On Nov 30 2016 or thereabouts, Brian Norris wrote: > 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 <briannorris@xxxxxxxxxxxx> > Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx> > Cc: Jiri Kosina <jikos@xxxxxxxxxx> > Cc: linux-input@xxxxxxxxxxxxxxx > --- > 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 = { Why is the struct "wacom" specific? If the vdd line is required, I don't see why there is a need to specify that this is a Wacom specifics. Then Elan, SYnaptics will want the same and we won't be able to to follow. > + .supply_name = "vdd", > + .init_delay_ms = 100, If the purpose of this declaration is to set the delay, why isn't this something provided by the device tree? > +}; > + > 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, > + }, NACK, see 1/2 I don't really like the v2. IMO, v1 was less intrusive (though it was missing the init_delay_ms). I believe it's possible to have a generic device tree description which doesn't require us to adapt the driver for each and every device. Cheers, Benjamin > { .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 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html