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Date: Thu, 1 Dec 2016 16:37:37 -0800
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Brian Norris <briannorris@...omium.org>
Cc: Jiri Kosina <jikos@...nel.org>,
Benjamin Tissoires <benjamin.tissoires@...hat.com>,
Caesar Wang <wxt@...k-chips.com>,
linux-rockchip@...ts.infradead.org,
Rob Herring <robh+dt@...nel.org>, linux-input@...r.kernel.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
Mark Rutland <mark.rutland@....com>,
Doug Anderson <dianders@...omium.org>
Subject: Re: [PATCH v3 2/2] HID: i2c-hid: support regulator power on/off
On Thu, Dec 01, 2016 at 04:31:10PM -0800, Brian Norris wrote:
> 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@...omium.org>
> Signed-off-by: Caesar Wang <wxt@...k-chips.com>
> Cc: Jiri Kosina <jikos@...nel.org>
> Cc: linux-input@...r.kernel.org
> ---
> 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");
Make it devm_regulator_get(), it's cleaner (you'll get a dummy regulator
that you can enable/disbale and not check if it is null or not).
pdata->supply = devm_regulator_get_optional(dev, "vdd");
if (IS_ERR(pdata->supply)) {
ret = PTR_ERR(pdata->supply);
if (ret != -EPROBE_DEFER)
dev_err(...);
return ret;
}
Thanks.
> + 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
>
--
Dmitry
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