[U-Boot] [PATCH] tegra2: Use new GPIO APIs in gpio_config_uart()

[Simon Glass]

Hi Stephen,

On Thu, Oct 6, 2011 at 3:52 PM, Stephen Warren <swarren at nvidia.com> wrote:
> ... rather than open-coding the register accesses.
>
> However, gpio_request() typically stores the "label" parameter in a global
> data structure. This causes problems when called from gpio_config_uart(),
> since the code is running before relocation. To solve this, pass a NULL
> string to gpio_request(), and modify gpio_request() not to touch the string
> if it's NULL.
>
> Signed-off-by: Stephen Warren <swarren at nvidia.com>

Acked-by: Simon Glass <sjg at chromium.org>
Tested-by: Simon Glass <sjg at chromium.org>

> ---
> I tested this on Seaboard. With the code in the patch below, the UART works.
> If I comment out the body of gpio_config_uart_seaboard(), the UART does not
> work.
>
> This patch should work with ToT U-Boot, but the context relies on the rename
> of gpio_config_uart() to gpio_config_uart_seaboard() contained in:
> http://patchwork.ozlabs.org/patch/118144/
>
>  board/nvidia/seaboard/seaboard.c |   18 ++----------------
>  drivers/gpio/tegra2_gpio.c       |    6 ++++--
>  2 files changed, 6 insertions(+), 18 deletions(-)
>
> diff --git a/board/nvidia/seaboard/seaboard.c b/board/nvidia/seaboard/seaboard.c
> index 260a56d..4492c28 100644
> --- a/board/nvidia/seaboard/seaboard.c
> +++ b/board/nvidia/seaboard/seaboard.c
> @@ -36,23 +36,9 @@
>  */
>  void gpio_config_uart_seaboard(void)
>  {
> -       int gp = GPIO_PI3;
> -       struct gpio_ctlr *gpio = (struct gpio_ctlr *)NV_PA_GPIO_BASE;
> -       struct gpio_ctlr_bank *bank = &gpio->gpio_bank[GPIO_BANK(gp)];
> -       u32 val;
> -
>        /* Enable UART via GPIO_PI3 (port 8, bit 3) so serial console works */
> -       val = readl(&bank->gpio_config[GPIO_PORT(gp)]);
> -       val |= 1 << GPIO_BIT(gp);
> -       writel(val, &bank->gpio_config[GPIO_PORT(gp)]);
> -
> -       val = readl(&bank->gpio_out[GPIO_PORT(gp)]);
> -       val &= ~(1 << GPIO_BIT(gp));
> -       writel(val, &bank->gpio_out[GPIO_PORT(gp)]);
> -
> -       val = readl(&bank->gpio_dir_out[GPIO_PORT(gp)]);
> -       val |= 1 << GPIO_BIT(gp);
> -       writel(val, &bank->gpio_dir_out[GPIO_PORT(gp)]);
> +       gpio_request(GPIO_PI3, NULL);
> +       gpio_direction_output(GPIO_PI3, 0);
>  }
>
>  void gpio_config_uart(void)
> diff --git a/drivers/gpio/tegra2_gpio.c b/drivers/gpio/tegra2_gpio.c
> index f686e80..22669b6 100644
> --- a/drivers/gpio/tegra2_gpio.c
> +++ b/drivers/gpio/tegra2_gpio.c
> @@ -146,8 +146,10 @@ int gpio_request(int gp, const char *label)
>        if (gp >= MAX_NUM_GPIOS)
>                return -1;
>
> -       strncpy(gpio_names[gp].name, label, GPIO_NAME_SIZE);
> -       gpio_names[gp].name[GPIO_NAME_SIZE - 1] = '\0';
> +       if (label != NULL) {
> +               strncpy(gpio_names[gp].name, label, GPIO_NAME_SIZE);
> +               gpio_names[gp].name[GPIO_NAME_SIZE - 1] = '\0';
> +       }
>
>        /* Configure as a GPIO */
>        set_config(gp, 1);
> --
> 1.7.0.4
>
>