]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - arch/arm/mach-omap2/serial.c
OMAP3: PM: UART: disable clocks when idle
[linux-2.6-omap-h63xx.git] / arch / arm / mach-omap2 / serial.c
index 4dcf39c285b94bac5e1e6292469299c633fcd0bf..8c161dde24a097dc2842374792801aaaec6b28f6 100644 (file)
@@ -6,6 +6,8 @@
  * Copyright (C) 2005-2008 Nokia Corporation
  * Author: Paul Mundt <paul.mundt@nokia.com>
  *
+ * Major rework for PM support by Kevin Hilman
+ *
  * Based off of arch/arm/mach-omap/omap1/serial.c
  *
  * This file is subject to the terms and conditions of the GNU General Public
 
 #include <mach/common.h>
 #include <mach/board.h>
+#include <mach/clock.h>
+#include <mach/control.h>
+
+#include "prm.h"
+#include "pm.h"
+#include "prm-regbits-34xx.h"
+
+#define DEFAULT_TIMEOUT (2 * HZ)
+
+struct omap_uart_state {
+       int num;
+       int can_sleep;
+       struct timer_list timer;
+       u32 timeout;
 
-static struct clk *uart_ick[OMAP_MAX_NR_PORTS];
-static struct clk *uart_fck[OMAP_MAX_NR_PORTS];
+       void __iomem *wk_st;
+       void __iomem *wk_en;
+       u32 wk_mask;
+       u32 padconf;
+
+       struct clk *ick;
+       struct clk *fck;
+       int clocked;
+
+       struct plat_serial8250_port *p;
+       struct list_head node;
+};
+
+static struct omap_uart_state omap_uart[OMAP_MAX_NR_PORTS];
+static LIST_HEAD(uart_list);
 
 static struct plat_serial8250_port serial_platform_data[] = {
        {
@@ -74,30 +103,257 @@ static inline void serial_write_reg(struct plat_serial8250_port *p, int offset,
  * properly. Note that the TX watermark initialization may not be needed
  * once the 8250.c watermark handling code is merged.
  */
-static inline void __init omap_serial_reset(struct plat_serial8250_port *p)
+static inline void __init omap_uart_reset(struct omap_uart_state *uart)
 {
+       struct plat_serial8250_port *p = uart->p;
+
        serial_write_reg(p, UART_OMAP_MDR1, 0x07);
        serial_write_reg(p, UART_OMAP_SCR, 0x08);
        serial_write_reg(p, UART_OMAP_MDR1, 0x00);
        serial_write_reg(p, UART_OMAP_SYSC, (0x02 << 3) | (1 << 2) | (1 << 0));
 }
 
-void omap_serial_enable_clocks(int enable)
+#ifdef CONFIG_PM
+static void omap_uart_smart_idle_enable(struct omap_uart_state *uart,
+                                         int enable)
 {
-       int i;
-       for (i = 0; i < OMAP_MAX_NR_PORTS; i++) {
-               if (uart_ick[i] && uart_fck[i]) {
-                       if (enable) {
-                               clk_enable(uart_ick[i]);
-                               clk_enable(uart_fck[i]);
-                       } else {
-                               clk_disable(uart_ick[i]);
-                               clk_disable(uart_fck[i]);
+       struct plat_serial8250_port *p = uart->p;
+       u16 sysc;
+
+       sysc = serial_read_reg(p, UART_OMAP_SYSC) & 0x7;
+       if (enable)
+               sysc |= 0x2 << 3;
+       else
+               sysc |= 0x1 << 3;
+
+       serial_write_reg(p, UART_OMAP_SYSC, sysc);
+}
+
+static inline void omap_uart_enable_clocks(struct omap_uart_state *uart)
+{
+       if (uart->clocked)
+               return;
+
+       clk_enable(uart->ick);
+       clk_enable(uart->fck);
+       uart->clocked = 1;
+}
+
+static inline void omap_uart_disable_clocks(struct omap_uart_state *uart)
+{
+       if (!uart->clocked)
+               return;
+
+       uart->clocked = 0;
+       clk_disable(uart->ick);
+       clk_disable(uart->fck);
+}
+
+static void omap_uart_block_sleep(struct omap_uart_state *uart)
+{
+       omap_uart_enable_clocks(uart);
+
+       omap_uart_smart_idle_enable(uart, 0);
+       uart->can_sleep = 0;
+       mod_timer(&uart->timer, jiffies + uart->timeout);
+}
+
+static void omap_uart_allow_sleep(struct omap_uart_state *uart)
+{
+       if (!uart->clocked)
+               return;
+
+       omap_uart_smart_idle_enable(uart, 1);
+       uart->can_sleep = 1;
+       del_timer(&uart->timer);
+}
+
+static void omap_uart_idle_timer(unsigned long data)
+{
+       struct omap_uart_state *uart = (struct omap_uart_state *)data;
+
+       omap_uart_allow_sleep(uart);
+}
+
+void omap_uart_prepare_idle(int num)
+{
+       struct omap_uart_state *uart;
+
+       list_for_each_entry(uart, &uart_list, node) {
+               if (!clocks_off_while_idle)
+                       continue;
+
+               if (num == uart->num && uart->can_sleep) {
+                       omap_uart_disable_clocks(uart);
+                       return;
+               }
+       }
+}
+
+void omap_uart_resume_idle(int num)
+{
+       struct omap_uart_state *uart;
+
+       list_for_each_entry(uart, &uart_list, node) {
+               if (num == uart->num) {
+                       omap_uart_enable_clocks(uart);
+
+                       /* Check for IO pad wakeup */
+                       if (cpu_is_omap34xx() && uart->padconf) {
+                               u16 p = omap_ctrl_readw(uart->padconf);
+
+                               if (p & OMAP3_PADCONF_WAKEUPEVENT0)
+                                       omap_uart_block_sleep(uart);
                        }
+
+                       /* Check for normal UART wakeup */
+                       if (__raw_readl(uart->wk_st) & uart->wk_mask)
+                               omap_uart_block_sleep(uart);
+
+                       return;
                }
        }
 }
 
+void omap_uart_prepare_suspend(void)
+{
+       struct omap_uart_state *uart;
+
+       list_for_each_entry(uart, &uart_list, node) {
+               omap_uart_allow_sleep(uart);
+       }
+}
+
+int omap_uart_can_sleep(void)
+{
+       struct omap_uart_state *uart;
+       int can_sleep = 1;
+
+       list_for_each_entry(uart, &uart_list, node) {
+               if (!uart->clocked)
+                       continue;
+
+               if (!uart->can_sleep) {
+                       can_sleep = 0;
+                       continue;
+               }
+
+               /* This UART can now safely sleep. */
+               omap_uart_allow_sleep(uart);
+       }
+
+       return can_sleep;
+}
+
+/**
+ * omap_uart_interrupt()
+ *
+ * This handler is used only to detect that *any* UART interrupt has
+ * occurred.  It does _nothing_ to handle the interrupt.  Rather,
+ * any UART interrupt will trigger the inactivity timer so the
+ * UART will not idle or sleep for its timeout period.
+ *
+ **/
+static irqreturn_t omap_uart_interrupt(int irq, void *dev_id)
+{
+       struct omap_uart_state *uart = dev_id;
+
+       omap_uart_block_sleep(uart);
+
+       return IRQ_NONE;
+}
+
+static void omap_uart_idle_init(struct omap_uart_state *uart)
+{
+       u32 v;
+       struct plat_serial8250_port *p = uart->p;
+       int ret;
+
+       uart->can_sleep = 0;
+       uart->timeout = DEFAULT_TIMEOUT;
+       setup_timer(&uart->timer, omap_uart_idle_timer,
+                   (unsigned long) uart);
+       mod_timer(&uart->timer, jiffies + uart->timeout);
+       omap_uart_smart_idle_enable(uart, 0);
+
+       if (cpu_is_omap34xx()) {
+               u32 mod = (uart->num == 2) ? OMAP3430_PER_MOD : CORE_MOD;
+               u32 wk_mask = 0;
+               u32 padconf = 0;
+
+               uart->wk_en = OMAP34XX_PRM_REGADDR(mod, PM_WKEN1);
+               uart->wk_st = OMAP34XX_PRM_REGADDR(mod, PM_WKST1);
+               switch (uart->num) {
+               case 0:
+                       wk_mask = OMAP3430_ST_UART1_MASK;
+                       padconf = 0x182;
+                       break;
+               case 1:
+                       wk_mask = OMAP3430_ST_UART2_MASK;
+                       padconf = 0x17a;
+                       break;
+               case 2:
+                       wk_mask = OMAP3430_ST_UART3_MASK;
+                       padconf = 0x19e;
+                       break;
+               }
+               uart->wk_mask = wk_mask;
+               uart->padconf = padconf;
+       } else if (cpu_is_omap24xx()) {
+               u32 wk_mask = 0;
+
+               if (cpu_is_omap2430()) {
+                       uart->wk_en = OMAP2430_PRM_REGADDR(CORE_MOD, PM_WKEN1);
+                       uart->wk_st = OMAP2430_PRM_REGADDR(CORE_MOD, PM_WKST1);
+               } else if (cpu_is_omap2420()) {
+                       uart->wk_en = OMAP2420_PRM_REGADDR(CORE_MOD, PM_WKEN1);
+                       uart->wk_st = OMAP2420_PRM_REGADDR(CORE_MOD, PM_WKST1);
+               }
+               switch (uart->num) {
+               case 0:
+                       wk_mask = OMAP24XX_ST_UART1_MASK;
+                       break;
+               case 1:
+                       wk_mask = OMAP24XX_ST_UART2_MASK;
+                       break;
+               case 2:
+                       wk_mask = OMAP24XX_ST_UART3_MASK;
+                       break;
+               }
+               uart->wk_mask = wk_mask;
+       } else {
+               uart->wk_en = 0;
+               uart->wk_st = 0;
+               uart->wk_mask = 0;
+               uart->padconf = 0;
+       }
+
+       /* Set wake-enable bit */
+       if (uart->wk_en && uart->wk_mask) {
+               v = __raw_readl(uart->wk_en);
+               v |= uart->wk_mask;
+               __raw_writel(v, uart->wk_en);
+       }
+
+       /* Ensure IOPAD wake-enables are set */
+       if (cpu_is_omap34xx() && uart->padconf) {
+               u16 v;
+
+               v = omap_ctrl_readw(uart->padconf);
+               v |= OMAP3_PADCONF_WAKEUPENABLE0;
+               omap_ctrl_writew(v, uart->padconf);
+       }
+
+       p->flags |= UPF_SHARE_IRQ;
+       ret = request_irq(p->irq, omap_uart_interrupt, IRQF_SHARED,
+                         "serial idle", (void *)uart);
+       WARN_ON(ret);
+}
+
+#else
+static inline void omap_uart_idle_init(struct omap_uart_state *uart) {}
+#endif /* CONFIG_PM */
+
 void __init omap_serial_init(void)
 {
        int i;
@@ -117,6 +373,7 @@ void __init omap_serial_init(void)
 
        for (i = 0; i < OMAP_MAX_NR_PORTS; i++) {
                struct plat_serial8250_port *p = serial_platform_data + i;
+               struct omap_uart_state *uart = &omap_uart[i];
 
                if (!(info->enabled_uarts & (1 << i))) {
                        p->membase = NULL;
@@ -125,22 +382,30 @@ void __init omap_serial_init(void)
                }
 
                sprintf(name, "uart%d_ick", i+1);
-               uart_ick[i] = clk_get(NULL, name);
-               if (IS_ERR(uart_ick[i])) {
+               uart->ick = clk_get(NULL, name);
+               if (IS_ERR(uart->ick)) {
                        printk(KERN_ERR "Could not get uart%d_ick\n", i+1);
-                       uart_ick[i] = NULL;
-               } else
-                       clk_enable(uart_ick[i]);
+                       uart->ick = NULL;
+               }
 
                sprintf(name, "uart%d_fck", i+1);
-               uart_fck[i] = clk_get(NULL, name);
-               if (IS_ERR(uart_fck[i])) {
+               uart->fck = clk_get(NULL, name);
+               if (IS_ERR(uart->fck)) {
                        printk(KERN_ERR "Could not get uart%d_fck\n", i+1);
-                       uart_fck[i] = NULL;
-               } else
-                       clk_enable(uart_fck[i]);
+                       uart->fck = NULL;
+               }
+
+               if (!uart->ick || !uart->fck)
+                       continue;
+
+               uart->num = i;
+               p->private_data = uart;
+               uart->p = p;
+               list_add(&uart->node, &uart_list);
 
-               omap_serial_reset(p);
+               omap_uart_enable_clocks(uart);
+               omap_uart_reset(uart);
+               omap_uart_idle_init(uart);
        }
 }