From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.coquelin@st.com (Maxime Coquelin) Date: Wed, 18 Mar 2015 18:00:04 +0100 Subject: [STLinux Kernel] [PATCH 2/6] pinctrl: st: Introduce a 'get pin function' call In-Reply-To: <20150318165116.GR3318@x1> References: <1426675899-19882-1-git-send-email-lee.jones@linaro.org> <1426675899-19882-3-git-send-email-lee.jones@linaro.org> <5509AAAB.8090906@st.com> <20150318165116.GR3318@x1> Message-ID: <5509AF14.1060200@st.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/18/2015 05:51 PM, Lee Jones wrote: > On Wed, 18 Mar 2015, Maxime Coquelin wrote: > >> >> On 03/18/2015 11:51 AM, Lee Jones wrote: >>> This call fetches the numerical function value a specified pin is >>> currently operating in. Function zero is more often than not the >>> GPIO function. Greater than zero values represent an alternative >>> function. You'd need to either look those up in the Device Tree >>> sources or the Programmer's Manual. >>> >>> Signed-off-by: Lee Jones >>> --- >>> drivers/pinctrl/pinctrl-st.c | 14 ++++++++++++++ >>> 1 file changed, 14 insertions(+) >>> >>> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c >>> index 9e5ec00..5362e45 100644 >>> --- a/drivers/pinctrl/pinctrl-st.c >>> +++ b/drivers/pinctrl/pinctrl-st.c >>> @@ -460,6 +460,20 @@ static void st_pctl_set_function(struct st_pio_control *pc, >>> regmap_field_write(alt, val); >>> } >>> +static unsigned int st_pctl_get_pin_function(struct st_pio_control *pc, int pin) >>> +{ >>> + struct regmap_field *alt = pc->alt; >>> + unsigned int val; >>> + int offset = pin * 4; >>> + >>> + if (!alt) >>> + return 0; >> Shouldn't we print something if alt is NULL? >> Else we can think we are on alternate 0. > That is the assumption that I've made. Is there isn't an alt, then a > pin can only be on Alt-0. Have I made the incorrect assumption here? Just re-checked the code, and yes you are right. No alt here means alt field of struct st_pctl_data is -1, which in turn means the register is not available. You can forget my remark, and add my: Acked-by: Maxime Coquelin Thanks, Maxime