Re: [PATCHv3 2/9] mfd: twl4030-madc: Add DT support and convert to IIO framework

From: Jonathan Cameron
Date: Sat Mar 15 2014 - 11:37:20 EST


On 10/03/14 17:25, Sebastian Reichel wrote:
This converts twl4030-madc module to use the Industrial IO ADC
framework and adds device tree support.

Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx>
Tested-by: Marek Belisko <marek@xxxxxxxxxxxxx>

One issue in the remove function. Reorder that
and I'm happy.

---
drivers/mfd/twl4030-madc.c | 127 +++++++++++++++++++++++++++++++++++++++++----
1 file changed, 116 insertions(+), 11 deletions(-)

diff --git a/drivers/mfd/twl4030-madc.c b/drivers/mfd/twl4030-madc.c
index 5458561..1c5c4db 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;
+ }
+
return 0;
+
err_i2c:
twl4030_madc_set_current_generator(madc, 0, 0);
err_current_generator:
@@ -790,20 +883,32 @@ err_current_generator:

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);

twl4030_madc_set_current_generator(madc, 0, 0);
twl4030_madc_set_power(madc, 0);

Disabling the user interface 'after' turning off the device is a bad idea.
Also as a general rule remove functions should reverse the order of probes.
That way they are obviously right. Hence this iio_device_unregister needs
to be the first thing in this function I think!
+ iio_device_unregister(iio_dev);
+
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),
},
};



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