HID: i2c-hid: support regulator power on/off

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@chromium.org>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: linux-input@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index ea3c3546cef7f81f0f1c82b996c3ed5ab9fb26ed..a3f6daf0886b476dfa23eebf254da12e47a5853e 100644 (file)
--- 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 @@ err_pm:
        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 7aa901d920585949b2ecf6c546d65cb004daceea..1fb088239d12b9f4a5a849a2ce662343743c8bd9 100644 (file)
--- 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 */