Commit 4f16cab1 authored by Sebastian Reichel's avatar Sebastian Reichel Committed by Lee Jones
Browse files

hwmon: da9052: Add support for TSI channel 



TSI channel has a 4 channel mux connected to it and is normally
used for touchscreen support. The hardware may alternatively
use it as general purpose adc.

Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent ebf55511

drivers/hwmon/da9052-hwmon.c

+245 −4
Original line number Diff line number Diff line
@@ -20,13 +20,19 @@ 
#include <linux/module.h>

#include <linux/slab.h>

#include <linux/platform_device.h>

#include <linux/property.h>



#include <linux/mfd/da9052/da9052.h>

#include <linux/mfd/da9052/reg.h>

#include <linux/regulator/consumer.h>



struct da9052_hwmon {

	struct da9052		*da9052;

	struct mutex		hwmon_lock;

	bool			tsi_as_adc;

	int			tsiref_mv;

	struct regulator	*tsiref;

	struct completion	tsidone;

};



static const char * const input_names[] = {
@@ -37,6 +43,10 @@ static const char * const input_names[] = { 
	[DA9052_ADC_IN4]	=	"ADC IN4",

	[DA9052_ADC_IN5]	=	"ADC IN5",

	[DA9052_ADC_IN6]	=	"ADC IN6",

	[DA9052_ADC_TSI_XP]	=	"ADC TS X+",

	[DA9052_ADC_TSI_YP]	=	"ADC TS Y+",

	[DA9052_ADC_TSI_XN]	=	"ADC TS X-",

	[DA9052_ADC_TSI_YN]	=	"ADC TS Y-",

	[DA9052_ADC_TJUNC]	=	"BATTERY JUNCTION TEMP",

	[DA9052_ADC_VBBAT]	=	"BACK-UP BATTERY VOLTAGE",

};
@@ -59,6 +69,11 @@ static inline int vbbat_reg_to_mv(int value) 
	return DIV_ROUND_CLOSEST(value * 5000, 1023);

}



static inline int input_tsireg_to_mv(struct da9052_hwmon *hwmon, int value)

{

	return DIV_ROUND_CLOSEST(value * hwmon->tsiref_mv, 1023);

}



static inline int da9052_enable_vddout_channel(struct da9052 *da9052)

{

	return da9052_reg_update(da9052, DA9052_ADC_CONT_REG,
@@ -154,6 +169,97 @@ static ssize_t da9052_read_misc_channel(struct device *dev, 
	return sprintf(buf, "%d\n", input_reg_to_mv(ret));

}



static int da9052_request_tsi_read(struct da9052_hwmon *hwmon, int channel)

{

	u8 val = DA9052_TSICONTB_TSIMAN;



	switch (channel) {

	case DA9052_ADC_TSI_XP:

		val |= DA9052_TSICONTB_TSIMUX_XP;

		break;

	case DA9052_ADC_TSI_YP:

		val |= DA9052_TSICONTB_TSIMUX_YP;

		break;

	case DA9052_ADC_TSI_XN:

		val |= DA9052_TSICONTB_TSIMUX_XN;

		break;

	case DA9052_ADC_TSI_YN:

		val |= DA9052_TSICONTB_TSIMUX_YN;

		break;

	}



	return da9052_reg_write(hwmon->da9052, DA9052_TSI_CONT_B_REG, val);

}



static int da9052_get_tsi_result(struct da9052_hwmon *hwmon, int channel)

{

	u8 regs[3];

	int msb, lsb, err;



	/* block read to avoid separation of MSB and LSB */

	err = da9052_group_read(hwmon->da9052, DA9052_TSI_X_MSB_REG,

				ARRAY_SIZE(regs), regs);

	if (err)

		return err;



	switch (channel) {

	case DA9052_ADC_TSI_XP:

	case DA9052_ADC_TSI_XN:

		msb = regs[0] << DA9052_TSILSB_TSIXL_BITS;

		lsb = regs[2] & DA9052_TSILSB_TSIXL;

		lsb >>= DA9052_TSILSB_TSIXL_SHIFT;

		break;

	case DA9052_ADC_TSI_YP:

	case DA9052_ADC_TSI_YN:

		msb = regs[1] << DA9052_TSILSB_TSIYL_BITS;

		lsb = regs[2] & DA9052_TSILSB_TSIYL;

		lsb >>= DA9052_TSILSB_TSIYL_SHIFT;

		break;

	default:

		return -EINVAL;

	}



	return msb | lsb;

}





static ssize_t __da9052_read_tsi(struct device *dev, int channel)

{

	struct da9052_hwmon *hwmon = dev_get_drvdata(dev);

	int ret;



	reinit_completion(&hwmon->tsidone);



	ret = da9052_request_tsi_read(hwmon, channel);

	if (ret < 0)

		return ret;



	/* Wait for an conversion done interrupt */

	if (!wait_for_completion_timeout(&hwmon->tsidone,

					 msecs_to_jiffies(500)))

		return -ETIMEDOUT;



	return da9052_get_tsi_result(hwmon, channel);

}



static ssize_t da9052_read_tsi(struct device *dev,

			       struct device_attribute *devattr,

			       char *buf)

{

	struct da9052_hwmon *hwmon = dev_get_drvdata(dev);

	int channel = to_sensor_dev_attr(devattr)->index;

	int ret;



	mutex_lock(&hwmon->hwmon_lock);

	ret = __da9052_read_tsi(dev, channel);

	mutex_unlock(&hwmon->hwmon_lock);



	if (ret < 0)

		return ret;

	else

		return sprintf(buf, "%d\n", input_tsireg_to_mv(hwmon, ret));

}



static ssize_t da9052_read_tjunc(struct device *dev,

				 struct device_attribute *devattr, char *buf)

{
@@ -196,6 +302,28 @@ static ssize_t show_label(struct device *dev, 
		       input_names[to_sensor_dev_attr(devattr)->index]);

}



static umode_t da9052_channel_is_visible(struct kobject *kobj,

					 struct attribute *attr, int index)

{

	struct device *dev = container_of(kobj, struct device, kobj);

	struct da9052_hwmon *hwmon = dev_get_drvdata(dev);

	struct device_attribute *dattr = container_of(attr,

				struct device_attribute, attr);

	struct sensor_device_attribute *sattr = to_sensor_dev_attr(dattr);



	if (!hwmon->tsi_as_adc) {

		switch (sattr->index) {

		case DA9052_ADC_TSI_XP:

		case DA9052_ADC_TSI_YP:

		case DA9052_ADC_TSI_XN:

		case DA9052_ADC_TSI_YN:

			return 0;

		}

	}



	return attr->mode;

}



static SENSOR_DEVICE_ATTR(in0_input, 0444, da9052_read_vddout, NULL,

			  DA9052_ADC_VDDOUT);

static SENSOR_DEVICE_ATTR(in0_label, 0444, show_label, NULL,
@@ -221,6 +349,23 @@ static SENSOR_DEVICE_ATTR(in9_input, 0444, da9052_read_vbbat, NULL, 
static SENSOR_DEVICE_ATTR(in9_label, 0444, show_label, NULL,

			  DA9052_ADC_VBBAT);



static SENSOR_DEVICE_ATTR(in70_input, 0444, da9052_read_tsi, NULL,

			  DA9052_ADC_TSI_XP);

static SENSOR_DEVICE_ATTR(in70_label, 0444, show_label, NULL,

			  DA9052_ADC_TSI_XP);

static SENSOR_DEVICE_ATTR(in71_input, 0444, da9052_read_tsi, NULL,

			  DA9052_ADC_TSI_XN);

static SENSOR_DEVICE_ATTR(in71_label, 0444, show_label, NULL,

			  DA9052_ADC_TSI_XN);

static SENSOR_DEVICE_ATTR(in72_input, 0444, da9052_read_tsi, NULL,

			  DA9052_ADC_TSI_YP);

static SENSOR_DEVICE_ATTR(in72_label, 0444, show_label, NULL,

			  DA9052_ADC_TSI_YP);

static SENSOR_DEVICE_ATTR(in73_input, 0444, da9052_read_tsi, NULL,

			  DA9052_ADC_TSI_YN);

static SENSOR_DEVICE_ATTR(in73_label, 0444, show_label, NULL,

			  DA9052_ADC_TSI_YN);



static SENSOR_DEVICE_ATTR(curr1_input, 0444, da9052_read_ich, NULL,

			  DA9052_ADC_ICH);

static SENSOR_DEVICE_ATTR(curr1_label, 0444, show_label, NULL,
@@ -246,6 +391,14 @@ static struct attribute *da9052_attrs[] = { 
	&sensor_dev_attr_in5_label.dev_attr.attr,

	&sensor_dev_attr_in6_input.dev_attr.attr,

	&sensor_dev_attr_in6_label.dev_attr.attr,

	&sensor_dev_attr_in70_input.dev_attr.attr,

	&sensor_dev_attr_in70_label.dev_attr.attr,

	&sensor_dev_attr_in71_input.dev_attr.attr,

	&sensor_dev_attr_in71_label.dev_attr.attr,

	&sensor_dev_attr_in72_input.dev_attr.attr,

	&sensor_dev_attr_in72_label.dev_attr.attr,

	&sensor_dev_attr_in73_input.dev_attr.attr,

	&sensor_dev_attr_in73_label.dev_attr.attr,

	&sensor_dev_attr_in9_input.dev_attr.attr,

	&sensor_dev_attr_in9_label.dev_attr.attr,

	&sensor_dev_attr_curr1_input.dev_attr.attr,
@@ -257,29 +410,117 @@ static struct attribute *da9052_attrs[] = { 
	NULL

};



ATTRIBUTE_GROUPS(da9052);

static const struct attribute_group da9052_group = {

	.attrs = da9052_attrs,

	.is_visible = da9052_channel_is_visible,

};

__ATTRIBUTE_GROUPS(da9052);



static irqreturn_t da9052_tsi_datardy_irq(int irq, void *data)

{

	struct da9052_hwmon *hwmon = data;



	complete(&hwmon->tsidone);

	return IRQ_HANDLED;

}



static int da9052_hwmon_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct da9052_hwmon *hwmon;

	struct device *hwmon_dev;

	int err;



	hwmon = devm_kzalloc(dev, sizeof(struct da9052_hwmon), GFP_KERNEL);

	if (!hwmon)

		return -ENOMEM;



	platform_set_drvdata(pdev, hwmon);



	mutex_init(&hwmon->hwmon_lock);

	hwmon->da9052 = dev_get_drvdata(pdev->dev.parent);



	init_completion(&hwmon->tsidone);



	hwmon->tsi_as_adc =

		device_property_read_bool(pdev->dev.parent, "dlg,tsi-as-adc");



	if (hwmon->tsi_as_adc) {

		hwmon->tsiref = devm_regulator_get(pdev->dev.parent, "tsiref");

		if (IS_ERR(hwmon->tsiref)) {

			err = PTR_ERR(hwmon->tsiref);

			dev_err(&pdev->dev, "failed to get tsiref: %d", err);

			return err;

		}



		err = regulator_enable(hwmon->tsiref);

		if (err)

			return err;



		hwmon->tsiref_mv = regulator_get_voltage(hwmon->tsiref);

		if (hwmon->tsiref_mv < 0) {

			err = hwmon->tsiref_mv;

			goto exit_regulator;

		}



		/* convert from microvolt (DT) to millivolt (hwmon) */

		hwmon->tsiref_mv /= 1000;



		/* TSIREF limits from datasheet */

		if (hwmon->tsiref_mv < 1800 || hwmon->tsiref_mv > 2600) {

			dev_err(hwmon->da9052->dev, "invalid TSIREF voltage: %d",

				hwmon->tsiref_mv);

			err = -ENXIO;

			goto exit_regulator;

		}



		/* disable touchscreen features */

		da9052_reg_write(hwmon->da9052, DA9052_TSI_CONT_A_REG, 0x00);



		err = da9052_request_irq(hwmon->da9052, DA9052_IRQ_TSIREADY,

					 "tsiready-irq", da9052_tsi_datardy_irq,

					 hwmon);

		if (err) {

			dev_err(&pdev->dev, "Failed to register TSIRDY IRQ: %d",

				err);

			goto exit_regulator;

		}

	}



	hwmon_dev = devm_hwmon_device_register_with_groups(dev, "da9052",

							   hwmon,

							   da9052_groups);

	return PTR_ERR_OR_ZERO(hwmon_dev);

	err = PTR_ERR_OR_ZERO(hwmon_dev);

	if (err)

		goto exit_irq;



	return 0;



exit_irq:

	if (hwmon->tsi_as_adc)

		da9052_free_irq(hwmon->da9052, DA9052_IRQ_TSIREADY, hwmon);

exit_regulator:

	if (hwmon->tsiref)

		regulator_disable(hwmon->tsiref);



	return err;

}



static int da9052_hwmon_remove(struct platform_device *pdev)

{

	struct da9052_hwmon *hwmon = platform_get_drvdata(pdev);



	if (hwmon->tsi_as_adc) {

		da9052_free_irq(hwmon->da9052, DA9052_IRQ_TSIREADY, hwmon);

		regulator_disable(hwmon->tsiref);

	}



	return 0;

}



static struct platform_driver da9052_hwmon_driver = {

	.probe = da9052_hwmon_probe,

	.remove = da9052_hwmon_remove,

	.driver = {

		.name = "da9052-hwmon",

	},