Linux/PROCESSOR-SDK-AM57X: Toggle GPIO for camera module from driver code

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Hi Biser,

Any update?

Feedback will be posted directly here when available.

Hello,

To check the hardware you can drop the code changes above you did. Have you done the following ?
1: Have you set the pinmux appropriately to select the gpio ?
2: Which bank is the gpio from, is the bank enabled can you read the revision number of it ?
3: Refer link [1] to test the hardware from user space to set the gpio pin as op/ip

[1] elinux.org/GPIO

Cheers,
--Prabhakar Lad

Hi Prabhakar,

Have you set the pinmux appropriately to select the gpio ?

Yes, i did the pinmux appropriately in mux_data.h and am57xx-beagle-x15-common.dtsi files.

Which bank is the gpio from, is the bank enabled can you read the revision number of it ?

My gpio is gpio1_19 (Ball name- GPMC_AD13). Can you please suggest me how to find the corresponding bank and enable it?

Refer link [1] to test the hardware from user space to set the gpio pin as op/ip 

I have gone through this, the values are updated software but not reflecting in Hardware.

Thanks.

Hi Yordan,

I added the above calls but still no result.

Please just verify my steps to toggle a perticular gpio (gpio1_19)-

1) I changed the pinmux setting in mux_data.h.

{GPMC_AD13, (M14 | PIN_OUTPUT)}, /* gpmc_ad13.BUFF_EN gpio1_19*/

2) Made a node in am57xx-beagle-x15-common.dtsi

gpio1_pins_default: gpio1_pins_default {
pinctrl-signle,pins = <
 0x34 (PIN_OUTPUT | MUX_MODE14) //gpmc_ad13.gpio1_19
>;

}; 

and the added the above calls that you stated.

&gpio1 {
pinctrl-names = "default";
pinctrl-0 = <&gpio1_pins_default>;
status = "okay"; // To enable GPIO1
};

also in same file in &i2c5 call,

&i2c5 {
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&i2c5_pins_default>;
clock-frequency = <400000>;
mt9t11x@3C {
compatible = "aptina,mt9t111";
reg = <0x3C>;

bufen-gpios = <&gpio1 19 GPIO_ACTIVE_HIGH>;

port {
cam: endpoint {
remote-endpoint = <&vin3a>;
hsync-active = <1>;
vsync-active = <1>;
pclk-sample = <0>;
input-clock-freq = <32000000>;
pixel-clock-freq = <96000000>;
};
};
};
};

In driver code, i added

//reading buffen_gpio status
gpio_read = gpiod_get_raw_value(priv->bufen_gpio);
dev_err(&client->dev, "BUFEN_PREV %d", gpio_read);
gpiod_set_raw_value_cansleep(priv->bufen_gpio, 1);
gpio_read = gpiod_get_raw_value(priv->bufen_gpio);
dev_err(&client->dev, "BUFEN_AFTER %d", gpio_read);

Any mistake in these changes? Still not working. I am not getting HIGH output.

Thanks.

Hi Yordan.
Any suggestion?

thanks.

Hi,

Can you test with raw writes to the corresponding GPIO_DATAOUT register?
Also have a look at omap-gpio.c driver, there is a omap_set_gpio_dataout_reg() function which is used to toggle bits (gpios) in the DATAOUT register.

Best Regards.
Yordan

Hi Yordan,

Can you test with raw writes to the corresponding GPIO_DATAOUT register? 
Also have a look at omap-gpio.c driver, there is a omap_set_gpio_dataout_reg() function which is used to toggle bits (gpios) in the DATAOUT register. 

I found omap_gpio_set_value() function in omap_gpio.c driver.

What is the difference of using omap_gpio_set_value()  and gpiod_set_value_cansleep()/gpiod_set_raw_value_cansleep(). As gpiod_set_value_cansleep() is already being used in mt9t11x.c driver to set the GPIO value i guess. Is this not correct?

Can you please go through the mt9t11x.c driver? And let me know what is the issue there if any?

when using gpiod_set_value_cansleep() you need to lock the gpio with mutex.

I did that but no satisfying output.

Hi Yordan,

Can you test with raw writes to the corresponding GPIO_DATAOUT register?

Also have a look at omap-gpio.c driver, there is a omap_set_gpio_dataout_reg() function which is used to toggle bits (gpios) in the DATAOUT register.

I found omap_gpio_set_value() function in omap_gpio.c driver.

What is the difference of using omap_gpio_set_value()  and gpiod_set_value_cansleep()/gpiod_set_raw_value_cansleep(). As gpiod_set_value_cansleep() is already being used in mt9t11x.c driver to set the GPIO value i guess. Is this not correct?

Can you please go through the mt9t11x.c driver? And let me know what is the issue there if any?

when using gpiod_set_value_cansleep() you need to lock the gpio with mutex.

I did that but no satisfying output.

Hello,

can you mention which gpio pin you want test ? Ill write out the register settings for you and you can test them at your end.

Cheers,
--Prabhakar Lad

Hi Prabhakar,
Thanks for that.

There are two GPIOs i want to set-
1)Ball name- gpmc_ad15, Ball number-H3. I want to configure this pin as gpio1_21. This pin is pulled up in Hardware through resister hence giving 3.3v output bydefault. I want to make it LOW.
2)Ball name- gpmc_ad12, Ball number-H1. I want to configure this pin as gpio1_18. This pin is pulled down in Hardware, giving 0v bydefault. I want to make it HIGH.

Eagerly waiting for that:-)
Thanks.

Hello,

My bad i read thre trm wrongly its only gpio1[0:3] are as i/p only.

Pinmux for GPIO1_18 register 0x4a003430 should be set to 0x5000E

Pinmux for GPIO1_21 register 0x4a00343c should be set to 0x5000E

Try this from the uboot first to check if the h/w is rite:

mw is cmd to write and md is to display:

0x4ae10134 = FFEBFFFF > set pins as o/p

0x4ae10194 = 140000 > to make the pin high

0x4ae10190 = 140000 > to make the pin low

Cheers,
--Prabhakar Lad

Hi prabhakar,
Thanks for the clarification.

But according to am57xx datasheet. Using muxmode 14, these pins can be configured as IO. I am not clear that these pins are only input.
Can you please tell me where these are defined as input? Also these are declared as input in mux_data.h file, but i changed that as output. Am i wrong?
I am doing that because I want to use the signals(HIGH and LOW) coming out from these pins to drive external hardware. Can this be done?

Hello,

Sorry about that, I rewrote the post please refer that.

Cheers,
--Prabhakar Lad

Hi prabhakar,
Please elaborate-

mw is cmd to write and md is to display:
0x4ae10134 = FFEBFFFF > set pins as o/p

Hello,

0x4ae10134 = FFEBFFFF > set pins as o/p
This is setting GPIO_OE register refer trm page 7110, so pin 18/21 are set as o/p.

So in uboot if you do the following:
mw 0x4a003430 0x5000E >>> Set the pinmux
mw 0x4a00343c 0x5000E >>> Set the pinmux

mw 0x4ae10134 0xFFEBFFFF >>> Make pin as o/p
mw 0x4ae10194 0x140000 >>> Make pin high

At this point if you scope the pin it should be high

Now to make it low

mw 0x4ae10190 0x140000 >>>>> Set pin low

Now if you scope thin it should be low.

Cheers,
--Prabhakar Lad

Hi,
I apologize, this could be a bit annoying to you. I am not expert in driver developement.
Please tell me where to do these changes. The files known to me for changes are - mux_data.h and am57xx dts files. Where should i add these changes.

Hello,

To firstly test your hardware, stop the board at uboot, And do the above steps which I mentioned. When you stop at uboot you get a prompt where you can enter commands. sp mw is a command in uboot which writes to memory.

Once you are happy that the hardware is working as expected in uboot I'll help you out of doing this in Linux.

Cheers,
--Prabhakar Lad

Oh, Very thanks.
I will reply you very quickly.

Hi Prabhakar,
Thanks for elaboration.
I get the output accordingly and its working correct.

Please guide me next.

Hello,

Great!

Can you post the changes which you did in dts for the gpio pinmux ?

Cheers,
--Prabhakar Lad

In mux_data.h file, These changes are done in const struct pad_conf_entry core_padconf_array_essential_x15[] function,
// {GPMC_AD12, (M2 | PIN_INPUT | MANUAL_MODE)}, /* gpmc_ad12.vin3a_d12 */
// {GPMC_AD13, (M2 | PIN_INPUT | MANUAL_MODE)}, /* gpmc_ad13.vin3a_d13 */
// {GPMC_AD14, (M2 | PIN_INPUT | MANUAL_MODE)}, /* gpmc_ad14.vin3a_d14 */
// {GPMC_AD15, (xM2 | PIN_INPUT | MANUAL_MODE)}, /* gpmc_ad15.vin3a_d15 */

//New Gpios for Camera
{GPMC_AD12, (M14 | PIN_OUTPUT)}, /* gpmc_ad12.OSC_EN gpio1_18*/
{GPMC_AD13, (M14 | PIN_OUTPUT)}, /* gpmc_ad13.BUFF_EN gpio1_19*/
{GPMC_AD14, (M14 | PIN_OUTPUT)}, /* gpmc_ad14.GPIO gpio1_20*/
{GPMC_AD15, (M14 | PIN_OUTPUT)}, /* gpmc_ad15.CAM_PWR gpio1_21*/
{GPMC_A13, (M14 | PIN_OUTPUT)}, /* gpmc_a13.gpio2_3 for Cam_En */
//New Gpios for Camera

// {MCASP1_AXR8, (M14 | PIN_OUTPUT)}, /* mcasp1_axr8.gpio5_10 for OSC_EN */
// {MCASP1_AXR9, (M14 | PIN_OUTPUT)}, /* mcasp1_axr9.gpio5_11 for CAM_PWRDN*/
// {MCASP1_AXR10, (M14 | PIN_OUTPUT)}, /* mcasp1_axr10.gpio5_12 for BUFF_EN*/
// {MCASP1_AXR11, (M14 | PIN_OUTPUT_PULLUP)}, /* mcasp1_axr11.gpio4_17 for RESET*/
// {GPIO6_11, (M0 | PIN_OUTPUT_PULLUP)}, /* gpio6_11.gpio6_11 used for Cam_En in LCD Module*/


In am57xx-beagle-x15-common.dtsi file i added/changed


//changes
&gpio1 {
pinctrl-names = "default";
pinctrl-0 = <&gpio1_pins_default>;
status = "okay";
};

&gpio2 {
pinctrl-names = "default";
pinctrl-0 = <&gpio2_pins_default>;
status = "okay";
};
//changes


&i2c5 {
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&i2c5_pins_default>;
clock-frequency = <400000>;
mt9t11x@3C {
compatible = "aptina,mt9t111";
reg = <0x3C>;

//Original definitions
// reset-gpios = <&gpio4 17 GPIO_ACTIVE_LOW>;
// oscen-gpios = <&gpio5 10 GPIO_ACTIVE_HIGH>;
// powerdown-gpios = <&gpio5 11 GPIO_ACTIVE_LOW>;
// bufen-gpios = <&gpio5 12 GPIO_ACTIVE_LOW>;
// camen-gpios = <&gpio6 11 GPIO_ACTIVE_LOW>;


//New Definitaions
reset-gpios = <&gpio1 20 GPIO_ACTIVE_LOW>;
oscen-gpios = <&gpio1 18 GPIO_ACTIVE_HIGH>;
powerdown-gpios = <&gpio1 21 GPIO_ACTIVE_LOW>;
bufen-gpios = <&gpio1 19 GPIO_ACTIVE_LOW>;
camen-gpios = <&gpio2 3 GPIO_ACTIVE_LOW>;
port {
cam: endpoint {
remote-endpoint = <&vin3a>;
hsync-active = <1>;
vsync-active = <1>;
pclk-sample = <0>;
input-clock-freq = <32000000>;
pixel-clock-freq = <96000000>;
};
};
};
};

In same file, i added following in &dra7_pmx_core node-
gpio1_pins_default: gpio1_pins_default {
pinctrl-single,pins = <
0x030 (PIN_OUTPUT | MUX_MODE14) //gpmc_ad12.gpio1_18
0x034 (PIN_OUTPUT | MUX_MODE14) //gpmc_ad13.gpio1_19
0x038 (PIN_OUTPUT | MUX_MODE14) //gpmc_ad14.gpio1_20
0x03C (PIN_OUTPUT | MUX_MODE14) //gpmc_ad15.gpio1_21

>;
};

gpio2_pins_default: gpio2_pins_default {
pinctrl-single,pins = <
0x074 (PIN_OUTPUT | MUX_MODE14) //gpmc_a13.gpio2_3
>;
};

Actually my aim with this is to run a camera. The configuration for i2c pins in p16 header is successfully done. Only these GPIOs were not reflecting my changes.

Hello,

On linux bootup what is the sate of the pins gpio1_18/gpio1_21 ? (please remove any code which you added in driver files to set the gpio pins )

Also what is the value of the registers in Linux:
[1] 0x4a003430
[2] 0x4a00343c

In case if you dont know how to read a register in linux use [1] and cross compile this application and use it on linux bootup.
[1] free-electrons.com/.../devmem2.c

Cheers,
--Prabhakar Lad

ok.

Hi,
Got the values-
for 0x4a003430
Memory mapped at address 0xb6fee000.
Value at address 0x4A003430 (0xb6fee430): 0x1000E

for 0x4a00343c
Memory mapped at address 0xb6f4f000.
Value at address 0x4A00343C (0xb6f4f43c): 0x1000E

On linux bootup what is the sate of the pins gpio1_18/gpio1_21 ? (please remove any code which you added in driver files to set the gpio pins )

Cheers,
--Prabhakar Lad

gpio1_18 = 0V,
gpio1_21 = 3.3V

Also I have removed all changes what i did in the driver code.

I am suspecting these values because of pulldown/pullup with 10k resister in hardware.

Hi prabhakar,

Any update? :-)

Hi Yordan,

Can you test with raw writes to the corresponding GPIO_DATAOUT register?

I checked and confirmed the raw writes during uboot. Its working fine.

Also have a look at omap-gpio.c driver, there is a omap_set_gpio_dataout_reg() function which is used to toggle bits (gpios) in the DATAOUT register. 

I want to ask that in mt9t11x.c which i am currently using, there are calls for setting gpios. So what is the difference in using omap_set_gpio_dataout_reg()?

Hello Prabhakar,
please update me the next step. I guess hardware checking is done. now need to configure the necessary dts files.

Hi,
I am facing the same question as u did.Could u explain the following gpios function to me?What are they used for and how to change them?
//Original definitions
// reset-gpios = <&gpio4 17 GPIO_ACTIVE_LOW>;
// oscen-gpios = <&gpio5 10 GPIO_ACTIVE_HIGH>;
// powerdown-gpios = <&gpio5 11 GPIO_ACTIVE_LOW>;
// bufen-gpios = <&gpio5 12 GPIO_ACTIVE_LOW>;
// camen-gpios = <&gpio6 11 GPIO_ACTIVE_LOW>;
i am confused and wondering if you can provide more insight for me on this.
Thanks in advance n BR,
Boycchi

Hi,
These pins are used to configure the GPIO states required for the TMDSEVM572x Camera Module.
If you want to change those pins according to your need, then have a look in am578 datasheet for pinmux setting.