[pandaboard] Pandaboard ES Rev B3 - Using GPIO with DeviceTree

Discussion:

Anna-Lena Marx

2015-04-10 08:33:53 UTC

Hi,

I'm new with Pandaboard and running a Pandaboard ES Rev B3 with a Linaro
Linux, Kernel 3.19 and Device Tree.
And there's my problem:
I has to use the GPIOs of the Expansion Headers on the Board, but I don't
understand at witch points I has to change the Device Tree files to enable
pinmuxing at these pins. I'm know which addresses and offsets for which pin
I need to add, but not which files should be edited in which way. I tryed
alone for a few days, but no success.

Can anyone may help me to understand how device tree works at pandaboard
and get GPIOs working?

Regards,
Anna

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m***@gmail.com

2015-04-10 13:48:10 UTC

Permalink

On Fri, Apr 10, 2015 at 3:33 AM, Anna-Lena Marx

Post by Anna-Lena Marx
Hi,
I'm new with Pandaboard and running a Pandaboard ES Rev B3 with a Linaro
Linux, Kernel 3.19 and Device Tree.
I has to use the GPIOs of the Expansion Headers on the Board, but I don't
understand at witch points I has to change the Device Tree files to enable
pinmuxing at these pins. I'm know which addresses and offsets for which pin
I need to add, but not which files should be edited in which way. I tryed
alone for a few days, but no success.
Can anyone may help me to understand how device tree works at pandaboard and
get GPIOs working?

Base address is here:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/omap4.dtsi#n176
if the pin belongs to core domain pins, 0x4a100040 , wakeup domain
pins start at 0x4a31e040
then you add to
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/omap4-panda-common.dtsi#n190
if core domain
Without looking at exact pin, lets use an example of 0xdead offset..

my_pins: pinmux_my_pins {
pinctrl-single,pins = <
0xdead (PIN_INPUT | MUX_MODE4) /* mux0.gpio5_4 */

Post by Anna-Lena Marx
;

};
--
Regards,
Nishanth Menon

Anna-Lena Marx

2015-04-13 10:35:32 UTC

Permalink

Thank you very much for your help, my changes seem to work.

Regards,
Anna-Lena Marx

Post by m***@gmail.com
On Fri, Apr 10, 2015 at 3:33 AM, Anna-Lena Marx

don't

Post by Anna-Lena Marx
understand at witch points I has to change the Device Tree files to

enable

Post by Anna-Lena Marx
pinmuxing at these pins. I'm know which addresses and offsets for which

Post by Anna-Lena Marx
I need to add, but not which files should be edited in which way. I

tryed

Post by Anna-Lena Marx
alone for a few days, but no success.
Can anyone may help me to understand how device tree works at pandaboard

and

Post by Anna-Lena Marx
get GPIOs working?

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/omap4.dtsi#n176
if the pin belongs to core domain pins, 0x4a100040 , wakeup domain
pins start at 0x4a31e040
then you add to
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/omap4-panda-common.dtsi#n190
if core domain
Without looking at exact pin, lets use an example of 0xdead offset..
my_pins: pinmux_my_pins {
pinctrl-single,pins = <
0xdead (PIN_INPUT | MUX_MODE4) /* mux0.gpio5_4 */

Post by Anna-Lena Marx
;

};
--
Regards,
Nishanth Menon

Anna-Lena Marx

2015-04-24 14:06:23 UTC

Permalink

Hi,
I hope you can help me once more. After getting basic GPIO functionality
working I need some interrupts on them.
I add this for get the GPIOs working:

&omap4_pmx_core {
pinctrl-names = "default";
pinctrl-0 = <
&dss_dpi_pins
&tfp410_pins
&dss_hdmi_pins
&tpd12s015_pins
&hsusbb1_pins

Post by Anna-Lena Marx
;

j3_gpios: pinmux_j3_gpios{
pinctrl-single,pins =<
0x1e (PIN_OUTPUT | MUX_MODE3) /* gpio_39 */

// 0xee (PIN_OUTPUT | MUX_MODE3) /*
i2c4_scl.gpio_132 used as i2c4 */
// 0xf0 (PIN_OUTPUT | MUX_MODE3) /*
i2c4_sda.gpio_133 used as i2c4 */

0xf2 (PIN_OUTPUT | MUX_MODE3) /* gpio_134 */
0xf4 (PIN_OUTPUT | MUX_MODE3) /* gpio_135 */
0xf6 (PIN_OUTPUT | MUX_MODE3) /* gpio_136 */
0xf8 (PIN_OUTPUT | MUX_MODE3) /* gpio_137 */
0xfa (PIN_OUTPUT | MUX_MODE3) /* gpio_138 */
0xfc (PIN_OUTPUT | MUX_MODE3) /* gpio_139 */
0xfe (PIN_OUTPUT | MUX_MODE3) /* gpio_140 */

0x11c (PIN_OUTPUT | MUX_MODE3) /* gpio_155 */
0x11e (PIN_OUTPUT | MUX_MODE3) /* gpio_156 */

Post by Anna-Lena Marx
;

};

j6_gpios: pinmux_j6_gpios{
pinctrl-single,pins = <
0x10 (PIN_OUTPUT | MUX_MODE3) /* gpio_32 */
0x12 (PIN_OUTPUT | MUX_MODE3) /* gpio_33 */
0x14 (PIN_OUTPUT | MUX_MODE3) /* gpio_34 */
0x16 (PIN_OUTPUT | MUX_MODE3) /* gpio_35 */
0x18 (PIN_OUTPUT | MUX_MODE3) /* gpio_36 */
0x1a (PIN_OUTPUT | MUX_MODE3) /* gpio_37 */
0x1c (PIN_OUTPUT | MUX_MODE3) /* gpio_38 */

0x34 (PIN_OUTPUT | MUX_MODE3) /* gpio_50 */
0x36 (PIN_OUTPUT | MUX_MODE3) /* gpio_51 */
0x3c (PIN_OUTPUT | MUX_MODE3) /* gpio_54 */
0x3e (PIN_OUTPUT | MUX_MODE3) /* gpio_55 */
0x40 (PIN_OUTPUT | MUX_MODE3) /* gpio_56 */
0x46 (PIN_OUTPUT | MUX_MODE3) /* gpio_59 */
0x4a (PIN_OUTPUT | MUX_MODE3) /* gpio_61 */

0xD4 (PIN_OUTPUT | MUX_MODE3) /* gpio_121 */

Post by Anna-Lena Marx
;

};

I need an irq at one gpio but for ***@4a100040 seems no irq domain
defined.
dmesg:
irq: no irq domain found for /ocp/***@4a100040

Where should I define the irq domain, which interrupts could I use for my
gpios?

Regards,
Anna-Lena Marx

Post by Anna-Lena Marx
Thank you very much for your help, my changes seem to work.
Regards,
Anna-Lena Marx

Post by m***@gmail.com
On Fri, Apr 10, 2015 at 3:33 AM, Anna-Lena Marx

Post by Anna-Lena Marx
Hi,
I'm new with Pandaboard and running a Pandaboard ES Rev B3 with a

Linaro

Post by Anna-Lena Marx
Linux, Kernel 3.19 and Device Tree.
I has to use the GPIOs of the Expansion Headers on the Board, but I

don't

Post by Anna-Lena Marx
understand at witch points I has to change the Device Tree files to

enable

Post by Anna-Lena Marx
pinmuxing at these pins. I'm know which addresses and offsets for which

Post by Anna-Lena Marx
I need to add, but not which files should be edited in which way. I

tryed

Post by Anna-Lena Marx
alone for a few days, but no success.
Can anyone may help me to understand how device tree works at

pandaboard and

Post by Anna-Lena Marx
get GPIOs working?

Post by Anna-Lena Marx
;

};
--
Regards,
Nishanth Menon

Anna-Lena Marx

2015-04-28 07:49:44 UTC

Permalink

For adding IRQ I modified omap4-panda-es.dts according to this
<https://www.mail-archive.com/linux-***@vger.kernel.org/msg99524.html>.
I need two pins for controlling a sensor, one as input with an interrupt,
the other as output. I added :

&omap4_pmx_core {
led_gpio_pins: gpio_led_pmx {
pinctrl-single,pins = <
0xb6 (PIN_OUTPUT | MUX_MODE3) /* gpio_110 */

Post by Anna-Lena Marx
;

};

+ hcsr04_pins: hcsr04_pins{
+ pinctrl-single,pins = <
+ 0xf6 (PIN_INPUT_PULLUP | MUX_MODE3) /* gpio_136 */
+ 0xfa (PIN_OUTPUT | MUX_MODE3) /* gpio_138 */
+ >;
+ };
};

+&omap4_pmx_core{
+
+ hcsr04{
+ pinctrl-names = "default";
+ pinctrl-0 = <&hcsr04_pins>;
+ reg = <0x03>;
+ interrupt-parent = <&gpio4>;
+ interrupts = <8 IRQ_TYPE_LEVEL_HIGH>;
+ };
+};

Sadly, I can't get this working. Could anyone help me to find the problem?

Regards,
Anna-Lena Marx

Post by Anna-Lena Marx
Hi,
I hope you can help me once more. After getting basic GPIO functionality
working I need some interrupts on them.
&omap4_pmx_core {
pinctrl-names = "default";
pinctrl-0 = <
&dss_dpi_pins
&tfp410_pins
&dss_hdmi_pins
&tpd12s015_pins
&hsusbb1_pins

Post by Anna-Lena Marx
;

j3_gpios: pinmux_j3_gpios{
pinctrl-single,pins =<
0x1e (PIN_OUTPUT | MUX_MODE3) /* gpio_39 */
// 0xee (PIN_OUTPUT | MUX_MODE3) /*
i2c4_scl.gpio_132 used as i2c4 */
// 0xf0 (PIN_OUTPUT | MUX_MODE3) /*
i2c4_sda.gpio_133 used as i2c4 */
0xf2 (PIN_OUTPUT | MUX_MODE3) /* gpio_134 */
0xf4 (PIN_OUTPUT | MUX_MODE3) /* gpio_135 */
0xf6 (PIN_OUTPUT | MUX_MODE3) /* gpio_136 */
0xf8 (PIN_OUTPUT | MUX_MODE3) /* gpio_137 */
0xfa (PIN_OUTPUT | MUX_MODE3) /* gpio_138 */
0xfc (PIN_OUTPUT | MUX_MODE3) /* gpio_139 */
0xfe (PIN_OUTPUT | MUX_MODE3) /* gpio_140 */
0x11c (PIN_OUTPUT | MUX_MODE3) /* gpio_155 */
0x11e (PIN_OUTPUT | MUX_MODE3) /* gpio_156 */

Post by Anna-Lena Marx
;

};
j6_gpios: pinmux_j6_gpios{
pinctrl-single,pins = <
0x10 (PIN_OUTPUT | MUX_MODE3) /* gpio_32 */
0x12 (PIN_OUTPUT | MUX_MODE3) /* gpio_33 */
0x14 (PIN_OUTPUT | MUX_MODE3) /* gpio_34 */
0x16 (PIN_OUTPUT | MUX_MODE3) /* gpio_35 */
0x18 (PIN_OUTPUT | MUX_MODE3) /* gpio_36 */
0x1a (PIN_OUTPUT | MUX_MODE3) /* gpio_37 */
0x1c (PIN_OUTPUT | MUX_MODE3) /* gpio_38 */
0x34 (PIN_OUTPUT | MUX_MODE3) /* gpio_50 */
0x36 (PIN_OUTPUT | MUX_MODE3) /* gpio_51 */
0x3c (PIN_OUTPUT | MUX_MODE3) /* gpio_54 */
0x3e (PIN_OUTPUT | MUX_MODE3) /* gpio_55 */
0x40 (PIN_OUTPUT | MUX_MODE3) /* gpio_56 */
0x46 (PIN_OUTPUT | MUX_MODE3) /* gpio_59 */
0x4a (PIN_OUTPUT | MUX_MODE3) /* gpio_61 */
0xD4 (PIN_OUTPUT | MUX_MODE3) /* gpio_121 */

Post by Anna-Lena Marx
;

};
defined.
Where should I define the irq domain, which interrupts could I use for my
gpios?
Regards,
Anna-Lena Marx

Post by Anna-Lena Marx
Thank you very much for your help, my changes seem to work.
Regards,
Anna-Lena Marx

Post by m***@gmail.com
On Fri, Apr 10, 2015 at 3:33 AM, Anna-Lena Marx

Post by Anna-Lena Marx
Hi,
I'm new with Pandaboard and running a Pandaboard ES Rev B3 with a

Linaro

Post by Anna-Lena Marx
Linux, Kernel 3.19 and Device Tree.
I has to use the GPIOs of the Expansion Headers on the Board, but I

don't

Post by Anna-Lena Marx
understand at witch points I has to change the Device Tree files to

enable

Post by Anna-Lena Marx
pinmuxing at these pins. I'm know which addresses and offsets for

which pin

Post by Anna-Lena Marx
I need to add, but not which files should be edited in which way. I

tryed

Post by Anna-Lena Marx
alone for a few days, but no success.
Can anyone may help me to understand how device tree works at

pandaboard and

Post by Anna-Lena Marx
get GPIOs working?

Post by Anna-Lena Marx
;

};
--
Regards,
Nishanth Menon