[PATCH v3 02/15] phy: rockchip-emmc: configure frequency range and drive impedance
From: dianders@chromium.org (Douglas Anderson)
Date: 2016-06-20 18:30:57
Also in:
linux-devicetree, linux-mmc, linux-rockchip, lkml
Subsystem:
arm/rockchip soc support, generic phy framework, the rest · Maintainers:
Heiko Stuebner, Vinod Koul, Linus Torvalds
From: Shawn Lin <shawn.lin@rock-chips.com> Signal integrity analysis has suggested we set these values. Do this in power_on(), so that they get reconfigured after suspend/resume. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Acked-by: Kishon Vijay Abraham I <redacted> Tested-by: Heiko Stuebner <heiko@sntech.de> --- Changes in v3: - Add Brian's PHY patches into my series Changes in v2: - Drop 170 MHz comment (only applicable to a subtly different Arasan PHY) drivers/phy/phy-rockchip-emmc.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/drivers/phy/phy-rockchip-emmc.c b/drivers/phy/phy-rockchip-emmc.c
index 48cbe691a889..f2f75cf69af1 100644
--- a/drivers/phy/phy-rockchip-emmc.c
+++ b/drivers/phy/phy-rockchip-emmc.c@@ -56,6 +56,19 @@ #define PHYCTRL_DLLRDY_SHIFT 0x5 #define PHYCTRL_DLLRDY_DONE 0x1 #define PHYCTRL_DLLRDY_GOING 0x0 +#define PHYCTRL_FREQSEL_200M 0x0 +#define PHYCTRL_FREQSEL_50M 0x1 +#define PHYCTRL_FREQSEL_100M 0x2 +#define PHYCTRL_FREQSEL_150M 0x3 +#define PHYCTRL_FREQSEL_MASK 0x3 +#define PHYCTRL_FREQSEL_SHIFT 0xc +#define PHYCTRL_DR_MASK 0x7 +#define PHYCTRL_DR_SHIFT 0x4 +#define PHYCTRL_DR_50OHM 0x0 +#define PHYCTRL_DR_33OHM 0x1 +#define PHYCTRL_DR_66OHM 0x2 +#define PHYCTRL_DR_100OHM 0x3 +#define PHYCTRL_DR_40OHM 0x4 struct rockchip_emmc_phy { unsigned int reg_offset;
@@ -154,6 +167,20 @@ static int rockchip_emmc_phy_power_on(struct phy *phy) struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy); int ret = 0; + /* DLL operation: 200 MHz */ + regmap_write(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_CON0, + HIWORD_UPDATE(PHYCTRL_FREQSEL_200M, + PHYCTRL_FREQSEL_MASK, + PHYCTRL_FREQSEL_SHIFT)); + + /* Drive impedance: 50 Ohm */ + regmap_write(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_CON6, + HIWORD_UPDATE(PHYCTRL_DR_50OHM, + PHYCTRL_DR_MASK, + PHYCTRL_DR_SHIFT)); + /* Power up emmc phy analog blocks */ ret = rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_ON); if (ret)
--
2.8.0.rc3.226.g39d4020