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Message-ID: <51712e34-c964-a5b3-3df8-1af10c7751f6@quicinc.com>
Date:   Wed, 7 Jun 2023 12:46:31 -0700
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Subject: Re: [Freedreno] [PATCH v3 6/7] drm/msm/dsi: Add phy configuration for
 MSM8226
Content-Language: en-US
To:     Luca Weiss <luca@z3ntu.xyz>,
        <~postmarketos/upstreaming@lists.sr.ht>,
        <phone-devel@vger.kernel.org>, Rob Clark <robdclark@gmail.com>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Krishna Manikandan <quic_mkrishn@quicinc.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>
CC:     <devicetree@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <dri-devel@lists.freedesktop.org>,
        <freedreno@lists.freedesktop.org>
References: <20230308-msm8226-mdp-v3-0-b6284145d67a@z3ntu.xyz>
 <20230308-msm8226-mdp-v3-6-b6284145d67a@z3ntu.xyz>
From:   Jeykumar Sankaran <quic_jeykumar@quicinc.com>
In-Reply-To: <20230308-msm8226-mdp-v3-6-b6284145d67a@z3ntu.xyz>
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On 6/1/2023 10:00 AM, Luca Weiss wrote:
> MSM8226 uses a modified PLL lock sequence compared to MSM8974, which is
> based on the function dsi_pll_enable_seq_m in the msm-3.10 kernel.
> 
> Worth noting that the msm-3.10 downstream kernel also will try other
> sequences in case this one doesn't work, but during testing it has shown
> that the _m sequence succeeds first time also:
> 
>    .pll_enable_seqs[0] = dsi_pll_enable_seq_m,
>    .pll_enable_seqs[1] = dsi_pll_enable_seq_m,
>    .pll_enable_seqs[2] = dsi_pll_enable_seq_d,
>    .pll_enable_seqs[3] = dsi_pll_enable_seq_d,
>    .pll_enable_seqs[4] = dsi_pll_enable_seq_f1,
>    .pll_enable_seqs[5] = dsi_pll_enable_seq_c,
>    .pll_enable_seqs[6] = dsi_pll_enable_seq_e,
> 
> We may need to expand this in the future.
> 
> Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
> ---
>   drivers/gpu/drm/msm/dsi/phy/dsi_phy.c      |  2 +
>   drivers/gpu/drm/msm/dsi/phy/dsi_phy.h      |  3 +-
>   drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c | 97 ++++++++++++++++++++++++++++++
>   3 files changed, 101 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
> index bb09cbe8ff86..9d5795c58a98 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
> @@ -541,6 +541,8 @@ static const struct of_device_id dsi_phy_dt_match[] = {
>   	  .data = &dsi_phy_28nm_hpm_famb_cfgs },
>   	{ .compatible = "qcom,dsi-phy-28nm-lp",
>   	  .data = &dsi_phy_28nm_lp_cfgs },
> +	{ .compatible = "qcom,dsi-phy-28nm-8226",
> +	  .data = &dsi_phy_28nm_8226_cfgs },
>   #endif
>   #ifdef CONFIG_DRM_MSM_DSI_20NM_PHY
>   	{ .compatible = "qcom,dsi-phy-20nm",
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.h b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.h
> index 7137a17ae523..8b640d174785 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.h
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.h
> @@ -46,8 +46,9 @@ struct msm_dsi_phy_cfg {
>   extern const struct msm_dsi_phy_cfg dsi_phy_28nm_hpm_cfgs;
>   extern const struct msm_dsi_phy_cfg dsi_phy_28nm_hpm_famb_cfgs;
>   extern const struct msm_dsi_phy_cfg dsi_phy_28nm_lp_cfgs;
> -extern const struct msm_dsi_phy_cfg dsi_phy_20nm_cfgs;
> +extern const struct msm_dsi_phy_cfg dsi_phy_28nm_8226_cfgs;
>   extern const struct msm_dsi_phy_cfg dsi_phy_28nm_8960_cfgs;
> +extern const struct msm_dsi_phy_cfg dsi_phy_20nm_cfgs;
>   extern const struct msm_dsi_phy_cfg dsi_phy_14nm_cfgs;
>   extern const struct msm_dsi_phy_cfg dsi_phy_14nm_660_cfgs;
>   extern const struct msm_dsi_phy_cfg dsi_phy_14nm_2290_cfgs;
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c
> index 4c1bf55c5f38..ceec7bb87bf1 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c
> @@ -37,6 +37,7 @@
>   
>   /* v2.0.0 28nm LP implementation */
>   #define DSI_PHY_28NM_QUIRK_PHY_LP	BIT(0)
> +#define DSI_PHY_28NM_QUIRK_PHY_8226	BIT(1)
>   
>   #define LPFR_LUT_SIZE			10
>   struct lpfr_cfg {
> @@ -377,6 +378,74 @@ static int dsi_pll_28nm_vco_prepare_hpm(struct clk_hw *hw)
>   	return ret;
>   }
>   
> +static int dsi_pll_28nm_vco_prepare_8226(struct clk_hw *hw)
> +{
> +	struct dsi_pll_28nm *pll_28nm = to_pll_28nm(hw);
> +	struct device *dev = &pll_28nm->phy->pdev->dev;
> +	void __iomem *base = pll_28nm->phy->pll_base;
> +	u32 max_reads = 5, timeout_us = 100;
> +	bool locked;
> +	u32 val;
> +	int i;
> +
> +	DBG("id=%d", pll_28nm->phy->id);
> +
> +	pll_28nm_software_reset(pll_28nm);
> +
> +	/*
> +	 * PLL power up sequence.
> +	 * Add necessary delays recommended by hardware.
> +	 */
> +	dsi_phy_write(base + REG_DSI_28nm_PHY_PLL_CAL_CFG1, 0x34);
> +
> +	val = DSI_28nm_PHY_PLL_GLB_CFG_PLL_PWRDN_B;
> +	dsi_phy_write_udelay(base + REG_DSI_28nm_PHY_PLL_GLB_CFG, val, 200);
> +
> +	val |= DSI_28nm_PHY_PLL_GLB_CFG_PLL_PWRGEN_PWRDN_B;
> +	dsi_phy_write_udelay(base + REG_DSI_28nm_PHY_PLL_GLB_CFG, val, 200);
> +
> +	val |= DSI_28nm_PHY_PLL_GLB_CFG_PLL_LDO_PWRDN_B;
> +	val |= DSI_28nm_PHY_PLL_GLB_CFG_PLL_ENABLE;
> +	dsi_phy_write_udelay(base + REG_DSI_28nm_PHY_PLL_GLB_CFG, val, 600);
> +
> +	for (i = 0; i < 7; i++) {
> +		/* DSI Uniphy lock detect setting */
> +		dsi_phy_write(base + REG_DSI_28nm_PHY_PLL_LKDET_CFG2, 0x0d);
> +		dsi_phy_write_udelay(base + REG_DSI_28nm_PHY_PLL_LKDET_CFG2,
> +				0x0c, 100);
> +		dsi_phy_write(base + REG_DSI_28nm_PHY_PLL_LKDET_CFG2, 0x0d);
> +
> +		/* poll for PLL ready status */
> +		locked = pll_28nm_poll_for_ready(pll_28nm,
> +						max_reads, timeout_us);
> +		if (locked)
> +			break;
> +
> +		pll_28nm_software_reset(pll_28nm);
> +
> +		/*
> +		 * PLL power up sequence.
> +		 * Add necessary delays recommended by hardware.
> +		 */
> +		dsi_phy_write_udelay(base + REG_DSI_28nm_PHY_PLL_PWRGEN_CFG, 0x00, 50);
> +
> +		val = DSI_28nm_PHY_PLL_GLB_CFG_PLL_PWRDN_B;
> +		val |= DSI_28nm_PHY_PLL_GLB_CFG_PLL_PWRGEN_PWRDN_B;
> +		dsi_phy_write_udelay(base + REG_DSI_28nm_PHY_PLL_GLB_CFG, val, 100);
> +
> +		val |= DSI_28nm_PHY_PLL_GLB_CFG_PLL_LDO_PWRDN_B;
> +		val |= DSI_28nm_PHY_PLL_GLB_CFG_PLL_ENABLE;
> +		dsi_phy_write_udelay(base + REG_DSI_28nm_PHY_PLL_GLB_CFG, val, 600);
> +	}
> +
> +	if (unlikely(!locked))
> +		DRM_DEV_ERROR(dev, "DSI PLL lock failed\n");
> +	else
> +		DBG("DSI PLL Lock success");
> +
> +	return locked ? 0 : -EINVAL;
> +}
> +
Could you please share the downstream reference you used to come up with 
this sequence?

Thanks and Regards,
Jeykumar S.
>   static int dsi_pll_28nm_vco_prepare_lp(struct clk_hw *hw)
>   {
>   	struct dsi_pll_28nm *pll_28nm = to_pll_28nm(hw);
> @@ -471,6 +540,15 @@ static const struct clk_ops clk_ops_dsi_pll_28nm_vco_lp = {
>   	.is_enabled = dsi_pll_28nm_clk_is_enabled,
>   };
>   
> +static const struct clk_ops clk_ops_dsi_pll_28nm_vco_8226 = {
> +	.round_rate = dsi_pll_28nm_clk_round_rate,
> +	.set_rate = dsi_pll_28nm_clk_set_rate,
> +	.recalc_rate = dsi_pll_28nm_clk_recalc_rate,
> +	.prepare = dsi_pll_28nm_vco_prepare_8226,
> +	.unprepare = dsi_pll_28nm_vco_unprepare,
> +	.is_enabled = dsi_pll_28nm_clk_is_enabled,
> +};
> +
>   /*
>    * PLL Callbacks
>    */
> @@ -536,6 +614,8 @@ static int pll_28nm_register(struct dsi_pll_28nm *pll_28nm, struct clk_hw **prov
>   
>   	if (pll_28nm->phy->cfg->quirks & DSI_PHY_28NM_QUIRK_PHY_LP)
>   		vco_init.ops = &clk_ops_dsi_pll_28nm_vco_lp;
> +	else if (pll_28nm->phy->cfg->quirks & DSI_PHY_28NM_QUIRK_PHY_8226)
> +		vco_init.ops = &clk_ops_dsi_pll_28nm_vco_8226;
>   	else
>   		vco_init.ops = &clk_ops_dsi_pll_28nm_vco_hpm;
>   
> @@ -820,3 +900,20 @@ const struct msm_dsi_phy_cfg dsi_phy_28nm_lp_cfgs = {
>   	.quirks = DSI_PHY_28NM_QUIRK_PHY_LP,
>   };
>   
> +const struct msm_dsi_phy_cfg dsi_phy_28nm_8226_cfgs = {
> +	.has_phy_regulator = true,
> +	.regulator_data = dsi_phy_28nm_regulators,
> +	.num_regulators = ARRAY_SIZE(dsi_phy_28nm_regulators),
> +	.ops = {
> +		.enable = dsi_28nm_phy_enable,
> +		.disable = dsi_28nm_phy_disable,
> +		.pll_init = dsi_pll_28nm_init,
> +		.save_pll_state = dsi_28nm_pll_save_state,
> +		.restore_pll_state = dsi_28nm_pll_restore_state,
> +	},
> +	.min_pll_rate = VCO_MIN_RATE,
> +	.max_pll_rate = VCO_MAX_RATE,
> +	.io_start = { 0xfd922b00 },
> +	.num_dsi_phy = 1,
> +	.quirks = DSI_PHY_28NM_QUIRK_PHY_8226,
> +};
>