On some boards, we need to enable a regulator before using the HID, and
it's also nice to save power in suspend by disabling it. Support an
optional "vdd-supply" and a companion initialization delay.
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>
Cc: Jiri Kosina <jikos@xxxxxxxxxx>
Cc: linux-input@xxxxxxxxxxxxxxx
---
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
v3:
* drop Wacom specifics and allow this to be used generically
* add "init-delay-ms" property support
drivers/hid/i2c-hid/i2c-hid.c | 48 ++++++++++++++++++++++++++++++++++++++++++-
include/linux/i2c/i2c-hid.h | 6 ++++++
2 files changed, 53 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index b3ec4f2de875..4cb523133d13 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>
@@ -937,6 +939,22 @@ static int i2c_hid_of_probe(struct i2c_client *client,
}
pdata->hid_descriptor_address = val;
+ ret = of_property_read_u32(dev->of_node, "init-delay-ms", &val);
+ if (!ret)
+ pdata->init_delay_ms = ret;
+
+ pdata->supply = devm_regulator_get_optional(dev, "vdd");
+ 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 regulator: %d\n", ret);
+ return ret;
+ }
+
return 0;
}
@@ -983,6 +1001,17 @@ 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 +1129,9 @@ 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 +1184,11 @@ 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 +1202,16 @@ 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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