For a broken touchpad, it may take several months or longer to be fixed.
Polling mode could be a fallback solution for enthusiastic Linux users
when they have a new laptop. It also acts like a debugging feature. If
polling mode works for a broken touchpad, we can almost be certain
the root cause is related to the interrupt or power setting.
This patch could fix touchpads of Lenovo AMD gaming laptops including
Legion-5 15ARH05 (R7000), Legion-5P (R7000P) and IdeaPad Gaming 3
15ARH05.
When polling mode is enabled, an I2C device can't wake up the suspended
system since enable/disable_irq_wake is invalid for polling mode.
Three module parameters are added to i2c-hid,
- polling_mode: by default set to 0, i.e., polling is disabled
- polling_interval_idle_ms: the polling internal when the touchpad
is idle, default to 10ms
- polling_interval_active_us: the polling internal when the touchpad
is active, default to 4000us
User can change the last two runtime polling parameter by writing to
/sys/module/i2c_hid/parameters/polling_interval_{idle_ms,active_us}.
Note xf86-input-synaptics doesn't work well with this polling mode
for the Synaptics touchpad. The Synaptics touchpad would often locks
into scroll mode when using multitouch gestures [1]. One remedy is to
decrease the polling interval.
Thanks to Barnabás's thorough review of this patch and the useful
feedback!
[1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1887190/comments/235
Cc: <sta...@vger.kernel.org>
Cc: Barnabás Pőcze <po...@protonmail.com>
BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1887190
Signed-off-by: Coiby Xu <coiby...@gmail.com>
---
drivers/hid/i2c-hid/i2c-hid-core.c | 152 +++++++++++++++++++++++++++--
1 file changed, 142 insertions(+), 10 deletions(-)
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c
b/drivers/hid/i2c-hid/i2c-hid-core.c
index aeff1ffb0c8b..f25503f31ccf 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -36,6 +36,8 @@
#include <linux/hid.h>
#include <linux/mutex.h>
#include <linux/acpi.h>
+#include <linux/kthread.h>
+#include <linux/gpio/driver.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>
@@ -60,6 +62,25 @@
#define I2C_HID_PWR_ON 0x00
#define I2C_HID_PWR_SLEEP 0x01
+/* polling mode */
+#define I2C_HID_POLLING_DISABLED 0
+#define I2C_HID_POLLING_GPIO_PIN 1
+#define I2C_HID_POLLING_INTERVAL_ACTIVE_US 4000
+#define I2C_HID_POLLING_INTERVAL_IDLE_MS 10
+
+static u8 polling_mode;
+module_param(polling_mode, byte, 0444);
+MODULE_PARM_DESC(polling_mode, "How to poll (default=0) - 0 disabled; 1 based
on GPIO pin's status");
+
+static unsigned int polling_interval_active_us __read_mostly =
I2C_HID_POLLING_INTERVAL_ACTIVE_US;
+module_param(polling_interval_active_us, uint, 0644);
+MODULE_PARM_DESC(polling_interval_active_us,
+ "Poll every {polling_interval_active_us} us when the touchpad
is active (default=" __stringify(I2C_HID_POLLING_INTERVAL_ACTIVE_US) " us)");
+
+static unsigned int polling_interval_idle_ms __read_mostly =
I2C_HID_POLLING_INTERVAL_IDLE_MS;
+module_param(polling_interval_idle_ms, uint, 0644);
+MODULE_PARM_DESC(polling_interval_idle_ms,
+ "Poll every {polling_interval_idle_ms} ms when the touchpad is
idle (default=" __stringify(I2C_HID_POLLING_INTERVAL_IDLE_MS) "ms)");
/* debug option */
static bool debug;
module_param(debug, bool, 0444);
@@ -158,6 +179,10 @@ struct i2c_hid {
struct i2c_hid_platform_data pdata;
+ struct task_struct *polling_thread;
+ unsigned long irq_trigger_type;
+ struct irq_desc *irq_desc;
+
bool irq_wake_enabled;
struct mutex reset_lock;
};
@@ -772,7 +797,9 @@ static int i2c_hid_start(struct hid_device *hid)
i2c_hid_free_buffers(ihid);
ret = i2c_hid_alloc_buffers(ihid, bufsize);
- enable_irq(client->irq);
+
+ if (polling_mode == I2C_HID_POLLING_DISABLED)
+ enable_irq(client->irq);
if (ret)
return ret;
@@ -814,6 +841,96 @@ struct hid_ll_driver i2c_hid_ll_driver = {
};
EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
+static int get_gpio_pin_state(struct irq_desc *irq_desc)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(&irq_desc->irq_data);
+ int value;
+
+ /*
+ * This part of code is borrowed from gpiod_get_raw_value_commit in
+ * drivers/gpio/gpiolib.c. Ideally, gpiod_get_value_cansleep can be
re-used
+ * instead but there is no API of converting (struct irq_desc *) to
+ * (struct gpio_desc*).
+ */
+ value = gc->get ? gc->get(gc, irq_desc->irq_data.hwirq) : -EIO;
+ value = value < 0 ? value : !!value;
+ return value;
+}
+
+static bool interrupt_line_active(struct i2c_hid *ihid)
+{
+ int status = get_gpio_pin_state(ihid->irq_desc);
+ struct i2c_client *client = ihid->client;
+
+ if (status < 0) {
+ dev_dbg_ratelimited(&client->dev,
+ "Failed to get GPIO Interrupt line status
for %s",
+ client->name);
+ return false;
+ }
+ /*
+ * According to Windows Precsiontion Touchpad's specs
+ *
https://docs.microsoft.com/en-us/windows-hardware/design/component-guidelines/windows-precision-touchpad-device-bus-connectivity,
+ * GPIO Interrupt Assertion Leve could be either ActiveLow or
+ * ActiveHigh.
+ */
+ if (ihid->irq_trigger_type & IRQF_TRIGGER_LOW)
+ return !status;
+
+ return status;
+}
+
+static int i2c_hid_polling_thread(void *i2c_hid)
+{
+ struct i2c_hid *ihid = i2c_hid;
+ unsigned int polling_interval_idle;
+
+ while (!kthread_should_stop()) {
+ while (interrupt_line_active(i2c_hid) &&
+ !test_bit(I2C_HID_READ_PENDING, &ihid->flags) &&
+ !kthread_should_stop()) {
+ i2c_hid_get_input(ihid);
+ usleep_range(polling_interval_active_us,
+ polling_interval_active_us + 100);
+ }
+ /*
+ * re-calculate polling_interval_idle
+ * so the module parameters polling_interval_idle_ms can be
+ * changed dynamically through sysfs as
polling_interval_active_us
+ */
+ polling_interval_idle = polling_interval_idle_ms * 1000;
+ usleep_range(polling_interval_idle,
+ polling_interval_idle + 1000);
+ }
+
+ return 0;
+}
+
+static int i2c_hid_init_polling(struct i2c_hid *ihid)
+{
+ struct i2c_client *client = ihid->client;
+
+ ihid->irq_trigger_type = irq_get_trigger_type(client->irq);
+ if (!ihid->irq_trigger_type) {
+ dev_dbg(&client->dev,
+ "Failed to get GPIO Interrupt Assertion Level, could
not enable polling mode for %s",
+ client->name);
+ return -EINVAL;
+ }
+
+ ihid->polling_thread = kthread_create(i2c_hid_polling_thread, ihid,
+ "I2C HID polling thread");
+
+ if (IS_ERR(ihid->polling_thread)) {
+ dev_err(&client->dev, "Failed to create I2C HID polling
thread");
+ return PTR_ERR(ihid->polling_thread);
+ }
+
+ ihid->irq_desc = irq_to_desc(client->irq);
+ wake_up_process(ihid->polling_thread);
+ return 0;
+}
+
static int i2c_hid_init_irq(struct i2c_client *client)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
@@ -1014,6 +1131,15 @@ static void i2c_hid_fwnode_probe(struct i2c_client
*client,
pdata->post_power_delay_ms = val;
}
+static void free_irq_or_stop_polling(struct i2c_client *client,
+ struct i2c_hid *ihid)
+{
+ if (polling_mode != I2C_HID_POLLING_DISABLED)
+ kthread_stop(ihid->polling_thread);
+ else
+ free_irq(client->irq, ihid);
+}
+
static int i2c_hid_probe(struct i2c_client *client,
const struct i2c_device_id *dev_id)
{
@@ -1109,7 +1235,11 @@ static int i2c_hid_probe(struct i2c_client *client,
if (ret < 0)
goto err_regulator;
- ret = i2c_hid_init_irq(client);
+ if (polling_mode != I2C_HID_POLLING_DISABLED)
+ ret = i2c_hid_init_polling(ihid);
+ else
+ ret = i2c_hid_init_irq(client);
+
if (ret < 0)
goto err_regulator;
@@ -1148,7 +1278,7 @@ static int i2c_hid_probe(struct i2c_client *client,
hid_destroy_device(hid);
err_irq:
- free_irq(client->irq, ihid);
+ free_irq_or_stop_polling(client, ihid);
err_regulator:
regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies),
@@ -1165,7 +1295,7 @@ static int i2c_hid_remove(struct i2c_client *client)
hid = ihid->hid;
hid_destroy_device(hid);
- free_irq(client->irq, ihid);
+ free_irq_or_stop_polling(client, ihid);
if (ihid->bufsize)
i2c_hid_free_buffers(ihid);
@@ -1181,7 +1311,7 @@ static void i2c_hid_shutdown(struct i2c_client *client)
struct i2c_hid *ihid = i2c_get_clientdata(client);
i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
- free_irq(client->irq, ihid);
+ free_irq_or_stop_polling(client, ihid);
i2c_hid_acpi_shutdown(&client->dev);
}
@@ -1204,15 +1334,16 @@ static int i2c_hid_suspend(struct device *dev)
/* Save some power */
i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
- disable_irq(client->irq);
+ if (polling_mode == I2C_HID_POLLING_DISABLED)
+ disable_irq(client->irq);
- if (device_may_wakeup(&client->dev)) {
+ if (device_may_wakeup(&client->dev) && polling_mode ==
I2C_HID_POLLING_DISABLED) {
wake_status = enable_irq_wake(client->irq);
if (!wake_status)
ihid->irq_wake_enabled = true;
else
hid_warn(hid, "Failed to enable irq wake: %d\n",
- wake_status);
+ wake_status);
} else {
regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies),
ihid->pdata.supplies);
@@ -1229,7 +1360,7 @@ static int i2c_hid_resume(struct device *dev)
struct hid_device *hid = ihid->hid;
int wake_status;
- if (!device_may_wakeup(&client->dev)) {
+ if (!device_may_wakeup(&client->dev) || polling_mode !=
I2C_HID_POLLING_DISABLED) {
ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies),
ihid->pdata.supplies);
if (ret)
@@ -1246,7 +1377,8 @@ static int i2c_hid_resume(struct device *dev)
wake_status);
}
- enable_irq(client->irq);
+ if (polling_mode == I2C_HID_POLLING_DISABLED)
+ enable_irq(client->irq);
/* Instead of resetting device, simply powers the device on. This
* solves "incomplete reports" on Raydium devices 2386:3118 and
--
2.29.2
