Re: [PATCH v2 4/4] usb: usb3503: Convert to use GPIO descriptors

From: Marek Szyprowski <m.szyprowski@samsung.com>
To: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: linux-usb@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
	linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Krzysztof Kozlowski <krzk@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Stefan Agner <stefan@agner.ch>,
	Linus Walleij <linus.walleij@linaro.org>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: Re: [PATCH v2 4/4] usb: usb3503: Convert to use GPIO descriptors
Date: Thu, 12 Dec 2019 09:23:07 +0100	[thread overview]
Message-ID: <f33fe872-50cf-c33b-ea6c-cfffb82c57a7@samsung.com> (raw)
In-Reply-To: <1576116600.21256.3.camel@mhfsdcap03>

Hi Chunfeng,

On 12.12.2019 03:10, Chunfeng Yun wrote:
> On Wed, 2019-12-11 at 15:52 +0100, Marek Szyprowski wrote:
>> From: Linus Walleij <linus.walleij@linaro.org>
>>
>> This converts the USB3503 to pick GPIO descriptors from the
>> device tree instead of iteratively picking out GPIO number
>> references and then referencing these from the global GPIO
>> numberspace.
>>
>> The USB3503 is only used from device tree among the in-tree
>> platforms. If board files would still desire to use it they can
>> provide machine descriptor tables.
>>
>> Make sure to preserve semantics such as the reset delay
>> introduced by Stefan.
>>
>> Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>
>> Cc: Marek Szyprowski <m.szyprowski@samsung.com>
>> Cc: Stefan Agner <stefan@agner.ch>
>> Cc: Krzysztof Kozlowski <krzk@kernel.org>
>> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
>> [mszyprow: invert the logic behind reset GPIO line]
>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
>> ---
>>   drivers/usb/misc/usb3503.c            | 94 ++++++++++-----------------
>>   include/linux/platform_data/usb3503.h |  3 -
>>   2 files changed, 35 insertions(+), 62 deletions(-)
>>
>> diff --git a/drivers/usb/misc/usb3503.c b/drivers/usb/misc/usb3503.c
>> index 72f39a9751b5..116bd789e568 100644
>> --- a/drivers/usb/misc/usb3503.c
>> +++ b/drivers/usb/misc/usb3503.c
>> @@ -7,11 +7,10 @@
>>   
>>   #include <linux/clk.h>
>>   #include <linux/i2c.h>
>> -#include <linux/gpio.h>
>> +#include <linux/gpio/consumer.h>
>>   #include <linux/delay.h>
>>   #include <linux/slab.h>
>>   #include <linux/module.h>
>> -#include <linux/of_gpio.h>
>>   #include <linux/platform_device.h>
>>   #include <linux/platform_data/usb3503.h>
>>   #include <linux/regmap.h>
>> @@ -47,19 +46,19 @@ struct usb3503 {
>>   	struct device		*dev;
>>   	struct clk		*clk;
>>   	u8	port_off_mask;
>> -	int	gpio_intn;
>> -	int	gpio_reset;
>> -	int	gpio_connect;
>> +	struct gpio_desc	*intn;
>> +	struct gpio_desc 	*reset;
>> +	struct gpio_desc 	*connect;
>>   	bool	secondary_ref_clk;
>>   };
>>   
>>   static int usb3503_reset(struct usb3503 *hub, int state)
>>   {
>> -	if (!state && gpio_is_valid(hub->gpio_connect))
>> -		gpio_set_value_cansleep(hub->gpio_connect, 0);
>> +	if (!state && hub->connect)
>> +		gpiod_set_value_cansleep(hub->connect, 0);
>>   
>> -	if (gpio_is_valid(hub->gpio_reset))
>> -		gpio_set_value_cansleep(hub->gpio_reset, state);
>> +	if (hub->reset)
>> +		gpiod_set_value_cansleep(hub->reset, !state);
> What about preparing another patch for @state before this path?

In such case the driver will be broken after such patch until a 
conversion to descriptor based GPIO api is done.

...

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland