[PATCH v11 14/56] Input: atmel_mxt_ts - add regulator control support

Jiada Wang
2020-05-08T05:58:00Z

From: Nick Dyer <nick.dyer@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.dyer@itdev.co.uk>
Acked-by: Benson Leung <bleung@chromium.org>
Acked-by: Yufeng Shen <miletus@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_davis@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.behme@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_wang@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