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

Stephen Warren
2011-11-15T22:07:24Z

On 10/11/2011 06:07 PM, Simon Glass wrote:
> Hi Stephen,
>
> On Thu, Oct 6, 2011 at 3:52 PM, Stephen Warren <swarren@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@nvidia.com>
>
> Acked-by: Simon Glass <sjg@chromium.org>
> Tested-by: Simon Glass <sjg@chromium.org>

Albert, sorry I forgot to CC you on my original patch submission. Can
you please also consider this patch. Thanks.

>> ---
>> 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

--
nvpublic