We need to power on the digitizer before using it, and it's also nice to save power in suspend by disabling it. Support an optional "vdd-supply" and wire it up for the new Wacom device.
Wacom recommended waiting up to 100ms after powering on before trying to access this device. Signed-off-by: Brian Norris <[email protected]> Signed-off-by: Caesar Wang <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: [email protected] --- v1 was a few months back. I finally got around to rewriting it based on DT binding feedback. 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 Documentation/devicetree/bindings/input/hid-over-i2c.txt | 6 +++++- drivers/hid/i2c-hid/i2c-hid.c | 70 ++++++++++++++++++++++++++++++++++++++++++- include/linux/i2c/i2c-hid.h | 6 ++++ 2 files changed, 75 insertions(+), 1 deletion(-) diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c index b3ec4f2de875..1bc174f3a788 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> @@ -918,10 +920,25 @@ static inline int i2c_hid_acpi_pdata(struct i2c_client *client, #endif #ifdef CONFIG_OF + +/* of_device_id match data */ +struct i2c_hid_of_data { + /* Name of supply regulator. */ + const char *supply_name; + /* Delay required after powering on device before it is usable. */ + int init_delay_ms; +}; + +static const struct i2c_hid_of_data wacom_w9013_data = { + .supply_name = "vdd", + .init_delay_ms = 100, +}; + static int i2c_hid_of_probe(struct i2c_client *client, struct i2c_hid_platform_data *pdata) { struct device *dev = &client->dev; + const struct i2c_hid_of_data *data = of_device_get_match_data(dev); u32 val; int ret; @@ -937,10 +954,33 @@ static int i2c_hid_of_probe(struct i2c_client *client, } pdata->hid_descriptor_address = val; + if (data) { + pdata->init_delay_ms = data->init_delay_ms; + if (data->supply_name) { + pdata->supply = devm_regulator_get_optional(&client->dev, + data->supply_name); + 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 %s regulator: %d\n", + data->supply_name, ret); + return ret; + } + } + } + return 0; } static const struct of_device_id i2c_hid_of_match[] = { + { + .compatible = "wacom,w9013", + .data = &wacom_w9013_data, + }, { .compatible = "hid-over-i2c" }, {}, }; @@ -983,6 +1023,17 @@ 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 +1151,9 @@ 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 +1206,11 @@ 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 +1224,16 @@ 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
