Commit a8cef928 authored by Chris Ruehl's avatar Chris Ruehl Committed by Vinod Koul
Browse files

phy: rockchip-emmc: output tap delay dt property 



Update the rockchip-emmc phy to set the otapdlysec register with
a dt property. This was mentioned from Brian Norris when he sent
the path to set the default value in the driver.
This patch add a dt property 'output-tapdelay-select' u32 and allow
to set the 0x0-0xf. If not set in dts, the old default 0x4 applies.

Tested with our customized rk3399 to tune the eMMC.

Signed-off-by: default avatarChris Ruehl <chris.ruehl@gtsys.com.hk>
Link: https://lore.kernel.org/r/20201202082507.3536-2-chris.ruehl@gtsys.com.hk


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 31de313d

drivers/phy/rockchip/phy-rockchip-emmc.c

+12 −1
Original line number Diff line number Diff line
@@ -65,6 +65,8 @@ 
#define PHYCTRL_OTAPDLYENA		0x1

#define PHYCTRL_OTAPDLYENA_MASK		0x1

#define PHYCTRL_OTAPDLYENA_SHIFT	0xb

#define PHYCTRL_OTAPDLYSEL_DEFAULT	0x4

#define PHYCTRL_OTAPDLYSEL_MAXVALUE	0xf

#define PHYCTRL_OTAPDLYSEL_MASK		0xf

#define PHYCTRL_OTAPDLYSEL_SHIFT	0x7

#define PHYCTRL_REN_STRB_DISABLE	0x0
@@ -85,6 +87,7 @@ struct rockchip_emmc_phy { 
	struct clk	*emmcclk;

	unsigned int drive_impedance;

	unsigned int enable_strobe_pulldown;

	unsigned int output_tapdelay_select;

};



static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
@@ -296,7 +299,7 @@ static int rockchip_emmc_phy_power_on(struct phy *phy) 
	/* Output tap delay */

	regmap_write(rk_phy->reg_base,

		     rk_phy->reg_offset + GRF_EMMCPHY_CON0,

		     HIWORD_UPDATE(4,

		     HIWORD_UPDATE(rk_phy->output_tapdelay_select,

				   PHYCTRL_OTAPDLYSEL_MASK,

				   PHYCTRL_OTAPDLYSEL_SHIFT));
@@ -372,6 +375,7 @@ static int rockchip_emmc_phy_probe(struct platform_device *pdev) 
	rk_phy->reg_base = grf;

	rk_phy->drive_impedance = PHYCTRL_DR_50OHM;

	rk_phy->enable_strobe_pulldown = PHYCTRL_REN_STRB_DISABLE;

	rk_phy->output_tapdelay_select = PHYCTRL_OTAPDLYSEL_DEFAULT;



	if (!of_property_read_u32(dev->of_node, "drive-impedance-ohm", &val))

		rk_phy->drive_impedance = convert_drive_impedance_ohm(pdev, val);
@@ -379,6 +383,13 @@ static int rockchip_emmc_phy_probe(struct platform_device *pdev) 
	if (of_property_read_bool(dev->of_node, "enable-strobe-pulldown"))

		rk_phy->enable_strobe_pulldown = PHYCTRL_REN_STRB_ENABLE;



	if (!of_property_read_u32(dev->of_node, "output-tapdelay-select", &val)) {

		if (val <= PHYCTRL_OTAPDLYSEL_MAXVALUE)

			rk_phy->output_tapdelay_select = val;

		else

			dev_err(dev, "output-tapdelay-select exceeds limit, apply default\n");

	}



	generic_phy = devm_phy_create(dev, dev->of_node, &ops);

	if (IS_ERR(generic_phy)) {

		dev_err(dev, "failed to create PHY\n");