linux-kernel - Re: [PATCH 2/3] phy: sun4i: add support for A64 usb phy

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Message-ID: <706a0517-a2bf-ee67-338d-859f67105cee@redhat.com>
Date:	Sun, 31 Jul 2016 16:39:16 +0200
From:	Hans de Goede <hdegoede@...hat.com>
To:	Icenowy Zheng <icenowy@...c.xyz>, Rob Herring <robh+dt@...nel.org>,
	Maxime Ripard <maxime.ripard@...e-electrons.com>,
	Chen-Yu Tsai <wens@...e.org>
Cc:	Mark Rutland <mark.rutland@....com>,
	Kishon Vijay Abraham I <kishon@...com>,
	Alan Stern <stern@...land.harvard.edu>,
	Tony Prisk <linux@...sktech.co.nz>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Reinder de Haan <patchesrdh@...as.com>,
	devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org
Subject: Re: [PATCH 2/3] phy: sun4i: add support for A64 usb phy

Hi,

On 31-07-16 13:25, Icenowy Zheng wrote:
> There's something unknown in the pmu part.
>
> Signed-off-by: Icenowy Zheng <icenowy@...c.xyz>

Cool, I really like the work you're doing on A64 support,
keep up the good work!

> ---
>  drivers/phy/phy-sun4i-usb.c | 21 +++++++++++++++++++--
>  1 file changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/phy/phy-sun4i-usb.c b/drivers/phy/phy-sun4i-usb.c
> index 0a45bc6..6f94369 100644
> --- a/drivers/phy/phy-sun4i-usb.c
> +++ b/drivers/phy/phy-sun4i-usb.c
> @@ -97,6 +97,7 @@ enum sun4i_usb_phy_type {
>  	sun6i_a31_phy,
>  	sun8i_a33_phy,
>  	sun8i_h3_phy,
> +	sun50i_a64_phy,
>  };
>
>  struct sun4i_usb_phy_cfg {
> @@ -180,8 +181,9 @@ static void sun4i_usb_phy_write(struct sun4i_usb_phy *phy, u32 addr, u32 data,
>
>  	mutex_lock(&phy_data->mutex);
>
> -	if (phy_data->cfg->type == sun8i_a33_phy) {
> -		/* A33 needs us to set phyctl to 0 explicitly */
> +	if (phy_data->cfg->type == sun8i_a33_phy ||
> +	    phy_data->cfg->type == sun50i_a64_phy) {
> +		/* A33 or A64 needs us to set phyctl to 0 explicitly */
>  		writel(0, phyctl);
>  	}
>

Maybe add a "bool explicitly_0_phyctl;" to sun4i_usb_phy_cfg ?

Note I'm not sure of this myself, feel free to keep this as is,
we can always introduce such a bool when we get a 3th SoC which
needs it.

> @@ -264,6 +266,12 @@ static int sun4i_usb_phy_init(struct phy *_phy)
>  		val = readl(phy->pmu + REG_PMU_UNK_H3);
>  		writel(val & ~2, phy->pmu + REG_PMU_UNK_H3);
>  	} else {
> +		/* A64 needs also this unknown bit */
> +		if (data->cfg->type == sun50i_a64_phy) {
> +			val = readl(phy->pmu + REG_PMU_UNK_H3);
> +			writel(val & ~2, phy->pmu + REG_PMU_UNK_H3);
> +		}
> +
>  		/* Enable USB 45 Ohm resistor calibration */
>  		if (phy->index == 0)
>  			sun4i_usb_phy_write(phy, PHY_RES45_CAL_EN, 0x01, 1);

Erm, as pointed out thus duplicates code from the H3 code path, I believe
that you should add a "bool needs_h3_pmu_unk_poke;" to sun4i_usb_phy_cfg
and then change this bit of the code to:

         if (data->cfg->needs_h3_pmu_unk_poke) {
                 val = readl(phy->pmu + REG_PMU_UNK_H3);
                 writel(val & ~2, phy->pmu + REG_PMU_UNK_H3);
         }

         if (data->cfg->type == sun8i_h3_phy) {
                 if (phy->index == 0) {
                         val = readl(data->base + REG_PHY_UNK_H3);
                         writel(val & ~1, data->base + REG_PHY_UNK_H3);
                 }
         } else {
		... (original code)
	}

That seems like a cleaner solution to me.

And do not forget to set the needs_h3_pmu_unk_poke for the h3!

I would not add it to the sun4i_usb_phy_cfg structs for the
other type SoCs, if part of the struct is initialized the
rest will get set to 0 by the compiler and I believe that
it things will be more readable without an explicit:

	.needs_h3_pmu_unk_poke = false

Everywhere.


Thanks & Regards,

Hans




> @@ -762,6 +770,14 @@ static const struct sun4i_usb_phy_cfg sun8i_h3_cfg = {
>  	.dedicated_clocks = true,
>  };
>
> +static const struct sun4i_usb_phy_cfg sun50i_a64_cfg = {
> +	.num_phys = 2,
> +	.type = sun50i_a64_phy,
> +	.disc_thresh = 3,
> +	.phyctl_offset = REG_PHYCTL_A33,
> +	.dedicated_clocks = true,
> +};
> +
>  static const struct of_device_id sun4i_usb_phy_of_match[] = {
>  	{ .compatible = "allwinner,sun4i-a10-usb-phy", .data = &sun4i_a10_cfg },
>  	{ .compatible = "allwinner,sun5i-a13-usb-phy", .data = &sun5i_a13_cfg },
> @@ -770,6 +786,7 @@ static const struct of_device_id sun4i_usb_phy_of_match[] = {
>  	{ .compatible = "allwinner,sun8i-a23-usb-phy", .data = &sun8i_a23_cfg },
>  	{ .compatible = "allwinner,sun8i-a33-usb-phy", .data = &sun8i_a33_cfg },
>  	{ .compatible = "allwinner,sun8i-h3-usb-phy", .data = &sun8i_h3_cfg },
> +	{ .compatible = "allwinner,sun50i-a64-usb-phy", .data = &sun50i_a64_cfg},
>  	{ },
>  };
>  MODULE_DEVICE_TABLE(of, sun4i_usb_phy_of_match);
>