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. This is the most effective power-saving mechanism. Disabling the device don't change the suspend logic because the hibernate mode needs a hardware reset anyway. [1] https://www.newhavendisplay.com/appnotes/datasheets/touchpanel/FT5x26.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@xxxxxxxxxxxxxx> Tested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- v3: - drop enable/disable_irq_wake() v2: - adapt commit message - don't return errors during suspend/resume - replace dev_err() by dev_warn() - add support to disable the regulator too --- drivers/input/touchscreen/edt-ft5x06.c | 65 ++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c index d2587724c52a..4fd97758cbdd 100644 --- a/drivers/input/touchscreen/edt-ft5x06.c +++ b/drivers/input/touchscreen/edt-ft5x06.c @@ -38,6 +38,9 @@ #define WORK_REGISTER_NUM_X 0x33 #define WORK_REGISTER_NUM_Y 0x34 +#define PMOD_REGISTER_ACTIVE 0x00 +#define PMOD_REGISTER_HIBERNATE 0x03 + #define M09_REGISTER_THRESHOLD 0x80 #define M09_REGISTER_GAIN 0x92 #define M09_REGISTER_OFFSET 0x93 @@ -53,6 +56,7 @@ #define WORK_REGISTER_OPMODE 0x3c #define FACTORY_REGISTER_OPMODE 0x01 +#define PMOD_REGISTER_OPMODE 0xa5 #define TOUCH_EVENT_DOWN 0x00 #define TOUCH_EVENT_UP 0x01 @@ -1227,6 +1231,66 @@ static int edt_ft5x06_ts_remove(struct i2c_client *client) 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); + int ret; + + if (device_may_wakeup(dev)) + return 0; + + /* + * Hibernate mode requires reset or wake signal to recover to active + * state. + */ + if (!tsdata->wake_gpio && !tsdata->reset_gpio) + return 0; + + ret = edt_ft5x06_register_write(tsdata, PMOD_REGISTER_OPMODE, + PMOD_REGISTER_HIBERNATE); + if (ret) + dev_warn(dev, "Failed to set hibernate mode\n"); + + 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; + + if (device_may_wakeup(dev)) + return 0; + + ret = regulator_enable(tsdata->vcc); + if (ret) + dev_warn(dev, "Failed to enable vcc\n"); + + /* Recover from hibernate mode if hardware supports it */ + if (tsdata->wake_gpio) { + gpiod_set_value_cansleep(tsdata->wake_gpio, 0); + usleep_range(5000, 6000); + gpiod_set_value_cansleep(tsdata->wake_gpio, 1); + msleep(300); + } else if (tsdata->reset_gpio) { + gpiod_set_value_cansleep(tsdata->reset_gpio, 1); + usleep_range(5000, 6000); + gpiod_set_value_cansleep(tsdata->reset_gpio, 0); + msleep(300); + } + + return 0; +} + +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 = { .max_support_points = 5, }; @@ -1265,6 +1329,7 @@ static struct i2c_driver edt_ft5x06_ts_driver = { .driver = { .name = "edt_ft5x06", .of_match_table = edt_ft5x06_of_match, + .pm = &edt_ft5x06_ts_pm_ops, }, .id_table = edt_ft5x06_ts_id, .probe = edt_ft5x06_ts_probe, -- 2.20.1
