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Subject: Re: [PATCH v2 12/26] drm/sun4i: Add support for multiple DW HDMI PHY
 clock parents
To:     =?UTF-8?Q?Jernej_=c5=a0krabec?= <jernej.skrabec@siol.net>
Cc:     Mark Rutland <mark.rutland@arm.com>, devicetree@vger.kernel.org,
        Michael Trimarchi <michael@amarulasolutions.com>,
        Maxime Ripard <maxime.ripard@bootlin.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Will Deacon <will.deacon@arm.com>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Chen-Yu Tsai <wens@csie.org>, David Airlie <airlied@linux.ie>,
        linux-sunxi@googlegroups.com, Rob Herring <robh+dt@kernel.org>,
        Jagan Teki <jagan@amarulasolutions.com>,
        Stephen Boyd <sboyd@kernel.org>, linux-clk@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        Icenowy Zheng <icenowy@aosc.io>
References: <20180518094536.17201-1-jagan@amarulasolutions.com>
 <4909574.Q3IFWM0xt6@jernej-laptop>
 <824c6989-7930-86dc-1195-494580f6cb38@orpaltech.com>
 <3135535.HuDyCXIRmt@jernej-laptop>
From:   Sergey Suloev <ssuloev@orpaltech.com>
Message-ID: <c75ec149-faee-2e56-4877-f7435dc0f376@orpaltech.com>
Date:   Fri, 18 May 2018 18:21:19 +0300
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Hi, Jernej,

On 05/18/2018 06:15 PM, Jernej Škrabec wrote:
> Hi,
>
> Dne petek, 18. maj 2018 ob 17:09:40 CEST je Sergey Suloev napisal(a):
>> Hi, guys,
>>
>> On 05/18/2018 05:46 PM, Jernej Škrabec wrote:
>>> Hi,
>>>
>>> Dne petek, 18. maj 2018 ob 12:01:16 CEST je Maxime Ripard napisal(a):
>>>> On Fri, May 18, 2018 at 03:15:22PM +0530, Jagan Teki wrote:
>>>>> From: Jernej Skrabec <jernej.skrabec@siol.net>
>>>>>
>>>>> Some SoCs with DW HDMI have multiple possible clock parents, like A64
>>>>> and R40.
>>>>>
>>>>> Expand HDMI PHY clock driver to support second clock parent.
>>>>>
>>>>> Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
>>>>> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
>>>>> ---
>>>>> Changes for v2:
>>>>> - new patch
>>>>>
>>>>>    drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h      |  9 ++-
>>>>>    drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c     | 33 ++++++++---
>>>>>    drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c | 89
>>>>>    ++++++++++++++++++++++-------- 3 files changed, 96 insertions(+), 35
>>>>>    deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
>>>>> b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h index 79154f0f674a..303189d6602c
>>>>> 100644
>>>>> --- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
>>>>> +++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
>>>>> @@ -98,7 +98,8 @@
>>>>>
>>>>>    #define SUN8I_HDMI_PHY_PLL_CFG1_LDO2_EN		BIT(29)
>>>>>    #define SUN8I_HDMI_PHY_PLL_CFG1_LDO1_EN		BIT(28)
>>>>>    #define SUN8I_HDMI_PHY_PLL_CFG1_HV_IS_33	BIT(27)
>>>>>
>>>>> -#define SUN8I_HDMI_PHY_PLL_CFG1_CKIN_SEL	BIT(26)
>>>>> +#define SUN8I_HDMI_PHY_PLL_CFG1_CKIN_SEL_MSK	BIT(26)
>>>>> +#define SUN8I_HDMI_PHY_PLL_CFG1_CKIN_SEL_SHIFT	26
>>>>>
>>>>>    #define SUN8I_HDMI_PHY_PLL_CFG1_PLLEN		BIT(25)
>>>>>    #define SUN8I_HDMI_PHY_PLL_CFG1_LDO_VSET(x)	((x) << 22)
>>>>>    #define SUN8I_HDMI_PHY_PLL_CFG1_UNKNOWN(x)	((x) << 20)
>>>>>
>>>>> @@ -146,7 +147,7 @@
>>>>>
>>>>>    struct sun8i_hdmi_phy;
>>>>>    
>>>>>    struct sun8i_hdmi_phy_variant {
>>>>>
>>>>> -	bool has_phy_clk;
>>>>> +	int  phy_clk_num;
>>>>>
>>>>>    	void (*phy_init)(struct sun8i_hdmi_phy *phy);
>>>>>    	void (*phy_disable)(struct dw_hdmi *hdmi,
>>>>>    	
>>>>>    			    struct sun8i_hdmi_phy *phy);
>>>>>
>>>>> @@ -160,6 +161,7 @@ struct sun8i_hdmi_phy {
>>>>>
>>>>>    	struct clk			*clk_mod;
>>>>>    	struct clk			*clk_phy;
>>>>>    	struct clk			*clk_pll0;
>>>>>
>>>>> +	struct clk			*clk_pll1;
>>>>>
>>>>>    	unsigned int			rcal;
>>>>>    	struct regmap			*regs;
>>>>>    	struct reset_control		*rst_phy;
>>>>>
>>>>> @@ -188,6 +190,7 @@ void sun8i_hdmi_phy_remove(struct sun8i_dw_hdmi
>>>>> *hdmi);
>>>>>
>>>>>    void sun8i_hdmi_phy_init(struct sun8i_hdmi_phy *phy);
>>>>>    const struct dw_hdmi_phy_ops *sun8i_hdmi_phy_get_ops(void);
>>>>>
>>>>> -int sun8i_phy_clk_create(struct sun8i_hdmi_phy *phy, struct device
>>>>> *dev);
>>>>> +int sun8i_phy_clk_create(struct sun8i_hdmi_phy *phy, struct device
>>>>> *dev,
>>>>> +			 int clk_num);
>>>>>
>>>>>    #endif /* _SUN8I_DW_HDMI_H_ */
>>>>>
>>>>> diff --git a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
>>>>> b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c index
>>>>> 5a52fc489a9d..0eadf087fc46
>>>>> 100644
>>>>> --- a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
>>>>> +++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
>>>>> @@ -183,7 +183,13 @@ static int sun8i_hdmi_phy_config_h3(struct dw_hdmi
>>>>> *hdmi,>
>>>>>
>>>>>    	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
>>>>>    	
>>>>>    			   SUN8I_HDMI_PHY_ANA_CFG1_TXEN_MASK, 0);
>>>>>
>>>>> -	regmap_write(phy->regs, SUN8I_HDMI_PHY_PLL_CFG1_REG, pll_cfg1_init);
>>>>> +	/*
>>>>> +	 * NOTE: We have to be careful not to overwrite PHY parent
>>>>> +	 * clock selection bit and clock divider.
>>>>> +	 */
>>>>> +	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_PLL_CFG1_REG,
>>>>> +			   (u32)~SUN8I_HDMI_PHY_PLL_CFG1_CKIN_SEL_MSK,
>>>>> +			   pll_cfg1_init);
>>>>>
>>>>>    	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_PLL_CFG2_REG,
>>>>>    	
>>>>>    			   (u32)~SUN8I_HDMI_PHY_PLL_CFG2_PREDIV_MSK,
>>>>>    			   pll_cfg2_init);
>>>>>
>>>>> @@ -232,7 +238,7 @@ static int sun8i_hdmi_phy_config(struct dw_hdmi
>>>>> *hdmi,
>>>>> void *data,>
>>>>>
>>>>>    	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_DBG_CTRL_REG,
>>>>>    	
>>>>>    			   SUN8I_HDMI_PHY_DBG_CTRL_POL_MASK, val);
>>>>>
>>>>> -	if (phy->variant->has_phy_clk)
>>>>> +	if (phy->variant->phy_clk_num)
>>>>>
>>>>>    		clk_set_rate(phy->clk_phy, mode->crtc_clock * 1000);
>>>>>    	
>>>>>    	return phy->variant->phy_config(hdmi, phy, mode->crtc_clock * 1000);
>>>>>
>>>>> @@ -393,7 +399,7 @@ static const struct sun8i_hdmi_phy_variant
>>>>> sun8i_a83t_hdmi_phy = {>
>>>>>
>>>>>    };
>>>>>    
>>>>>    static const struct sun8i_hdmi_phy_variant sun8i_h3_hdmi_phy = {
>>>>>
>>>>> -	.has_phy_clk = true,
>>>>> +	.phy_clk_num = 1,
>>>>>
>>>>>    	.phy_init = &sun8i_hdmi_phy_init_h3,
>>>>>    	.phy_disable = &sun8i_hdmi_phy_disable_h3,
>>>>>    	.phy_config = &sun8i_hdmi_phy_config_h3,
>>>>>
>>>>> @@ -464,7 +470,7 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi,
>>>>> struct device_node *node)>
>>>>>
>>>>>    		goto err_put_clk_bus;
>>>>>    	
>>>>>    	}
>>>>>
>>>>> -	if (phy->variant->has_phy_clk) {
>>>>> +	if (phy->variant->phy_clk_num) {
>>>>>
>>>>>    		phy->clk_pll0 = of_clk_get_by_name(node, "pll-0");
>>>>>    		if (IS_ERR(phy->clk_pll0)) {
>>>>>    		
>>>>>    			dev_err(dev, "Could not get pll-0 clock\n");
>>>>>
>>>>> @@ -472,7 +478,16 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi
>>>>> *hdmi,
>>>>> struct device_node *node)>
>>>>>
>>>>>    			goto err_put_clk_mod;
>>>>>    		
>>>>>    		}
>>>>>
>>>>> -		ret = sun8i_phy_clk_create(phy, dev);
>>>>> +		if (phy->variant->phy_clk_num) {
>>>>> +			phy->clk_pll1 = of_clk_get_by_name(node, "pll-1");
>>>>> +			if (IS_ERR(phy->clk_pll1)) {
>>>>> +				dev_err(dev, "Could not get pll-1 clock\n");
>>>>> +				ret = PTR_ERR(phy->clk_pll1);
>>>>> +				goto err_put_clk_mod;
>>>>> +			}
>>>>> +		}
>>>>> +
>>>> You have a bug here. If phy_clk_num == 1, you'll still try to lookup
>>>> pll-1.
>>> This is actually WIP patch taken from my github. This issue was fixed
>>> already locally on disk. I thought Jagan will not use it until SRAM C
>>> patches land.>
>>>> And this is a bit sloppy, since if phy_clk_num == 3, you won't try to
>>>> lookup pll-2 either.
>>> It is highly unlikely this will be higher than 2, at least for this HDMI
>>> PHY, since it has only 1 bit reserved for parent selection. But since I
>>> have to fix it, I'll add ">= 2"
>>>
>>>>> +		ret = sun8i_phy_clk_create(phy, dev, phy->variant->phy_clk_num);
>>>>>
>>>>>    		if (ret) {
>>>>>    		
>>>>>    			dev_err(dev, "Couldn't create the PHY clock\n");
>>>>>    			goto err_put_clk_pll0;
>>>>>
>>>>> @@ -515,8 +530,8 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi,
>>>>> struct device_node *node)>
>>>>>
>>>>>    err_put_rst_phy:
>>>>>    	reset_control_put(phy->rst_phy);
>>>>>    
>>>>>    err_put_clk_pll0:
>>>>> -	if (phy->variant->has_phy_clk)
>>>>> -		clk_put(phy->clk_pll0);
>>>>> +	clk_put(phy->clk_pll0);
>>>>> +	clk_put(phy->clk_pll1);
>>>>>
>>>>>    err_put_clk_mod:
>>>>>    	clk_put(phy->clk_mod);
>>>>>    
>>>>>    err_put_clk_bus:
>>>>> @@ -536,8 +551,8 @@ void sun8i_hdmi_phy_remove(struct sun8i_dw_hdmi
>>>>> *hdmi)
>>>>>
>>>>>    	reset_control_put(phy->rst_phy);
>>>>>
>>>>> -	if (phy->variant->has_phy_clk)
>>>>> -		clk_put(phy->clk_pll0);
>>>>> +	clk_put(phy->clk_pll0);
>>>>> +	clk_put(phy->clk_pll1);
>>>>>
>>>>>    	clk_put(phy->clk_mod);
>>>>>    	clk_put(phy->clk_bus);
>>>>>    
>>>>>    }
>>>>>
>>>>> diff --git a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c
>>>>> b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c index
>>>>> faea449812f8..85b12fc96dbc 100644
>>>>> --- a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c
>>>>> +++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c
>>>>> @@ -22,29 +22,36 @@ static int sun8i_phy_clk_determine_rate(struct
>>>>> clk_hw
>>>>> *hw,>
>>>>>
>>>>>    {
>>>>>    
>>>>>    	unsigned long rate = req->rate;
>>>>>    	unsigned long best_rate = 0;
>>>>>
>>>>> -	struct clk_hw *parent;
>>>>> +	struct clk_hw *best_parent = NULL;
>>>>> +	struct clk_hw *parent = NULL;
>>>>>
>>>>>    	int best_div = 1;
>>>>>
>>>>> -	int i;
>>>>> +	int i, p;
>>>>>
>>>>> -	parent = clk_hw_get_parent(hw);
>>>>> -
>>>>> -	for (i = 1; i <= 16; i++) {
>>>>> -		unsigned long ideal = rate * i;
>>>>> -		unsigned long rounded;
>>>>> -
>>>>> -		rounded = clk_hw_round_rate(parent, ideal);
>>>>> -
>>>>> -		if (rounded == ideal) {
>>>>> -			best_rate = rounded;
>>>>> -			best_div = i;
>>>>> -			break;
>>>>> -		}
>>>>> +	for (p = 0; p < clk_hw_get_num_parents(hw); p++) {
>>>>> +		parent = clk_hw_get_parent_by_index(hw, p);
>>>>> +		if (!parent)
>>>>> +			continue;
>>>>>
>>>>> -		if (!best_rate ||
>>>>> -		    abs(rate - rounded / i) <
>>>>> -		    abs(rate - best_rate / best_div)) {
>>>>> -			best_rate = rounded;
>>>>> -			best_div = i;
>>>>> +		for (i = 1; i <= 16; i++) {
>>>>> +			unsigned long ideal = rate * i;
>>>>> +			unsigned long rounded;
>>>>> +
>>>>> +			rounded = clk_hw_round_rate(parent, ideal);
>>>>> +
>>>>> +			if (rounded == ideal) {
>>>>> +				best_rate = rounded;
>>>>> +				best_div = i;
>>>>> +				best_parent = parent;
>>>>> +				break;
>>>>> +			}
>>>>> +
>>>>> +			if (!best_rate ||
>>>>> +			    abs(rate - rounded / i) <
>>>>> +			    abs(rate - best_rate / best_div)) {
>>>>> +				best_rate = rounded;
>>>>> +				best_div = i;
>>>>> +				best_parent = parent;
>>>>> +			}
>>>>>
>>>>>    		}
>>>>>    	
>>>>>    	}
>>>>>
>>>>> @@ -95,22 +102,58 @@ static int sun8i_phy_clk_set_rate(struct clk_hw
>>>>> *hw,
>>>>> unsigned long rate,>
>>>>>
>>>>>    	return 0;
>>>>>    
>>>>>    }
>>>>>
>>>>> +static u8 sun8i_phy_clk_get_parent(struct clk_hw *hw)
>>>>> +{
>>>>> +	struct sun8i_phy_clk *priv = hw_to_phy_clk(hw);
>>>>> +	u32 reg;
>>>>> +
>>>>> +	regmap_read(priv->phy->regs, SUN8I_HDMI_PHY_PLL_CFG1_REG, &reg);
>>>>> +	reg = (reg & SUN8I_HDMI_PHY_PLL_CFG1_CKIN_SEL_MSK) >>
>>>>> +	      SUN8I_HDMI_PHY_PLL_CFG1_CKIN_SEL_SHIFT;
>>>>> +
>>>>> +	return reg;
>>>>> +}
>>>>> +
>>>>> +static int sun8i_phy_clk_set_parent(struct clk_hw *hw, u8 index)
>>>>> +{
>>>>> +	struct sun8i_phy_clk *priv = hw_to_phy_clk(hw);
>>>>> +
>>>>> +	if (index > 1)
>>>>> +		return -EINVAL;
>>>>> +
>>>>> +	regmap_update_bits(priv->phy->regs, SUN8I_HDMI_PHY_PLL_CFG1_REG,
>>>>> +			   SUN8I_HDMI_PHY_PLL_CFG1_CKIN_SEL_MSK,
>>>>> +			   index << SUN8I_HDMI_PHY_PLL_CFG1_CKIN_SEL_SHIFT);
>>>>> +
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>> The DT bindings changes and the clk changes should be part of separate
>>>> patches.
>>> By DT bindings changes you mean code which reads DT and not DT
>>> documentation, right?
>>>
>>> Ok, I'll split it.
>>>
>>> BTW, I'll resend fixed version of this patch for my R40 HDMI series, since
>>> there is nothing to hold it back, unlike for this.
>>>
>>> Best regards,
>>> Jernej
>>>
>>>
>>>
>>> _______________________________________________
>>> linux-arm-kernel mailing list
>>> linux-arm-kernel@lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>> you have been talking about SRAM patches, required for A64 DE2, for
>> about a half a year.
>> May I ask you to explain in a couple of words why they are so important ?
>> I am really curious because I have DE2 already working on my A64 without
>> those magic patches..
>>
> You probably have HDMI enabled in U-Boot, right? If you disable that driver in
> U-Boot, Linux driver shouldn't work anymore. There is consensus that Linux A64
> DE2 driver shouldn't rely on U-Boot setting bits. Those SRAM C patches will
> probably also affect how DT DE2 entries are written, especially if it will be
> implemented as a bus, as once proposed by Icenowy.
>
> Best regards,
> Jernej
>
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

thanks, got it. yes , I think U-Boot is handing this for me. And I am 
not using the "bus way".