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Date: Fri, 22 Feb 2013 17:58:26 +0000
From: Nick Dyer <nick.dyer@...ev.co.uk>
To: Dmitry Torokhov <dmitry.torokhov@...il.com>,
Daniel Kurtz <djkurtz@...omium.org>,
Henrik Rydberg <rydberg@...omail.se>,
Joonyoung Shim <jy0922.shim@...sung.com>,
Alan.Bowens@...el.com, linux-input@...r.kernel.org,
linux-kernel@...r.kernel.org, pmeerw@...erw.net,
bleung@...omium.org, olofj@...omium.org
Cc: Nick Dyer <nick.dyer@...ev.co.uk>
Subject: [PATCH 39/40] Input: atmel_mxt_ts - Add regulator control support
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@...ev.co.uk>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 95 +++++++++++++++++++++++++++---
include/linux/i2c/atmel_mxt_ts.h | 1 +
2 files changed, 87 insertions(+), 9 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 1c878fb..24c262c 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -21,6 +21,8 @@
#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 @@ static unsigned long mxt_t15_keystatus;
#define MXT_RESET_NOCHGREAD 200 /* msec */
#define MXT_FWRESET_TIME 1000 /* 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
@@ -221,6 +225,10 @@ struct mxt_data {
u8 num_touchids;
u8 num_stylusids;
u8(*read_chg) (void);
+ bool use_regulator;
+ unsigned long gpio_reset;
+ struct regulator *reg_vdd;
+ struct regulator *reg_avdd;
/* Cached parameters from object table */
u16 T5_address;
@@ -1657,12 +1665,71 @@ 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->gpio_reset, 0);
+ regulator_enable(data->reg_vdd);
+ regulator_enable(data->reg_avdd);
+ msleep(MXT_REGULATOR_DELAY);
+ gpio_set_value(data->gpio_reset, 1);
+ mxt_wait_for_chg(data, 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->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;
int error;
u8 retry_count = 0;
+ mxt_probe_regulators(data);
+
retry_probe:
error = mxt_read_info_block(data);
if (error) {
@@ -2067,27 +2134,34 @@ static void mxt_reset_slots(struct mxt_data *data)
static void mxt_start(struct mxt_data *data)
{
- /* Discard any 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);
+ }
if (data->state != APPMODE) {
enable_irq(data->irq);
data->state = APPMODE;
}
-
- /* Recalibrate since chip has been in deep sleep */
- mxt_t6_command(data, MXT_COMMAND_CALIBRATE, 1, false);
}
static void mxt_stop(struct mxt_data *data)
{
- mxt_set_t7_power_cfg(data, MXT_POWER_CFG_DEEPSLEEP);
-
disable_irq(data->irq);
+ if (data->use_regulator)
+ mxt_regulator_disable(data);
+ else
+ mxt_set_t7_power_cfg(data, MXT_POWER_CFG_DEEPSLEEP);
+
data->state = SUSPEND;
mxt_reset_slots(data);
@@ -2223,6 +2297,7 @@ static int mxt_probe(struct i2c_client *client,
data->client = client;
data->pdata = pdata;
data->read_chg = pdata->read_chg;
+ data->gpio_reset = pdata->gpio_reset;
data->irq = client->irq;
i2c_set_clientdata(client, data);
@@ -2289,6 +2364,8 @@ 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);
kfree(data);
diff --git a/include/linux/i2c/atmel_mxt_ts.h b/include/linux/i2c/atmel_mxt_ts.h
index b96b265..a952cbe 100644
--- a/include/linux/i2c/atmel_mxt_ts.h
+++ b/include/linux/i2c/atmel_mxt_ts.h
@@ -20,6 +20,7 @@ struct mxt_platform_data {
unsigned long irqflags;
u8(*read_chg) (void);
const char *input_name;
+ unsigned long gpio_reset;
};
#endif /* __LINUX_ATMEL_MXT_TS_H */
--
1.7.10.4
--
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