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Input: edt-ft5x06 - improve power management operations 

It is possible to bring the device into a deep sleep state. To exit this
state the reset or wakeup pin must be toggeled as documented in [1].
Because of the poor documentation I used the several downstream kernels
[2] and other applications notes [3] to indentify the related registers.

Furthermore I added the support to disable the device completely which
is obviously the most effective power-saving mechanism. This mechanism
needs the reset pin to ensure the power-up/down sequence.

We can't apply any of these power-saving mechanism if both pins are
missing (not connected) or if it is a wakeup device.

[1] https://www.newhavendisplay.com/appnotes/datasheets/touchpanel/FT5x26.pdf
    https://www.newhavendisplay.com/appnotes/datasheets/touchpanel/FT5x06.pdf
[2] https://github.com/linux-sunxi/linux-sunxi/blob/sunxi-3.4/drivers/input/touchscreen/ft5x_ts.c
    https://github.com/Pablito2020/focaltech-touch-driver/blob/master/ft5336_driver.c
[3] https://www.newhavendisplay.com/appnotes/datasheets/touchpanel/FT5x16_registers.pdf

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://lore.kernel.org/r/20200227112819.16754-4-m.felsch@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Marco Felsch 2020-05-09 12:10:40 -07:00 committed by Dmitry Torokhov
parent f4ee52f3ad
commit 21d1611a83
1 changed files with 132 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

142
drivers/input/touchscreen/edt-ft5x06.c
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@ -38,6 +38,9 @@
#define WORK_REGISTER_NUM_X 0x33 #define WORK_REGISTER_NUM_X 0x33
#define WORK_REGISTER_NUM_Y 0x34 #define WORK_REGISTER_NUM_Y 0x34
#define PMOD_REGISTER_ACTIVE 0x00
#define PMOD_REGISTER_HIBERNATE 0x03
#define M09_REGISTER_THRESHOLD 0x80 #define M09_REGISTER_THRESHOLD 0x80
#define M09_REGISTER_GAIN 0x92 #define M09_REGISTER_GAIN 0x92
#define M09_REGISTER_OFFSET 0x93 #define M09_REGISTER_OFFSET 0x93
@ -53,6 +56,7 @@
#define WORK_REGISTER_OPMODE 0x3c #define WORK_REGISTER_OPMODE 0x3c
#define FACTORY_REGISTER_OPMODE 0x01 #define FACTORY_REGISTER_OPMODE 0x01
#define PMOD_REGISTER_OPMODE 0xa5
#define TOUCH_EVENT_DOWN 0x00 #define TOUCH_EVENT_DOWN 0x00
#define TOUCH_EVENT_UP 0x01 #define TOUCH_EVENT_UP 0x01
@ -65,6 +69,12 @@
#define EDT_RAW_DATA_RETRIES 100 #define EDT_RAW_DATA_RETRIES 100
#define EDT_RAW_DATA_DELAY 1000 /* usec */ #define EDT_RAW_DATA_DELAY 1000 /* usec */
enum edt_pmode {
EDT_PMODE_NOT_SUPPORTED,
EDT_PMODE_HIBERNATE,
EDT_PMODE_POWEROFF,
};
enum edt_ver { enum edt_ver {
EDT_M06, EDT_M06,
EDT_M09, EDT_M09,
@ -103,6 +113,7 @@ struct edt_ft5x06_ts_data {
struct mutex mutex; struct mutex mutex;
bool factory_mode; bool factory_mode;
enum edt_pmode suspend_mode;
int threshold; int threshold;
int gain; int gain;
int offset; int offset;
@ -767,9 +778,8 @@ static const struct file_operations debugfs_raw_data_fops = {
.read = edt_ft5x06_debugfs_raw_data_read, .read = edt_ft5x06_debugfs_raw_data_read,
}; };
static void static void edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata, const char *debugfs_name)
const char *debugfs_name)
{ {
tsdata->debug_dir = debugfs_create_dir(debugfs_name, NULL); tsdata->debug_dir = debugfs_create_dir(debugfs_name, NULL);
@ -782,8 +792,7 @@ edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
tsdata->debug_dir, tsdata, &debugfs_raw_data_fops); tsdata->debug_dir, tsdata, &debugfs_raw_data_fops);
} }
static void static void edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
{ {
debugfs_remove_recursive(tsdata->debug_dir); debugfs_remove_recursive(tsdata->debug_dir);
kfree(tsdata->raw_buffer); kfree(tsdata->raw_buffer);
@ -791,14 +800,17 @@ edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
#else #else
static inline void static int edt_ft5x06_factory_mode(struct edt_ft5x06_ts_data *tsdata)
edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata, {
const char *debugfs_name) return -ENOSYS;
}
static void edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
const char *debugfs_name)
{ {
} }
static inline void static void edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
{ {
} }
@ -1125,6 +1137,19 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
return error; return error;
} }
/*
* Check which sleep modes we can support. Power-off requieres the
* reset-pin to ensure correct power-down/power-up behaviour. Start with
* the EDT_PMODE_POWEROFF test since this is the deepest possible sleep
* mode.
*/
if (tsdata->reset_gpio)
tsdata->suspend_mode = EDT_PMODE_POWEROFF;
else if (tsdata->wake_gpio)
tsdata->suspend_mode = EDT_PMODE_HIBERNATE;
else
tsdata->suspend_mode = EDT_PMODE_NOT_SUPPORTED;
if (tsdata->wake_gpio) { if (tsdata->wake_gpio) {
usleep_range(5000, 6000); usleep_range(5000, 6000);
gpiod_set_value_cansleep(tsdata->wake_gpio, 1); gpiod_set_value_cansleep(tsdata->wake_gpio, 1);
@ -1238,6 +1263,102 @@ static int edt_ft5x06_ts_remove(struct i2c_client *client)
return 0; return 0;
} }
static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
struct gpio_desc *reset_gpio = tsdata->reset_gpio;
int ret;
if (device_may_wakeup(dev))
return 0;
if (tsdata->suspend_mode == EDT_PMODE_NOT_SUPPORTED)
return 0;
/* Enter hibernate mode. */
ret = edt_ft5x06_register_write(tsdata, PMOD_REGISTER_OPMODE,
PMOD_REGISTER_HIBERNATE);
if (ret)
dev_warn(dev, "Failed to set hibernate mode\n");
if (tsdata->suspend_mode == EDT_PMODE_HIBERNATE)
return 0;
/*
* Power-off according the datasheet. Cut the power may leaf the irq
* line in an undefined state depending on the host pull resistor
* settings. Disable the irq to avoid adjusting each host till the
* device is back in a full functional state.
*/
disable_irq(tsdata->client->irq);
gpiod_set_value_cansleep(reset_gpio, 1);
usleep_range(1000, 2000);
ret = regulator_disable(tsdata->vcc);
if (ret)
dev_warn(dev, "Failed to disable vcc\n");
return 0;
}
static int __maybe_unused edt_ft5x06_ts_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
int ret = 0;
if (device_may_wakeup(dev))
return 0;
if (tsdata->suspend_mode == EDT_PMODE_NOT_SUPPORTED)
return 0;
if (tsdata->suspend_mode == EDT_PMODE_POWEROFF) {
struct gpio_desc *reset_gpio = tsdata->reset_gpio;
/*
* We can't check if the regulator is a dummy or a real
* regulator. So we need to specify the 5ms reset time (T_rst)
* here instead of the 100us T_rtp time. We also need to wait
* 300ms in case it was a real supply and the power was cutted
* of. Toggle the reset pin is also a way to exit the hibernate
* mode.
*/
gpiod_set_value_cansleep(reset_gpio, 1);
usleep_range(5000, 6000);
ret = regulator_enable(tsdata->vcc);
if (ret) {
dev_err(dev, "Failed to enable vcc\n");
return ret;
}
usleep_range(1000, 2000);
gpiod_set_value_cansleep(reset_gpio, 0);
msleep(300);
edt_ft5x06_restore_reg_parameters(tsdata);
enable_irq(tsdata->client->irq);
if (tsdata->factory_mode)
ret = edt_ft5x06_factory_mode(tsdata);
} else {
struct gpio_desc *wake_gpio = tsdata->wake_gpio;
gpiod_set_value_cansleep(wake_gpio, 0);
usleep_range(5000, 6000);
gpiod_set_value_cansleep(wake_gpio, 1);
}
return ret;
}
static SIMPLE_DEV_PM_OPS(edt_ft5x06_ts_pm_ops,
edt_ft5x06_ts_suspend, edt_ft5x06_ts_resume);
static const struct edt_i2c_chip_data edt_ft5x06_data = { static const struct edt_i2c_chip_data edt_ft5x06_data = {
.max_support_points = 5, .max_support_points = 5,
}; };
@ -1276,6 +1397,7 @@ static struct i2c_driver edt_ft5x06_ts_driver = {
.driver = { .driver = {
.name = "edt_ft5x06", .name = "edt_ft5x06",
.of_match_table = edt_ft5x06_of_match, .of_match_table = edt_ft5x06_of_match,
.pm = &edt_ft5x06_ts_pm_ops,
}, },
.id_table = edt_ft5x06_ts_id, .id_table = edt_ft5x06_ts_id,
.probe = edt_ft5x06_ts_probe, .probe = edt_ft5x06_ts_probe,