From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Cherian Subject: Re: [PATCH 2/2] extcon: gpio: Add dt support for the driver. Date: Thu, 19 Jun 2014 09:00:27 +0530 Message-ID: <53A25953.9030107@ti.com> References: <1402977500-19987-1-git-send-email-george.cherian@ti.com> <1402977500-19987-3-git-send-email-george.cherian@ti.com> <20140617155719.GC8930@leverpostej> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140617155719.GC8930@leverpostej> Sender: linux-doc-owner@vger.kernel.org To: Mark Rutland Cc: "cw00.choi@samsung.com" , "myungjoo.ham@samsung.com" , "grant.likely@linaro.org" , "rdunlap@infradead.org" , "galak@codeaurora.org" , "ijc+devicetree@hellion.org.uk" , "robh+dt@kernel.org" , Pawel Moll , "linux@roeck-us.net" , "linux-kernel@vger.kernel.org" , "linux-doc@vger.kernel.org" , "devicetree@vger.kernel.org" List-Id: devicetree@vger.kernel.org On 6/17/2014 9:27 PM, Mark Rutland wrote: > On Tue, Jun 17, 2014 at 04:58:20AM +0100, George Cherian wrote: >> Add device tree support to extcon-gpio driver. >> Add devicetree binding documentation >> >> Signed-off-by: George Cherian >> --- >> .../devicetree/bindings/extcon/extcon-gpio.txt | 34 ++++++++++++++++++++++ >> drivers/extcon/extcon-gpio.c | 29 ++++++++++++++++++ >> 2 files changed, 63 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/extcon/extcon-gpio.txt >> >> diff --git a/Documentation/devicetree/bindings/extcon/extcon-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt >> new file mode 100644 >> index 0000000..80b791b >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt >> @@ -0,0 +1,34 @@ >> +GPIO based EXTCON >> + >> +EXTCON GPIO >> +----------- >> + >> +Required Properties: >> + - compatible: should be: >> + * "ti,extcon-gpio" >> + - gpios: specifies the gpio pin used. >> + - debounce: Debounce time for GPIO IRQ in ms >> + - irq-flags: IRQ flag to be used ( eg: IRQ_TYPE_EDGE_FALLING) > This looks distinctly odd. Why do you need this here? The driver takes this as part of platform data. It never continues operation if an invalid irq-flag is supplied. Also these can be used for different SoC's whose GPIO's might support IRQ_TYPE_EDGE_FALLING/RISING. Now since this is based on gpio we cant up front give a seperate "interrupts = " property, since we dont know the gpio-pin irq number. Chanwoo any comments? > >> +Optional Properties: >> + - gpio-active-low: Property describing whether gpio active state is 1 or 0 >> + If defined , low state of gpio means active. > Surely this is defined in the gpio flags? Yes, I will make necessary changes. > >> + - check-on-resume: Property describing whether to check the gpio state >> + while resuming from SLEEP. > Does this need to be in DT? Surely we could jsut always check this? okay. For my use-case I dont need this. Chanwoo, any comments? >> + - state-on: print_state is overriden with state_on string if provided. >> + If NULL, default method of extcon class is used. >> + - state_off: print_state is overriden with state_off string if provided. >> + If NUll, default method of extcon class is used. > This means nothing from a HW perspective. This describes linux internal > details. You mean to say this should not be part of dt? > [...] > >> + of_property_read_u32(np, "debounce", (u32 *)&pdata->debounce); >> + of_property_read_u32(np, "irq-flags", (u32 *)&pdata->irq_flags); > If you need theses casts, the code is broken. I dont need this, will remove in v2. > > These functions can only read into a u32. If you pass a smaller type > you'll trash aribtrary memory locations, and if you pass a larger type > this is broken for BE. true. > Mark. -- -George