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* [PATCH v4] ARM: dts: am335x-pocketbeagle: set default mux for gpio pins
@ 2020-07-12 10:37 Drew Fustini
  2020-07-13 18:10 ` Tony Lindgren
  0 siblings, 1 reply; 2+ messages in thread
From: Drew Fustini @ 2020-07-12 10:37 UTC (permalink / raw)
  To: Tony Lindgren, Rob Herring, bcousson, Linus Walleij,
	Jason Kridner, Robert Nelson, linux-omap, devicetree,
	linux-kernel
  Cc: Drew Fustini

These pins on the PocketBeagle P1 and P2 headers are connected to AM3358
balls with gpio lines, and these pins are not used for any other
peripherals by default. These GPIO lines are unclaimed and could be used
by userspace program through the gpiod ABI.

This patch adds a "default" state in the am33xx_pinmux node and sets the
mux for those pins to gpio (mode 7) and input enable.

The "pinctrl-single,bias-pullup" and "pinctrl-single,bias-pulldown"
pinconf properties are also set for each pin per the ball reset state in
section 4.2 of the datasheet [0].

This is the AM335x pin control register format in Table 9-60 [1]:

 bit     attribute      value
----------------------------------
31-7     reserved       0 on reset
   6     slew           { 0: fast, 1: slow }
   5     rx_active      { 0: rx disable, 1: rx enabled }
   4     pu_typesel     { 0: pulldown select, 1: pullup select }
   3     puden          { 0: pud enable, 1: disabled }
   2     mode           3 bits to selec mode 0 to 7
   1     mode
   0     mode

The values for the bias pinconf properties are derived as follows:

pinctrl-single,bias-pullup   = <[input] [enabled] [disable] [mask]>;
pinctrl-single,bias-pullup   = <  0x10      0x10      0x10   0x18 >;

          2^5    2^4    2^3    2^2    2^1    2^0  |
         0x20   0x10   0x08   0x04   0x02   0x01  |
--------------------------------------------------|
input       x      1      0     x      x      x   | 0x10
enabled     x      1      0     x      x      x   | 0x10
disabled    x      0      0     x      x      x   | 0x00
mask        x      1      1     x      x      x   | 0x18

pinctrl-single,bias-pulldown = <[input] [enabled] [disable] [mask]>;
pinctrl-single,bias-pulldown = <   0x0       0x0      0x10   0x18 >;

          2^5    2^4    2^3    2^2    2^1    2^0  |
         0x20   0x10   0x08   0x04   0x02   0x01  |
--------------------------------------------------|
input       x      0      0     x      x      x   | 0x00
enabled     x      0      0     x      x      x   | 0x00
disabled    x      1      0     x      x      x   | 0x10
mask        x      1      1     x      x      x   | 0x18

[0] http://www.ti.com/lit/ds/symlink/am3358.pdf
[1] https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf

Signed-off-by: Drew Fustini <drew@beagleboard.org>
---
v4 changes:
- patch on top of tony's omap-for-v5.9/dt as there is already
  e14d2c766392 ("ARM: dts: am335x-pocketbeagle: add gpio-line-names")

- correct values for input and disable in pinctrl-single,bias-pullup
  and pinctrl-single,bias-pulldown

v3 changes:
- add pinconf bias properties as it is necessary for pcs_pinconf_set()
  to find the requested bias parameter in the PIN_MAP_TYPE_CONFIGS_GROUP
  pinctrl map.

v2 changes:
- change default mux from output to input.  Input is safer as it does
  not drive the line.  If the user wants output, they will need to edit
  this device tree.

 arch/arm/boot/dts/am335x-pocketbeagle.dts | 125 ++++++++++++++++++++++
 1 file changed, 125 insertions(+)

diff --git a/arch/arm/boot/dts/am335x-pocketbeagle.dts b/arch/arm/boot/dts/am335x-pocketbeagle.dts
index e08b5f73ccb5..e083ea36184d 100644
--- a/arch/arm/boot/dts/am335x-pocketbeagle.dts
+++ b/arch/arm/boot/dts/am335x-pocketbeagle.dts
@@ -204,6 +204,131 @@ &gpio3 {
 };
 
 &am33xx_pinmux {
+
+	pinctrl-names = "default";
+
+	pinctrl-0 =   < &P2_03_gpio &P1_34_gpio &P2_19_gpio &P2_24_gpio
+			&P2_33_gpio &P2_22_gpio &P2_18_gpio &P2_10_gpio
+			&P2_06_gpio &P2_04_gpio &P2_02_gpio &P2_08_gpio
+			&P2_17_gpio >;
+
+	/* P2_03 (ZCZ ball T10) gpio0_23 0x824 PIN 9 */
+	P2_03_gpio: pinmux_P2_03_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_AD9, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P1_34 (ZCZ ball T11) gpio0_26 0x828 PIN 10 */
+	P1_34_gpio: pinmux_P1_34_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_AD10, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_19 (ZCZ ball U12) gpio0_27 0x82c PIN 11 */
+	P2_19_gpio: pinmux_P2_19_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_AD11, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_24 (ZCZ ball T12) gpio1_12 0x830 PIN 12 */
+	P2_24_gpio: pinmux_P2_24_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_AD12, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_33 (ZCZ ball R12) gpio1_13 0x834 PIN 13 */
+	P2_33_gpio: pinmux_P2_33_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_AD13, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_22 (ZCZ ball V13) gpio1_14 0x838 PIN 14 */
+	P2_22_gpio: pinmux_P2_22_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_AD14, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_18 (ZCZ ball U13) gpio1_15 0x83c PIN 15 */
+	P2_18_gpio: pinmux_P2_18_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_AD15, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_10 (ZCZ ball R14) gpio1_20 0x850 PIN 20 */
+	P2_10_gpio: pinmux_P2_10_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_A4, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_06 (ZCZ ball U16) gpio1_25 0x864 PIN 25 */
+	P2_06_gpio: pinmux_P2_06_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_A9, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_04 (ZCZ ball T16) gpio1_26 0x868 PIN 26 */
+	P2_04_gpio: pinmux_P2_04_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_A10, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_02 (ZCZ ball V17) gpio1_27 0x86c PIN 27 */
+	P2_02_gpio: pinmux_P2_02_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_A11, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
+	/* P2_08 (ZCZ ball U18) gpio1_28 0x878 PIN 30 */
+	P2_08_gpio: pinmux_P2_08_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_BEN1, PIN_INPUT_PULLDOWN, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x00  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x00  0x00  0x10  0x18>;
+	};
+
+	/* P2_17 (ZCZ ball V12) gpio2_1 0x88c PIN 35 */
+	P2_17_gpio: pinmux_P2_17_gpio {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_GPMC_CLK, PIN_INPUT_PULLUP, MUX_MODE7)
+		>;
+		pinctrl-single,bias-pullup   =   < 0x10  0x10  0x00  0x18>;
+		pinctrl-single,bias-pulldown   = < 0x10  0x00  0x10  0x18>;
+	};
+
 	i2c2_pins: pinmux-i2c2-pins {
 		pinctrl-single,pins = <
 			AM33XX_PADCONF(AM335X_PIN_UART1_RTSN, PIN_INPUT_PULLUP, MUX_MODE3)	/* (D17) uart1_rtsn.I2C2_SCL */
-- 
2.25.1


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH v4] ARM: dts: am335x-pocketbeagle: set default mux for gpio pins
  2020-07-12 10:37 [PATCH v4] ARM: dts: am335x-pocketbeagle: set default mux for gpio pins Drew Fustini
@ 2020-07-13 18:10 ` Tony Lindgren
  0 siblings, 0 replies; 2+ messages in thread
From: Tony Lindgren @ 2020-07-13 18:10 UTC (permalink / raw)
  To: Drew Fustini
  Cc: Rob Herring, bcousson, Linus Walleij, Jason Kridner,
	Robert Nelson, linux-omap, devicetree, linux-kernel

* Drew Fustini <drew@beagleboard.org> [200712 03:40]:
> These pins on the PocketBeagle P1 and P2 headers are connected to AM3358
> balls with gpio lines, and these pins are not used for any other
> peripherals by default. These GPIO lines are unclaimed and could be used
> by userspace program through the gpiod ABI.
> 
> This patch adds a "default" state in the am33xx_pinmux node and sets the
> mux for those pins to gpio (mode 7) and input enable.

Thanks applying into omap-for-v5.9/dt.

Tony

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2020-07-12 10:37 [PATCH v4] ARM: dts: am335x-pocketbeagle: set default mux for gpio pins Drew Fustini
2020-07-13 18:10 ` Tony Lindgren

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