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>

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;
+	}
+
 	return 0;
+
 err_i2c:
 	twl4030_madc_set_current_generator(madc, 0, 0);
 err_current_generator:
@@ -790,7 +883,10 @@ static int twl4030_madc_probe(struct platform_device *pdev)
 
 static int twl4030_madc_remove(struct platform_device *pdev)
 {
-	struct twl4030_madc_data *madc = platform_get_drvdata(pdev);
+	struct iio_dev *iio_dev = platform_get_drvdata(pdev);
+	struct twl4030_madc_data *madc = iio_priv(iio_dev);
+
+	iio_device_unregister(iio_dev);
 
 	twl4030_madc_set_current_generator(madc, 0, 0);
 	twl4030_madc_set_power(madc, 0);
@@ -798,12 +894,21 @@ static int twl4030_madc_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id twl_madc_of_match[] = {
+	{ .compatible = "ti,twl4030-madc", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, twl_madc_of_match);
+#endif
+
 static struct platform_driver twl4030_madc_driver = {
 	.probe = twl4030_madc_probe,
 	.remove = twl4030_madc_remove,
 	.driver = {
 		   .name = "twl4030_madc",
 		   .owner = THIS_MODULE,
+		   .of_match_table = of_match_ptr(twl_madc_of_match),
 		   },
 };