On 6 June 2013 23:30, Christian Ruppert <christian.ruppert@xxxxxxxxxx> wrote:
> On Thu, Jun 06, 2013 at 10:32:21PM +0800, Haojian Zhuang wrote:
>> On 6 June 2013 22:11, Christian Ruppert <christian.ruppert@xxxxxxxxxx> wrote:
>> > On Wed, Jun 05, 2013 at 09:44:27AM +0800, Haojian Zhuang wrote:
>> >> On 3 June 2013 20:30, Christian Ruppert <christian.ruppert@xxxxxxxxxx> wrote:
>> >> > OK, here's a simplified example of what we would like to do (this seems
>> >> > pretty common so I suppose there is a way I haven't understood). Our
>> >> > situation is slightly more complex but for the purpose of discussion
>> >> > let's assume a chip with 8 pins which can be configured for the
>> >> > following functions:
>> >> >
>> >> > Pin GPIO-A I2C SPI0 SPI1
>> >> > ------------------------------------
>> >> > 1 GPIOA0 SDA MISO1
>> >> > 2 GPIOA1 SCL MOSI1
>> >> > 3 GPIOA2 SS1_B
>> >> > 4 GPIOA3 SCLK1
>> >> > 5 GPIOA4 MISO0
>> >> > 6 GPIOA5 MOSI0
>> >> > 7 GPIOA6 SS0_B
>> >> > 8 GPIOA7 SCLK0
>> >> >
>> >> > We can now define the following pinctrl-single:
>> >> >
>> >> > pinmux: pinmux@0xFFEE0000 {
>> >> > compatible = "pinctrl-single";
>> >> > reg = <0xFFEE0000 0x8>;
>> >> > #address-cells = <1>;
>> >> > #size-cells = <0>;
>> >> > #gpio-range-cells = <3>;
>> >> > pinctrl-single,register-width = <32>;
>> >> > pinctrl-single,function-mask = <0xffffffff>;
>> >> > pinctrl-single,gpio-range = <&range 1 8 0>;
>> >> > gpioa_pins: pinmux_gpioa_pins {
>> >> > pinctrl-single,pins = <0x0 0 0x4 0>
>> >> > };
>> >> > i2c_pins: pinmux_i2c_pins {
>> >> > pinctrl-single,pins = <0x0 1>
>> >> > };
>> >> > spi0_pins: pinmux_spi0_pins {
>> >> > pinctrl-single,pins = <0x1 1>
>> >> <0x1 1>?
>> >>
>> >> If each pinmux register is only for one pin in your SoC.
>> >> I think that your definitions are wrong above. We use
>> >> register offset as the first argument, not pin number.
>> >> And the second argument should be pin function number.
>> >
>> > In our case each pinmux register (bit field) actually controls an entire
>> > group of pins.
>> >
>> >> If multiple pins are sharing one register with different bits,
>> >> you need to enable "pinctrl-single,bit-per-mux".
>> >
>> > Multiple pins are sharing the same bits in the same register. Do you
>> > think this prevents us from using pinctrl-single?
>> >
>> Could you give me your register definition? Then I can understand you
>> better.
>
> In our example, the register map would look a bit like the following.
> Note that every register configures four pins at a time.
>
> Register 0x0:
> Mode GPIO-A I2C SPI1
> Value 0x0 0x1 0x2
> ---------------------------
> Pin1 GPIOA0 SDA MISO1
> Pin2 GPIOA1 SCL MOSI1
> Pin3 GPIOA2 SS1_B
> Pin4 GPIOA3 SCLK1
>
> Register 0x4:
> Mode GPIO-A SPI0
> Value 0x0 0x1
> ---------------------
> Pin5 GPIOA4 MISO0
> Pin6 GPIOA5 MOSI0
> Pin7 GPIOA6 SS0_B
> Pin8 GPIOA7 SCLK0
>
You said "Multiple pins are sharing the same bits in the same register.".
I need to understand which bits you're talking about in your register.
Regards
Haojian
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