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

Sebastian Reichel
2017-06-30T14:35:06Z

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@collabora.co.uk>
---
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 +-
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
--
2.11.0