Re: [PATCHv2 3/3] hwmon: da9052: add support for TSI channel

From: Guenter Roeck
Date: Wed Jun 28 2017 - 07:40:35 EST

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In reply to: Sebastian Reichel: "[PATCHv2 3/3] hwmon: da9052: add support for TSI channel"
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On 06/27/2017 07:38 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>
---
.../devicetree/bindings/mfd/da9052-i2c.txt | 8 +
drivers/hwmon/da9052-hwmon.c | 252 ++++++++++++++++++++-
drivers/input/touchscreen/da9052_tsi.c | 5 +
include/linux/mfd/da9052/da9052.h | 6 +
4 files changed, 267 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/mfd/da9052-i2c.txt b/Documentation/devicetree/bindings/mfd/da9052-i2c.txt
index 9554292dc6cb..a4fcf6ee4d7b 100644
--- a/Documentation/devicetree/bindings/mfd/da9052-i2c.txt
+++ b/Documentation/devicetree/bindings/mfd/da9052-i2c.txt
@@ -4,6 +4,14 @@ Required properties:
- compatible : Should be "dlg,da9052", "dlg,da9053-aa",
"dlg,da9053-ab", or "dlg,da9053-bb"
+Optional properties:
+- diag,tsi-as-adc : Boolean, if set the X+, X-, Y+, Y- touchscreen
+ input lines are used as general purpose analogue
+ input.
+- tsiref-supply: Phandle to the regulator, which provides the reference
+ voltage for the TSIREF pin. Must be provided when the
+ touchscreen pins are used for ADC purposes.
+

The subject line does not include a notion that devicetree properties are added,
meaning DT maintainers probably won;t have a look. It is better to split
the DT changes into a separate patch to make sure they get the necessary attention.

Sub-nodes:
- regulators : Contain the regulator nodes. The DA9052/53 regulators are
bound using their names as listed below:
diff --git a/drivers/hwmon/da9052-hwmon.c b/drivers/hwmon/da9052-hwmon.c
index 708c91ac601f..85bfff9cf43b 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 +169,101 @@ 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 = BIT(6); /* TSI_MAN */
+
+ switch (channel) {
+ case DA9052_ADC_TSI_XP:
+ val |= (0 << 4); /* TSI_MUX */
+ break;
+ case DA9052_ADC_TSI_YP:
+ val |= (1 << 4); /* TSI_MUX */
+ break;
+ case DA9052_ADC_TSI_XN:
+ val |= (2 << 4); /* TSI_MUX */
+ break;
+ case DA9052_ADC_TSI_YN:
+ val |= (3 << 4); /* TSI_MUX */
+ 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)
+{
+ int msb, lsb;
+
+ switch (channel) {
+ case DA9052_ADC_TSI_XP:
+ case DA9052_ADC_TSI_XN:
+ msb = da9052_reg_read(hwmon->da9052, DA9052_TSI_X_MSB_REG);
+ if (msb < 0)
+ return msb;
+
+ lsb = da9052_reg_read(hwmon->da9052, DA9052_TSI_LSB_REG);
+ if (lsb < 0)
+ return lsb;
+
+ break;
+ case DA9052_ADC_TSI_YP:
+ case DA9052_ADC_TSI_YN:
+ msb = da9052_reg_read(hwmon->da9052, DA9052_TSI_Y_MSB_REG);
+ if (msb < 0)
+ return msb;
+
+ lsb = da9052_reg_read(hwmon->da9052, DA9052_TSI_LSB_REG);
+ if (lsb < 0)
+ return lsb;
+ lsb >>= 2;
+
+ break;
+ default:
+ return -ENXIO;
+ }
+
+ return (msb << 2) | (lsb & 0x3);
+}
+
+
+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 +306,27 @@ 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 *a, int index)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct da9052_hwmon *hwmon = dev_get_drvdata(dev);
+
+ switch (index) {
+ case DA9052_ADC_TSI_XP:
+ case DA9052_ADC_TSI_YP:
+ case DA9052_ADC_TSI_XN:
+ case DA9052_ADC_TSI_YN:
+ if (!hwmon->tsi_as_adc)
+ return 0;
+ break;
+ default:
+ break;
+ }
+
+ return a->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 +352,23 @@ 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 +394,14 @@ 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 +413,117 @@ 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, "diag,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/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c
index 5a013bb7bcad..f0cb239546a9 100644
--- a/drivers/input/touchscreen/da9052_tsi.c
+++ b/drivers/input/touchscreen/da9052_tsi.c
@@ -16,6 +16,7 @@
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
+#include <linux/property.h>
#include <linux/mfd/da9052/reg.h>
#include <linux/mfd/da9052/da9052.h>
@@ -238,6 +239,10 @@ static int da9052_ts_probe(struct platform_device *pdev)
if (!da9052)
return -EINVAL;
+ /* check if pins are used as general purpose ADC input */
+ if (device_property_read_bool(pdev->dev.parent, "diag,tsi-as-adc"))
+ return -ENODEV;
+
tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
input_dev = input_allocate_device();
if (!tsi || !input_dev) {
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

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In reply to: Sebastian Reichel: "[PATCHv2 3/3] hwmon: da9052: add support for TSI channel"
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