linux-kernel - Re: [PATCH v4 03/11] drm/bridge: analogix_dp: some rockchip chips need to flip REF

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Date:	Wed, 29 Jun 2016 09:46:52 -0400
From:	Sean Paul <seanpaul@...omium.org>
To:	Yakir Yang <ykk@...k-chips.com>
Cc:	Mark Yao <yzq@...k-chips.com>, Inki Dae <inki.dae@...sung.com>,
	Jingoo Han <jingoohan1@...il.com>,
	Heiko Stuebner <heiko@...ech.de>,
	Javier Martinez Canillas <javier@....samsung.com>,
	Stéphane Marchesin <marcheu@...omium.org>,
	Tomasz Figa <tfiga@...omium.org>,
	David Airlie <airlied@...ux.ie>,
	Daniel Vetter <daniel.vetter@...ll.ch>,
	Thierry Reding <treding@...dia.com>,
	Douglas Anderson <dianders@...omium.org>,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	Emil Velikov <emil.l.velikov@...il.com>,
	Dan Carpenter <dan.carpenter@...cle.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	dri-devel <dri-devel@...ts.freedesktop.org>,
	linux-samsung-soc <linux-samsung-soc@...r.kernel.org>,
	linux-rockchip@...ts.infradead.org
Subject: Re: [PATCH v4 03/11] drm/bridge: analogix_dp: some rockchip chips
 need to flip REF_CLK bit setting

On Wed, Jun 29, 2016 at 5:15 AM, Yakir Yang <ykk@...k-chips.com> wrote:
> As vendor document indicate, when REF_CLK bit set 0, then DP
> phy's REF_CLK should switch to 24M source clock.
>
> But due to IC PHY layout mistaken, some chips need to flip this
> bit(like RK3288), and unfortunately they didn't indicate in the
> DP version register. That's why we have to make this little hack.
>
> Signed-off-by: Yakir Yang <ykk@...k-chips.com>
> Reviewed-by: Tomasz Figa <tomasz.figa@...omium.com>
> Tested-by: Javier Martinez Canillas <javier@....samsung.com>


Reviewed-by: Sean Paul <seanpaul@...omium.org>

> ---
> Changes in v4:
> - Remove subdev_type number, and add 'is_rockchip(type)' helper function (Sean)
> - Add reviewed flag from Tomasz.
>
> Changes in v3:
> - Make this hack code more clear (Tomasz, reviewed at Google Gerrit)
>   reg = ~reg & REF_CLK_MASK;  --->  reg ^= REF_CLK_MASK;
>     [https://chromium-review.googlesource.com/#/c/346852/7/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c@80]
> - Add tested flag from Javier
>
>  drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 12 ++++++++----
>  drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h |  1 +
>  include/drm/bridge/analogix_dp.h                  |  5 +++++
>  3 files changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> index 49205ef..48030f0 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> @@ -74,8 +74,12 @@ void analogix_dp_init_analog_param(struct analogix_dp_device *dp)
>         reg = SEL_24M | TX_DVDD_BIT_1_0625V;
>         writel(reg, dp->reg_base + ANALOGIX_DP_ANALOG_CTL_2);
>
> -       if (dp->plat_data && (dp->plat_data->dev_type == RK3288_DP)) {
> -               writel(REF_CLK_24M, dp->reg_base + ANALOGIX_DP_PLL_REG_1);
> +       if (dp->plat_data && is_rockchip(dp->plat_data->dev_type)) {
> +               reg = REF_CLK_24M;
> +               if (dp->plat_data->dev_type == RK3288_DP)
> +                       reg ^= REF_CLK_MASK;
> +
> +               writel(reg, dp->reg_base + ANALOGIX_DP_PLL_REG_1);
>                 writel(0x95, dp->reg_base + ANALOGIX_DP_PLL_REG_2);
>                 writel(0x40, dp->reg_base + ANALOGIX_DP_PLL_REG_3);
>                 writel(0x58, dp->reg_base + ANALOGIX_DP_PLL_REG_4);
> @@ -244,7 +248,7 @@ void analogix_dp_set_analog_power_down(struct analogix_dp_device *dp,
>         u32 reg;
>         u32 phy_pd_addr = ANALOGIX_DP_PHY_PD;
>
> -       if (dp->plat_data && (dp->plat_data->dev_type == RK3288_DP))
> +       if (dp->plat_data && is_rockchip(dp->plat_data->dev_type))
>                 phy_pd_addr = ANALOGIX_DP_PD;
>
>         switch (block) {
> @@ -448,7 +452,7 @@ void analogix_dp_init_aux(struct analogix_dp_device *dp)
>         analogix_dp_reset_aux(dp);
>
>         /* Disable AUX transaction H/W retry */
> -       if (dp->plat_data && (dp->plat_data->dev_type == RK3288_DP))
> +       if (dp->plat_data && is_rockchip(dp->plat_data->dev_type))
>                 reg = AUX_BIT_PERIOD_EXPECTED_DELAY(0) |
>                       AUX_HW_RETRY_COUNT_SEL(3) |
>                       AUX_HW_RETRY_INTERVAL_600_MICROSECONDS;
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h
> index 88d56ad..cdcc6c5 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h
> @@ -165,6 +165,7 @@
>  /* ANALOGIX_DP_PLL_REG_1 */
>  #define REF_CLK_24M                            (0x1 << 0)
>  #define REF_CLK_27M                            (0x0 << 0)
> +#define REF_CLK_MASK                           (0x1 << 0)
>
>  /* ANALOGIX_DP_LANE_MAP */
>  #define LANE3_MAP_LOGIC_LANE_0                 (0x0 << 6)
> diff --git a/include/drm/bridge/analogix_dp.h b/include/drm/bridge/analogix_dp.h
> index 25afb31..790ab5d 100644
> --- a/include/drm/bridge/analogix_dp.h
> +++ b/include/drm/bridge/analogix_dp.h
> @@ -18,6 +18,11 @@ enum analogix_dp_devtype {
>         RK3288_DP,
>  };
>
> +static inline bool is_rockchip(enum analogix_dp_devtype type)
> +{
> +       return type == RK3288_DP;
> +}
> +
>  struct analogix_dp_plat_data {
>         enum analogix_dp_devtype dev_type;
>         struct drm_panel *panel;
> --
> 1.9.1
>
>