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>
Acked-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
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
v4:
* use devm_regulator_get() (with a 'dummy' regulator for most cases)
instead of _optional() version, to make code less conditional (Dmitry)
* fix but where 'init_delay_ms' wasn't getting assigned properly
* disable regulator in probe() failure path
v5:
* rebase
* use 'post-power-on-delay-ms' name
---
drivers/hid/i2c-hid/i2c-hid.c | 42 ++++++++++++++++++++++++++++++++++++++++--
include/linux/i2c/i2c-hid.h | 6 ++++++
2 files changed, 46 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index ea3c3546cef7..a3f6daf0886b 100644
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -994,6 +994,11 @@ static int i2c_hid_of_probe(struct i2c_client *client,
}
pdata->hid_descriptor_address = val;
+ ret = of_property_read_u32(dev->of_node, "post-power-on-delay-ms",
+ &val);
+ if (!ret)
+ pdata->post_power_delay_ms = val;
+
return 0;
}
@@ -1053,6 +1058,24 @@ static int i2c_hid_probe(struct i2c_client *client,
ihid->pdata = *platform_data;
}
+ ihid->pdata.supply = devm_regulator_get(&client->dev, "vdd");
+ if (IS_ERR(ihid->pdata.supply)) {
+ ret = PTR_ERR(ihid->pdata.supply);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&client->dev, "Failed to get regulator: %d\n",
+ ret);
+ return ret;
+ }
+
+ ret = regulator_enable(ihid->pdata.supply);
+ if (ret < 0) {
+ dev_err(&client->dev, "Failed to enable regulator: %d\n",
+ ret);
+ goto err;
+ }
+ if (ihid->pdata.post_power_delay_ms)
+ msleep(ihid->pdata.post_power_delay_ms);
+
i2c_set_clientdata(client, ihid);
ihid->client = client;
@@ -1068,7 +1091,7 @@ static int i2c_hid_probe(struct i2c_client *client,
* real computation later. */
ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
if (ret < 0)
- goto err;
+ goto err_regulator;
pm_runtime_get_noresume(&client->dev);
pm_runtime_set_active(&client->dev);
@@ -1125,6 +1148,9 @@ static int i2c_hid_probe(struct i2c_client *client,
pm_runtime_put_noidle(&client->dev);
pm_runtime_disable(&client->dev);
+err_regulator:
+ regulator_disable(ihid->pdata.supply);
+
err:
i2c_hid_free_buffers(ihid);
kfree(ihid);
@@ -1149,6 +1175,8 @@ static int i2c_hid_remove(struct i2c_client *client)
if (ihid->bufsize)
i2c_hid_free_buffers(ihid);
+ regulator_disable(ihid->pdata.supply);
+
kfree(ihid);
return 0;
@@ -1199,6 +1227,10 @@ static int i2c_hid_suspend(struct device *dev)
else
hid_warn(hid, "Failed to enable irq wake: %d\n",
wake_status);
+ } else {
+ ret = regulator_disable(ihid->pdata.supply);
+ if (ret < 0)
+ hid_warn(hid, "Failed to disable supply: %d\n", ret);
}
return 0;
@@ -1212,7 +1244,13 @@ 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)) {
+ ret = regulator_enable(ihid->pdata.supply);
+ if (ret < 0)
+ hid_warn(hid, "Failed to enable supply: %d\n", ret);
+ if (ihid->pdata.post_power_delay_ms)
+ msleep(ihid->pdata.post_power_delay_ms);
+ } else if (ihid->irq_wake_enabled) {
wake_status = disable_irq_wake(client->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..1fb088239d12 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.
+ * @post_power_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 post_power_delay_ms;
};
#endif /* __LINUX_I2C_HID_H */
--
2.11.0.483.g087da7b7c-goog
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