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Message-ID: <20180518100116.4bf2qcffg7ekxa7u@flea>
Date: Fri, 18 May 2018 12:01:16 +0200
From: Maxime Ripard <maxime.ripard@...tlin.com>
To: Jagan Teki <jagan@...rulasolutions.com>
Cc: Chen-Yu Tsai <wens@...e.org>, Icenowy Zheng <icenowy@...c.io>,
Jernej Skrabec <jernej.skrabec@...l.net>,
Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
David Airlie <airlied@...ux.ie>,
dri-devel@...ts.freedesktop.org,
Michael Turquette <mturquette@...libre.com>,
Stephen Boyd <sboyd@...nel.org>, linux-clk@...r.kernel.org,
Michael Trimarchi <michael@...rulasolutions.com>,
linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-sunxi@...glegroups.com
Subject: Re: [PATCH v2 12/26] drm/sun4i: Add support for multiple DW HDMI PHY
clock parents
On Fri, May 18, 2018 at 03:15:22PM +0530, Jagan Teki wrote:
> From: Jernej Skrabec <jernej.skrabec@...l.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@...l.net>
> Signed-off-by: Jagan Teki <jagan@...rulasolutions.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.
And this is a bit sloppy, since if phy_clk_num == 3, you won't try to
lookup pll-2 either.
> + 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 & 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.
Maxime
--
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
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