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@xxxxxxxxxxx>
Acked-by: Benson Leung <bleung@xxxxxxxxxxxx>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 95 +++++++++++++++++++++++++++---
include/linux/i2c/atmel_mxt_ts.h | 1 +
2 files changed, 89 insertions(+), 7 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 5ab3861..b75cf38 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -24,6 +24,8 @@
#include <linux/input/mt.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
+#include <linux/regulator/consumer.h>
+#include <linux/gpio.h>
/* Firmware files */
#define MXT_FW_NAME "maxtouch.fw"
@@ -152,6 +154,8 @@ struct t9_range {
#define MXT_FW_RESET_TIME 3000 /* msec */
#define MXT_FW_CHG_TIMEOUT 300 /* msec */
#define MXT_WAKEUP_TIME 25 /* msec */
+#define MXT_REGULATOR_DELAY 150 /* msec */
+#define MXT_POWERON_DELAY 150 /* msec */
/* Command to unlock bootloader */
#define MXT_UNLOCK_CMD_MSB 0xaa
@@ -218,6 +222,9 @@ struct mxt_data {
u8 num_stylusids;
unsigned long t15_keystatus;
bool use_retrigen_workaround;
+ bool use_regulator;
+ struct regulator *reg_vdd;
+ struct regulator *reg_avdd;
/* Cached parameters from object table */
u16 T5_address;
@@ -1840,6 +1847,66 @@ static int mxt_read_t9_resolution(struct mxt_data *data)
return 0;
}
+static void mxt_regulator_enable(struct mxt_data *data)
+{
+ gpio_set_value(data->pdata->gpio_reset, 0);
+
+ regulator_enable(data->reg_vdd);
+ regulator_enable(data->reg_avdd);
+ msleep(MXT_REGULATOR_DELAY);
+
+ INIT_COMPLETION(data->bl_completion);
+ gpio_set_value(data->pdata->gpio_reset, 1);
+ mxt_wait_for_completion(data, &data->bl_completion, MXT_POWERON_DELAY);
+}
+
+static void mxt_regulator_disable(struct mxt_data *data)
+{
+ regulator_disable(data->reg_vdd);
+ regulator_disable(data->reg_avdd);
+}
+
+static void mxt_probe_regulators(struct mxt_data *data)
+{
+ struct device *dev = &data->client->dev;
+ int error;
+
+ /* According to maXTouch power sequencing specification, RESET line
+ * must be kept low until some time after regulators come up to
+ * voltage */
+ if (!data->pdata->gpio_reset) {
+ dev_warn(dev, "Must have reset GPIO to use regulator support\n");
+ goto fail;
+ }
+
+ data->reg_vdd = 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 = regulator_get(dev, "avdd");
+ if (IS_ERR(data->reg_vdd)) {
+ error = PTR_ERR(data->reg_vdd);
+ dev_err(dev, "Error %d getting avdd regulator\n", error);
+ goto fail_release;
+ }
+
+ data->use_regulator = true;
+ mxt_regulator_enable(data);
+
+ dev_dbg(dev, "Initialised regulators\n");
+ return;
+
+fail_release:
+ regulator_put(data->reg_vdd);
+fail:
+ data->reg_vdd = NULL;
+ data->reg_avdd = NULL;
+ data->use_regulator = false;
+}
+
static int mxt_initialize(struct mxt_data *data)
{
struct i2c_client *client = data->client;
@@ -2034,6 +2101,9 @@ static int mxt_load_fw(struct device *dev, const char *fn)
goto release_firmware;
if (data->suspended) {
+ if (data->use_regulator)
+ mxt_regulator_enable(data);
+
enable_irq(data->irq);
data->suspended = false;
}
@@ -2198,14 +2268,18 @@ static void mxt_start(struct mxt_data *data)
if (!data->suspended || data->in_bootloader)
return;
- /* Discard any touch messages still in message buffer from before chip
- * went to sleep */
- mxt_process_messages_until_invalid(data);
+ if (data->use_regulator) {
+ mxt_regulator_enable(data);
+ } else {
+ /* Discard any messages still in message buffer from before
+ * chip went to sleep */
+ mxt_process_messages_until_invalid(data);
- mxt_set_t7_power_cfg(data, MXT_POWER_CFG_RUN);
+ mxt_set_t7_power_cfg(data, MXT_POWER_CFG_RUN);
- /* Recalibrate since chip has been in deep sleep */
- mxt_t6_command(data, MXT_COMMAND_CALIBRATE, 1, false);
+ /* Recalibrate since chip has been in deep sleep */
+ mxt_t6_command(data, MXT_COMMAND_CALIBRATE, 1, false);
+ }
mxt_acquire_irq(data);
data->enable_reporting = true;
@@ -2220,7 +2294,10 @@ static void mxt_stop(struct mxt_data *data)
data->enable_reporting = false;
disable_irq(data->irq);
- mxt_set_t7_power_cfg(data, MXT_POWER_CFG_DEEPSLEEP);
+ if (data->use_regulator)
+ mxt_regulator_disable(data);
+ else
+ mxt_set_t7_power_cfg(data, MXT_POWER_CFG_DEEPSLEEP);
mxt_reset_slots(data);
data->suspended = true;
@@ -2408,6 +2485,8 @@ static int mxt_probe(struct i2c_client *client,
goto err_free_pdata;
}
+ mxt_probe_regulators(data);
+
disable_irq(data->irq);
error = mxt_initialize(data);
@@ -2451,6 +2530,8 @@ static int mxt_remove(struct i2c_client *client)
sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
free_irq(data->irq, data);
input_unregister_device(data->input_dev);
+ regulator_put(data->reg_avdd);
+ regulator_put(data->reg_vdd);
mxt_free_object_table(data);
if (!dev_get_platdata(&data->client->dev))
kfree(data->pdata);
diff --git a/include/linux/i2c/atmel_mxt_ts.h b/include/linux/i2c/atmel_mxt_ts.h
index b7d2092..a01f2e8 100644
--- a/include/linux/i2c/atmel_mxt_ts.h
+++ b/include/linux/i2c/atmel_mxt_ts.h
@@ -22,6 +22,7 @@ struct mxt_platform_data {
const unsigned int *t19_keymap;
int t15_num_keys;
const unsigned int *t15_keymap;
+ unsigned long gpio_reset;
};
#endif /* __LINUX_ATMEL_MXT_TS_H */
--
1.7.10.4
--
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