We need to power on the digitizer before using it, and it's also nice to
save power in suspend by disabling it. Support an optional "vdd-supply"
and wire it up for the new Wacom device.
Wacom recommended waiting up to 100ms after powering on before trying to
access this device.
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>
Cc: Jiri Kosina <jikos@xxxxxxxxxx>
Cc: linux-input@xxxxxxxxxxxxxxx
---
v1 was a few months back. I finally got around to rewriting it based on
DT binding feedback.
v2:
* support compatible property for wacom, with specific "vdd-supply" name
* support the 100ms delay needed for this digitizer
* target regulator support only at specific device
Documentation/devicetree/bindings/input/hid-over-i2c.txt | 6 +++++-
drivers/hid/i2c-hid/i2c-hid.c | 70 ++++++++++++++++++++++++++++++++++++++++++-
include/linux/i2c/i2c-hid.h | 6 ++++
2 files changed, 75 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index b3ec4f2de875..1bc174f3a788 100644
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -37,7 +37,9 @@
#include <linux/mutex.h>
#include <linux/acpi.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
#include <linux/i2c/i2c-hid.h>
@@ -918,10 +920,25 @@ static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
#endif
#ifdef CONFIG_OF
+
+/* of_device_id match data */
+struct i2c_hid_of_data {
+ /* Name of supply regulator. */
+ const char *supply_name;
+ /* Delay required after powering on device before it is usable. */
+ int init_delay_ms;
+};
+
+static const struct i2c_hid_of_data wacom_w9013_data = {
+ .supply_name = "vdd",
+ .init_delay_ms = 100,
+};
+
static int i2c_hid_of_probe(struct i2c_client *client,
struct i2c_hid_platform_data *pdata)
{
struct device *dev = &client->dev;
+ const struct i2c_hid_of_data *data = of_device_get_match_data(dev);
u32 val;
int ret;
@@ -937,10 +954,33 @@ static int i2c_hid_of_probe(struct i2c_client *client,
}
pdata->hid_descriptor_address = val;
+ if (data) {
+ pdata->init_delay_ms = data->init_delay_ms;
+ if (data->supply_name) {
+ pdata->supply = devm_regulator_get_optional(&client->dev,
+ data->supply_name);
+ if (IS_ERR(pdata->supply)) {
+ ret = PTR_ERR(pdata->supply);
+ pdata->supply = NULL;
+ if (ret == -EPROBE_DEFER)
+ return ret;
+ if (ret == -ENODEV)
+ return 0;
+ dev_err(dev, "Failed to get %s regulator: %d\n",
+ data->supply_name, ret);
+ return ret;
+ }
+ }
+ }
+
return 0;
}
static const struct of_device_id i2c_hid_of_match[] = {
+ {
+ .compatible = "wacom,w9013",
+ .data = &wacom_w9013_data,
+ },
{ .compatible = "hid-over-i2c" },
{},
};
@@ -983,6 +1023,17 @@ static int i2c_hid_probe(struct i2c_client *client,
ihid->pdata = *platform_data;
}
+ if (ihid->pdata.supply) {
+ ret = regulator_enable(ihid->pdata.supply);
+ if (ret < 0) {
+ dev_err(&client->dev, "Failed to enable regulator: %d\n",
+ ret);
+ return ret;
+ }
+ if (ihid->pdata.init_delay_ms)
+ msleep(ihid->pdata.init_delay_ms);
+ }
+
if (client->irq > 0) {
ihid->irq = client->irq;
} else if (ACPI_COMPANION(&client->dev)) {
@@ -1100,6 +1151,9 @@ static int i2c_hid_remove(struct i2c_client *client)
if (ihid->desc)
gpiod_put(ihid->desc);
+ if (ihid->pdata.supply)
+ regulator_disable(ihid->pdata.supply);
+
kfree(ihid);
acpi_dev_remove_driver_gpios(ACPI_COMPANION(&client->dev));
@@ -1152,6 +1206,11 @@ static int i2c_hid_suspend(struct device *dev)
else
hid_warn(hid, "Failed to enable irq wake: %d\n",
wake_status);
+ } else if (ihid->pdata.supply) {
+ ret = regulator_disable(ihid->pdata.supply);
+ if (ret < 0)
+ hid_warn(hid, "Failed to disable supply: %d\n",
+ ret);
}
return 0;
@@ -1165,7 +1224,16 @@ static int i2c_hid_resume(struct device *dev)
struct hid_device *hid = ihid->hid;
int wake_status;
- if (device_may_wakeup(&client->dev) && ihid->irq_wake_enabled) {
+ if (!device_may_wakeup(&client->dev)) {
+ if (ihid->pdata.supply) {
+ ret = regulator_enable(ihid->pdata.supply);
+ if (ret < 0)
+ hid_warn(hid, "Failed to enable supply: %d\n",
+ ret);
+ if (ihid->pdata.init_delay_ms)
+ msleep(ihid->pdata.init_delay_ms);
+ }
+ } else if (ihid->irq_wake_enabled) {
wake_status = disable_irq_wake(ihid->irq);
if (!wake_status)
ihid->irq_wake_enabled = false;
diff --git a/include/linux/i2c/i2c-hid.h b/include/linux/i2c/i2c-hid.h
index 7aa901d92058..97688cde4a91 100644
--- a/include/linux/i2c/i2c-hid.h
+++ b/include/linux/i2c/i2c-hid.h
@@ -14,9 +14,13 @@
#include <linux/types.h>
+struct regulator;
+
/**
* struct i2chid_platform_data - used by hid over i2c implementation.
* @hid_descriptor_address: i2c register where the HID descriptor is stored.
+ * @supply: regulator for powering on the device.
+ * @init_delay_ms: delay after powering on before device is usable.
*
* Note that it is the responsibility of the platform driver (or the acpi 5.0
* driver, or the flattened device tree) to setup the irq related to the gpio in
@@ -31,6 +35,8 @@
*/
struct i2c_hid_platform_data {
u16 hid_descriptor_address;
+ struct regulator *supply;
+ int init_delay_ms;
};
#endif /* __LINUX_I2C_HID_H */
--
2.8.0.rc3.226.g39d4020
--
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