mfd: twl4030-madc: Add DT support and convert to IIO framework

This converts twl4030-madc module to use the Industrial IO ADC
framework and adds device tree support.

Signed-off-by: Sebastian Reichel <sre@debian.org>
Tested-by: Marek Belisko <marek@goldelico.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 116 insertions, 11 deletions

diff --git a/drivers/mfd/twl4030-madc.c b/drivers/mfd/twl4030-madc.c
index 54585617ab51..93ef91229cd3 100644
--- a/drivers/mfd/twl4030-madc.c
+++ b/drivers/mfd/twl4030-madc.c
@@ -47,11 +47,14 @@
 #include <linux/gfp.h>
 #include <linux/err.h>
 
+#include <linux/iio/iio.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
+ * @use_second_irq - IRQ selection (main or co-processor)
  * @imr - Interrupt mask register of MADC
  * @isr - Interrupt status register of MADC
  */
@@ -59,10 +62,71 @@ struct twl4030_madc_data {
         struct device *dev;
         struct mutex lock;      /* mutex protecting this data structure */
         struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
+        bool use_second_irq;
         int imr;
         int isr;
 };
 
+static int twl4030_madc_read(struct iio_dev *iio_dev,
+                             const struct iio_chan_spec *chan,
+                             int *val, int *val2, long mask)
+{
+        struct twl4030_madc_data *madc = iio_priv(iio_dev);
+        struct twl4030_madc_request req;
+        int ret;
+
+        req.method = madc->use_second_irq ? TWL4030_MADC_SW2 : TWL4030_MADC_SW1;
+
+        req.channels = BIT(chan->channel);
+        req.active = false;
+        req.func_cb = NULL;
+        req.type = TWL4030_MADC_WAIT;
+        req.raw = !(mask == IIO_CHAN_INFO_PROCESSED);
+        req.do_avg = (mask == IIO_CHAN_INFO_AVERAGE_RAW);
+
+        ret = twl4030_madc_conversion(&req);
+        if (ret < 0)
+                return ret;
+
+        *val = req.rbuf[chan->channel];
+
+        return IIO_VAL_INT;
+}
+
+static const struct iio_info twl4030_madc_iio_info = {
+        .read_raw = &twl4030_madc_read,
+        .driver_module = THIS_MODULE,
+};
+
+#define TWL4030_ADC_CHANNEL(_channel, _type, _name) {   \
+        .type = _type,                                  \
+        .channel = _channel,                            \
+        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |  \
+                              BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \
+                              BIT(IIO_CHAN_INFO_PROCESSED), \
+        .datasheet_name = _name,                        \
+        .indexed = 1,                                   \
+}
+
+static const struct iio_chan_spec twl4030_madc_iio_channels[] = {
+        TWL4030_ADC_CHANNEL(0, IIO_VOLTAGE, "ADCIN0"),
+        TWL4030_ADC_CHANNEL(1, IIO_TEMP, "ADCIN1"),
+        TWL4030_ADC_CHANNEL(2, IIO_VOLTAGE, "ADCIN2"),
+        TWL4030_ADC_CHANNEL(3, IIO_VOLTAGE, "ADCIN3"),
+        TWL4030_ADC_CHANNEL(4, IIO_VOLTAGE, "ADCIN4"),
+        TWL4030_ADC_CHANNEL(5, IIO_VOLTAGE, "ADCIN5"),
+        TWL4030_ADC_CHANNEL(6, IIO_VOLTAGE, "ADCIN6"),
+        TWL4030_ADC_CHANNEL(7, IIO_VOLTAGE, "ADCIN7"),
+        TWL4030_ADC_CHANNEL(8, IIO_VOLTAGE, "ADCIN8"),
+        TWL4030_ADC_CHANNEL(9, IIO_VOLTAGE, "ADCIN9"),
+        TWL4030_ADC_CHANNEL(10, IIO_CURRENT, "ADCIN10"),
+        TWL4030_ADC_CHANNEL(11, IIO_VOLTAGE, "ADCIN11"),
+        TWL4030_ADC_CHANNEL(12, IIO_VOLTAGE, "ADCIN12"),
+        TWL4030_ADC_CHANNEL(13, IIO_VOLTAGE, "ADCIN13"),
+        TWL4030_ADC_CHANNEL(14, IIO_VOLTAGE, "ADCIN14"),
+        TWL4030_ADC_CHANNEL(15, IIO_VOLTAGE, "ADCIN15"),
+};
+
 static struct twl4030_madc_data *twl4030_madc;
 
 struct twl4030_prescale_divider_ratios {
@@ -702,28 +766,49 @@ static int twl4030_madc_probe(struct platform_device *pdev)
 {
         struct twl4030_madc_data *madc;
         struct twl4030_madc_platform_data *pdata = dev_get_platdata(&pdev->dev);
+        struct device_node *np = pdev->dev.of_node;
         int irq, ret;
         u8 regval;
+        struct iio_dev *iio_dev = NULL;
 
-        if (!pdata) {
-                dev_err(&pdev->dev, "platform_data not available\n");
+        if (!pdata && !np) {
+                dev_err(&pdev->dev, "neither platform data nor Device Tree node available\n");
                 return -EINVAL;
         }
-        madc = devm_kzalloc(&pdev->dev, sizeof(*madc), GFP_KERNEL);
-        if (!madc)
+
+        iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*madc));
+        if (!iio_dev) {
+                dev_err(&pdev->dev, "failed allocating iio device\n");
                 return -ENOMEM;
+        }
 
+        madc = iio_priv(iio_dev);
         madc->dev = &pdev->dev;
 
+        iio_dev->name = dev_name(&pdev->dev);
+        iio_dev->dev.parent = &pdev->dev;
+        iio_dev->dev.of_node = pdev->dev.of_node;
+        iio_dev->info = &twl4030_madc_iio_info;
+        iio_dev->modes = INDIO_DIRECT_MODE;
+        iio_dev->channels = twl4030_madc_iio_channels;
+        iio_dev->num_channels = ARRAY_SIZE(twl4030_madc_iio_channels);
+
         /*
          * 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;
+        if (pdata)
+                madc->use_second_irq = (pdata->irq_line != 1);
+        else
+                madc->use_second_irq = of_property_read_bool(np,
+                                       "ti,system-uses-second-madc-irq");
+
+        madc->imr = madc->use_second_irq ? TWL4030_MADC_IMR2 :
+                                           TWL4030_MADC_IMR1;
+        madc->isr = madc->use_second_irq ? TWL4030_MADC_ISR2 :
+                                           TWL4030_MADC_ISR1;
+
         ret = twl4030_madc_set_power(madc, 1);
         if (ret < 0)
                 return ret;
@@ -768,7 +853,7 @@ static int twl4030_madc_probe(struct platform_device *pdev)
                 }
         }
 
-        platform_set_drvdata(pdev, madc);
+        platform_set_drvdata(pdev, iio_dev);
         mutex_init(&madc->lock);
 
         irq = platform_get_irq(pdev, 0);
@@ -776,11 +861,19 @@ static int twl4030_madc_probe(struct platform_device *pdev)
                                    twl4030_madc_threaded_irq_handler,
                                    IRQF_TRIGGER_RISING, "twl4030_madc", madc);
         if (ret) {
-                dev_dbg(&pdev->dev, "could not request irq\n");
+                dev_err(&pdev->dev, "could not request irq\n");
                 goto err_i2c;
         }
         twl4030_madc = madc;
+
+        ret = iio_device_register(iio_dev);
+        if (ret) {
+                dev_err(&pdev->dev, "could not register iio device\n");
+                goto err_i2c;
+        }
+