[PATCH v11 53/56] input: touchscreen: atmel_mxt_ts: Added sysfs entry for touchscreen status

Jiada Wang
2020-05-08T06:00:27Z

From: Naveen Chakka <Naveen.Chakka@in.bosch.com>

To know the current communication status of the touch controller during
runtime, sysfs interface is added

sysfs interface: /sys/class/i2c-dev/i2c-*/device/*/touch_dev_stat
Executing the above sysfs interface provides two output values

1)Status of the touch device
value 0 represents device is inactive
value 1 represents device is active
2)Error counter
value represents the number of times device in inactive since last read

New module_param "debug_state" is introduced, by set its value,
a watchdog work is scheduled to periodically check device state.
default value is false.

Signed-off-by: Naveen Chakka <Naveen.Chakka@in.bosch.com>
Signed-off-by: Sanjeev Chugh <sanjeev_chugh@mentor.com>
Signed-off-by: George G. Davis <george_davis@mentor.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 85 +++++++++++++++++++++++-
1 file changed, 82 insertions(+), 3 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 20d6ada778e5..5c2f4ea1a362 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -223,6 +223,7 @@ enum t100_type {
#define MXT_CHG_DELAY 100 /* msec */
#define MXT_POWERON_DELAY 150 /* msec */
#define MXT_BOOTLOADER_WAIT 36E5 /* 1 minute */
+#define MXT_WATCHDOG_TIMEOUT 1000 /* msec */

/* Command to unlock bootloader */
#define MXT_UNLOCK_CMD_MSB 0xaa
@@ -246,6 +247,9 @@ enum t100_type {

#define DEBUG_MSG_MAX 200

+#define MXT_DEBUG_STATE false
+static bool debug_state = MXT_DEBUG_STATE;
+
struct mxt_info {
u8 family_id;
u8 variant_id;
@@ -318,6 +322,11 @@ struct mxt_flash {
struct delayed_work work;
};

+struct mxt_statusinfo {
+ bool dev_status;
+ u32 error_count;
+};
+
/* Each client has this additional data */
struct mxt_data {
struct i2c_client *client;
@@ -373,6 +382,8 @@ struct mxt_data {
const char *pcfg_name;
const char *input_name;
struct mxt_flash *flash;
+ struct delayed_work watchdog_work;
+ struct mxt_statusinfo mxt_status;

/* Cached parameters from object table */
u16 T5_address;
@@ -2956,6 +2967,26 @@ static int mxt_bootloader_status(struct mxt_data *data)
return 0;
}

+static void mxt_watchdog_work(struct work_struct *work)
+{
+ struct mxt_data *data =
+ container_of(work, struct mxt_data, watchdog_work.work);
+ u16 info_buf;
+ int ret;
+
+ ret = __mxt_read_reg(data->client, 0, sizeof(info_buf), &info_buf);
+
+ if (ret) {
+ data->mxt_status.error_count++;
+ data->mxt_status.dev_status = false;
+ } else {
+ data->mxt_status.dev_status = true;
+ }
+
+ schedule_delayed_work(&data->watchdog_work,
+ msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
+}
+
static int mxt_initialize(struct mxt_data *data)
{
struct i2c_client *client = data->client;
@@ -3730,6 +3761,9 @@ static int mxt_load_fw(struct device *dev)
INIT_DELAYED_WORK(&data->flash->work, mxt_fw_work);
reinit_completion(&data->flash->flash_completion);

+ if (debug_state)
+ cancel_delayed_work_sync(&data->watchdog_work);
+
if (!data->in_bootloader) {
ret = mxt_enter_bootloader(data);
if (ret)
@@ -3749,6 +3783,9 @@ static int mxt_load_fw(struct device *dev)
cancel_delayed_work_sync(&data->flash->work);
data->in_bootloader = false;
release_firmware:
+ if (debug_state)
+ schedule_delayed_work(&data->watchdog_work,
+ msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
release_firmware(data->flash->fw);
free:
devm_kfree(dev, data->flash);
@@ -3936,6 +3973,22 @@ static const struct attribute_group mxt_fw_attr_group = {
.attrs = mxt_fw_attrs,
};

+static ssize_t touch_dev_stat_show(struct device *dev, struct
+ device_attribute * attr, char *buf)
+{
+ struct mxt_data *data = dev_get_drvdata(dev);
+ int ret = 0;
+
+ if (data->mxt_status.dev_status)
+ data->mxt_status.error_count = 0;
+
+ ret = snprintf(buf, PAGE_SIZE, "%d %d\n", data->mxt_status.dev_status,
+ data->mxt_status.error_count);
+ /* clear the error counter once it is read */
+ data->mxt_status.error_count = 0;
+ return ret;
+}
+
static DEVICE_ATTR_RO(fw_version);
static DEVICE_ATTR_RO(hw_version);
static DEVICE_ATTR_RO(object);
@@ -3945,6 +3998,7 @@ static DEVICE_ATTR_RW(debug_enable);
static DEVICE_ATTR_RW(debug_v2_enable);
static DEVICE_ATTR_RO(debug_notify);
static DEVICE_ATTR_RW(t25_selftest);
+static DEVICE_ATTR_RO(touch_dev_stat);

static struct attribute *mxt_attrs[] = {
&dev_attr_fw_version.attr,
@@ -3956,6 +4010,7 @@ static struct attribute *mxt_attrs[] = {
&dev_attr_debug_v2_enable.attr,
&dev_attr_debug_notify.attr,
&dev_attr_t25_selftest.attr,
+ &dev_attr_touch_dev_stat.attr,
NULL
};

@@ -4050,10 +4105,16 @@ static int mxt_start(struct mxt_data *data)
ret = mxt_acquire_irq(data);
}

- if (!ret)
- data->suspended = false;
+ if (ret)
+ return ret;

- return ret;
+ if (debug_state)
+ schedule_delayed_work(&data->watchdog_work,
+ msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
+
+ data->suspended = false;
+
+ return 0;
}

static int mxt_stop(struct mxt_data *data)
@@ -4063,6 +4124,9 @@ static int mxt_stop(struct mxt_data *data)
if (data->suspended || data->in_bootloader || data->updating_config)
return 0;

+ if (debug_state)
+ cancel_delayed_work_sync(&data->watchdog_work);
+
switch (data->suspend_mode) {
case MXT_SUSPEND_T9_CTRL:
/* Touch disable */
@@ -4313,6 +4377,12 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
msleep(MXT_RESET_TIME);
}

+ if (debug_state) {
+ INIT_DELAYED_WORK(&data->watchdog_work, mxt_watchdog_work);
+ schedule_delayed_work(&data->watchdog_work,
+ msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
+ }
+
error = mxt_initialize(data);
if (error)
goto err_free_object;
@@ -4327,6 +4397,8 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
return 0;

err_free_object:
+ if (debug_state)
+ cancel_delayed_work_sync(&data->watchdog_work);
mxt_free_input_device(data);
mxt_free_object_table(data);
if (data->reset_gpio) {
@@ -4346,6 +4418,10 @@ static int mxt_remove(struct i2c_client *client)
sysfs_remove_link(&client->dev.kobj, "reset");
gpiod_unexport(data->reset_gpio);
}
+
+ if (debug_state)
+ cancel_delayed_work_sync(&data->watchdog_work);
+
mxt_debug_msg_remove(data);
mxt_sysfs_remove(data);
mxt_free_input_device(data);
@@ -4447,3 +4523,6 @@ module_i2c_driver(mxt_driver);
MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
MODULE_DESCRIPTION("Atmel maXTouch Touchscreen driver");
MODULE_LICENSE("GPL");
+
+module_param(debug_state, bool, 0);
+MODULE_PARM_DESC(debug_state, "Enable/Disable watchdog work to check device state (default=false)");
--
2.17.1