+/*
+ * drivers/i2c/chips/twl4030-madc.c
+ *
+ * TWL4030 MADC module driver
+ *
+ * Copyright (C) 2008 Nokia Corporation
+ * Mikko Ylinen <mikko.k.ylinen@nokia.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/i2c/twl4030.h>
+#include <linux/i2c/twl4030-madc.h>
+
+#include <asm/uaccess.h>
+
+#define TWL4030_MADC_PFX "twl4030-madc: "
+
+static struct twl4030_madc_data {
+ struct mutex lock;
+ struct work_struct ws;
+ struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
+} twl4030_madc;
+
+static const char irq_pin = 1; /* XXX Read from platfrom data */
+
+static
+const struct twl4030_madc_conversion_method twl4030_conversion_methods[] = {
+ [TWL4030_MADC_RT] = {
+ .sel = TWL4030_MADC_RTSELECT_LSB,
+ .avg = TWL4030_MADC_RTAVERAGE_LSB,
+ .rbase = TWL4030_MADC_RTCH0_LSB,
+ },
+ [TWL4030_MADC_SW1] = {
+ .sel = TWL4030_MADC_SW1SELECT_LSB,
+ .avg = TWL4030_MADC_SW1AVERAGE_LSB,
+ .rbase = TWL4030_MADC_GPCH0_LSB,
+ .ctrl = TWL4030_MADC_CTRL_SW1,
+ },
+ [TWL4030_MADC_SW2] = {
+ .sel = TWL4030_MADC_SW2SELECT_LSB,
+ .avg = TWL4030_MADC_SW2AVERAGE_LSB,
+ .rbase = TWL4030_MADC_GPCH0_LSB,
+ .ctrl = TWL4030_MADC_CTRL_SW2,
+ },
+};
+
+static void twl4030_madc_read(u8 reg, u8 *val)
+{
+ int ret = twl4030_i2c_read_u8(TWL4030_MODULE_MADC, val, reg);
+ if (ret)
+ printk(KERN_ERR TWL4030_MADC_PFX
+ "unable to read register 0x%X\n", reg);
+}
+
+static void twl4030_madc_write(u8 reg, u8 val)
+{
+ int ret = twl4030_i2c_write_u8(TWL4030_MODULE_MADC, val, reg);
+ if (ret)
+ printk(KERN_ERR TWL4030_MADC_PFX
+ "unable to write register 0x%X\n", reg);
+}
+
+static int twl4030_madc_channel_raw_read(u8 reg)
+{
+ u8 msb, lsb;
+
+ /* For each ADC channel, we have MSB and LSB register pair. MSB address
+ * is always LSB address+1. reg parameter is the addr of LSB register */
+ twl4030_madc_read(reg+1, &msb);
+ twl4030_madc_read(reg, &lsb);
+
+ return (int)(((msb << 8) | lsb) >> 6);
+}
+
+static int twl4030_madc_read_channels(u8 reg_base, u16 channels, int *buf)
+{
+ int count = 0;
+ u8 reg, i;
+
+ if (unlikely(!buf))
+ return 0;
+
+ for (i = 0; i < TWL4030_MADC_MAX_CHANNELS; i++) {
+ if (channels & (1<<i)) {
+ reg = reg_base + 2*i;
+ buf[i] = twl4030_madc_channel_raw_read(reg);
+ count++;
+ }
+ }
+ return count;
+}
+
+static void twl4030_madc_enable_irq(int id)
+{
+ u8 val;
+
+ static u8 imr = (irq_pin == 1) ? TWL4030_MADC_IMR1 : TWL4030_MADC_IMR2;
+
+ twl4030_madc_read(imr, &val);
+ val &= ~(1 << id);
+ twl4030_madc_write(imr, val);
+}
+
+static void twl4030_madc_disable_irq(int id)
+{
+ u8 val;
+
+ static u8 imr = (irq_pin == 1) ? TWL4030_MADC_IMR1 : TWL4030_MADC_IMR2;
+
+ twl4030_madc_read(imr, &val);
+ val |= (1 << id);
+ twl4030_madc_write(imr, val);
+}
+
+static irqreturn_t twl4030_madc_irq_handler(int irq, void *madc_dev)
+{
+ u8 isr_val, imr_val;
+ static u8 isr, imr;
+ int i;
+
+ imr = (irq_pin == 1) ? TWL4030_MADC_IMR1 : TWL4030_MADC_IMR2;
+ isr = (irq_pin == 1) ? TWL4030_MADC_ISR1 : TWL4030_MADC_ISR2;
+
+ /* Use COR to ack interrupts since we have no shared IRQs in ISRx */
+ twl4030_madc_read(isr, &isr_val);
+ twl4030_madc_read(imr, &imr_val);
+
+ isr_val &= ~imr_val;
+
+ for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
+
+ if (!(isr_val & (1<<i)))
+ continue;
+
+ twl4030_madc_disable_irq(i);
+ twl4030_madc.requests[i].result_pending = 1;
+ }
+
+ schedule_work(&twl4030_madc.ws);
+
+ return IRQ_HANDLED;
+}
+
+static void twl4030_madc_work(struct work_struct *ws)
+{
+ const struct twl4030_madc_conversion_method *method;
+ struct twl4030_madc_request *r;
+ int len, i;
+
+ mutex_lock(&twl4030_madc.lock);
+
+ for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
+
+ r = &twl4030_madc.requests[i];
+
+ /* No pending results for this method, move to next one */
+ if (!r->result_pending)
+ continue;
+
+ method = &twl4030_conversion_methods[r->method];
+
+ /* Read results */
+ len = twl4030_madc_read_channels(method->rbase,
+ r->channels, r->rbuf);
+
+ /* Return results to caller */
+ if (r->func_cb != NULL) {
+ r->func_cb(len, r->channels, r->rbuf);
+ r->func_cb = NULL;
+ }
+
+ /* Free request */
+ r->result_pending = 0;
+ r->active = 0;
+ }
+
+ mutex_unlock(&twl4030_madc.lock);
+}
+
+static int twl4030_madc_set_irq(struct twl4030_madc_request *req)
+{
+ struct twl4030_madc_request *p;
+
+ p = &twl4030_madc.requests[req->method];
+
+ memcpy(p, req, sizeof *req);
+
+ twl4030_madc_enable_irq(req->method);
+
+ return 0;
+}
+
+static inline void twl4030_madc_start_conversion(int conv_method)
+{
+ const struct twl4030_madc_conversion_method *method;
+
+ method = &twl4030_conversion_methods[conv_method];
+
+ switch (conv_method) {
+ case TWL4030_MADC_SW1:
+ case TWL4030_MADC_SW2:
+ twl4030_madc_write(method->ctrl, TWL4030_MADC_SW_START);
+ break;
+ case TWL4030_MADC_RT:
+ default:
+ break;
+ }
+}
+
+static void twl4030_madc_wait_conversion_ready_ms(u8 *time, u8 status_reg)
+{
+ u8 reg = 0;
+
+ do {
+ msleep(1);
+ (*time)--;
+ twl4030_madc_read(status_reg, ®);
+ } while (((reg & TWL4030_MADC_BUSY) && !(reg & TWL4030_MADC_EOC_SW)) &&
+ (*time != 0));
+}
+
+int twl4030_madc_conversion(struct twl4030_madc_request *req)
+{
+ const struct twl4030_madc_conversion_method *method;
+ u8 wait_time, ch_msb, ch_lsb;
+ int ret;
+
+ if (unlikely(!req))
+ return -EINVAL;
+
+ /* Do we have a conversion request ongoing */
+ if (twl4030_madc.requests[req->method].active)
+ return -EBUSY;
+
+ ch_msb = (req->channels >> 8) & 0xff;
+ ch_lsb = req->channels & 0xff;
+
+ method = &twl4030_conversion_methods[req->method];
+
+ mutex_lock(&twl4030_madc.lock);
+
+ /* Select channels to be converted */
+ twl4030_madc_write(method->sel + 1, ch_msb);
+ twl4030_madc_write(method->sel, ch_lsb);
+
+ /* Select averaging for all channels if do_avg is set */
+ if (req->do_avg) {
+ twl4030_madc_write(method->avg + 1, ch_msb);
+ twl4030_madc_write(method->avg, ch_lsb);
+ }
+
+ if ((req->type == TWL4030_MADC_IRQ_ONESHOT) && (req->func_cb != NULL)) {
+ twl4030_madc_set_irq(req);
+ twl4030_madc_start_conversion(req->method);
+ twl4030_madc.requests[req->method].active = 1;
+ ret = 0;
+ goto out;
+ }
+
+ /* With RT method we should not be here anymore */
+ if (req->method == TWL4030_MADC_RT) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ twl4030_madc_start_conversion(req->method);
+ twl4030_madc.requests[req->method].active = 1;
+
+ /* Wait until conversion is ready (ctrl register returns EOC) */
+ wait_time = 50;
+ twl4030_madc_wait_conversion_ready_ms(&wait_time, method->ctrl);
+ if (wait_time == 0) {
+ printk(KERN_ERR TWL4030_MADC_PFX "conversion timeout!\n");
+ ret = -EAGAIN;
+ goto out;
+ }
+
+ ret = twl4030_madc_read_channels(method->rbase, req->channels,
+ req->rbuf);
+
+ twl4030_madc.requests[req->method].active = 0;
+
+out:
+ mutex_unlock(&twl4030_madc.lock);
+
+ return ret;
+}
+
+EXPORT_SYMBOL(twl4030_madc_conversion);
+
+static int twl4030_madc_set_current_generator(int chan, int on)
+{
+ int ret;
+ u8 regval;
+
+ /* Current generator is only available for ADCIN0 and ADCIN1. NB:
+ * ADCIN1 current generator only works when AC or VBUS is present */
+ if (chan > 1)
+ return EINVAL;
+
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE,
+ ®val, TWL4030_BCI_BCICTL1);
+ if (on)
+ regval |= (chan) ? TWL4030_BCI_ITHEN : TWL4030_BCI_TYPEN;
+ else
+ regval &= (chan) ? ~TWL4030_BCI_ITHEN : ~TWL4030_BCI_TYPEN;
+ ret = twl4030_i2c_write_u8(TWL4030_MODULE_MAIN_CHARGE,
+ regval, TWL4030_BCI_BCICTL1);
+
+ return ret;
+}
+
+static int twl4030_madc_set_power(int on)
+{
+ u8 regval;
+
+ twl4030_madc_read(TWL4030_MADC_CTRL1, ®val);
+ if (on)
+ regval |= TWL4030_MADC_MADCON;
+ else
+ regval &= ~TWL4030_MADC_MADCON;
+ twl4030_madc_write(TWL4030_MADC_CTRL1, regval);
+
+ return 0;
+}
+
+static int twl4030_madc_ioctl(struct inode *inode, struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct twl4030_madc_user_parms par;
+ int val, ret;
+
+ ret = copy_from_user(&par, (void __user *) arg, sizeof(par));
+ if (ret) {
+ printk(KERN_ERR TWL4030_MADC_PFX "copy_from_user: %d\n", ret);
+ return -EACCES;
+ }
+
+ switch (cmd) {
+ case TWL4030_MADC_IOCX_ADC_RAW_READ: {
+ struct twl4030_madc_request req;
+ if (par.channel >= TWL4030_MADC_MAX_CHANNELS)
+ return -EINVAL;
+
+ req.channels = (1<<par.channel);
+ req.do_avg = par.average;
+ req.method = TWL4030_MADC_SW1;
+
+ val = twl4030_madc_conversion(&req);
+ if (val <= 0) {
+ par.status = -1;
+ } else {
+ par.status = 0;
+ par.result = (u16)req.rbuf[par.channel];
+ }
+ break;
+ }
+ default:
+ return -EINVAL;
+ }
+
+ ret = copy_to_user((void __user *) arg, &par, sizeof(par));
+ if (ret) {
+ printk(KERN_ERR TWL4030_MADC_PFX "copy_to_user: %d\n", ret);
+ return -EACCES;
+ }
+
+ return 0;
+}
+
+static struct file_operations twl4030_madc_fileops = {
+ .owner = THIS_MODULE,
+ .ioctl = twl4030_madc_ioctl
+};
+
+static struct miscdevice twl4030_madc_device = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "twl4030-adc",
+ .fops = &twl4030_madc_fileops
+};
+
+static int __init twl4030_madc_init(void)
+{
+ int ret;
+ u8 regval;
+
+ ret = misc_register(&twl4030_madc_device);
+ if (ret == -1) {
+ printk(KERN_ERR TWL4030_MADC_PFX "misc_register() failed!\n");
+ return ret;
+ }
+ twl4030_madc_set_power(1);
+ twl4030_madc_set_current_generator(0, 1);
+
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE,
+ ®val, TWL4030_BCI_BCICTL1);
+
+ regval |= TWL4030_BCI_MESBAT;
+
+ ret = twl4030_i2c_write_u8(TWL4030_MODULE_MAIN_CHARGE,
+ regval, TWL4030_BCI_BCICTL1);
+
+ ret = request_irq(TWL4030_MODIRQ_MADC, twl4030_madc_irq_handler,
+ IRQF_DISABLED, "twl4030_madc", &twl4030_madc);
+ if (ret)
+ printk(KERN_ERR TWL4030_MADC_PFX "request_irq: %d\n", ret);
+
+ mutex_init(&twl4030_madc.lock);
+
+ INIT_WORK(&twl4030_madc.ws, twl4030_madc_work);
+
+ printk(KERN_INFO TWL4030_MADC_PFX "initialised\n");
+
+ return ret;
+}
+
+static void __exit twl4030_madc_exit(void)
+{
+ twl4030_madc_set_power(0);
+ twl4030_madc_set_current_generator(0, 0);
+ free_irq(TWL4030_MODIRQ_MADC, &twl4030_madc);
+ cancel_work_sync(&twl4030_madc.ws);
+ misc_deregister(&twl4030_madc_device);
+}
+
+module_init(twl4030_madc_init);
+module_exit(twl4030_madc_exit);
+
+MODULE_AUTHOR("Nokia Corporation");
+MODULE_DESCRIPTION("twl4030 ADC driver");
+MODULE_LICENSE("GPL");