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From: Lars-Peter Clausen <lars@metafoo.de>
To: Kukjin Kim <kgene.kim@samsung.com>
Cc: "'Ben Dooks'" <ben-linux@fluff.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 08/09] ARM: s3c2440: gta02: Request usb pullup pin before using it
Date: Mon, 28 Feb 2011 11:25:42 +0100	[thread overview]
Message-ID: <4D6B7826.1030500@metafoo.de> (raw)
In-Reply-To: <000301cbd70f$12367070$36a35150$%kim@samsung.com>

On 02/28/2011 07:16 AM, Kukjin Kim wrote:
> Lars-Peter Clausen wrote:
>>
>> Request the gpio pin used to control the usb pullup before using it to
> avoid
>> a
>> runtime warning about an auto-requested gpio.
>>
>> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
>> ---
>>  arch/arm/mach-s3c2440/mach-gta02.c |   17 +++++++++++++++--
>>  1 files changed, 15 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/mach-s3c2440/mach-gta02.c
> b/arch/arm/mach-s3c2440/mach-
>> gta02.c
>> index 1396639..94456fa 100644
>> --- a/arch/arm/mach-s3c2440/mach-gta02.c
>> +++ b/arch/arm/mach-s3c2440/mach-gta02.c
>> @@ -451,11 +451,11 @@ static void gta02_udc_command(enum s3c2410_udc_cmd_e
>> cmd)
>>  	switch (cmd) {
>>  	case S3C2410_UDC_P_ENABLE:
>>  		pr_debug("%s S3C2410_UDC_P_ENABLE\n", __func__);
>> -		gpio_direction_output(GTA02_GPIO_USB_PULLUP, 1);
>> +		gpio_set_value(GTA02_GPIO_USB_PULLUP, 1);
> 
> How about following instead?
> 	gpio_request(GTA02_GPIO_USB_PULLUP, "USB_PULLUP");
> 	gpio_direction_output(GTA02_GPIO_USB_PULLUP, 1);
> 	gpio_free(GTA02_GPIO_USB_PULLUP);
> 

I don't think that is a good idea. This gpio should really be reserved for the
udc driver. If it is freed again, it could be requested from someone else which
could lead to undefined behaviour.


>>  		break;
>>  	case S3C2410_UDC_P_DISABLE:
>>  		pr_debug("%s S3C2410_UDC_P_DISABLE\n", __func__);
>> -		gpio_direction_output(GTA02_GPIO_USB_PULLUP, 0);
>> +		gpio_set_value(GTA02_GPIO_USB_PULLUP, 0);
>>  		break;
>>  	case S3C2410_UDC_P_RESET:
>>  		pr_debug("%s S3C2410_UDC_P_RESET\n", __func__);
>> @@ -572,11 +572,24 @@ static void gta02_poweroff(void)
>>  	pcf50633_reg_set_bit_mask(gta02_pcf, PCF50633_REG_OOCSHDWN, 1, 1);
>>  }
>>
>> +static void gta02_request_gpios(void)
>> +{
>> +	int ret;
>> +	ret = gpio_request_one(GTA02_GPIO_USB_PULLUP, GPIOF_OUT_INIT_LOW,
>> +				"USB pullup");
>> +	if (ret) {
>> +		printk(KERN_ERR "Failed to request USB pullup gpio pin:
> %d\n",
>> +			ret);
>> +	}
>> +}
>> +
>>  static void __init gta02_machine_init(void)
>>  {
>>  	/* Set the panic callback to turn AUX LED on or off. */
>>  	panic_blink = gta02_panic_blink;
>>
>> +	gta02_request_gpios();
>> +
>>  	s3c_pm_init();
>>
>>  #ifdef CONFIG_CHARGER_PCF50633
>> --
> 
> 
> 
> Thanks.
> 
> Best regards,
> Kgene.
> --
> Kukjin Kim <kgene.kim@samsung.com>, Senior Engineer,
> SW Solution Development Team, Samsung Electronics Co., Ltd.
> 


  reply	other threads:[~2011-02-28 10:24 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-07  1:51 [PATCH 01/09] ARM: s3c2442: gta02: Fix usage gpio bank j pin definitions Lars-Peter Clausen
2011-02-07  1:51 ` [PATCH 02/09] ARM: s3c2440: gta02: Register PCM device Lars-Peter Clausen
2011-02-28  6:38   ` Kukjin Kim
2011-02-07  1:51 ` [PATCH 03/09] ARM: s3c2440: gta02: Add button support Lars-Peter Clausen
2011-02-28  6:37   ` Kukjin Kim
2011-02-07  1:51 ` [PATCH 04/09] ARM: s3c2440: gta02: Select missing S3C_DEV_USB_HOST Lars-Peter Clausen
2011-02-28  6:31   ` Kukjin Kim
2011-02-07  1:51 ` [PATCH 05/09] ARM: s3c2440: gta02: Fix regulator valid_modes_ops Lars-Peter Clausen
2011-02-28  6:48   ` Kukjin Kim
2011-02-07  1:51 ` [PATCH 06/09] ARM: s3c2440: gta02: Remove state_mem constraints for the pcf50633 regulators Lars-Peter Clausen
2011-02-28  6:26   ` Kukjin Kim
2011-02-28 10:28     ` Lars-Peter Clausen
2011-02-28 10:58       ` Kukjin Kim
2011-02-07  1:51 ` [PATCH 07/09] ARM: s3c2440: gta02: Call regulator_has_full_constraints Lars-Peter Clausen
2011-02-07 11:58   ` Mark Brown
2011-02-08  2:55   ` [PATCH v2 " Lars-Peter Clausen
2011-02-28  6:47     ` Kukjin Kim
2011-02-07  1:52 ` [PATCH 08/09] ARM: s3c2440: gta02: Request usb pullup pin before using it Lars-Peter Clausen
2011-02-28  6:16   ` Kukjin Kim
2011-02-28 10:25     ` Lars-Peter Clausen [this message]
2011-02-28 10:44       ` Kukjin Kim
2011-02-28 10:58         ` Lars-Peter Clausen
2011-03-07  6:42           ` Kukjin Kim
2011-03-07  7:00             ` Lars-Peter Clausen
2011-02-07  1:52 ` [PATCH 09/09] ARM: s3c2440: gta02: Add touchscreen support Lars-Peter Clausen
2011-02-28  6:04   ` Kukjin Kim
2011-02-28 10:44     ` Lars-Peter Clausen
2011-02-28 10:57       ` Kukjin Kim
2011-02-28 11:17   ` [PATCH v2 " Lars-Peter Clausen
2011-02-28 11:56     ` Kukjin Kim
2011-02-18 10:41 ` [PATCH 01/09] ARM: s3c2442: gta02: Fix usage gpio bank j pin definitions Lars-Peter Clausen
2011-02-21  9:58   ` Kukjin Kim
2011-02-28  6:41 ` Kukjin Kim
2011-02-28 10:46   ` Lars-Peter Clausen
2011-02-28 10:49     ` Kukjin Kim

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