linux-kernel - Re: [PATCH V2 3/6] pinctrl: sprd: Modify pull-up parameters

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Date:   Tue, 12 Sep 2023 16:22:01 +0800
From:   Baolin Wang <baolin.wang@...ux.alibaba.com>
To:     Linhua Xu <Linhua.xu@...soc.com>,
        Linus Walleij <linus.walleij@...aro.org>
Cc:     Orson Zhai <orsonzhai@...il.com>,
        Chunyan Zhang <zhang.lyra@...il.com>,
        linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        lh xu <xulh0829@...il.com>,
        Zhirong Qiu <zhirong.qiu@...soc.com>,
        Xiongpeng Wu <xiongpeng.wu@...soc.com>
Subject: Re: [PATCH V2 3/6] pinctrl: sprd: Modify pull-up parameters



On 9/8/2023 1:51 PM, Linhua Xu wrote:
> From: Linhua Xu <Linhua.Xu@...soc.com>
> 
> For UNISOC pin controller, there are three different configurations of
> pull-up drive current. Modify the 20K pull-up resistor configuration and
> add the 1.8K pull-up resistor configuration.
> 
> Signed-off-by: Linhua Xu <Linhua.Xu@...soc.com>

Please add a Fixes tag.

> ---
>   drivers/pinctrl/sprd/pinctrl-sprd.c | 10 ++++++----
>   1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pinctrl/sprd/pinctrl-sprd.c b/drivers/pinctrl/sprd/pinctrl-sprd.c
> index 5b9126b2cde2..6c75e6b8d2ca 100644
> --- a/drivers/pinctrl/sprd/pinctrl-sprd.c
> +++ b/drivers/pinctrl/sprd/pinctrl-sprd.c
> @@ -69,7 +69,8 @@
>   #define SLEEP_PULL_UP_MASK		GENMASK(1, 0)
>   #define SLEEP_PULL_UP_SHIFT		2
>   
> -#define PULL_UP_4_7K			(BIT(12) | BIT(7))
> +#define PULL_UP_1_8K			(BIT(12) | BIT(7))
> +#define PULL_UP_4_7K			BIT(12)
>   #define PULL_UP_20K			BIT(7)
>   #define PULL_UP_MASK			(GENMASK(1, 0) | BIT(6))
>   #define PULL_UP_SHIFT			6
> @@ -499,7 +500,7 @@ static int sprd_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin_id,
>   			break;
>   		case PIN_CONFIG_BIAS_DISABLE:
>   			if ((reg & (SLEEP_PULL_DOWN | SLEEP_PULL_UP)) ||
> -			    (reg & (PULL_DOWN | PULL_UP_4_7K | PULL_UP_20K)))
> +			    (reg & (PULL_DOWN | PULL_UP_1_8K)))

The math logic is correct, but the code is not readable now. Since we 
should mask all PULL UP configration, but the code only mask 'PULL_UP_1_8K'.

So changing to below will be more clear:
(reg & (PULL_DOWN | PULL_UP_4_7K | PULL_UP_20K | PULL_UP_1_8K)

>   				return -EINVAL;
>   
>   			arg = 1;
> @@ -701,6 +702,8 @@ static int sprd_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin_id,
>   						val |= PULL_UP_20K;
>   					else if (arg == 4700)
>   						val |= PULL_UP_4_7K;
> +					else if (arg == 1800)
> +						val |= PULL_UP_1_8K;
>   
>   					mask = PULL_UP_MASK;
>   					shift = PULL_UP_SHIFT;
> @@ -712,8 +715,7 @@ static int sprd_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin_id,
>   					mask = SLEEP_PULL_DOWN | SLEEP_PULL_UP;
>   				} else {
>   					val = shift = 0;
> -					mask = PULL_DOWN | PULL_UP_20K |
> -						PULL_UP_4_7K;
> +					mask = PULL_DOWN | PULL_UP_1_8K;

ditto.

>   				}
>   				break;
>   			case PIN_CONFIG_SLEEP_HARDWARE_STATE: