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Message-ID: <20171030165753.GA10752@google.com>
Date: Mon, 30 Oct 2017 09:57:55 -0700
From: Brian Norris <briannorris@...omium.org>
To: Lin Huang <hl@...k-chips.com>
Cc: dmitry.torokhov@...il.com, jikos@...nel.org,
benjamin.tissoires@...hat.com, jani.nikula@...el.com,
linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
devicetree@...r.kernel.org
Subject: Re: [PATCH] HID: i2c-hid: add reset gpio property
+ devicetree list
Hi,
On Mon, Oct 30, 2017 at 10:49:49AM +0800, Lin Huang wrote:
> some i2c hid devices have reset gpio, need to control
> it in the driver.
>
> Change-Id: I87bca954bffc7eb7b35711406f522cb3d0fc2ded
You should be removing these Gerrit ID lines from patches before sending
them to these mailing lists.
> Signed-off-by: Lin Huang <hl@...k-chips.com>
> ---
> drivers/hid/i2c-hid/i2c-hid.c | 63 +++++++++++++++++++++++++++--------
> include/linux/platform_data/i2c-hid.h | 4 +++
> 2 files changed, 53 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
> index 9145c21..a0e3a8e 100644
> --- a/drivers/hid/i2c-hid/i2c-hid.c
> +++ b/drivers/hid/i2c-hid/i2c-hid.c
> @@ -38,6 +38,7 @@
> #include <linux/mutex.h>
> #include <linux/acpi.h>
> #include <linux/of.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/regulator/consumer.h>
>
> #include <linux/platform_data/i2c-hid.h>
> @@ -793,6 +794,34 @@ struct hid_ll_driver i2c_hid_ll_driver = {
> };
> EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
>
> +static int i2c_hid_hw_power_on(struct i2c_hid *ihid)
> +{
> + int ret;
> +
> + ret = regulator_enable(ihid->pdata.supply);
> + if (ret < 0)
> + return ret;
> +
> + if (ihid->pdata.post_power_delay_ms)
> + msleep(ihid->pdata.post_power_delay_ms);
> +
> + gpiod_set_value_cansleep(ihid->pdata.reset_gpio, 1);
> + usleep_range(ihid->pdata.assert_reset_us,
> + ihid->pdata.assert_reset_us);
What's the point of using the same value on both ends of the range? Does
it make sense to give some padding to this? e.g., from X to X + 10% ?
(Note that reasonable values for this are on the order of a few
milliseconds.)
Also, the above msleep() has a 'if non-zero' condition on it...but
that's not actually necessary now that I look again, since msleep() and
usleep_range() both handle zero times OK... But it feels a little
inconsistent. We should probably change one or the other sometime.
> + gpiod_set_value_cansleep(ihid->pdata.reset_gpio, 0);
> + usleep_range(ihid->pdata.deassert_reset_us,
> + ihid->pdata.deassert_reset_us);
> +
> + return ret;
> +}
> +
> +static int i2c_hid_hw_power_off(struct i2c_hid *ihid)
> +{
> + gpiod_set_value_cansleep(ihid->pdata.reset_gpio, 1);
> +
> + return regulator_disable(ihid->pdata.supply);
> +}
> +
> static int i2c_hid_init_irq(struct i2c_client *client)
> {
> struct i2c_hid *ihid = i2c_get_clientdata(client);
> @@ -934,6 +963,12 @@ static int i2c_hid_of_probe(struct i2c_client *client,
> if (!ret)
> pdata->post_power_delay_ms = val;
>
> + ret = of_property_read_u32(dev->of_node, "assert-reset-us",
> + &pdata->assert_reset_us);
> +
> + ret = of_property_read_u32(dev->of_node, "deassert-reset-us",
> + &pdata->deassert_reset_us);
You need to document these.
Brian
> +
> return 0;
> }
>
> @@ -1002,14 +1037,16 @@ static int i2c_hid_probe(struct i2c_client *client,
> goto err;
> }
>
> - ret = regulator_enable(ihid->pdata.supply);
> + ihid->pdata.reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(ihid->pdata.reset_gpio))
> + goto err;
> +
> + ret = i2c_hid_hw_power_on(ihid);
> if (ret < 0) {
> - dev_err(&client->dev, "Failed to enable regulator: %d\n",
> - ret);
> + dev_err(&client->dev, "Failed to power on: %d\n", ret);
> goto err;
> }
> - if (ihid->pdata.post_power_delay_ms)
> - msleep(ihid->pdata.post_power_delay_ms);
>
> i2c_set_clientdata(client, ihid);
>
> @@ -1086,7 +1123,7 @@ static int i2c_hid_probe(struct i2c_client *client,
> pm_runtime_disable(&client->dev);
>
> err_regulator:
> - regulator_disable(ihid->pdata.supply);
> + i2c_hid_hw_power_off(ihid);
>
> err:
> i2c_hid_free_buffers(ihid);
> @@ -1112,8 +1149,7 @@ static int i2c_hid_remove(struct i2c_client *client)
> if (ihid->bufsize)
> i2c_hid_free_buffers(ihid);
>
> - regulator_disable(ihid->pdata.supply);
> -
> + i2c_hid_hw_power_off(ihid);
> kfree(ihid);
>
> return 0;
> @@ -1165,9 +1201,10 @@ static int i2c_hid_suspend(struct device *dev)
> hid_warn(hid, "Failed to enable irq wake: %d\n",
> wake_status);
> } else {
> - ret = regulator_disable(ihid->pdata.supply);
> + ret = i2c_hid_hw_power_off(ihid);
> if (ret < 0)
> - hid_warn(hid, "Failed to disable supply: %d\n", ret);
> + hid_warn(hid, "Failed to disable hw power: %d\n",
> + ret);
> }
>
> return 0;
> @@ -1182,11 +1219,9 @@ static int i2c_hid_resume(struct device *dev)
> int wake_status;
>
> if (!device_may_wakeup(&client->dev)) {
> - ret = regulator_enable(ihid->pdata.supply);
> + ret = i2c_hid_hw_power_on(ihid);
> 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);
> + hid_warn(hid, "Failed to enable hw power: %d\n", ret);
> } else if (ihid->irq_wake_enabled) {
> wake_status = disable_irq_wake(client->irq);
> if (!wake_status)
> diff --git a/include/linux/platform_data/i2c-hid.h b/include/linux/platform_data/i2c-hid.h
> index 1fb0882..3afc781 100644
> --- a/include/linux/platform_data/i2c-hid.h
> +++ b/include/linux/platform_data/i2c-hid.h
> @@ -14,6 +14,7 @@
>
> #include <linux/types.h>
>
> +struct gpio_desc;
> struct regulator;
>
> /**
> @@ -37,6 +38,9 @@ struct i2c_hid_platform_data {
> u16 hid_descriptor_address;
> struct regulator *supply;
> int post_power_delay_ms;
> + struct gpio_desc *reset_gpio;
> + int assert_reset_us;
> + int deassert_reset_us;
> };
>
> #endif /* __LINUX_I2C_HID_H */
> --
> 2.7.4
>
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