[PATCH v6 2/4] Input: goodix - Add regulators suppot

[Jagan Teki]

Goodix CTP controllers require AVDD28, VDDIO regulators for power-on
sequence.

The delay between these regualtor operations as per Power-on Timing
from datasheet[1] is 0 (T1 >= 0 usec).

So, enable and disable these regulators in proper order using normal
regulator functions without any delay in between.

[1] GT5663 Datasheet_English_20151106_Rev.01

Signed-off-by: Jagan Teki <ja...@amarulasolutions.com>
---
 drivers/input/touchscreen/goodix.c | 58 ++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/drivers/input/touchscreen/goodix.c 
b/drivers/input/touchscreen/goodix.c
index f2d9c2c41885..5f9e755c5bc7 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -27,6 +27,7 @@
 #include <linux/delay.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/of.h>
@@ -47,6 +48,8 @@ struct goodix_ts_data {
        struct touchscreen_properties prop;
        unsigned int max_touch_num;
        unsigned int int_trigger_type;
+       struct regulator *avdd28;
+       struct regulator *vddio;
        struct gpio_desc *gpiod_int;
        struct gpio_desc *gpiod_rst;
        u16 id;
@@ -531,6 +534,24 @@ static int goodix_get_gpio_config(struct goodix_ts_data 
*ts)
                return -EINVAL;
        dev = &ts->client->dev;
 
+       ts->avdd28 = devm_regulator_get(dev, "AVDD28");
+       if (IS_ERR(ts->avdd28)) {
+               error = PTR_ERR(ts->avdd28);
+               if (error != -EPROBE_DEFER)
+                       dev_err(dev,
+                               "Failed to get AVDD28 regulator: %d\n", error);
+               return error;
+       }
+
+       ts->vddio = devm_regulator_get(dev, "VDDIO");
+       if (IS_ERR(ts->vddio)) {
+               error = PTR_ERR(ts->vddio);
+               if (error != -EPROBE_DEFER)
+                       dev_err(dev,
+                               "Failed to get VDDIO regulator: %d\n", error);
+               return error;
+       }
+
        /* Get the interrupt GPIO pin number */
        gpiod = devm_gpiod_get_optional(dev, GOODIX_GPIO_INT_NAME, GPIOD_IN);
        if (IS_ERR(gpiod)) {
@@ -761,6 +782,17 @@ static void goodix_config_cb(const struct firmware *cfg, 
void *ctx)
        complete_all(&ts->firmware_loading_complete);
 }
 
+static void goodix_disable_regulator(void *arg)
+{
+       struct goodix_ts_data *ts = arg;
+
+       if (!IS_ERR(ts->vddio))
+               regulator_disable(ts->vddio);
+
+       if (!IS_ERR(ts->avdd28))
+               regulator_disable(ts->avdd28);
+}
+
 static int goodix_ts_probe(struct i2c_client *client,
                           const struct i2c_device_id *id)
 {
@@ -786,6 +818,32 @@ static int goodix_ts_probe(struct i2c_client *client,
        if (error)
                return error;
 
+       error = devm_add_action_or_reset(&client->dev,
+                                        goodix_disable_regulator, ts);
+       if (error)
+               return error;
+
+       /* power the controller */
+       if (!IS_ERR(ts->avdd28)) {
+               error = regulator_enable(ts->avdd28);
+               if (error) {
+                       dev_err(&client->dev,
+                               "Failed to enable AVDD28 regulator: %d\n",
+                               error);
+                       return error;
+               }
+       }
+
+       if (!IS_ERR(ts->vddio)) {
+               error = regulator_enable(ts->vddio);
+               if (error) {
+                       dev_err(&client->dev,
+                               "Failed to enable VDDIO regulator: %d\n",
+                               error);
+                       return error;
+               }
+       }
+
        if (ts->gpiod_int && ts->gpiod_rst) {
                /* reset the controller */
                error = goodix_reset(ts);
-- 
2.18.0.321.gffc6fa0e3