Re: [PATCH v2 12/26] drm/sun4i: Add support for multiple DW HDMI PHY clock parents

From: Sergey Suloev
Date: Fri May 18 2018 - 10:25:28 EST


Hi, Jernej,

On 05/18/2018 06:15 PM, Jernej Åkrabec 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 Åkrabec 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@xxxxxxxx>

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@xxxxxxxx>
Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
---
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



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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



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