This patch add support to set the internal pulldown via dt property
and allow simplify the board design for the trace from emmc-phy to
the eMMC chipset.
Default to not set the pull-down.
This patch was inspired from the 4.4 tree of the
Rockchip SDK, where it is enabled unconditional.
The patch had been tested with our rk3399 customized board.
Signed-off-by: Chris Ruehl <chris.ruehl@xxxxxxxxxxxx>
---
drivers/phy/rockchip/phy-rockchip-emmc.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c b/drivers/phy/rockchip/phy-rockchip-emmc.c
index 2dc19ddd120f..48e2d75b1004 100644
--- a/drivers/phy/rockchip/phy-rockchip-emmc.c
+++ b/drivers/phy/rockchip/phy-rockchip-emmc.c
@@ -67,6 +67,10 @@
#define PHYCTRL_OTAPDLYENA_SHIFT 0xb
#define PHYCTRL_OTAPDLYSEL_MASK 0xf
#define PHYCTRL_OTAPDLYSEL_SHIFT 0x7
+#define PHYCTRL_REN_STRB_DISABLE 0x0
+#define PHYCTRL_REN_STRB_ENABLE 0x1
+#define PHYCTRL_REN_STRB_MASK 0x1
+#define PHYCTRL_REN_STRB_SHIFT 0x9
#define PHYCTRL_IS_CALDONE(x) \
((((x) >> PHYCTRL_CALDONE_SHIFT) & \
@@ -80,6 +84,7 @@ struct rockchip_emmc_phy {
struct regmap *reg_base;
struct clk *emmcclk;
unsigned int drive_impedance;
+ unsigned int enable_strobe_pulldown;
};
static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
@@ -295,6 +300,13 @@ static int rockchip_emmc_phy_power_on(struct phy *phy)
PHYCTRL_OTAPDLYSEL_MASK,
PHYCTRL_OTAPDLYSEL_SHIFT));
+ /* Internal pull-down for strobe line */
+ regmap_write(rk_phy->reg_base,
+ rk_phy->reg_offset + GRF_EMMCPHY_CON2,
+ HIWORD_UPDATE(rk_phy->enable_strobe_pulldown,
+ PHYCTRL_REN_STRB_MASK,
+ PHYCTRL_REN_STRB_SHIFT));
+
/* Power up emmc phy analog blocks */
return rockchip_emmc_phy_power(phy, PHYCTRL_PDB_PWR_ON);
}
@@ -359,10 +371,14 @@ static int rockchip_emmc_phy_probe(struct platform_device *pdev)
rk_phy->reg_offset = reg_offset;
rk_phy->reg_base = grf;
rk_phy->drive_impedance = PHYCTRL_DR_50OHM;
+ rk_phy->enable_strobe_pulldown = PHYCTRL_REN_STRB_DISABLE;
if (!of_property_read_u32(dev->of_node, "drive-impedance-ohm", &val))
rk_phy->drive_impedance = convert_drive_impedance_ohm(pdev, val);
+ if (of_property_read_bool(dev->of_node, "enable-strobe-pulldown"))
+ rk_phy->enable_strobe_pulldown = PHYCTRL_REN_STRB_ENABLE;
+
generic_phy = devm_phy_create(dev, dev->of_node, &ops);
if (IS_ERR(generic_phy)) {
dev_err(dev, "failed to create PHY\n");
--
2.20.1
