From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Norris Subject: Re: [PATCH v3 2/2] HID: i2c-hid: support regulator power on/off Date: Thu, 1 Dec 2016 18:43:00 -0800 Message-ID: <20161202024259.GA39759@google.com> References: <1480638670-111492-1-git-send-email-briannorris@chromium.org> <1480638670-111492-2-git-send-email-briannorris@chromium.org> <20161202003737.GA24901@dtor-ws> <20161202004214.GA112550@google.com> <20161202011615.GB24901@dtor-ws> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20161202011615.GB24901@dtor-ws> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+glpar-linux-rockchip=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Dmitry Torokhov Cc: Mark Rutland , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jiri Kosina , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Rob Herring , Doug Anderson , linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Benjamin Tissoires , linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Caesar Wang List-Id: devicetree@vger.kernel.org On Thu, Dec 01, 2016 at 05:16:15PM -0800, Dmitry Torokhov wrote: > On Thu, Dec 01, 2016 at 04:42:15PM -0800, Brian Norris wrote: > > On Thu, Dec 01, 2016 at 04:37:37PM -0800, Dmitry Torokhov wrote: > > > 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 > > > > Signed-off-by: Caesar Wang > > > > Cc: Jiri Kosina > > > > Cc: linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.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 ... > > > > @@ -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; > > > } > > > > I had it as devm_regulator_get() in v1, but at that time, I was faking > > the firmware init delay using a regulator property. Now that I want to > > delay in this driver after enabling the regulator, I'd like to know the > > difference between a dummy and a real regulator. There's no need to wait > > after messing with the dummy regulator. > > If there is no regulator in ACPI/DT there would not be "init-delay-ms" > property either. I suppose that's a fair assumption... the difference being that you assumed it, and I enforced it :) Anyway, I can respin without the _optional(). I'll wait at least a day or so, as the DT binding could use some review (it's the more controversial piece). Brian