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From: Vikram Narayanan <vikram186@gmail.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 2/3] tx25: Use generic gpio_* calls
Date: Mon, 11 Jun 2012 20:28:30 +0530	[thread overview]
Message-ID: <4FD60796.8050003@gmail.com> (raw)
In-Reply-To: <CAOMZO5CNd9A-vv7VftMJ2Ph=LS9-mqhoO6ibaW0RcxqMfidHiQ@mail.gmail.com>

Hi Fabio,

On 6/10/2012 8:08 PM, Fabio Estevam wrote:
> On Sun, Jun 10, 2012 at 10:03 AM, Vikram Narayanan<vikram186@gmail.com>  wrote:
>
>>         /* drop PHY power and assert reset (low) */
>> -       val = readl(&gpio4->gpio_dr)&  ~((1<<  7) | (1<<  9));
>> -       writel(val,&gpio4->gpio_dr);
>> -       val = readl(&gpio4->gpio_dir) | (1<<  7) | (1<<  9);
>> -       writel(val,&gpio4->gpio_dir);
>> +       gpio_direction_output(GPIO_FEC_RESET_B, 0);
>> +       gpio_direction_output(GPIO_FEC_ENABLE_B, 0);
>> +
>> +       gpio_direction_output(GPIO_FEC_RESET_B, 1);
>> +       gpio_direction_output(GPIO_FEC_ENABLE_B, 1);
>
> gpio_direction_output should be set only once for each GPIO.
>
> After you set the direction (input or output) you should use
> 'gpio_set_value' for setting the GPIO to 0 or 1.

That was my understanding too. But some board file used it in the above 
way. Hope I got a wrong example. I'll fix this.

> Also, please remove the:
>
>> +       gpio_direction_output(GPIO_FEC_RESET_B, 1);
>> +       gpio_direction_output(GPIO_FEC_ENABLE_B, 1);
>
> lines, as the setting to 1 should be after the delay (via gpio_set_value).

Any idea about the delay value?

Thanks,
Vikram

  reply	other threads:[~2012-06-11 14:58 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-10 13:01 [U-Boot] imx: gpio cleanups Vikram Narayanan
2012-06-10 13:02 ` [U-Boot] [PATCH 1/3] imx25: Move MXC_GPIO_PORT_TO_NUM to imx-regs.h Vikram Narayanan
2012-06-10 14:33   ` Fabio Estevam
2012-06-11 15:00     ` Vikram Narayanan
2012-06-11 19:56       ` Troy Kisky
2012-06-10 15:03   ` Fabio Estevam
2012-06-11 15:02     ` Vikram Narayanan
2012-06-13 11:37       ` Fabio Estevam
2012-06-15 14:55         ` Stefano Babic
2012-06-15 18:10           ` Vikram Narayanan
2012-06-15 18:13             ` Fabio Estevam
2012-06-10 13:03 ` [U-Boot] [PATCH 2/3] tx25: Use generic gpio_* calls Vikram Narayanan
2012-06-10 14:38   ` Fabio Estevam
2012-06-11 14:58     ` Vikram Narayanan [this message]
2012-06-11 15:01       ` Fabio Estevam
2012-06-10 13:04 ` [U-Boot] [PATCH 3/3] imx: Define a common header file for gpio.h Vikram Narayanan
2012-06-10 13:06 ` [U-Boot] imx: gpio cleanups Vikram Narayanan

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