Re: [PATCH v2 2/5] pinctrl: imx: add gpio pinmux support for vf610

[Shawn Guo <shawn.guo@freescale.com>]

On Tue, Sep 23, 2014 at 07:37:54PM +0200, Stefan Agner wrote:
> Add pinmux support for GPIO for Vybrid (vf610) IOMUX controller.
> This is needed since direction configuration is not part of the
> GPIO module in Vybrid.
> 
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
>  drivers/pinctrl/pinctrl-imx.c   | 54 +++++++++++++++++++++++++++++++++++++++++
>  drivers/pinctrl/pinctrl-imx.h   |  1 +
>  drivers/pinctrl/pinctrl-vf610.c |  2 +-
>  3 files changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pinctrl/pinctrl-imx.c b/drivers/pinctrl/pinctrl-imx.c
> index 0d4558b..64d1b59 100644
> --- a/drivers/pinctrl/pinctrl-imx.c
> +++ b/drivers/pinctrl/pinctrl-imx.c
> @@ -294,10 +294,59 @@ static int imx_pmx_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
>  	return 0;
>  }
>  
> +static int imx_pmx_gpio_request_enable(struct pinctrl_dev *pctldev,
> +			struct pinctrl_gpio_range *range, unsigned offset)
> +{
> +	struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
> +	const struct imx_pinctrl_soc_info *info = ipctl->info;
> +	const struct imx_pin_reg *pin_reg;
> +	u32 reg;
> +
> +	if (!(info->flags & GPIO_CONTROL))
> +		return -EINVAL;
> +
> +	pin_reg = &info->pin_regs[offset];
> +	if (pin_reg->mux_reg == -1)
> +		return -EINVAL;
> +
> +	reg = readl(ipctl->base + pin_reg->mux_reg);
> +	reg &= ~(0x7 << 20);
> +	writel(reg, ipctl->base + pin_reg->mux_reg);

Isn't this setup redundant at all, since imx_pmx_enable() already takes
care of setting mux register including GPIO mode?

> +
> +	return 0;
> +}
> +
> +static int imx_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
> +	   struct pinctrl_gpio_range *range, unsigned offset, bool input)
> +{
> +	struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
> +	const struct imx_pinctrl_soc_info *info = ipctl->info;
> +	const struct imx_pin_reg *pin_reg;
> +	u32 reg;
> +
> +	if (!(info->flags & GPIO_CONTROL))
> +		return -EINVAL;
> +
> +	pin_reg = &info->pin_regs[offset];
> +	if (pin_reg->mux_reg == -1)
> +		return -EINVAL;
> +
> +	reg = readl(ipctl->base + pin_reg->mux_reg);
> +	if (input)
> +		reg &= ~0x2;
> +	else
> +		reg |= 0x2;

This is all about Output Buffer Enable (OBE) bit.  What about Input
Buffer Enable (IBE) bit?  Don't we need to set or clear it as per GPIO
direction as well?

> +	writel(reg, ipctl->base + pin_reg->mux_reg);
> +
> +	return 0;
> +}
> +
>  static const struct pinmux_ops imx_pmx_ops = {
>  	.get_functions_count = imx_pmx_get_funcs_count,
>  	.get_function_name = imx_pmx_get_func_name,
>  	.get_function_groups = imx_pmx_get_groups,
> +	.gpio_request_enable = imx_pmx_gpio_request_enable,
> +	.gpio_set_direction = imx_pmx_gpio_set_direction,
>  	.enable = imx_pmx_enable,
>  };
>  
> @@ -579,6 +628,11 @@ int imx_pinctrl_probe(struct platform_device *pdev,
>  		dev_err(&pdev->dev, "wrong pinctrl info\n");
>  		return -EINVAL;
>  	}
> +
> +	/* GPIO control functions only intended for shared mux/conf register */
> +	if (info->flags & GPIO_CONTROL)
> +		BUG_ON(!(info->flags & SHARE_MUX_CONF_REG));
> +

If this is always true, why don't we just use flag SHARE_MUX_CONF_REG
and save GPIO_CONTROL?  This check doesn't make too much sense to me if
we choose to have a new flag for GPIO setup.  IMO, we should probably
either drop the GPIO_CONTROL flag or the check.

Shawn

>  	info->dev = &pdev->dev;
>  
>  	/* Create state holders etc for this driver */
> diff --git a/drivers/pinctrl/pinctrl-imx.h b/drivers/pinctrl/pinctrl-imx.h
> index 49e55d3..8f37ca4 100644
> --- a/drivers/pinctrl/pinctrl-imx.h
> +++ b/drivers/pinctrl/pinctrl-imx.h
> @@ -84,6 +84,7 @@ struct imx_pinctrl_soc_info {
>  };
>  
>  #define SHARE_MUX_CONF_REG	0x1
> +#define GPIO_CONTROL		0x2
>  
>  #define NO_MUX		0x0
>  #define NO_PAD		0x0
> diff --git a/drivers/pinctrl/pinctrl-vf610.c b/drivers/pinctrl/pinctrl-vf610.c
> index b788e15..fdf5661 100644
> --- a/drivers/pinctrl/pinctrl-vf610.c
> +++ b/drivers/pinctrl/pinctrl-vf610.c
> @@ -299,7 +299,7 @@ static const struct pinctrl_pin_desc vf610_pinctrl_pads[] = {
>  static struct imx_pinctrl_soc_info vf610_pinctrl_info = {
>  	.pins = vf610_pinctrl_pads,
>  	.npins = ARRAY_SIZE(vf610_pinctrl_pads),
> -	.flags = SHARE_MUX_CONF_REG,
> +	.flags = SHARE_MUX_CONF_REG | GPIO_CONTROL,
>  };
>  
>  static struct of_device_id vf610_pinctrl_of_match[] = {
> -- 
> 2.1.0
>