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authorMarco Felsch <m.felsch@pengutronix.de>2020-05-09 12:10:40 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2020-05-09 14:39:37 -0700
commit21d1611a83f8aa3907ca653b5851dd01951d4da6 (patch)
tree90068f3ee4092cd12caa71785108896d0161fef3
parentf4ee52f3ad8c9210030a9fe48bbb74dbc7c9f90e (diff)
downloadlinux-21d1611a83f8aa3907ca653b5851dd01951d4da6.tar.bz2
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>
-rw-r--r--drivers/input/touchscreen/edt-ft5x06.c142
1 files changed, 132 insertions, 10 deletions
diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index bb9107093796..d423bd6bfeda 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
@@ -65,6 +69,12 @@
#define EDT_RAW_DATA_RETRIES 100
#define EDT_RAW_DATA_DELAY 1000 /* usec */
+enum edt_pmode {
+ EDT_PMODE_NOT_SUPPORTED,
+ EDT_PMODE_HIBERNATE,
+ EDT_PMODE_POWEROFF,
+};
+
enum edt_ver {
EDT_M06,
EDT_M09,
@@ -103,6 +113,7 @@ struct edt_ft5x06_ts_data {
struct mutex mutex;
bool factory_mode;
+ enum edt_pmode suspend_mode;
int threshold;
int gain;
int offset;
@@ -767,9 +778,8 @@ static const struct file_operations debugfs_raw_data_fops = {
.read = edt_ft5x06_debugfs_raw_data_read,
};
-static void
-edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
- const char *debugfs_name)
+static void edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
+ const char *debugfs_name)
{
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);
}
-static void
-edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
+static void edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
{
debugfs_remove_recursive(tsdata->debug_dir);
kfree(tsdata->raw_buffer);
@@ -791,14 +800,17 @@ edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
#else
-static inline void
-edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
- const char *debugfs_name)
+static int edt_ft5x06_factory_mode(struct edt_ft5x06_ts_data *tsdata)
{
+ return -ENOSYS;
}
-static inline void
-edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
+static void edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
+ const char *debugfs_name)
+{
+}
+
+static void 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;
}
+ /*
+ * 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) {
usleep_range(5000, 6000);
gpiod_set_value_cansleep(tsdata->wake_gpio, 1);
@@ -1238,6 +1263,102 @@ 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);
+ 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 = {
.max_support_points = 5,
};
@@ -1276,6 +1397,7 @@ 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,