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hwmon: da9052: Add support for TSI channel
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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: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
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@sre
sre authored and Lee Jones committed Aug 22, 2017
1 parent ebf5551 commit 4f16cab
Showing 1 changed file with 245 additions and 4 deletions.
249 changes: 245 additions & 4 deletions drivers/hwmon/da9052-hwmon.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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[] = {
Expand All @@ -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",
};
Expand All @@ -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,
Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -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,
Expand All @@ -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,
Expand All @@ -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,
Expand All @@ -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",
},
Expand Down

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