0 = 7;            /* Red bit width - 1 */
+               params->ip.wid1 = 7;            /* Green bit width - 1 */
+               params->ip.wid2 = 7;            /* Blue bit width - 1 */
+               params->ip.wid3 = 7;            /* Alpha bit width - 1 */
+               break;
+       case IPU_PIX_FMT_ABGR32:
+               params->ip.bpp  = 0;
+               params->ip.pfs  = 4;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               params->ip.ofs0 = 8;            /* Red bit offset */
+               params->ip.ofs1 = 16;           /* Green bit offset */
+               params->ip.ofs2 = 24;           /* Blue bit offset */
+               params->ip.ofs3 = 0;            /* Alpha bit offset */
+               params->ip.wid0 = 7;            /* Red bit width - 1 */
+               params->ip.wid1 = 7;            /* Green bit width - 1 */
+               params->ip.wid2 = 7;            /* Blue bit width - 1 */
+               params->ip.wid3 = 7;            /* Alpha bit width - 1 */
+               break;
+       case IPU_PIX_FMT_UYVY:
+               params->ip.bpp  = 2;
+               params->ip.pfs  = 6;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               break;
+       case IPU_PIX_FMT_YUV420P2:
+       case IPU_PIX_FMT_YUV420P:
+               params->ip.bpp  = 3;
+               params->ip.pfs  = 3;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               u_offset = stride * height;
+               v_offset = u_offset + u_offset / 4;
+               ipu_ch_param_set_plane_offset(params, u_offset, v_offset);
+               break;
+       case IPU_PIX_FMT_YVU422P:
+               params->ip.bpp  = 3;
+               params->ip.pfs  = 2;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               v_offset = stride * height;
+               u_offset = v_offset + v_offset / 2;
+               ipu_ch_param_set_plane_offset(params, u_offset, v_offset);
+               break;
+       case IPU_PIX_FMT_YUV422P:
+               params->ip.bpp  = 3;
+               params->ip.pfs  = 2;
+               params->ip.npb  = 7;
+               params->ip.sat  = 2;            /* SAT = 32-bit access */
+               u_offset = stride * height;
+               v_offset = u_offset + u_offset / 2;
+               ipu_ch_param_set_plane_offset(params, u_offset, v_offset);
+               break;
+       default:
+               dev_err(ipu_data.dev,
+                       "mxc ipu: unimplemented pixel format %d\n", pixel_fmt);
+               break;
+       }
+
+       params->pp.nsb = 1;
+}
+
+static void ipu_ch_param_set_burst_size(union chan_param_mem *params,
+                                       uint16_t burst_pixels)
+{
+       params->pp.npb = burst_pixels - 1;
+};
+
+static void ipu_ch_param_set_buffer(union chan_param_mem *params,
+                                   dma_addr_t buf0, dma_addr_t buf1)
+{
+       params->pp.eba0 = buf0;
+       params->pp.eba1 = buf1;
+};
+
+static void ipu_ch_param_set_rotation(union chan_param_mem *params,
+                                     enum ipu_rotate_mode rotate)
+{
+       params->pp.bam = rotate;
+};
+
+static void ipu_write_param_mem(uint32_t addr, uint32_t *data,
+                               uint32_t num_words)
+{
+       for (; num_words > 0; num_words--) {
+               dev_dbg(ipu_data.dev,
+                       "write param mem - addr = 0x%08X, data = 0x%08X\n",
+                       addr, *data);
+               idmac_write_ipureg(&ipu_data, addr, IPU_IMA_ADDR);
+               idmac_write_ipureg(&ipu_data, *data++, IPU_IMA_DATA);
+               addr++;
+               if ((addr & 0x7) == 5) {
+                       addr &= ~0x7;   /* set to word 0 */
+                       addr += 8;      /* increment to next row */
+               }
+       }
+}
+
+static int calc_resize_coeffs(uint32_t in_size, uint32_t out_size,
+                             uint32_t *resize_coeff,
+                             uint32_t *downsize_coeff)
+{
+       uint32_t temp_size;
+       uint32_t temp_downsize;
+
+       *resize_coeff   = 1 << 13;
+       *downsize_coeff = 1 << 13;
+
+       /* Cannot downsize more than 8:1 */
+       if (out_size << 3 < in_size)
+               return -EINVAL;
+
+       /* compute downsizing coefficient */
+       temp_downsize = 0;
+       temp_size = in_size;
+       while (temp_size >= out_size * 2 && temp_downsize < 2) {
+               temp_size >>= 1;
+               temp_downsize++;
+       }
+       *downsize_coeff = temp_downsize;
+
+       /*
+        * compute resizing coefficient using the following formula:
+        * resize_coeff = M*(SI -1)/(SO - 1)
+        * where M = 2^13, SI - input size, SO - output size
+        */
+       *resize_coeff = (8192L * (temp_size - 1)) / (out_size - 1);
+       if (*resize_coeff >= 16384L) {
+               dev_err(ipu_data.dev, "Warning! Overflow on resize coeff.\n");
+               *resize_coeff = 0x3FFF;
+       }
+
+       dev_dbg(ipu_data.dev, "resizing from %u -> %u pixels, "
+               "downsize=%u, resize=%u.%lu (reg=%u)\n", in_size, out_size,
+               *downsize_coeff, *resize_coeff >= 8192L ? 1 : 0,
+               ((*resize_coeff & 0x1FFF) * 10000L) / 8192L, *resize_coeff);
+
+       return 0;
+}
+
+static enum ipu_color_space format_to_colorspace(enum pixel_fmt fmt)
+{
+       switch (fmt) {
+       case IPU_PIX_FMT_RGB565:
+       case IPU_PIX_FMT_BGR24:
+       case IPU_PIX_FMT_RGB24:
+       case IPU_PIX_FMT_BGR32:
+       case IPU_PIX_FMT_RGB32:
+               return IPU_COLORSPACE_RGB;
+       default:
+               return IPU_COLORSPACE_YCBCR;
+       }
+}
+
+static int ipu_ic_init_prpenc(struct ipu *ipu,
+                             union ipu_channel_param *params, bool src_is_csi)
+{
+       uint32_t reg, ic_conf;
+       uint32_t downsize_coeff, resize_coeff;
+       enum ipu_color_space in_fmt, out_fmt;
+
+       /* Setup vertical resizing */
+       calc_resize_coeffs(params->video.in_height,
+                           params->video.out_height,
+                           &resize_coeff, &downsize_coeff);
+       reg = (downsize_coeff << 30) | (resize_coeff << 16);
+
+       /* Setup horizontal resizing */
+       calc_resize_coeffs(params->video.in_width,
+                           params->video.out_width,
+                           &resize_coeff, &downsize_coeff);
+       reg |= (downsize_coeff << 14) | resize_coeff;
+
+       /* Setup color space conversion */
+       in_fmt = format_to_colorspace(params->video.in_pixel_fmt);
+       out_fmt = format_to_colorspace(params->video.out_pixel_fmt);
+
+       /*
+        * Colourspace conversion unsupported yet - see _init_csc() in
+        * Freescale sources
+        */
+       if (in_fmt != out_fmt) {
+               dev_err(ipu->dev, "Colourspace conversion unsupported!\n");
+               return -EOPNOTSUPP;
+       }
+
+       idmac_write_icreg(ipu, reg, IC_PRP_ENC_RSC);
+
+       ic_conf = idmac_read_icreg(ipu, IC_CONF);
+
+       if (src_is_csi)
+               ic_conf &= ~IC_CONF_RWS_EN;
+       else
+               ic_conf |= IC_CONF_RWS_EN;
+
+       idmac_write_icreg(ipu, ic_conf, IC_CONF);
+
+       return 0;
+}
+
+static uint32_t dma_param_addr(uint32_t dma_ch)
+{
+       /* Channel Parameter Memory */
+       return 0x10000 | (dma_ch << 4);
+};
+
+static void ipu_channel_set_priority(struct ipu *ipu, enum ipu_channel channel,
+                                    bool prio)
+{
+       u32 reg = idmac_read_icreg(ipu, IDMAC_CHA_PRI);
+
+       if (prio)
+               reg |= 1UL << channel;
+       else
+               reg &= ~(1UL << channel);
+
+       idmac_write_icreg(ipu, reg, IDMAC_CHA_PRI);
+
+       dump_idmac_reg(ipu);
+}
+
+static uint32_t ipu_channel_conf_mask(enum ipu_channel channel)
+{
+       uint32_t mask;
+
+       switch (channel) {
+       case IDMAC_IC_0:
+       case IDMAC_IC_7:
+               mask = IPU_CONF_CSI_EN | IPU_CONF_IC_EN;
+               break;
+       case IDMAC_SDC_0:
+       case IDMAC_SDC_1:
+               mask = IPU_CONF_SDC_EN | IPU_CONF_DI_EN;
+               break;
+       default:
+               mask = 0;
+               break;
+       }
+
+       return mask;
+}
+
+/**
+ * ipu_enable_channel() - enable an IPU channel.
+ * @channel:   channel ID.
+ * @return:    0 on success or negative error code on failure.
+ */
+static int ipu_enable_channel(struct idmac *idmac, struct idmac_channel *ichan)
+{
+       struct ipu *ipu = to_ipu(idmac);
+       enum ipu_channel channel = ichan->dma_chan.chan_id;
+       uint32_t reg;
+       unsigned long flags;
+
+       spin_lock_irqsave(&ipu->lock, flags);
+
+       /* Reset to buffer 0 */
+       idmac_write_ipureg(ipu, 1UL << channel, IPU_CHA_CUR_BUF);
+       ichan->active_buffer = 0;
+       ichan->status = IPU_CHANNEL_ENABLED;
+
+       switch (channel) {
+       case IDMAC_SDC_0:
+       case IDMAC_SDC_1:
+       case IDMAC_IC_7:
+               ipu_channel_set_priority(ipu, channel, true);
+       default:
+               break;
+       }
+
+       reg = idmac_read_icreg(ipu, IDMAC_CHA_EN);
+
+       idmac_write_icreg(ipu, reg | (1UL << channel), IDMAC_CHA_EN);
+
+       ipu_ic_enable_task(ipu, channel);
+
+       spin_unlock_irqrestore(&ipu->lock, flags);
+       return 0;
+}
+
+/**
+ * ipu_init_channel_buffer() - initialize a buffer for logical IPU channel.
+ * @channel:   channel ID.
+ * @pixel_fmt: pixel format of buffer. Pixel format is a FOURCC ASCII code.
+ * @width:     width of buffer in pixels.
+ * @height:    height of buffer in pixels.
+ * @stride:    stride length of buffer in pixels.
+ * @rot_mode:  rotation mode of buffer. A rotation setting other than
+ *             IPU_ROTATE_VERT_FLIP should only be used for input buffers of
+ *             rotation channels.
+ * @phyaddr_0: buffer 0 physical address.
+ * @phyaddr_1: buffer 1 physical address. Setting this to a value other than
+ *             NULL enables double buffering mode.
+ * @return:    0 on success or negative error code on failure.
+ */
+static int ipu_init_channel_buffer(struct idmac_channel *ichan,
+                                  enum pixel_fmt pixel_fmt,
+                                  uint16_t width, uint16_t height,
+                                  uint32_t stride,
+                                  enum ipu_rotate_mode rot_mode,
+                                  dma_addr_t phyaddr_0, dma_addr_t phyaddr_1)
+{
+       enum ipu_channel channel = ichan->dma_chan.chan_id;
+       struct idmac *idmac = to_idmac(ichan->dma_chan.device);
+       struct ipu *ipu = to_ipu(idmac);
+       union chan_param_mem params = {};
+       unsigned long flags;
+       uint32_t reg;
+       uint32_t stride_bytes;
+
+       stride_bytes = stride * bytes_per_pixel(pixel_fmt);
+
+       if (stride_bytes % 4) {
+               dev_err(ipu->dev,
+                       "Stride length must be 32-bit aligned, stride = %d, bytes = %d\n",
+                       stride, stride_bytes);
+               return -EINVAL;
+       }
+
+       /* IC channel's stride must be a multiple of 8 pixels */
+       if ((channel <= 13) && (stride % 8)) {
+               dev_err(ipu->dev, "Stride must be 8 pixel multiple\n");
+               return -EINVAL;
+       }
+
+       /* Build parameter memory data for DMA channel */
+       ipu_ch_param_set_size(¶ms, pixel_fmt, width, height, stride_bytes);
+       ipu_ch_param_set_buffer(¶ms, phyaddr_0, phyaddr_1);
+       ipu_ch_param_set_rotation(¶ms, rot_mode);
+       /* Some channels (rotation) have restriction on burst length */
+       switch (channel) {
+       case IDMAC_IC_7:        /* Hangs with burst 8, 16, other values
+                                  invalid - Table 44-30 */
+/*
+               ipu_ch_param_set_burst_size(¶ms, 8);
+ */
+               break;
+       case IDMAC_SDC_0:
+       case IDMAC_SDC_1:
+               /* In original code only IPU_PIX_FMT_RGB565 was setting burst */
+               ipu_ch_param_set_burst_size(¶ms, 16);
+               break;
+       case IDMAC_IC_0:
+       default:
+               break;
+       }
+
+       spin_lock_irqsave(&ipu->lock, flags);
+
+       ipu_write_param_mem(dma_param_addr(channel), (uint32_t *)¶ms, 10);
+
+       reg = idmac_read_ipureg(ipu, IPU_CHA_DB_MODE_SEL);
+
+       if (phyaddr_1)
+               reg |= 1UL << channel;
+       else
+               reg &= ~(1UL << channel);
+
+       idmac_write_ipureg(ipu, reg, IPU_CHA_DB_MODE_SEL);
+
+       ichan->status = IPU_CHANNEL_READY;
+
+       spin_unlock_irqrestore(ipu->lock, flags);
+
+       return 0;
+}
+
+/**
+ * ipu_select_buffer() - mark a channel's buffer as ready.
+ * @channel:   channel ID.
+ * @buffer_n:  buffer number to mark ready.
+ */
+static void ipu_select_buffer(enum ipu_channel channel, int buffer_n)
+{
+       /* No locking - this is a write-one-to-set register, cleared by IPU */
+       if (buffer_n == 0)
+               /* Mark buffer 0 as ready. */
+               idmac_write_ipureg(&ipu_data, 1UL << channel, IPU_CHA_BUF0_RDY);
+       else
+               /* Mark buffer 1 as ready. */
+               idmac_write_ipureg(&ipu_data, 1UL << channel, IPU_CHA_BUF1_RDY);
+}
+
+/**
+ * ipu_update_channel_buffer() - update physical address of a channel buffer.
+ * @channel:   channel ID.
+ * @buffer_n:  buffer number to update.
+ *             0 or 1 are the only valid values.
+ * @phyaddr:   buffer physical address.
+ * @return:    Returns 0 on success or negative error code on failure. This
+ *              function will fail if the buffer is set to ready.
+ */
+/* Called under spin_lock(_irqsave)(&ichan->lock) */
+static int ipu_update_channel_buffer(enum ipu_channel channel,
+                                    int buffer_n, dma_addr_t phyaddr)
+{
+       uint32_t reg;
+       unsigned long flags;
+
+       spin_lock_irqsave(&ipu_data.lock, flags);
+
+       if (buffer_n == 0) {
+               reg = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF0_RDY);
+               if (reg & (1UL << channel)) {
+                       spin_unlock_irqrestore(&ipu_data.lock, flags);
+                       return -EACCES;
+               }
+
+               /* 44.3.3.1.9 - Row Number 1 (WORD1, offset 0) */
+               idmac_write_ipureg(&ipu_data, dma_param_addr(channel) +
+                                  0x0008UL, IPU_IMA_ADDR);
+               idmac_write_ipureg(&ipu_data, phyaddr, IPU_IMA_DATA);
+       } else {
+               reg = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF1_RDY);
+               if (reg & (1UL << channel)) {
+                       spin_unlock_irqrestore(&ipu_data.lock, flags);
+                       return -EACCES;
+               }
+
+               /* Check if double-buffering is already enabled */
+               reg = idmac_read_ipureg(&ipu_data, IPU_CHA_DB_MODE_SEL);
+
+               if (!(reg & (1UL << channel)))
+                       idmac_write_ipureg(&ipu_data, reg | (1UL << channel),
+                                          IPU_CHA_DB_MODE_SEL);
+
+               /* 44.3.3.1.9 - Row Number 1 (WORD1, offset 1) */
+               idmac_write_ipureg(&ipu_data, dma_param_addr(channel) +
+                                  0x0009UL, IPU_IMA_ADDR);
+               idmac_write_ipureg(&ipu_data, phyaddr, IPU_IMA_DATA);
+       }
+
+       spin_unlock_irqrestore(&ipu_data.lock, flags);
+
+       return 0;
+}
+
+/* Called under spin_lock_irqsave(&ichan->lock) */
+static int ipu_submit_channel_buffers(struct idmac_channel *ichan,
+                                     struct idmac_tx_desc *desc)
+{
+       struct scatterlist *sg;
+       int i, ret = 0;
+
+       for (i = 0, sg = desc->sg; i < 2 && sg; i++) {
+               if (!ichan->sg[i]) {
+                       ichan->sg[i] = sg;
+
+                       /*
+                        * On first invocation this shouldn't be necessary, the
+                        * call to ipu_init_channel_buffer() above will set
+                        * addresses for us, so we could make it conditional
+                        * on status >= IPU_CHANNEL_ENABLED, but doing it again
+                        * shouldn't hurt either.
+                        */
+                       ret = ipu_update_channel_buffer(ichan->dma_chan.chan_id, i,
+                                                       sg_dma_address(sg));
+                       if (ret < 0)
+                               return ret;
+
+                       ipu_select_buffer(ichan->dma_chan.chan_id, i);
+
+                       sg = sg_next(sg);
+               }
+       }
+
+       return ret;
+}
+
+static dma_cookie_t idmac_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+       struct idmac_tx_desc *desc = to_tx_desc(tx);
+       struct idmac_channel *ichan = to_idmac_chan(tx->chan);
+       struct idmac *idmac = to_idmac(tx->chan->device);
+       struct ipu *ipu = to_ipu(idmac);
+       dma_cookie_t cookie;
+       unsigned long flags;
+
+       /* Sanity check */
+       if (!list_empty(&desc->list)) {
+               /* The descriptor doesn't belong to client */
+               dev_err(&ichan->dma_chan.dev->device,
+                       "Descriptor %p not prepared!\n", tx);
+               return -EBUSY;
+       }
+
+       mutex_lock(&ichan->chan_mutex);
+
+       if (ichan->status < IPU_CHANNEL_READY) {
+               struct idmac_video_param *video = &ichan->params.video;
+               /*
+                * Initial buffer assignment - the first two sg-entries from
+                * the descriptor will end up in the IDMAC buffers
+                */
+               dma_addr_t dma_1 = sg_is_last(desc->sg) ? 0 :
+                       sg_dma_address(&desc->sg[1]);
+
+               WARN_ON(ichan->sg[0] || ichan->sg[1]);
+
+               cookie = ipu_init_channel_buffer(ichan,
+                                                video->out_pixel_fmt,
+                                                video->out_width,
+                                                video->out_height,
+                                                video->out_stride,
+                                                IPU_ROTATE_NONE,
+                                                sg_dma_address(&desc->sg[0]),
+                                                dma_1);
+               if (cookie < 0)
+                       goto out;
+       }
+
+       /* ipu->lock can be taken under ichan->lock, but not v.v. */
+       spin_lock_irqsave(&ichan->lock, flags);
+
+       /* submit_buffers() atomically verifies and fills empty sg slots */
+       cookie = ipu_submit_channel_buffers(ichan, desc);
+
+       spin_unlock_irqrestore(&ichan->lock, flags);
+
+       if (cookie < 0)
+               goto out;
+
+       cookie = ichan->dma_chan.cookie;
+
+       if (++cookie < 0)
+               cookie = 1;
+
+       /* from dmaengine.h: "last cookie value returned to client" */
+       ichan->dma_chan.cookie = cookie;
+       tx->cookie = cookie;
+       spin_lock_irqsave(&ichan->lock, flags);
+       list_add_tail(&desc->list, &ichan->queue);
+       spin_unlock_irqrestore(&ichan->lock, flags);
+
+       if (ichan->status < IPU_CHANNEL_ENABLED) {
+               int ret = ipu_enable_channel(idmac, ichan);
+               if (ret < 0) {
+                       cookie = ret;
+                       spin_lock_irqsave(&ichan->lock, flags);
+                       list_del_init(&desc->list);
+                       spin_unlock_irqrestore(&ichan->lock, flags);
+                       tx->cookie = cookie;
+                       ichan->dma_chan.cookie = cookie;
+               }
+       }
+
+       dump_idmac_reg(ipu);
+
+out:
+       mutex_unlock(&ichan->chan_mutex);
+
+       return cookie;
+}
+
+/* Called with ichan->chan_mutex held */
+static int idmac_desc_alloc(struct idmac_channel *ichan, int n)
+{
+       struct idmac_tx_desc *desc = vmalloc(n * sizeof(struct idmac_tx_desc));
+       struct idmac *idmac = to_idmac(ichan->dma_chan.device);
+
+       if (!desc)
+               return -ENOMEM;
+
+       /* No interrupts, just disable the tasklet for a moment */
+       tasklet_disable(&to_ipu(idmac)->tasklet);
+
+       ichan->n_tx_desc = n;
+       ichan->desc = desc;
+       INIT_LIST_HEAD(&ichan->queue);
+       INIT_LIST_HEAD(&ichan->free_list);
+
+       while (n--) {
+               struct dma_async_tx_descriptor *txd = &desc->txd;
+
+               memset(txd, 0, sizeof(*txd));
+               dma_async_tx_descriptor_init(txd, &ichan->dma_chan);
+               txd->tx_submit          = idmac_tx_submit;
+               txd->chan               = &ichan->dma_chan;
+               INIT_LIST_HEAD(&txd->tx_list);
+
+               list_add(&desc->list, &ichan->free_list);
+
+               desc++;
+       }
+
+       tasklet_enable(&to_ipu(idmac)->tasklet);
+
+       return 0;
+}
+
+/**
+ * ipu_init_channel() - initialize an IPU channel.
+ * @idmac:     IPU DMAC context.
+ * @ichan:     pointer to the channel object.
+ * @return      0 on success or negative error code on failure.
+ */
+static int ipu_init_channel(struct idmac *idmac, struct idmac_channel *ichan)
+{
+       union ipu_channel_param *params = &ichan->params;
+       uint32_t ipu_conf;
+       enum ipu_channel channel = ichan->dma_chan.chan_id;
+       unsigned long flags;
+       uint32_t reg;
+       struct ipu *ipu = to_ipu(idmac);
+       int ret = 0, n_desc = 0;
+
+       dev_dbg(ipu->dev, "init channel = %d\n", channel);
+
+       if (channel != IDMAC_SDC_0 && channel != IDMAC_SDC_1 &&
+           channel != IDMAC_IC_7)
+               return -EINVAL;
+
+       spin_lock_irqsave(&ipu->lock, flags);
+
+       switch (channel) {
+       case IDMAC_IC_7:
+               n_desc = 16;
+               reg = idmac_read_icreg(ipu, IC_CONF);
+               idmac_write_icreg(ipu, reg & ~IC_CONF_CSI_MEM_WR_EN, IC_CONF);
+               break;
+       case IDMAC_IC_0:
+               n_desc = 16;
+               reg = idmac_read_ipureg(ipu, IPU_FS_PROC_FLOW);
+               idmac_write_ipureg(ipu, reg & ~FS_ENC_IN_VALID, IPU_FS_PROC_FLOW);
+               ret = ipu_ic_init_prpenc(ipu, params, true);
+               break;
+       case IDMAC_SDC_0:
+       case IDMAC_SDC_1:
+               n_desc = 4;
+       default:
+               break;
+       }
+
+       ipu->channel_init_mask |= 1L << channel;
+
+       /* Enable IPU sub module */
+       ipu_conf = idmac_read_ipureg(ipu, IPU_CONF) |
+               ipu_channel_conf_mask(channel);
+       idmac_write_ipureg(ipu, ipu_conf, IPU_CONF);
+
+       spin_unlock_irqrestore(&ipu->lock, flags);
+
+       if (n_desc && !ichan->desc)
+               ret = idmac_desc_alloc(ichan, n_desc);
+
+       dump_idmac_reg(ipu);
+
+       return ret;
+}
+
+/**
+ * ipu_uninit_channel() - uninitialize an IPU channel.
+ * @idmac:     IPU DMAC context.
+ * @ichan:     pointer to the channel object.
+ */
+static void ipu_uninit_channel(struct idmac *idmac, struct idmac_channel *ichan)
+{
+       enum ipu_channel channel = ichan->dma_chan.chan_id;
+       unsigned long flags;
+       uint32_t reg;
+       unsigned long chan_mask = 1UL << channel;
+       uint32_t ipu_conf;
+       struct ipu *ipu = to_ipu(idmac);
+
+       spin_lock_irqsave(&ipu->lock, flags);
+
+       if (!(ipu->channel_init_mask & chan_mask)) {
+               dev_err(ipu->dev, "Channel already uninitialized %d\n",
+                       channel);
+               spin_unlock_irqrestore(&ipu->lock, flags);
+               return;
+       }
+
+       /* Reset the double buffer */
+       reg = idmac_read_ipureg(ipu, IPU_CHA_DB_MODE_SEL);
+       idmac_write_ipureg(ipu, reg & ~chan_mask, IPU_CHA_DB_MODE_SEL);
+
+       ichan->sec_chan_en = false;
+
+       switch (channel) {
+       case IDMAC_IC_7:
+               reg = idmac_read_icreg(ipu, IC_CONF);
+               idmac_write_icreg(ipu, reg & ~(IC_CONF_RWS_EN | IC_CONF_PRPENC_EN),
+                            IC_CONF);
+               break;
+       case IDMAC_IC_0:
+               reg = idmac_read_icreg(ipu, IC_CONF);
+               idmac_write_icreg(ipu, reg & ~(IC_CONF_PRPENC_EN | IC_CONF_PRPENC_CSC1),
+                                 IC_CONF);
+               break;
+       case IDMAC_SDC_0:
+       case IDMAC_SDC_1:
+       default:
+               break;
+       }
+
+       ipu->channel_init_mask &= ~(1L << channel);
+
+       ipu_conf = idmac_read_ipureg(ipu, IPU_CONF) &
+               ~ipu_channel_conf_mask(channel);
+       idmac_write_ipureg(ipu, ipu_conf, IPU_CONF);
+
+       spin_unlock_irqrestore(&ipu->lock, flags);
+
+       ichan->n_tx_desc = 0;
+       vfree(ichan->desc);
+       ichan->desc = NULL;
+}
+
+/**
+ * ipu_disable_channel() - disable an IPU channel.
+ * @idmac:             IPU DMAC context.
+ * @ichan:             channel object pointer.
+ * @wait_for_stop:     flag to set whether to wait for channel end of frame or
+ *                     return immediately.
+ * @return:            0 on success or negative error code on failure.
+ */
+static int ipu_disable_channel(struct idmac *idmac, struct idmac_channel *ichan,
+                              bool wait_for_stop)
+{
+       enum ipu_channel channel = ichan->dma_chan.chan_id;
+       struct ipu *ipu = to_ipu(idmac);
+       uint32_t reg;
+       unsigned long flags;
+       unsigned long chan_mask = 1UL << channel;
+       unsigned int timeout;
+
+       if (wait_for_stop && channel != IDMAC_SDC_1 && channel != IDMAC_SDC_0) {
+               timeout = 40;
+               /* This waiting always fails. Related to spurious irq problem */
+               while ((idmac_read_icreg(ipu, IDMAC_CHA_BUSY) & chan_mask) ||
+                      (ipu_channel_status(ipu, channel) == TASK_STAT_ACTIVE)) {
+                       timeout--;
+                       msleep(10);
+
+                       if (!timeout) {
+                               dev_dbg(ipu->dev,
+                                       "Warning: timeout waiting for channel %u to "
+                                       "stop: buf0_rdy = 0x%08X, buf1_rdy = 0x%08X, "
+                                       "busy = 0x%08X, tstat = 0x%08X\n", channel,
+                                       idmac_read_ipureg(ipu, IPU_CHA_BUF0_RDY),
+                                       idmac_read_ipureg(ipu, IPU_CHA_BUF1_RDY),
+                                       idmac_read_icreg(ipu, IDMAC_CHA_BUSY),
+                                       idmac_read_ipureg(ipu, IPU_TASKS_STAT));
+                               break;
+                       }
+               }
+               dev_dbg(ipu->dev, "timeout = %d * 10ms\n", 40 - timeout);
+       }
+       /* SDC BG and FG must be disabled before DMA is disabled */
+       if (wait_for_stop && (channel == IDMAC_SDC_0 ||
+                             channel == IDMAC_SDC_1)) {
+               for (timeout = 5;
+                    timeout && !ipu_irq_status(ichan->eof_irq); timeout--)
+                       msleep(5);
+       }
+
+       spin_lock_irqsave(&ipu->lock, flags);
+
+       /* Disable IC task */
+       ipu_ic_disable_task(ipu, channel);
+
+       /* Disable DMA channel(s) */
+       reg = idmac_read_icreg(ipu, IDMAC_CHA_EN);
+       idmac_write_icreg(ipu, reg & ~chan_mask, IDMAC_CHA_EN);
+
+       /*
+        * Problem (observed with channel DMAIC_7): after enabling the channel
+        * and initialising buffers, there comes an interrupt with current still
+        * pointing at buffer 0, whereas it should use buffer 0 first and only
+        * generate an interrupt when it is done, then current should already
+        * point to buffer 1. This spurious interrupt also comes on channel
+        * DMASDC_0. With DMAIC_7 normally, is we just leave the ISR after the
+        * first interrupt, there comes the second with current correctly
+        * pointing to buffer 1 this time. But sometimes this second interrupt
+        * doesn't come and the channel hangs. Clearing BUFx_RDY when disabling
+        * the channel seems to prevent the channel from hanging, but it doesn't
+        * prevent the spurious interrupt. This might also be unsafe. Think
+        * about the IDMAC controller trying to switch to a buffer, when we
+        * clear the ready bit, and re-enable it a moment later.
+        */
+       reg = idmac_read_ipureg(ipu, IPU_CHA_BUF0_RDY);
+       idmac_write_ipureg(ipu, 0, IPU_CHA_BUF0_RDY);
+       idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF0_RDY);
+
+       reg = idmac_read_ipureg(ipu, IPU_CHA_BUF1_RDY);
+       idmac_write_ipureg(ipu, 0, IPU_CHA_BUF1_RDY);
+       idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF1_RDY);
+
+       spin_unlock_irqrestore(&ipu->lock, flags);
+
+       return 0;
+}
+
+/*
+ * We have several possibilities here:
+ * current BUF         next BUF
+ *
+ * not last sg         next not last sg
+ * not last sg         next last sg
+ * last sg             first sg from next descriptor
+ * last sg             NULL
+ *
+ * Besides, the descriptor queue might be empty or not. We process all these
+ * cases carefully.
+ */
+static irqreturn_t idmac_interrupt(int irq, void *dev_id)
+{
+       struct idmac_channel *ichan = dev_id;
+       unsigned int chan_id = ichan->dma_chan.chan_id;
+       struct scatterlist **sg, *sgnext, *sgnew = NULL;
+       /* Next transfer descriptor */
+       struct idmac_tx_desc *desc = NULL, *descnew;
+       dma_async_tx_callback callback;
+       void *callback_param;
+       bool done = false;
+       u32     ready0 = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF0_RDY),
+               ready1 = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF1_RDY),
+               curbuf = idmac_read_ipureg(&ipu_data, IPU_CHA_CUR_BUF);
+
+       /* IDMAC has cleared the respective BUFx_RDY bit, we manage the buffer */
+
+       pr_debug("IDMAC irq %d\n", irq);
+       /* Other interrupts do not interfere with this channel */
+       spin_lock(&ichan->lock);
+
+       if (unlikely(chan_id != IDMAC_SDC_0 && chan_id != IDMAC_SDC_1 &&
+                    ((curbuf >> chan_id) & 1) == ichan->active_buffer)) {
+               int i = 100;
+
+               /* This doesn't help. See comment in ipu_disable_channel() */
+               while (--i) {
+                       curbuf = idmac_read_ipureg(&ipu_data, IPU_CHA_CUR_BUF);
+                       if (((curbuf >> chan_id) & 1) != ichan->active_buffer)
+                               break;
+                       cpu_relax();
+               }
+
+               if (!i) {
+                       spin_unlock(&ichan->lock);
+                       dev_dbg(ichan->dma_chan.device->dev,
+                               "IRQ on active buffer on channel %x, active "
+                               "%d, ready %x, %x, current %x!\n", chan_id,
+                               ichan->active_buffer, ready0, ready1, curbuf);
+                       return IRQ_NONE;
+               }
+       }
+
+       if (unlikely((ichan->active_buffer && (ready1 >> chan_id) & 1) ||
+                    (!ichan->active_buffer && (ready0 >> chan_id) & 1)
+                    )) {
+               spin_unlock(&ichan->lock);
+               dev_dbg(ichan->dma_chan.device->dev,
+                       "IRQ with active buffer still ready on channel %x, "
+                       "active %d, ready %x, %x!\n", chan_id,
+                       ichan->active_buffer, ready0, ready1);
+               return IRQ_NONE;
+       }
+
+       if (unlikely(list_empty(&ichan->queue))) {
+               spin_unlock(&ichan->lock);
+               dev_err(ichan->dma_chan.device->dev,
+                       "IRQ without queued buffers on channel %x, active %d, "
+                       "ready %x, %x!\n", chan_id,
+                       ichan->active_buffer, ready0, ready1);
+               return IRQ_NONE;
+       }
+
+       /*
+        * active_buffer is a software flag, it shows which buffer we are
+        * currently expecting back from the hardware, IDMAC should be
+        * processing the other buffer already
+        */
+       sg = &ichan->sg[ichan->active_buffer];
+       sgnext = ichan->sg[!ichan->active_buffer];
+
+       /*
+        * if sgnext == NULL sg must be the last element in a scatterlist and
+        * queue must be empty
+        */
+       if (unlikely(!sgnext)) {
+               if (unlikely(sg_next(*sg))) {
+                       dev_err(ichan->dma_chan.device->dev,
+                               "Broken buffer-update locking on channel %x!\n",
+                               chan_id);
+                       /* We'll let the user catch up */
+               } else {
+                       /* Underrun */
+                       ipu_ic_disable_task(&ipu_data, chan_id);
+                       dev_dbg(ichan->dma_chan.device->dev,
+                               "Underrun on channel %x\n", chan_id);
+                       ichan->status = IPU_CHANNEL_READY;
+                       /* Continue to check for complete descriptor */
+               }
+       }
+
+       desc = list_entry(ichan->queue.next, struct idmac_tx_desc, list);
+
+       /* First calculate and submit the next sg element */
+       if (likely(sgnext))
+               sgnew = sg_next(sgnext);
+
+       if (unlikely(!sgnew)) {
+               /* Start a new scatterlist, if any queued */
+               if (likely(desc->list.next != &ichan->queue)) {
+                       descnew = list_entry(desc->list.next,
+                                            struct idmac_tx_desc, list);
+                       sgnew = &descnew->sg[0];
+               }
+       }
+
+       if (unlikely(!sg_next(*sg)) || !sgnext) {
+               /*
+                * Last element in scatterlist done, remove from the queue,
+                * _init for debugging
+                */
+               list_del_init(&desc->list);
+               done = true;
+       }
+
+       *sg = sgnew;
+
+       if (likely(sgnew)) {
+               int ret;
+
+               ret = ipu_update_channel_buffer(chan_id, ichan->active_buffer,
+                                               sg_dma_address(*sg));
+               if (ret < 0)
+                       dev_err(ichan->dma_chan.device->dev,
+                               "Failed to update buffer on channel %x buffer %d!\n",
+                               chan_id, ichan->active_buffer);
+               else
+                       ipu_select_buffer(chan_id, ichan->active_buffer);
+       }
+
+       /* Flip the active buffer - even if update above failed */
+       ichan->active_buffer = !ichan->active_buffer;
+       if (done)
+               ichan->completed = desc->txd.cookie;
+
+       callback = desc->txd.callback;
+       callback_param = desc->txd.callback_param;
+
+       spin_unlock(&ichan->lock);
+
+       if (done && (desc->txd.flags & DMA_PREP_INTERRUPT) && callback)
+               callback(callback_param);
+
+       return IRQ_HANDLED;
+}
+
+static void ipu_gc_tasklet(unsigned long arg)
+{
+       struct ipu *ipu = (struct ipu *)arg;
+       int i;
+
+       for (i = 0; i < IPU_CHANNELS_NUM; i++) {
+               struct idmac_channel *ichan = ipu->channel + i;
+               struct idmac_tx_desc *desc;
+               unsigned long flags;
+               int j;
+
+               for (j = 0; j < ichan->n_tx_desc; j++) {
+                       desc = ichan->desc + j;
+                       spin_lock_irqsave(&ichan->lock, flags);
+                       if (async_tx_test_ack(&desc->txd)) {
+                               list_move(&desc->list, &ichan->free_list);
+                               async_tx_clear_ack(&desc->txd);
+                       }
+                       spin_unlock_irqrestore(&ichan->lock, flags);
+               }
+       }
+}
+
+/*
+ * At the time .device_alloc_chan_resources() method is called, we cannot know,
+ * whether the client will accept the channel. Thus we must only check, if we
+ * can satisfy client's request but the only real criterion to verify, whether
+ * the client has accepted our offer is the client_count. That's why we have to
+ * perform the rest of our allocation tasks on the first call to this function.
+ */
+static struct dma_async_tx_descriptor *idmac_prep_slave_sg(struct dma_chan *chan,
+               struct scatterlist *sgl, unsigned int sg_len,
+               enum dma_data_direction direction, unsigned long tx_flags)
+{
+       struct idmac_channel *ichan = to_idmac_chan(chan);
+       struct idmac_tx_desc *desc = NULL;
+       struct dma_async_tx_descriptor *txd = NULL;
+       unsigned long flags;
+
+       /* We only can handle these three channels so far */
+       if (ichan->dma_chan.chan_id != IDMAC_SDC_0 && ichan->dma_chan.chan_id != IDMAC_SDC_1 &&
+           ichan->dma_chan.chan_id != IDMAC_IC_7)
+               return NULL;
+
+       if (direction != DMA_FROM_DEVICE && direction != DMA_TO_DEVICE) {
+               dev_err(chan->device->dev, "Invalid DMA direction %d!\n", direction);
+               return NULL;
+       }
+
+       mutex_lock(&ichan->chan_mutex);
+
+       spin_lock_irqsave(&ichan->lock, flags);
+       if (!list_empty(&ichan->free_list)) {
+               desc = list_entry(ichan->free_list.next,
+                                 struct idmac_tx_desc, list);
+
+               list_del_init(&desc->list);
+
+               desc->sg_len    = sg_len;
+               desc->sg        = sgl;
+               txd             = &desc->txd;
+               txd->flags      = tx_flags;
+       }
+       spin_unlock_irqrestore(&ichan->lock, flags);
+
+       mutex_unlock(&ichan->chan_mutex);
+
+       tasklet_schedule(&to_ipu(to_idmac(chan->device))->tasklet);
+
+       return txd;
+}
+
+/* Re-select the current buffer and re-activate the channel */
+static void idmac_issue_pending(struct dma_chan *chan)
+{
+       struct idmac_channel *ichan = to_idmac_chan(chan);
+       struct idmac *idmac = to_idmac(chan->device);
+       struct ipu *ipu = to_ipu(idmac);
+       unsigned long flags;
+
+       /* This is not always needed, but doesn't hurt either */
+       spin_lock_irqsave(&ipu->lock, flags);
+       ipu_select_buffer(ichan->dma_chan.chan_id, ichan->active_buffer);
+       spin_unlock_irqrestore(&ipu->lock, flags);
+
+       /*
+        * Might need to perform some parts of initialisation from
+        * ipu_enable_channel(), but not all, we do not want to reset to buffer
+        * 0, don't need to set priority again either, but re-enabling the task
+        * and the channel might be a good idea.
+        */
+}
+
+static void __idmac_terminate_all(struct dma_chan *chan)
+{
+       struct idmac_channel *ichan = to_idmac_chan(chan);
+       struct idmac *idmac = to_idmac(chan->device);
+       unsigned long flags;
+       int i;
+
+       ipu_disable_channel(idmac, ichan,
+                           ichan->status >= IPU_CHANNEL_ENABLED);
+
+       tasklet_disable(&to_ipu(idmac)->tasklet);
+
+       /* ichan->queue is modified in ISR, have to spinlock */
+       spin_lock_irqsave(&ichan->lock, flags);
+       list_splice_init(&ichan->queue, &ichan->free_list);
+
+       if (ichan->desc)
+               for (i = 0; i < ichan->n_tx_desc; i++) {
+                       struct idmac_tx_desc *desc = ichan->desc + i;
+                       if (list_empty(&desc->list))
+                               /* Descriptor was prepared, but not submitted */
+                               list_add(&desc->list,
+                                        &ichan->free_list);
+
+                       async_tx_clear_ack(&desc->txd);
+               }
+
+       ichan->sg[0] = NULL;
+       ichan->sg[1] = NULL;
+       spin_unlock_irqrestore(&ichan->lock, flags);
+
+       tasklet_enable(&to_ipu(idmac)->tasklet);
+
+       ichan->status = IPU_CHANNEL_INITIALIZED;
+}
+
+static void idmac_terminate_all(struct dma_chan *chan)
+{
+       struct idmac_channel *ichan = to_idmac_chan(chan);
+
+       mutex_lock(&ichan->chan_mutex);
+
+       __idmac_terminate_all(chan);
+
+       mutex_unlock(&ichan->chan_mutex);
+}
+
+static int idmac_alloc_chan_resources(struct dma_chan *chan)
+{
+       struct idmac_channel *ichan = to_idmac_chan(chan);
+       struct idmac *idmac = to_idmac(chan->device);
+       int ret;
+
+       /* dmaengine.c now guarantees to only offer free channels */
+       BUG_ON(chan->client_count > 1);
+       WARN_ON(ichan->status != IPU_CHANNEL_FREE);
+
+       chan->cookie            = 1;
+       ichan->completed        = -ENXIO;
+
+       ret = ipu_irq_map(ichan->dma_chan.chan_id);
+       if (ret < 0)
+               goto eimap;
+
+       ichan->eof_irq = ret;
+       ret = request_irq(ichan->eof_irq, idmac_interrupt, 0,
+                         ichan->eof_name, ichan);
+       if (ret < 0)
+               goto erirq;
+
+       ret = ipu_init_channel(idmac, ichan);
+       if (ret < 0)
+               goto eichan;
+
+       ichan->status = IPU_CHANNEL_INITIALIZED;
+
+       dev_dbg(&ichan->dma_chan.dev->device, "Found channel 0x%x, irq %d\n",
+               ichan->dma_chan.chan_id, ichan->eof_irq);
+
+       return ret;
+
+eichan:
+       free_irq(ichan->eof_irq, ichan);
+erirq:
+       ipu_irq_unmap(ichan->dma_chan.chan_id);
+eimap:
+       return ret;
+}
+
+static void idmac_free_chan_resources(struct dma_chan *chan)
+{
+       struct idmac_channel *ichan = to_idmac_chan(chan);
+       struct idmac *idmac = to_idmac(chan->device);
+
+       mutex_lock(&ichan->chan_mutex);
+
+       __idmac_terminate_all(chan);
+
+       if (ichan->status > IPU_CHANNEL_FREE) {
+               free_irq(ichan->eof_irq, ichan);
+               ipu_irq_unmap(ichan->dma_chan.chan_id);
+       }
+
+       ichan->status = IPU_CHANNEL_FREE;
+
+       ipu_uninit_channel(idmac, ichan);
+
+       mutex_unlock(&ichan->chan_mutex);
+
+       tasklet_schedule(&to_ipu(idmac)->tasklet);
+}
+
+static enum dma_status idmac_is_tx_complete(struct dma_chan *chan,
+               dma_cookie_t cookie, dma_cookie_t *done, dma_cookie_t *used)
+{
+       struct idmac_channel *ichan = to_idmac_chan(chan);
+
+       if (done)
+               *done = ichan->completed;
+       if (used)
+               *used = chan->cookie;
+       if (cookie != chan->cookie)
+               return DMA_ERROR;
+       return DMA_SUCCESS;
+}
+
+static int __init ipu_idmac_init(struct ipu *ipu)
+{
+       struct idmac *idmac = &ipu->idmac;
+       struct dma_device *dma = &idmac->dma;
+       int i;
+
+       dma_cap_set(DMA_SLAVE, dma->cap_mask);
+       dma_cap_set(DMA_PRIVATE, dma->cap_mask);
+
+       /* Compulsory common fields */
+       dma->dev                                = ipu->dev;
+       dma->device_alloc_chan_resources        = idmac_alloc_chan_resources;
+       dma->device_free_chan_resources         = idmac_free_chan_resources;
+       dma->device_is_tx_complete              = idmac_is_tx_complete;
+       dma->device_issue_pending               = idmac_issue_pending;
+
+       /* Compulsory for DMA_SLAVE fields */
+       dma->device_prep_slave_sg               = idmac_prep_slave_sg;
+       dma->device_terminate_all               = idmac_terminate_all;
+
+       INIT_LIST_HEAD(&dma->channels);
+       for (i = 0; i < IPU_CHANNELS_NUM; i++) {
+               struct idmac_channel *ichan = ipu->channel + i;
+               struct dma_chan *dma_chan = &ichan->dma_chan;
+
+               spin_lock_init(&ichan->lock);
+               mutex_init(&ichan->chan_mutex);
+
+               ichan->status           = IPU_CHANNEL_FREE;
+               ichan->sec_chan_en      = false;
+               ichan->completed        = -ENXIO;
+               snprintf(ichan->eof_name, sizeof(ichan->eof_name), "IDMAC EOF %d", i);
+
+               dma_chan->device        = &idmac->dma;
+               dma_chan->cookie        = 1;
+               dma_chan->chan_id       = i;
+               list_add_tail(&ichan->dma_chan.device_node, &dma->channels);
+       }
+
+       idmac_write_icreg(ipu, 0x00000070, IDMAC_CONF);
+
+       return dma_async_device_register(&idmac->dma);
+}
+
+static void ipu_idmac_exit(struct ipu *ipu)
+{
+       int i;
+       struct idmac *idmac = &ipu->idmac;
+
+       for (i = 0; i < IPU_CHANNELS_NUM; i++) {
+               struct idmac_channel *ichan = ipu->channel + i;
+
+               idmac_terminate_all(&ichan->dma_chan);
+               idmac_prep_slave_sg(&ichan->dma_chan, NULL, 0, DMA_NONE, 0);
+       }
+
+       dma_async_device_unregister(&idmac->dma);
+}
+
+/*****************************************************************************
+ * IPU common probe / remove
+ */
+
+static int ipu_probe(struct platform_device *pdev)
+{
+       struct ipu_platform_data *pdata = pdev->dev.platform_data;
+       struct resource *mem_ipu, *mem_ic;
+       int ret;
+
+       spin_lock_init(&ipu_data.lock);
+
+       mem_ipu = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       mem_ic  = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+       if (!pdata || !mem_ipu || !mem_ic)
+               return -EINVAL;
+
+       ipu_data.dev = &pdev->dev;
+
+       platform_set_drvdata(pdev, &ipu_data);
+
+       ret = platform_get_irq(pdev, 0);
+       if (ret < 0)
+               goto err_noirq;
+
+       ipu_data.irq_fn = ret;
+       ret = platform_get_irq(pdev, 1);
+       if (ret < 0)
+               goto err_noirq;
+
+       ipu_data.irq_err = ret;
+       ipu_data.irq_base = pdata->irq_base;
+
+       dev_dbg(&pdev->dev, "fn irq %u, err irq %u, irq-base %u\n",
+               ipu_data.irq_fn, ipu_data.irq_err, ipu_data.irq_base);
+
+       /* Remap IPU common registers */
+       ipu_data.reg_ipu = ioremap(mem_ipu->start,
+                                  mem_ipu->end - mem_ipu->start + 1);
+       if (!ipu_data.reg_ipu) {
+               ret = -ENOMEM;
+               goto err_ioremap_ipu;
+       }
+
+       /* Remap Image Converter and Image DMA Controller registers */
+       ipu_data.reg_ic = ioremap(mem_ic->start,
+                                 mem_ic->end - mem_ic->start + 1);
+       if (!ipu_data.reg_ic) {
+               ret = -ENOMEM;
+               goto err_ioremap_ic;
+       }
+
+       /* Get IPU clock */
+       ipu_data.ipu_clk = clk_get(&pdev->dev, "ipu_clk");
+       if (IS_ERR(ipu_data.ipu_clk)) {
+               ret = PTR_ERR(ipu_data.ipu_clk);
+               goto err_clk_get;
+       }
+
+       /* Make sure IPU HSP clock is running */
+       clk_enable(ipu_data.ipu_clk);
+
+       /* Disable all interrupts */
+       idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_1);
+       idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_2);
+       idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_3);
+       idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_4);
+       idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_5);
+
+       dev_dbg(&pdev->dev, "%s @ 0x%08lx, fn irq %u, err irq %u\n", pdev->name,
+               (unsigned long)mem_ipu->start, ipu_data.irq_fn, ipu_data.irq_err);
+
+       ret = ipu_irq_attach_irq(&ipu_data, pdev);
+       if (ret < 0)
+               goto err_attach_irq;
+
+       /* Initialize DMA engine */
+       ret = ipu_idmac_init(&ipu_data);
+       if (ret < 0)
+               goto err_idmac_init;
+
+       tasklet_init(&ipu_data.tasklet, ipu_gc_tasklet, (unsigned long)&ipu_data);
+
+       ipu_data.dev = &pdev->dev;
+
+       dev_dbg(ipu_data.dev, "IPU initialized\n");
+
+       return 0;
+
+err_idmac_init:
+err_attach_irq:
+       ipu_irq_detach_irq(&ipu_data, pdev);
+       clk_disable(ipu_data.ipu_clk);
+       clk_put(ipu_data.ipu_clk);
+err_clk_get:
+       iounmap(ipu_data.reg_ic);
+err_ioremap_ic:
+       iounmap(ipu_data.reg_ipu);
+err_ioremap_ipu:
+err_noirq:
+       dev_err(&pdev->dev, "Failed to probe IPU: %d\n", ret);
+       return ret;
+}
+
+static int ipu_remove(struct platform_device *pdev)
+{
+       struct ipu *ipu = platform_get_drvdata(pdev);
+
+       ipu_idmac_exit(ipu);
+       ipu_irq_detach_irq(ipu, pdev);
+       clk_disable(ipu->ipu_clk);
+       clk_put(ipu->ipu_clk);
+       iounmap(ipu->reg_ic);
+       iounmap(ipu->reg_ipu);
+       tasklet_kill(&ipu->tasklet);
+       platform_set_drvdata(pdev, NULL);
+
+       return 0;
+}
+
+/*
+ * We need two MEM resources - with IPU-common and Image Converter registers,
+ * including PF_CONF and IDMAC_* registers, and two IRQs - function and error
+ */
+static struct platform_driver ipu_platform_driver = {
+       .driver = {
+               .name   = "ipu-core",
+               .owner  = THIS_MODULE,
+       },
+       .remove         = ipu_remove,
+};
+
+static int __init ipu_init(void)
+{
+       return platform_driver_probe(&ipu_platform_driver, ipu_probe);
+}
+subsys_initcall(ipu_init);
+
+MODULE_DESCRIPTION("IPU core driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
+MODULE_ALIAS("platform:ipu-core");
 
--- /dev/null
+/*
+ * Copyright (C) 2008
+ * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <mach/ipu.h>
+
+#include "ipu_intern.h"
+
+/*
+ * Register read / write - shall be inlined by the compiler
+ */
+static u32 ipu_read_reg(struct ipu *ipu, unsigned long reg)
+{
+       return __raw_readl(ipu->reg_ipu + reg);
+}
+
+static void ipu_write_reg(struct ipu *ipu, u32 value, unsigned long reg)
+{
+       __raw_writel(value, ipu->reg_ipu + reg);
+}
+
+
+/*
+ * IPU IRQ chip driver
+ */
+
+#define IPU_IRQ_NR_FN_BANKS 3
+#define IPU_IRQ_NR_ERR_BANKS 2
+#define IPU_IRQ_NR_BANKS (IPU_IRQ_NR_FN_BANKS + IPU_IRQ_NR_ERR_BANKS)
+
+struct ipu_irq_bank {
+       unsigned int    control;
+       unsigned int    status;
+       spinlock_t      lock;
+       struct ipu      *ipu;
+};
+
+static struct ipu_irq_bank irq_bank[IPU_IRQ_NR_BANKS] = {
+       /* 3 groups of functional interrupts */
+       {
+               .control        = IPU_INT_CTRL_1,
+               .status         = IPU_INT_STAT_1,
+       }, {
+               .control        = IPU_INT_CTRL_2,
+               .status         = IPU_INT_STAT_2,
+       }, {
+               .control        = IPU_INT_CTRL_3,
+               .status         = IPU_INT_STAT_3,
+       },
+       /* 2 groups of error interrupts */
+       {
+               .control        = IPU_INT_CTRL_4,
+               .status         = IPU_INT_STAT_4,
+       }, {
+               .control        = IPU_INT_CTRL_5,
+               .status         = IPU_INT_STAT_5,
+       },
+};
+
+struct ipu_irq_map {
+       unsigned int            irq;
+       int                     source;
+       struct ipu_irq_bank     *bank;
+       struct ipu              *ipu;
+};
+
+static struct ipu_irq_map irq_map[CONFIG_MX3_IPU_IRQS];
+/* Protects allocations from the above array of maps */
+static DEFINE_MUTEX(map_lock);
+/* Protects register accesses and individual mappings */
+static DEFINE_SPINLOCK(bank_lock);
+
+static struct ipu_irq_map *src2map(unsigned int src)
+{
+       int i;
+
+       for (i = 0; i < CONFIG_MX3_IPU_IRQS; i++)
+               if (irq_map[i].source == src)
+                       return irq_map + i;
+
+       return NULL;
+}
+
+static void ipu_irq_unmask(unsigned int irq)
+{
+       struct ipu_irq_map *map = get_irq_chip_data(irq);
+       struct ipu_irq_bank *bank;
+       uint32_t reg;
+       unsigned long lock_flags;
+
+       spin_lock_irqsave(&bank_lock, lock_flags);
+
+       bank = map->bank;
+       if (!bank) {
+               spin_unlock_irqrestore(&bank_lock, lock_flags);
+               pr_err("IPU: %s(%u) - unmapped!\n", __func__, irq);
+               return;
+       }
+
+       reg = ipu_read_reg(bank->ipu, bank->control);
+       reg |= (1UL << (map->source & 31));
+       ipu_write_reg(bank->ipu, reg, bank->control);
+
+       spin_unlock_irqrestore(&bank_lock, lock_flags);
+}
+
+static void ipu_irq_mask(unsigned int irq)
+{
+       struct ipu_irq_map *map = get_irq_chip_data(irq);
+       struct ipu_irq_bank *bank;
+       uint32_t reg;
+       unsigned long lock_flags;
+
+       spin_lock_irqsave(&bank_lock, lock_flags);
+
+       bank = map->bank;
+       if (!bank) {
+               spin_unlock_irqrestore(&bank_lock, lock_flags);
+               pr_err("IPU: %s(%u) - unmapped!\n", __func__, irq);
+               return;
+       }
+
+       reg = ipu_read_reg(bank->ipu, bank->control);
+       reg &= ~(1UL << (map->source & 31));
+       ipu_write_reg(bank->ipu, reg, bank->control);
+
+       spin_unlock_irqrestore(&bank_lock, lock_flags);
+}
+
+static void ipu_irq_ack(unsigned int irq)
+{
+       struct ipu_irq_map *map = get_irq_chip_data(irq);
+       struct ipu_irq_bank *bank;
+       unsigned long lock_flags;
+
+       spin_lock_irqsave(&bank_lock, lock_flags);
+
+       bank = map->bank;
+       if (!bank) {
+               spin_unlock_irqrestore(&bank_lock, lock_flags);
+               pr_err("IPU: %s(%u) - unmapped!\n", __func__, irq);
+               return;
+       }
+
+       ipu_write_reg(bank->ipu, 1UL << (map->source & 31), bank->status);
+       spin_unlock_irqrestore(&bank_lock, lock_flags);
+}
+
+/**
+ * ipu_irq_status() - returns the current interrupt status of the specified IRQ.
+ * @irq:       interrupt line to get status for.
+ * @return:    true if the interrupt is pending/asserted or false if the
+ *             interrupt is not pending.
+ */
+bool ipu_irq_status(unsigned int irq)
+{
+       struct ipu_irq_map *map = get_irq_chip_data(irq);
+       struct ipu_irq_bank *bank;
+       unsigned long lock_flags;
+       bool ret;
+
+       spin_lock_irqsave(&bank_lock, lock_flags);
+       bank = map->bank;
+       ret = bank && ipu_read_reg(bank->ipu, bank->status) &
+               (1UL << (map->source & 31));
+       spin_unlock_irqrestore(&bank_lock, lock_flags);
+
+       return ret;
+}
+
+/**
+ * ipu_irq_map() - map an IPU interrupt source to an IRQ number
+ * @source:    interrupt source bit position (see below)
+ * @return:    mapped IRQ number or negative error code
+ *
+ * The source parameter has to be explained further. On i.MX31 IPU has 137 IRQ
+ * sources, they are broken down in 5 32-bit registers, like 32, 32, 24, 32, 17.
+ * However, the source argument of this function is not the sequence number of
+ * the possible IRQ, but rather its bit position. So, first interrupt in fourth
+ * register has source number 96, and not 88. This makes calculations easier,
+ * and also provides forward compatibility with any future IPU implementations
+ * with any interrupt bit assignments.
+ */
+int ipu_irq_map(unsigned int source)
+{
+       int i, ret = -ENOMEM;
+       struct ipu_irq_map *map;
+
+       might_sleep();
+
+       mutex_lock(&map_lock);
+       map = src2map(source);
+       if (map) {
+               pr_err("IPU: Source %u already mapped to IRQ %u\n", source, map->irq);
+               ret = -EBUSY;
+               goto out;
+       }
+
+       for (i = 0; i < CONFIG_MX3_IPU_IRQS; i++) {
+               if (irq_map[i].source < 0) {
+                       unsigned long lock_flags;
+
+                       spin_lock_irqsave(&bank_lock, lock_flags);
+                       irq_map[i].source = source;
+                       irq_map[i].bank = irq_bank + source / 32;
+                       spin_unlock_irqrestore(&bank_lock, lock_flags);
+
+                       ret = irq_map[i].irq;
+                       pr_debug("IPU: mapped source %u to IRQ %u\n",
+                                source, ret);
+                       break;
+               }
+       }
+out:
+       mutex_unlock(&map_lock);
+
+       if (ret < 0)
+               pr_err("IPU: couldn't map source %u: %d\n", source, ret);
+
+       return ret;
+}
+
+/**
+ * ipu_irq_map() - map an IPU interrupt source to an IRQ number
+ * @source:    interrupt source bit position (see ipu_irq_map())
+ * @return:    0 or negative error code
+ */
+int ipu_irq_unmap(unsigned int source)
+{
+       int i, ret = -EINVAL;
+
+       might_sleep();
+
+       mutex_lock(&map_lock);
+       for (i = 0; i < CONFIG_MX3_IPU_IRQS; i++) {
+               if (irq_map[i].source == source) {
+                       unsigned long lock_flags;
+
+                       pr_debug("IPU: unmapped source %u from IRQ %u\n",
+                                source, irq_map[i].irq);
+
+                       spin_lock_irqsave(&bank_lock, lock_flags);
+                       irq_map[i].source = -EINVAL;
+                       irq_map[i].bank = NULL;
+                       spin_unlock_irqrestore(&bank_lock, lock_flags);
+
+                       ret = 0;
+                       break;
+               }
+       }
+       mutex_unlock(&map_lock);
+
+       return ret;
+}
+
+/* Chained IRQ handler for IPU error interrupt */
+static void ipu_irq_err(unsigned int irq, struct irq_desc *desc)
+{
+       struct ipu *ipu = get_irq_data(irq);
+       u32 status;
+       int i, line;
+
+       for (i = IPU_IRQ_NR_FN_BANKS; i < IPU_IRQ_NR_BANKS; i++) {
+               struct ipu_irq_bank *bank = irq_bank + i;
+
+               spin_lock(&bank_lock);
+               status = ipu_read_reg(ipu, bank->status);
+               /*
+                * Don't think we have to clear all interrupts here, they will
+                * be acked by ->handle_irq() (handle_level_irq). However, we
+                * might want to clear unhandled interrupts after the loop...
+                */
+               status &= ipu_read_reg(ipu, bank->control);
+               spin_unlock(&bank_lock);
+               while ((line = ffs(status))) {
+                       struct ipu_irq_map *map;
+
+                       line--;
+                       status &= ~(1UL << line);
+
+                       spin_lock(&bank_lock);
+                       map = src2map(32 * i + line);
+                       if (map)
+                               irq = map->irq;
+                       spin_unlock(&bank_lock);
+
+                       if (!map) {
+                               pr_err("IPU: Interrupt on unmapped source %u bank %d\n",
+                                      line, i);
+                               continue;
+                       }
+                       generic_handle_irq(irq);
+               }
+       }
+}
+
+/* Chained IRQ handler for IPU function interrupt */
+static void ipu_irq_fn(unsigned int irq, struct irq_desc *desc)
+{
+       struct ipu *ipu = get_irq_data(irq);
+       u32 status;
+       int i, line;
+
+       for (i = 0; i < IPU_IRQ_NR_FN_BANKS; i++) {
+               struct ipu_irq_bank *bank = irq_bank + i;
+
+               spin_lock(&bank_lock);
+               status = ipu_read_reg(ipu, bank->status);
+               /* Not clearing all interrupts, see above */
+               status &= ipu_read_reg(ipu, bank->control);
+               spin_unlock(&bank_lock);
+               while ((line = ffs(status))) {
+                       struct ipu_irq_map *map;
+
+                       line--;
+                       status &= ~(1UL << line);
+
+                       spin_lock(&bank_lock);
+                       map = src2map(32 * i + line);
+                       if (map)
+                               irq = map->irq;
+                       spin_unlock(&bank_lock);
+
+                       if (!map) {
+                               pr_err("IPU: Interrupt on unmapped source %u bank %d\n",
+                                      line, i);
+                               continue;
+                       }
+                       generic_handle_irq(irq);
+               }
+       }
+}
+
+static struct irq_chip ipu_irq_chip = {
+       .name   = "ipu_irq",
+       .ack    = ipu_irq_ack,
+       .mask   = ipu_irq_mask,
+       .unmask = ipu_irq_unmask,
+};
+
+/* Install the IRQ handler */
+int ipu_irq_attach_irq(struct ipu *ipu, struct platform_device *dev)
+{
+       struct ipu_platform_data *pdata = dev->dev.platform_data;
+       unsigned int irq, irq_base, i;
+
+       irq_base = pdata->irq_base;
+
+       for (i = 0; i < IPU_IRQ_NR_BANKS; i++)
+               irq_bank[i].ipu = ipu;
+
+       for (i = 0; i < CONFIG_MX3_IPU_IRQS; i++) {
+               int ret;
+
+               irq = irq_base + i;
+               ret = set_irq_chip(irq, &ipu_irq_chip);
+               if (ret < 0)
+                       return ret;
+               ret = set_irq_chip_data(irq, irq_map + i);
+               if (ret < 0)
+                       return ret;
+               irq_map[i].ipu = ipu;
+               irq_map[i].irq = irq;
+               irq_map[i].source = -EINVAL;
+               set_irq_handler(irq, handle_level_irq);
+#ifdef CONFIG_ARM
+               set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+#endif
+       }
+
+       set_irq_data(ipu->irq_fn, ipu);
+       set_irq_chained_handler(ipu->irq_fn, ipu_irq_fn);
+
+       set_irq_data(ipu->irq_err, ipu);
+       set_irq_chained_handler(ipu->irq_err, ipu_irq_err);
+
+       return 0;
+}
+
+void ipu_irq_detach_irq(struct ipu *ipu, struct platform_device *dev)
+{
+       struct ipu_platform_data *pdata = dev->dev.platform_data;
+       unsigned int irq, irq_base;
+
+       irq_base = pdata->irq_base;
+
+       set_irq_chained_handler(ipu->irq_fn, NULL);
+       set_irq_data(ipu->irq_fn, NULL);
+
+       set_irq_chained_handler(ipu->irq_err, NULL);
+       set_irq_data(ipu->irq_err, NULL);
+
+       for (irq = irq_base; irq < irq_base + CONFIG_MX3_IPU_IRQS; irq++) {
+#ifdef CONFIG_ARM
+               set_irq_flags(irq, 0);
+#endif
+               set_irq_chip(irq, NULL);
+               set_irq_chip_data(irq, NULL);
+       }
+}