mfd: Add twl4030 madc driver
Introducing a driver for MADC on TWL4030 powerIC. MADC stands for monitoring
ADC. This driver monitors the real time conversion of analog signals like
battery temperature, battery cuurent etc.
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/twl4030-madc.c b/drivers/mfd/twl4030-madc.c
new file mode 100644
index 0000000..e9884e2
--- /dev/null
+++ b/drivers/mfd/twl4030-madc.c
@@ -0,0 +1,802 @@
+/*
+ *
+ * TWL4030 MADC module driver-This driver monitors the real time
+ * conversion of analog signals like battery temperature,
+ * battery type, battery level etc.
+ *
+ * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
+ * J Keerthy <j-keerthy@ti.com>
+ *
+ * Based on twl4030-madc.c
+ * Copyright (C) 2008 Nokia Corporation
+ * Mikko Ylinen <mikko.k.ylinen@nokia.com>
+ *
+ * Amit Kucheria <amit.kucheria@canonical.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/device.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/i2c/twl.h>
+#include <linux/i2c/twl4030-madc.h>
+#include <linux/module.h>
+#include <linux/stddef.h>
+#include <linux/mutex.h>
+#include <linux/bitops.h>
+#include <linux/jiffies.h>
+#include <linux/types.h>
+#include <linux/gfp.h>
+#include <linux/err.h>
+
+/*
+ * struct twl4030_madc_data - a container for madc info
+ * @dev - pointer to device structure for madc
+ * @lock - mutex protecting this data structure
+ * @requests - Array of request struct corresponding to SW1, SW2 and RT
+ * @imr - Interrupt mask register of MADC
+ * @isr - Interrupt status register of MADC
+ */
+struct twl4030_madc_data {
+ struct device *dev;
+ struct mutex lock; /* mutex protecting this data structure */
+ struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
+ int imr;
+ int isr;
+};
+
+static struct twl4030_madc_data *twl4030_madc;
+
+struct twl4030_prescale_divider_ratios {
+ s16 numerator;
+ s16 denominator;
+};
+
+static const struct twl4030_prescale_divider_ratios
+twl4030_divider_ratios[16] = {
+ {1, 1}, /* CHANNEL 0 No Prescaler */
+ {1, 1}, /* CHANNEL 1 No Prescaler */
+ {6, 10}, /* CHANNEL 2 */
+ {6, 10}, /* CHANNEL 3 */
+ {6, 10}, /* CHANNEL 4 */
+ {6, 10}, /* CHANNEL 5 */
+ {6, 10}, /* CHANNEL 6 */
+ {6, 10}, /* CHANNEL 7 */
+ {3, 14}, /* CHANNEL 8 */
+ {1, 3}, /* CHANNEL 9 */
+ {1, 1}, /* CHANNEL 10 No Prescaler */
+ {15, 100}, /* CHANNEL 11 */
+ {1, 4}, /* CHANNEL 12 */
+ {1, 1}, /* CHANNEL 13 Reserved channels */
+ {1, 1}, /* CHANNEL 14 Reseved channels */
+ {5, 11}, /* CHANNEL 15 */
+};
+
+
+/*
+ * Conversion table from -3 to 55 degree Celcius
+ */
+static int therm_tbl[] = {
+30800, 29500, 28300, 27100,
+26000, 24900, 23900, 22900, 22000, 21100, 20300, 19400, 18700, 17900,
+17200, 16500, 15900, 15300, 14700, 14100, 13600, 13100, 12600, 12100,
+11600, 11200, 10800, 10400, 10000, 9630, 9280, 8950, 8620, 8310,
+8020, 7730, 7460, 7200, 6950, 6710, 6470, 6250, 6040, 5830,
+5640, 5450, 5260, 5090, 4920, 4760, 4600, 4450, 4310, 4170,
+4040, 3910, 3790, 3670, 3550
+};
+
+/*
+ * Structure containing the registers
+ * of different conversion methods supported by MADC.
+ * Hardware or RT real time conversion request initiated by external host
+ * processor for RT Signal conversions.
+ * External host processors can also request for non RT conversions
+ * SW1 and SW2 software conversions also called asynchronous or GPC request.
+ */
+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,
+ },
+};
+
+/*
+ * Function to read a particular channel value.
+ * @madc - pointer to struct twl4030_madc_data
+ * @reg - lsb of ADC Channel
+ * If the i2c read fails it returns an error else returns 0.
+ */
+static int twl4030_madc_channel_raw_read(struct twl4030_madc_data *madc, u8 reg)
+{
+ u8 msb, lsb;
+ int ret;
+ /*
+ * For each ADC channel, we have MSB and LSB register pair. MSB address
+ * is always LSB address+1. reg parameter is the address of LSB register
+ */
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &msb, reg + 1);
+ if (ret) {
+ dev_err(madc->dev, "unable to read MSB register 0x%X\n",
+ reg + 1);
+ return ret;
+ }
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &lsb, reg);
+ if (ret) {
+ dev_err(madc->dev, "unable to read LSB register 0x%X\n", reg);
+ return ret;
+ }
+
+ return (int)(((msb << 8) | lsb) >> 6);
+}
+
+/*
+ * Return battery temperature
+ * Or < 0 on failure.
+ */
+static int twl4030battery_temperature(int raw_volt)
+{
+ u8 val;
+ int temp, curr, volt, res, ret;
+
+ volt = (raw_volt * TEMP_STEP_SIZE) / TEMP_PSR_R;
+ /* Getting and calculating the supply current in micro ampers */
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, &val,
+ REG_BCICTL2);
+ if (ret < 0)
+ return ret;
+ curr = ((val & TWL4030_BCI_ITHEN) + 1) * 10;
+ /* Getting and calculating the thermistor resistance in ohms */
+ res = volt * 1000 / curr;
+ /* calculating temperature */
+ for (temp = 58; temp >= 0; temp--) {
+ int actual = therm_tbl[temp];
+
+ if ((actual - res) >= 0)
+ break;
+ }
+
+ return temp + 1;
+}
+
+static int twl4030battery_current(int raw_volt)
+{
+ int ret;
+ u8 val;
+
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, &val,
+ TWL4030_BCI_BCICTL1);
+ if (ret)
+ return ret;
+ if (val & TWL4030_BCI_CGAIN) /* slope of 0.44 mV/mA */
+ return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R1;
+ else /* slope of 0.88 mV/mA */
+ return (raw_volt * CURR_STEP_SIZE) / CURR_PSR_R2;
+}
+/*
+ * Function to read channel values
+ * @madc - pointer to twl4030_madc_data struct
+ * @reg_base - Base address of the first channel
+ * @Channels - 16 bit bitmap. If the bit is set, channel value is read
+ * @buf - The channel values are stored here. if read fails error
+ * value is stored
+ * Returns the number of successfully read channels.
+ */
+static int twl4030_madc_read_channels(struct twl4030_madc_data *madc,
+ u8 reg_base, unsigned
+ long channels, int *buf)
+{
+ int count = 0, count_req = 0, i;
+ u8 reg;
+
+ for_each_set_bit(i, &channels, TWL4030_MADC_MAX_CHANNELS) {
+ reg = reg_base + 2 * i;
+ buf[i] = twl4030_madc_channel_raw_read(madc, reg);
+ if (buf[i] < 0) {
+ dev_err(madc->dev,
+ "Unable to read register 0x%X\n", reg);
+ count_req++;
+ continue;
+ }
+ switch (i) {
+ case 10:
+ buf[i] = twl4030battery_current(buf[i]);
+ if (buf[i] < 0) {
+ dev_err(madc->dev, "err reading current\n");
+ count_req++;
+ } else {
+ count++;
+ buf[i] = buf[i] - 750;
+ }
+ break;
+ case 1:
+ buf[i] = twl4030battery_temperature(buf[i]);
+ if (buf[i] < 0) {
+ dev_err(madc->dev, "err reading temperature\n");
+ count_req++;
+ } else {
+ buf[i] -= 3;
+ count++;
+ }
+ break;
+ default:
+ count++;
+ /* Analog Input (V) = conv_result * step_size / R
+ * conv_result = decimal value of 10-bit conversion
+ * result
+ * step size = 1.5 / (2 ^ 10 -1)
+ * R = Prescaler ratio for input channels.
+ * Result given in mV hence multiplied by 1000.
+ */
+ buf[i] = (buf[i] * 3 * 1000 *
+ twl4030_divider_ratios[i].denominator)
+ / (2 * 1023 *
+ twl4030_divider_ratios[i].numerator);
+ }
+ }
+ if (count_req)
+ dev_err(madc->dev, "%d channel conversion failed\n", count_req);
+
+ return count;
+}
+
+/*
+ * Enables irq.
+ * @madc - pointer to twl4030_madc_data struct
+ * @id - irq number to be enabled
+ * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2
+ * corresponding to RT, SW1, SW2 conversion requests.
+ * If the i2c read fails it returns an error else returns 0.
+ */
+static int twl4030_madc_enable_irq(struct twl4030_madc_data *madc, u8 id)
+{
+ u8 val;
+ int ret;
+
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr);
+ if (ret) {
+ dev_err(madc->dev, "unable to read imr register 0x%X\n",
+ madc->imr);
+ return ret;
+ }
+ val &= ~(1 << id);
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr);
+ if (ret) {
+ dev_err(madc->dev,
+ "unable to write imr register 0x%X\n", madc->imr);
+ return ret;
+
+ }
+
+ return 0;
+}
+
+/*
+ * Disables irq.
+ * @madc - pointer to twl4030_madc_data struct
+ * @id - irq number to be disabled
+ * can take one of TWL4030_MADC_RT, TWL4030_MADC_SW1, TWL4030_MADC_SW2
+ * corresponding to RT, SW1, SW2 conversion requests.
+ * Returns error if i2c read/write fails.
+ */
+static int twl4030_madc_disable_irq(struct twl4030_madc_data *madc, u8 id)
+{
+ u8 val;
+ int ret;
+
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &val, madc->imr);
+ if (ret) {
+ dev_err(madc->dev, "unable to read imr register 0x%X\n",
+ madc->imr);
+ return ret;
+ }
+ val |= (1 << id);
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, val, madc->imr);
+ if (ret) {
+ dev_err(madc->dev,
+ "unable to write imr register 0x%X\n", madc->imr);
+ return ret;
+ }
+
+ return 0;
+}
+
+static irqreturn_t twl4030_madc_threaded_irq_handler(int irq, void *_madc)
+{
+ struct twl4030_madc_data *madc = _madc;
+ const struct twl4030_madc_conversion_method *method;
+ u8 isr_val, imr_val;
+ int i, len, ret;
+ struct twl4030_madc_request *r;
+
+ mutex_lock(&madc->lock);
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &isr_val, madc->isr);
+ if (ret) {
+ dev_err(madc->dev, "unable to read isr register 0x%X\n",
+ madc->isr);
+ goto err_i2c;
+ }
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, &imr_val, madc->imr);
+ if (ret) {
+ dev_err(madc->dev, "unable to read imr register 0x%X\n",
+ madc->imr);
+ goto err_i2c;
+ }
+ isr_val &= ~imr_val;
+ for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
+ if (!(isr_val & (1 << i)))
+ continue;
+ ret = twl4030_madc_disable_irq(madc, i);
+ if (ret < 0)
+ dev_dbg(madc->dev, "Disable interrupt failed%d\n", i);
+ madc->requests[i].result_pending = 1;
+ }
+ for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
+ r = &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(madc, 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(&madc->lock);
+
+ return IRQ_HANDLED;
+
+err_i2c:
+ /*
+ * In case of error check whichever request is active
+ * and service the same.
+ */
+ for (i = 0; i < TWL4030_MADC_NUM_METHODS; i++) {
+ r = &madc->requests[i];
+ if (r->active == 0)
+ continue;
+ method = &twl4030_conversion_methods[r->method];
+ /* Read results */
+ len = twl4030_madc_read_channels(madc, 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(&madc->lock);
+
+ return IRQ_HANDLED;
+}
+
+static int twl4030_madc_set_irq(struct twl4030_madc_data *madc,
+ struct twl4030_madc_request *req)
+{
+ struct twl4030_madc_request *p;
+ int ret;
+
+ p = &madc->requests[req->method];
+ memcpy(p, req, sizeof(*req));
+ ret = twl4030_madc_enable_irq(madc, req->method);
+ if (ret < 0) {
+ dev_err(madc->dev, "enable irq failed!!\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * Function which enables the madc conversion
+ * by writing to the control register.
+ * @madc - pointer to twl4030_madc_data struct
+ * @conv_method - can be TWL4030_MADC_RT, TWL4030_MADC_SW2, TWL4030_MADC_SW1
+ * corresponding to RT SW1 or SW2 conversion methods.
+ * Returns 0 if succeeds else a negative error value
+ */
+static int twl4030_madc_start_conversion(struct twl4030_madc_data *madc,
+ int conv_method)
+{
+ const struct twl4030_madc_conversion_method *method;
+ int ret = 0;
+ method = &twl4030_conversion_methods[conv_method];
+ switch (conv_method) {
+ case TWL4030_MADC_SW1:
+ case TWL4030_MADC_SW2:
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MADC,
+ TWL4030_MADC_SW_START, method->ctrl);
+ if (ret) {
+ dev_err(madc->dev,
+ "unable to write ctrl register 0x%X\n",
+ method->ctrl);
+ return ret;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+/*
+ * Function that waits for conversion to be ready
+ * @madc - pointer to twl4030_madc_data struct
+ * @timeout_ms - timeout value in milliseconds
+ * @status_reg - ctrl register
+ * returns 0 if succeeds else a negative error value
+ */
+static int twl4030_madc_wait_conversion_ready(struct twl4030_madc_data *madc,
+ unsigned int timeout_ms,
+ u8 status_reg)
+{
+ unsigned long timeout;
+ int ret;
+
+ timeout = jiffies + msecs_to_jiffies(timeout_ms);
+ do {
+ u8 reg;
+
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MADC, ®, status_reg);
+ if (ret) {
+ dev_err(madc->dev,
+ "unable to read status register 0x%X\n",
+ status_reg);
+ return ret;
+ }
+ if (!(reg & TWL4030_MADC_BUSY) && (reg & TWL4030_MADC_EOC_SW))
+ return 0;
+ usleep_range(500, 2000);
+ } while (!time_after(jiffies, timeout));
+ dev_err(madc->dev, "conversion timeout!\n");
+
+ return -EAGAIN;
+}
+
+/*
+ * An exported function which can be called from other kernel drivers.
+ * @req twl4030_madc_request structure
+ * req->rbuf will be filled with read values of channels based on the
+ * channel index. If a particular channel reading fails there will
+ * be a negative error value in the corresponding array element.
+ * returns 0 if succeeds else error value
+ */
+int twl4030_madc_conversion(struct twl4030_madc_request *req)
+{
+ const struct twl4030_madc_conversion_method *method;
+ u8 ch_msb, ch_lsb;
+ int ret;
+
+ if (!req)
+ return -EINVAL;
+ mutex_lock(&twl4030_madc->lock);
+ if (req->method < TWL4030_MADC_RT || req->method > TWL4030_MADC_SW2) {
+ ret = -EINVAL;
+ goto out;
+ }
+ /* Do we have a conversion request ongoing */
+ if (twl4030_madc->requests[req->method].active) {
+ ret = -EBUSY;
+ goto out;
+ }
+ ch_msb = (req->channels >> 8) & 0xff;
+ ch_lsb = req->channels & 0xff;
+ method = &twl4030_conversion_methods[req->method];
+ /* Select channels to be converted */
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, ch_msb, method->sel + 1);
+ if (ret) {
+ dev_err(twl4030_madc->dev,
+ "unable to write sel register 0x%X\n", method->sel + 1);
+ return ret;
+ }
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, ch_lsb, method->sel);
+ if (ret) {
+ dev_err(twl4030_madc->dev,
+ "unable to write sel register 0x%X\n", method->sel + 1);
+ return ret;
+ }
+ /* Select averaging for all channels if do_avg is set */
+ if (req->do_avg) {
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MADC,
+ ch_msb, method->avg + 1);
+ if (ret) {
+ dev_err(twl4030_madc->dev,
+ "unable to write avg register 0x%X\n",
+ method->avg + 1);
+ return ret;
+ }
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MADC,
+ ch_lsb, method->avg);
+ if (ret) {
+ dev_err(twl4030_madc->dev,
+ "unable to write sel reg 0x%X\n",
+ method->sel + 1);
+ return ret;
+ }
+ }
+ if (req->type == TWL4030_MADC_IRQ_ONESHOT && req->func_cb != NULL) {
+ ret = twl4030_madc_set_irq(twl4030_madc, req);
+ if (ret < 0)
+ goto out;
+ ret = twl4030_madc_start_conversion(twl4030_madc, req->method);
+ if (ret < 0)
+ goto out;
+ 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;
+ }
+ ret = twl4030_madc_start_conversion(twl4030_madc, req->method);
+ if (ret < 0)
+ goto out;
+ twl4030_madc->requests[req->method].active = 1;
+ /* Wait until conversion is ready (ctrl register returns EOC) */
+ ret = twl4030_madc_wait_conversion_ready(twl4030_madc, 5, method->ctrl);
+ if (ret) {
+ twl4030_madc->requests[req->method].active = 0;
+ goto out;
+ }
+ ret = twl4030_madc_read_channels(twl4030_madc, method->rbase,
+ req->channels, req->rbuf);
+ twl4030_madc->requests[req->method].active = 0;
+
+out:
+ mutex_unlock(&twl4030_madc->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(twl4030_madc_conversion);
+
+/*
+ * Return channel value
+ * Or < 0 on failure.
+ */
+int twl4030_get_madc_conversion(int channel_no)
+{
+ struct twl4030_madc_request req;
+ int temp = 0;
+ int ret;
+
+ req.channels = (1 << channel_no);
+ req.method = TWL4030_MADC_SW2;
+ req.active = 0;
+ req.func_cb = NULL;
+ ret = twl4030_madc_conversion(&req);
+ if (ret < 0)
+ return ret;
+ if (req.rbuf[channel_no] > 0)
+ temp = req.rbuf[channel_no];
+
+ return temp;
+}
+EXPORT_SYMBOL_GPL(twl4030_get_madc_conversion);
+
+/*
+ * Function to enable or disable bias current for
+ * main battery type reading or temperature sensing
+ * @madc - pointer to twl4030_madc_data struct
+ * @chan - can be one of the two values
+ * TWL4030_BCI_ITHEN - Enables bias current for main battery type reading
+ * TWL4030_BCI_TYPEN - Enables bias current for main battery temperature
+ * sensing
+ * @on - enable or disable chan.
+ */
+static int twl4030_madc_set_current_generator(struct twl4030_madc_data *madc,
+ int chan, int on)
+{
+ int ret;
+ u8 regval;
+
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE,
+ ®val, TWL4030_BCI_BCICTL1);
+ if (ret) {
+ dev_err(madc->dev, "unable to read BCICTL1 reg 0x%X",
+ TWL4030_BCI_BCICTL1);
+ return ret;
+ }
+ if (on)
+ regval |= chan ? TWL4030_BCI_ITHEN : TWL4030_BCI_TYPEN;
+ else
+ regval &= chan ? ~TWL4030_BCI_ITHEN : ~TWL4030_BCI_TYPEN;
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MAIN_CHARGE,
+ regval, TWL4030_BCI_BCICTL1);
+ if (ret) {
+ dev_err(madc->dev, "unable to write BCICTL1 reg 0x%X\n",
+ TWL4030_BCI_BCICTL1);
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * Function that sets MADC software power on bit to enable MADC
+ * @madc - pointer to twl4030_madc_data struct
+ * @on - Enable or disable MADC software powen on bit.
+ * returns error if i2c read/write fails else 0
+ */
+static int twl4030_madc_set_power(struct twl4030_madc_data *madc, int on)
+{
+ u8 regval;
+ int ret;
+
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE,
+ ®val, TWL4030_MADC_CTRL1);
+ if (ret) {
+ dev_err(madc->dev, "unable to read madc ctrl1 reg 0x%X\n",
+ TWL4030_MADC_CTRL1);
+ return ret;
+ }
+ if (on)
+ regval |= TWL4030_MADC_MADCON;
+ else
+ regval &= ~TWL4030_MADC_MADCON;
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MADC, regval, TWL4030_MADC_CTRL1);
+ if (ret) {
+ dev_err(madc->dev, "unable to write madc ctrl1 reg 0x%X\n",
+ TWL4030_MADC_CTRL1);
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * Initialize MADC and request for threaded irq
+ */
+static int __devinit twl4030_madc_probe(struct platform_device *pdev)
+{
+ struct twl4030_madc_data *madc;
+ struct twl4030_madc_platform_data *pdata = pdev->dev.platform_data;
+ int ret;
+ u8 regval;
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "platform_data not available\n");
+ return -EINVAL;
+ }
+ madc = kzalloc(sizeof(*madc), GFP_KERNEL);
+ if (!madc)
+ return -ENOMEM;
+
+ /*
+ * Phoenix provides 2 interrupt lines. The first one is connected to
+ * the OMAP. The other one can be connected to the other processor such
+ * as modem. Hence two separate ISR and IMR registers.
+ */
+ madc->imr = (pdata->irq_line == 1) ?
+ TWL4030_MADC_IMR1 : TWL4030_MADC_IMR2;
+ madc->isr = (pdata->irq_line == 1) ?
+ TWL4030_MADC_ISR1 : TWL4030_MADC_ISR2;
+ ret = twl4030_madc_set_power(madc, 1);
+ if (ret < 0)
+ goto err_power;
+ ret = twl4030_madc_set_current_generator(madc, 0, 1);
+ if (ret < 0)
+ goto err_current_generator;
+
+ ret = twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE,
+ ®val, TWL4030_BCI_BCICTL1);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to read reg BCI CTL1 0x%X\n",
+ TWL4030_BCI_BCICTL1);
+ goto err_i2c;
+ }
+ regval |= TWL4030_BCI_MESBAT;
+ ret = twl_i2c_write_u8(TWL4030_MODULE_MAIN_CHARGE,
+ regval, TWL4030_BCI_BCICTL1);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to write reg BCI Ctl1 0x%X\n",
+ TWL4030_BCI_BCICTL1);
+ goto err_i2c;
+ }
+ platform_set_drvdata(pdev, madc);
+ mutex_init(&madc->lock);
+ ret = request_threaded_irq(platform_get_irq(pdev, 0), NULL,
+ twl4030_madc_threaded_irq_handler,
+ IRQF_TRIGGER_RISING, "twl4030_madc", madc);
+ if (ret) {
+ dev_dbg(&pdev->dev, "could not request irq\n");
+ goto err_irq;
+ }
+ twl4030_madc = madc;
+ return 0;
+err_irq:
+ platform_set_drvdata(pdev, NULL);
+err_i2c:
+ twl4030_madc_set_current_generator(madc, 0, 0);
+err_current_generator:
+ twl4030_madc_set_power(madc, 0);
+err_power:
+ kfree(madc);
+
+ return ret;
+}
+
+static int __devexit twl4030_madc_remove(struct platform_device *pdev)
+{
+ struct twl4030_madc_data *madc = platform_get_drvdata(pdev);
+
+ free_irq(platform_get_irq(pdev, 0), madc);
+ platform_set_drvdata(pdev, NULL);
+ twl4030_madc_set_current_generator(madc, 0, 0);
+ twl4030_madc_set_power(madc, 0);
+ kfree(madc);
+
+ return 0;
+}
+
+static struct platform_driver twl4030_madc_driver = {
+ .probe = twl4030_madc_probe,
+ .remove = __exit_p(twl4030_madc_remove),
+ .driver = {
+ .name = "twl4030_madc",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init twl4030_madc_init(void)
+{
+ return platform_driver_register(&twl4030_madc_driver);
+}
+
+module_init(twl4030_madc_init);
+
+static void __exit twl4030_madc_exit(void)
+{
+ platform_driver_unregister(&twl4030_madc_driver);
+}
+
+module_exit(twl4030_madc_exit);
+
+MODULE_DESCRIPTION("TWL4030 ADC driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("J Keerthy");
+MODULE_ALIAS("twl4030_madc");