Subject: [PATCH] ARM: iop32x: fix reset handling for the EM7210 board

From: [email-masked] (Arnaud Patard (Rtp))
Date: Wed, 29 Jan 2014 13:57:53 +0100

Linus Walleij <[email-masked]> writes:

Hi,

don't know how to comment about the subjet but it's _not_ about
resetting the board but about powering it off.

> This board was missed when converting all the others to proper
> abstracted GPIO handling. Fix it up the right way by requesting
> and driving GPIO line 0 high through gpiolib to reset the machine.
>
> Reported-by: Arnd Bergmann <[email-masked]>
> Signed-off-by: Linus Walleij <[email-masked]>
> ---
> ARM SoC folks, if you're happy with this fix, please apply it
> directly to fixes in the ARM SoC tree.
> ---
>  arch/arm/mach-iop32x/em7210.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/mach-iop32x/em7210.c b/arch/arm/mach-iop32x/em7210.c
> index 177cd073a83b..e0c4187f3799 100644
> --- a/arch/arm/mach-iop32x/em7210.c
> +++ b/arch/arm/mach-iop32x/em7210.c
> @@ -23,6 +23,7 @@
>  #include <linux/mtd/physmap.h>
>  #include <linux/platform_device.h>
>  #include <linux/i2c.h>
> +#include <linux/gpio.h>
>  #include <mach/hardware.h>
>  #include <linux/io.h>
>  #include <linux/irq.h>
> @@ -176,14 +177,21 @@ static struct platform_device em7210_serial_device = {
>  	.resource	= &em7210_uart_resource,
>  };
>  
> +#define EM7210_HARDWARE_RESET 0
> +

please fix accoring to my previous comment.

>  void em7210_power_off(void)
>  {
> -	*IOP3XX_GPOE &= 0xfe;
> -	*IOP3XX_GPOD |= 0x01;
> +	int ret;
> +
> +	ret = gpio_direction_output(EM7210_HARDWARE_RESET, 1);
> +	if (ret)
> +		pr_crit("could not drive reset GPIO high\n");
>  }
>  
>  static void __init em7210_init_machine(void)
>  {
> +	int ret;
> +
>  	register_iop32x_gpio();
>  	platform_device_register(&em7210_serial_device);
>  	platform_device_register(&iop3xx_i2c0_device);
> @@ -194,7 +202,9 @@ static void __init em7210_init_machine(void)
>  
>  	i2c_register_board_info(0, em7210_i2c_devices,
>  		ARRAY_SIZE(em7210_i2c_devices));
> -
> +	ret = gpio_request(EM7210_HARDWARE_RESET, "reset");
> +	if (ret)
> +		pr_err("could not request reset GPIO\n");

no chance to work. too early. you'll get a -EPROBE_DEFER.

Arnaud