| Message ID | 20190307084159.25236-1-christoph.muellner@theobroma-systems.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/4] phy: rockchip-emmc: Allow to set drive impedance via DTS. | expand |
Am Donnerstag, 7. März 2019, 09:41:53 CET schrieb Christoph Muellner: > The rockchip-emmc PHY can be configured with different > drive impedance values. Currenlty a value of 50 Ohm is > hard coded into the driver. > > This patch introduces the DTS property 'drive-impedance-ohm' > for the rockchip-emmc phy node, which uses the value from the DTS > to setup the drive impedance accordingly. > > Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com> > Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com> change itself looks good Reviewed-by: Heiko Stuebner <heiko@sntech.de> Though I cannot say too much about the electrical side. Heiko > --- > drivers/phy/rockchip/phy-rockchip-emmc.c | 30 ++++++++++++++++++++++++++++-- > 1 file changed, 28 insertions(+), 2 deletions(-) > > diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c b/drivers/phy/rockchip/phy-rockchip-emmc.c > index 19bf84f0bc67..b804c6bf4b55 100644 > --- a/drivers/phy/rockchip/phy-rockchip-emmc.c > +++ b/drivers/phy/rockchip/phy-rockchip-emmc.c > @@ -87,6 +87,7 @@ struct rockchip_emmc_phy { > unsigned int reg_offset; > struct regmap *reg_base; > struct clk *emmcclk; > + unsigned int drive_impedance; > }; > > static int rockchip_emmc_phy_power(struct phy *phy, bool on_off) > @@ -281,10 +282,10 @@ static int rockchip_emmc_phy_power_on(struct phy *phy) > { > struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy); > > - /* Drive impedance: 50 Ohm */ > + /* Drive impedance: from DTS */ > regmap_write(rk_phy->reg_base, > rk_phy->reg_offset + GRF_EMMCPHY_CON6, > - HIWORD_UPDATE(PHYCTRL_DR_50OHM, > + HIWORD_UPDATE(rk_phy->drive_impedance, > PHYCTRL_DR_MASK, > PHYCTRL_DR_SHIFT)); > > @@ -314,6 +315,26 @@ static const struct phy_ops ops = { > .owner = THIS_MODULE, > }; > > +static u32 convert_drive_impedance_ohm(struct platform_device *pdev, u32 dr_ohm) > +{ > + switch (dr_ohm) { > + case 100: > + return PHYCTRL_DR_100OHM; > + case 66: > + return PHYCTRL_DR_66OHM; > + case 50: > + return PHYCTRL_DR_50OHM; > + case 40: > + return PHYCTRL_DR_40OHM; > + case 33: > + return PHYCTRL_DR_33OHM; > + } > + > + dev_warn(&pdev->dev, "Invalid value %u for drive-impedance-ohm.\n", > + dr_ohm); > + return PHYCTRL_DR_50OHM; > +} > + > static int rockchip_emmc_phy_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -322,6 +343,7 @@ static int rockchip_emmc_phy_probe(struct platform_device *pdev) > struct phy_provider *phy_provider; > struct regmap *grf; > unsigned int reg_offset; > + u32 val; > > if (!dev->parent || !dev->parent->of_node) > return -ENODEV; > @@ -344,6 +366,10 @@ 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; > + > + if (!of_property_read_u32(dev->of_node, "drive-impedance-ohm", &val)) > + rk_phy->drive_impedance = convert_drive_impedance_ohm(pdev, val); > > generic_phy = devm_phy_create(dev, dev->of_node, &ops); > if (IS_ERR(generic_phy)) { >
diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c b/drivers/phy/rockchip/phy-rockchip-emmc.c index 19bf84f0bc67..b804c6bf4b55 100644 --- a/drivers/phy/rockchip/phy-rockchip-emmc.c +++ b/drivers/phy/rockchip/phy-rockchip-emmc.c @@ -87,6 +87,7 @@ struct rockchip_emmc_phy { unsigned int reg_offset; struct regmap *reg_base; struct clk *emmcclk; + unsigned int drive_impedance; }; static int rockchip_emmc_phy_power(struct phy *phy, bool on_off) @@ -281,10 +282,10 @@ static int rockchip_emmc_phy_power_on(struct phy *phy) { struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy); - /* Drive impedance: 50 Ohm */ + /* Drive impedance: from DTS */ regmap_write(rk_phy->reg_base, rk_phy->reg_offset + GRF_EMMCPHY_CON6, - HIWORD_UPDATE(PHYCTRL_DR_50OHM, + HIWORD_UPDATE(rk_phy->drive_impedance, PHYCTRL_DR_MASK, PHYCTRL_DR_SHIFT)); @@ -314,6 +315,26 @@ static const struct phy_ops ops = { .owner = THIS_MODULE, }; +static u32 convert_drive_impedance_ohm(struct platform_device *pdev, u32 dr_ohm) +{ + switch (dr_ohm) { + case 100: + return PHYCTRL_DR_100OHM; + case 66: + return PHYCTRL_DR_66OHM; + case 50: + return PHYCTRL_DR_50OHM; + case 40: + return PHYCTRL_DR_40OHM; + case 33: + return PHYCTRL_DR_33OHM; + } + + dev_warn(&pdev->dev, "Invalid value %u for drive-impedance-ohm.\n", + dr_ohm); + return PHYCTRL_DR_50OHM; +} + static int rockchip_emmc_phy_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -322,6 +343,7 @@ static int rockchip_emmc_phy_probe(struct platform_device *pdev) struct phy_provider *phy_provider; struct regmap *grf; unsigned int reg_offset; + u32 val; if (!dev->parent || !dev->parent->of_node) return -ENODEV; @@ -344,6 +366,10 @@ 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; + + if (!of_property_read_u32(dev->of_node, "drive-impedance-ohm", &val)) + rk_phy->drive_impedance = convert_drive_impedance_ohm(pdev, val); generic_phy = devm_phy_create(dev, dev->of_node, &ops); if (IS_ERR(generic_phy)) {