From: Nick Dyer <nick.d...@itdev.co.uk>

Allow the driver to optionally manage enabling/disable power to the touch
controller itself. If the regulators are not present then use the deep
sleep power mode instead.

For a correct power on sequence, it is required that we have control over
the RESET line.

Signed-off-by: Nick Dyer <nick.d...@itdev.co.uk>
Acked-by: Benson Leung <ble...@chromium.org>
Acked-by: Yufeng Shen <mile...@chromium.org>
(cherry picked from ndyer/linux/for-upstream commit 
14052b61bb66c2f2283c00e733e131be7a9b8bfc)
[gdavis: Resolve forward port conflicts due to v4.14-rc1 commmit
         f657b00df22e ("Input: atmel_mxt_ts - add support for reset
         line") and applying upstream commit 96a938aa214e ("Input:
         atmel_mxt_ts - remove platform data support").]
Signed-off-by: George G. Davis <george_da...@mentor.com>
[gdavis: Squash fixes from Dirk Behme:
         - Input: atmel_mxt_ts - in failure case disable the regulator
         - Input: atmel_mxt_ts - disable only enabled regulators
         - Input: atmel_mxt_ts - use devm_regulator_get()]
Signed-off-by: Dirk Behme <dirk.be...@de.bosch.com>
[jiada: Replace white-spaces with tab for MXT_CHG_DELAY
        separate Documentation/ and include/dt-bindings/ portion change to 
another commit]
Signed-off-by: Jiada Wang <jiada_w...@mentor.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 130 +++++++++++++++++++++--
 1 file changed, 121 insertions(+), 9 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c 
b/drivers/input/touchscreen/atmel_mxt_ts.c
index 9aafed92db9c..ef8baf64659e 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -26,10 +26,12 @@
 #include <linux/slab.h>
 #include <linux/gpio/consumer.h>
 #include <asm/unaligned.h>
+#include <linux/regulator/consumer.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-ioctl.h>
 #include <media/videobuf2-v4l2.h>
 #include <media/videobuf2-vmalloc.h>
+#include <dt-bindings/input/atmel_mxt_ts.h>
 
 /* Firmware files */
 #define MXT_FW_NAME            "maxtouch.fw"
@@ -215,6 +217,9 @@ enum t100_type {
 #define MXT_CRC_TIMEOUT                1000    /* msec */
 #define MXT_FW_RESET_TIME      3000    /* msec */
 #define MXT_FW_CHG_TIMEOUT     300     /* msec */
+#define MXT_REGULATOR_DELAY    150     /* msec */
+#define MXT_CHG_DELAY          100     /* msec */
+#define MXT_POWERON_DELAY      150     /* msec */
 
 /* Command to unlock bootloader */
 #define MXT_UNLOCK_CMD_MSB     0xaa
@@ -275,11 +280,6 @@ enum v4l_dbg_inputs {
        MXT_V4L_INPUT_MAX,
 };
 
-enum mxt_suspend_mode {
-       MXT_SUSPEND_DEEP_SLEEP  = 0,
-       MXT_SUSPEND_T9_CTRL     = 1,
-};
-
 /* Config update context */
 struct mxt_cfg {
        u8 *raw;
@@ -333,6 +333,8 @@ struct mxt_data {
        u8 stylus_aux_pressure;
        u8 stylus_aux_peak;
        bool use_retrigen_workaround;
+       struct regulator *reg_vdd;
+       struct regulator *reg_avdd;
 
        /* Cached parameters from object table */
        u16 T5_address;
@@ -2073,6 +2075,94 @@ static int mxt_read_info_block(struct mxt_data *data)
        return error;
 }
 
+static void mxt_regulator_enable(struct mxt_data *data)
+{
+       int error;
+
+       if (!data->reg_vdd || !data->reg_avdd)
+               return;
+
+       gpiod_set_value(data->reset_gpio, 0);
+
+       error = regulator_enable(data->reg_vdd);
+       if (error)
+               return;
+
+       error = regulator_enable(data->reg_avdd);
+       if (error) {
+               regulator_disable(data->reg_vdd);
+               return;
+       }
+
+       /*
+        * According to maXTouch power sequencing specification, RESET line
+        * must be kept low until some time after regulators come up to
+        * voltage
+        */
+       msleep(MXT_REGULATOR_DELAY);
+       gpiod_set_value(data->reset_gpio, 1);
+       msleep(MXT_CHG_DELAY);
+
+retry_wait:
+       reinit_completion(&data->bl_completion);
+       data->in_bootloader = true;
+       error = mxt_wait_for_completion(data, &data->bl_completion,
+                                       MXT_POWERON_DELAY);
+       if (error == -EINTR)
+               goto retry_wait;
+
+       data->in_bootloader = false;
+}
+
+static void mxt_regulator_disable(struct mxt_data *data)
+{
+       if (!data->reg_vdd || !data->reg_avdd)
+               return;
+
+       if (regulator_is_enabled(data->reg_vdd))
+               regulator_disable(data->reg_vdd);
+       if (regulator_is_enabled(data->reg_avdd))
+               regulator_disable(data->reg_avdd);
+}
+
+static int mxt_probe_regulators(struct mxt_data *data)
+{
+       struct device *dev = &data->client->dev;
+       int error;
+
+       /* Must have reset GPIO to use regulator support */
+       if (!data->reset_gpio) {
+               error = -EINVAL;
+               goto fail;
+       }
+
+       data->reg_vdd = devm_regulator_get(dev, "vdd");
+       if (IS_ERR(data->reg_vdd)) {
+               error = PTR_ERR(data->reg_vdd);
+               dev_err(dev, "Error %d getting vdd regulator\n", error);
+               goto fail;
+       }
+
+       data->reg_avdd = devm_regulator_get(dev, "avdd");
+       if (IS_ERR(data->reg_avdd)) {
+               error = PTR_ERR(data->reg_avdd);
+               dev_err(dev, "Error %d getting avdd regulator\n", error);
+               goto fail_release;
+       }
+
+       mxt_regulator_enable(data);
+
+       dev_dbg(dev, "Initialised regulators\n");
+       return 0;
+
+fail_release:
+       regulator_put(data->reg_vdd);
+fail:
+       data->reg_vdd = NULL;
+       data->reg_avdd = NULL;
+       return error;
+}
+
 static int mxt_read_t9_resolution(struct mxt_data *data)
 {
        struct i2c_client *client = data->client;
@@ -3139,7 +3229,12 @@ static int mxt_load_fw(struct device *dev, const char 
*fn)
                goto release_firmware;
 
        if (data->suspended) {
-               enable_irq(data->irq);
+               if (data->suspend_mode == MXT_SUSPEND_REGULATOR)
+                       mxt_regulator_enable(data);
+
+               if (data->suspend_mode == MXT_SUSPEND_DEEP_SLEEP)
+                       enable_irq(data->irq);
+
                data->suspended = false;
        }
 
@@ -3345,6 +3440,11 @@ static void mxt_start(struct mxt_data *data)
                                MXT_TOUCH_MULTI_T9, MXT_T9_CTRL, 0x83);
                break;
 
+       case MXT_SUSPEND_REGULATOR:
+               enable_irq(data->irq);
+               mxt_regulator_enable(data);
+               break;
+
        case MXT_SUSPEND_DEEP_SLEEP:
        default:
                /*
@@ -3377,6 +3477,12 @@ static void mxt_stop(struct mxt_data *data)
                                MXT_TOUCH_MULTI_T9, MXT_T9_CTRL, 0);
                break;
 
+       case MXT_SUSPEND_REGULATOR:
+               disable_irq(data->irq);
+               mxt_regulator_disable(data);
+               mxt_reset_slots(data);
+               break;
+
        case MXT_SUSPEND_DEEP_SLEEP:
        default:
                disable_irq(data->irq);
@@ -3469,6 +3575,8 @@ static int mxt_parse_device_properties(struct mxt_data 
*data)
                data->t15_num_keys = n_keys;
        }
 
+       device_property_read_u32(dev, "atmel,suspend-mode",
+                                &data->suspend_mode);
        return 0;
 }
 
@@ -3555,14 +3663,18 @@ static int mxt_probe(struct i2c_client *client, const 
struct i2c_device_id *id)
                return error;
        }
 
-       disable_irq(client->irq);
-
-       if (data->reset_gpio) {
+       if (data->suspend_mode == MXT_SUSPEND_REGULATOR) {
+               error = mxt_probe_regulators(data);
+               if (error)
+                       return error;
+       } else if (data->reset_gpio) {
                msleep(MXT_RESET_GPIO_TIME);
                gpiod_set_value(data->reset_gpio, 1);
                msleep(MXT_RESET_INVALID_CHG);
        }
 
+       disable_irq(data->irq);
+
        error = mxt_initialize(data);
        if (error)
                return error;
-- 
2.17.1

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