[PATCH v7 45/48] input: touchscreen: atmel_mxt_ts: Added sysfs entry for touchscreen status

From: Jiada Wang
Date: Wed Feb 12 2020 - 03:47:58 EST


From: Naveen Chakka <Naveen.Chakka@xxxxxxxxxxxx>

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

Signed-off-by: Naveen Chakka <Naveen.Chakka@xxxxxxxxxxxx>
Signed-off-by: Sanjeev Chugh <sanjeev_chugh@xxxxxxxxxx>
Signed-off-by: George G. Davis <george_davis@xxxxxxxxxx>
Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 112 +++++++++++++++++++++--
1 file changed, 105 insertions(+), 7 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 3784182d896f..afe58b30ecb1 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -25,6 +25,7 @@
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/gpio/consumer.h>
+#include <linux/timer.h>
#include <asm/unaligned.h>
#include <linux/regulator/consumer.h>
#include <linux/workqueue.h>
@@ -222,6 +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
@@ -317,6 +319,12 @@ struct mxt_flash {
struct delayed_work work;
};

+struct mxt_statusinfo {
+ bool dev_status;
+ bool intp_triggered;
+ u32 error_count;
+};
+
/* Each client has this additional data */
struct mxt_data {
struct i2c_client *client;
@@ -372,6 +380,9 @@ struct mxt_data {
const char *pcfg_name;
const char *input_name;
struct mxt_flash *flash;
+ struct work_struct watchdog_work;
+ struct timer_list watchdog_timer;
+ struct mxt_statusinfo mxt_status;

/* Cached parameters from object table */
u16 T5_address;
@@ -1621,11 +1632,30 @@ static int mxt_process_messages(struct mxt_data *data)
return total_handled;
}

+static void mxt_start_wd_timer(struct mxt_data *data)
+{
+ mod_timer(&data->watchdog_timer, jiffies +
+ msecs_to_jiffies(MXT_WATCHDOG_TIMEOUT));
+}
+
+static void mxt_stop_wd_timer(struct mxt_data *data)
+{
+ /*
+ * Ensure we wait until the watchdog timer
+ * running on a different CPU finishes
+ */
+ del_timer_sync(&data->watchdog_timer);
+ cancel_work_sync(&data->watchdog_work);
+ del_timer_sync(&data->watchdog_timer);
+}
+
static irqreturn_t mxt_interrupt(int irq, void *dev_id)
{
struct mxt_data *data = dev_id;
int ret;

+ data->mxt_status.intp_triggered = true;
+
if (data->in_bootloader) {
complete(&data->chg_completion);

@@ -1633,21 +1663,25 @@ static irqreturn_t mxt_interrupt(int irq, void *dev_id)
cancel_delayed_work_sync(&data->flash->work);

ret = mxt_check_bootloader(data);
- return IRQ_RETVAL(ret);
+ ret = IRQ_RETVAL(ret);
+ goto exit;
}

- if (!data->object_table)
- return IRQ_HANDLED;
+ if (!data->object_table) {
+ ret = IRQ_HANDLED;
+ goto exit;
+ }

if (data->T44_address)
ret = mxt_process_messages_t44(data);
else
ret = mxt_process_messages(data);

- if (ret <= 0)
- return IRQ_NONE;
- else
- return IRQ_HANDLED;
+ ret = (ret <= 0) ? IRQ_NONE : IRQ_HANDLED;
+
+exit:
+ data->mxt_status.intp_triggered = false;
+ return ret;
}

static int mxt_t6_command(struct mxt_data *data, u16 cmd_offset,
@@ -2967,6 +3001,39 @@ static int mxt_bootloader_status(struct mxt_data *data)
return 0;
}

+static void mxt_watchdog_timer(struct timer_list *t)
+{
+ struct mxt_data *data = from_timer(data, t, watchdog_timer);
+
+ if (!work_pending(&data->watchdog_work)) {
+ if (!data->mxt_status.intp_triggered)
+ schedule_work(&data->watchdog_work);
+ }
+
+ mxt_start_wd_timer(data);
+}
+
+static void mxt_watchdog_work(struct work_struct *work)
+{
+ struct mxt_data *data =
+ container_of(work, struct mxt_data, watchdog_work);
+ u16 info_buf;
+ int ret = 0;
+ u8 size = 2;
+
+ if (data->suspended || data->in_bootloader)
+ return;
+
+ ret = __mxt_read_reg(data->client, 0, size, &info_buf);
+
+ if (ret) {
+ data->mxt_status.error_count++;
+ data->mxt_status.dev_status = false;
+ } else {
+ data->mxt_status.dev_status = true;
+ }
+}
+
static int mxt_initialize(struct mxt_data *data)
{
struct i2c_client *client = data->client;
@@ -3944,6 +4011,22 @@ static const struct attribute_group mxt_fw_attr_group = {
.attrs = mxt_fw_attrs,
};

+static ssize_t mxt_touch_device_status(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(fw_version, S_IRUGO, mxt_fw_version_show, NULL);
static DEVICE_ATTR(hw_version, S_IRUGO, mxt_hw_version_show, NULL);
static DEVICE_ATTR(object, S_IRUGO, mxt_object_show, NULL);
@@ -3955,6 +4038,7 @@ static DEVICE_ATTR(debug_v2_enable, S_IWUSR | S_IRUSR, NULL,
mxt_debug_v2_enable_store);
static DEVICE_ATTR(debug_notify, S_IRUGO, mxt_debug_notify_show, NULL);
static DEVICE_ATTR(t25, 0600, mxt_t25_selftest_show, mxt_t25_selftest_store);
+static DEVICE_ATTR(touch_dev_stat, 0444, mxt_touch_device_status, NULL);

static struct attribute *mxt_attrs[] = {
&dev_attr_fw_version.attr,
@@ -3966,6 +4050,7 @@ static struct attribute *mxt_attrs[] = {
&dev_attr_debug_v2_enable.attr,
&dev_attr_debug_notify.attr,
&dev_attr_t25.attr,
+ &dev_attr_touch_dev_stat.attr,
NULL
};

@@ -4318,6 +4403,13 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
msleep(MXT_RESET_TIME);
}

+ INIT_WORK(&data->watchdog_work, mxt_watchdog_work);
+
+ /* setup watchdog timer */
+ timer_setup(&data->watchdog_timer, mxt_watchdog_timer, 0);
+
+ mxt_start_wd_timer(data);
+
error = mxt_initialize(data);
if (error)
goto err_free_object;
@@ -4332,8 +4424,11 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
return 0;

err_free_object:
+ cancel_work_sync(&data->watchdog_work);
+ mxt_stop_wd_timer(data);
mxt_free_input_device(data);
mxt_free_object_table(data);
+ del_timer(&data->watchdog_timer);
if (data->reset_gpio) {
sysfs_remove_link(&client->dev.kobj, "reset");
gpiod_unexport(data->reset_gpio);
@@ -4356,6 +4451,9 @@ static int mxt_remove(struct i2c_client *client)
mxt_free_input_device(data);
mxt_free_object_table(data);

+ cancel_work_sync(&data->watchdog_work);
+ mxt_stop_wd_timer(data);
+
return 0;
}

--
2.17.1