Re: [PATCHv4 4/4] hwmon: da9052: add support for TSI channel

[Guenter Roeck <linux@xxxxxxxxxxxx>]

On 06/30/2017 07:35 AM, Sebastian Reichel wrote:
> 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.
>
> Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxxxx>
> ---
>   drivers/hwmon/da9052-hwmon.c      | 249 +++++++++++++++++++++++++++++++++++++-
>   drivers/mfd/da9052-core.c         |  28 ++++-
>   include/linux/mfd/da9052/da9052.h |   6 +
>   include/linux/mfd/da9052/reg.h    |  11 +-

I just realized that you packed the hwmon and mfd changes into a single patch.
Please separate.

Thanks,
Guenter

>   4 files changed, 286 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/hwmon/da9052-hwmon.c b/drivers/hwmon/da9052-hwmon.c
> index 708c91ac601f..97a62f5b9ea4 100644
> --- a/drivers/hwmon/da9052-hwmon.c
> +++ b/drivers/hwmon/da9052-hwmon.c
> @@ -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;
> +	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",
>   	},
> diff --git a/drivers/mfd/da9052-core.c b/drivers/mfd/da9052-core.c
> index 977418ca9117..a671c18381d7 100644
> --- a/drivers/mfd/da9052-core.c
> +++ b/drivers/mfd/da9052-core.c
> @@ -18,6 +18,7 @@
>   #include <linux/mfd/core.h>
>   #include <linux/slab.h>
>   #include <linux/module.h>
> +#include <linux/property.h>
>   
>   #include <linux/mfd/da9052/da9052.h>
>   #include <linux/mfd/da9052/pdata.h>
> @@ -521,9 +522,6 @@ static const struct mfd_cell da9052_subdev_info[] = {
>   		.name = "da9052-wled3",
>   	},
>   	{
> -		.name = "da9052-tsi",
> -	},
> -	{
>   		.name = "da9052-bat",
>   	},
>   	{
> @@ -531,6 +529,12 @@ static const struct mfd_cell da9052_subdev_info[] = {
>   	},
>   };
>   
> +static const struct mfd_cell da9052_tsi_subdev_info[] = {
> +	{
> +		.name = "da9052-tsi",
> +	},
> +};
> +
>   const struct regmap_config da9052_regmap_config = {
>   	.reg_bits = 8,
>   	.val_bits = 8,
> @@ -621,9 +625,27 @@ int da9052_device_init(struct da9052 *da9052, u8 chip_id)
>   		goto err;
>   	}
>   
> +	/*
> +	 * Check if touchscreen pins are used are analogue input instead
> +	 * of having a touchscreen connected to them. The analogue input
> +	 * functionality will be provided by hwmon driver (if enabled).
> +	 */
> +	if (!device_property_read_bool(da9052->dev, "dlg,tsi-as-adc")) {
> +		ret = mfd_add_devices(da9052->dev, PLATFORM_DEVID_AUTO,
> +				      da9052_tsi_subdev_info,
> +				      ARRAY_SIZE(da9052_tsi_subdev_info),
> +				      NULL, 0, NULL);
> +		if (ret) {
> +			dev_err(da9052->dev, "failed to add TSI subdev: %d\n",
> +				ret);
> +			goto err;
> +		}
> +	}
> +
>   	return 0;
>   
>   err:
> +	mfd_remove_devices(da9052->dev);
>   	da9052_irq_exit(da9052);
>   
>   	return ret;
> diff --git a/include/linux/mfd/da9052/da9052.h b/include/linux/mfd/da9052/da9052.h
> index ce9230af09c2..ae5b663836d0 100644
> --- a/include/linux/mfd/da9052/da9052.h
> +++ b/include/linux/mfd/da9052/da9052.h
> @@ -45,6 +45,12 @@
>   #define DA9052_ADC_TJUNC	8
>   #define DA9052_ADC_VBBAT	9
>   
> +/* TSI channel has its own 4 channel mux */
> +#define DA9052_ADC_TSI_XP	70
> +#define DA9052_ADC_TSI_XN	71
> +#define DA9052_ADC_TSI_YP	72
> +#define DA9052_ADC_TSI_YN	73
> +
>   #define DA9052_IRQ_DCIN	0
>   #define DA9052_IRQ_VBUS	1
>   #define DA9052_IRQ_DCINREM	2
> diff --git a/include/linux/mfd/da9052/reg.h b/include/linux/mfd/da9052/reg.h
> index 5010f978725c..76780ea8849c 100644
> --- a/include/linux/mfd/da9052/reg.h
> +++ b/include/linux/mfd/da9052/reg.h
> @@ -690,7 +690,10 @@
>   /* TSI CONTROL REGISTER B BITS */
>   #define DA9052_TSICONTB_ADCREF		0X80
>   #define DA9052_TSICONTB_TSIMAN		0X40
> -#define DA9052_TSICONTB_TSIMUX		0X30
> +#define DA9052_TSICONTB_TSIMUX_XP	0X00
> +#define DA9052_TSICONTB_TSIMUX_YP	0X10
> +#define DA9052_TSICONTB_TSIMUX_XN	0X20
> +#define DA9052_TSICONTB_TSIMUX_YN	0X30
>   #define DA9052_TSICONTB_TSISEL3	0X08
>   #define DA9052_TSICONTB_TSISEL2	0X04
>   #define DA9052_TSICONTB_TSISEL1	0X02
> @@ -705,8 +708,14 @@
>   /* TSI CO-ORDINATE LSB RESULT REGISTER BITS */
>   #define DA9052_TSILSB_PENDOWN		0X40
>   #define DA9052_TSILSB_TSIZL		0X30
> +#define DA9052_TSILSB_TSIZL_SHIFT	4
> +#define DA9052_TSILSB_TSIZL_BITS	2
>   #define DA9052_TSILSB_TSIYL		0X0C
> +#define DA9052_TSILSB_TSIYL_SHIFT	2
> +#define DA9052_TSILSB_TSIYL_BITS	2
>   #define DA9052_TSILSB_TSIXL		0X03
> +#define DA9052_TSILSB_TSIXL_SHIFT	0
> +#define DA9052_TSILSB_TSIXL_BITS	2
>   
>   /* TSI Z MEASUREMENT MSB RESULT REGISTER BIT */
>   #define DA9052_TSIZMSB_TSIZM		0XFF

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