On Tuesday 14 June 2016 04:34 AM, Douglas Anderson wrote: > The "phyctrl_frqsel" is described in the Arasan datasheet [1] as "the > frequency range of DLL operation". Although the Rockchip variant of > this PHY has different ranges than the reference Arasan PHY it appears > as if the functionality is similar. We should set this phyctrl field > properly. > > Note: as per Rockchip engineers, apparently the "phyctrl_frqsel" is > actually only useful in HS200 / HS400 modes even though the DLL itself > it used for some purposes in all modes. See the discussion in the > earlier change in this series: ("mmc: sdhci-of-arasan: Always power the > PHY off/on when clock changes"). In any case, it shouldn't hurt to set > this always. > > Note that this change should allow boards to run at HS200 / HS400 speed > modes while running at 100 MHz or 150 MHz. In fact, running HS400 at > 150 MHz (giving 300 MB/s) is the main motivation of this series, since > performance is still good but signal integrity problems are less > prevelant at 150 MHz. > > [1]: https://arasan.com/wp-content/media/eMMC-5-1-Total-Solution_Rev-1-3.pdf > > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx> > --- > Changes in v2: > - Warn if we're more than 15 MHz from ideal rate (Shawn) > - Move code cleanup before set phyctrl_frqsel based on card clock (Shawn) > - Fix typo USB => SDHCI (Shawn) > > drivers/phy/phy-rockchip-emmc.c | 82 ++++++++++++++++++++++++++++++++++------- > 1 file changed, 69 insertions(+), 13 deletions(-) > > diff --git a/drivers/phy/phy-rockchip-emmc.c b/drivers/phy/phy-rockchip-emmc.c > index 23fe50864526..51ddd543fd04 100644 > --- a/drivers/phy/phy-rockchip-emmc.c > +++ b/drivers/phy/phy-rockchip-emmc.c > @@ -14,6 +14,7 @@ > * GNU General Public License for more details. > */ > > +#include <linux/clk.h> > #include <linux/delay.h> > #include <linux/mfd/syscon.h> > #include <linux/module.h> > @@ -78,16 +79,73 @@ > struct rockchip_emmc_phy { > unsigned int reg_offset; > struct regmap *reg_base; > + struct clk *emmcclk; > }; > > -static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy, > - bool on_off) > +static int rockchip_emmc_phy_power(struct phy *phy, bool on_off) > { > + struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy); > unsigned int caldone; > unsigned int dllrdy; > + unsigned int freqsel = PHYCTRL_FREQSEL_200M; > unsigned long timeout; > > /* > + * We purposely get the clock here and not in probe to avoid the > + * circular dependency problem. We expect: > + * - PHY driver to probe > + * - SDHCI driver to start probe > + * - SDHCI driver to register it's clock > + * - SDHCI driver to get the PHY > + * - SDHCI driver to power on the PHY > + */ > + if (!rk_phy->emmcclk) { > + rk_phy->emmcclk = devm_clk_get(&phy->dev, "emmcclk"); > + > + /* Don't expect defer at this point; try next time */ > + if (PTR_ERR(rk_phy->emmcclk) == -EPROBE_DEFER) { > + dev_warn(&phy->dev, "Unexpected emmcclk defer\n"); > + rk_phy->emmcclk = NULL; > + } > + } > + > + if (!IS_ERR_OR_NULL(rk_phy->emmcclk)) { > + unsigned long rate = clk_get_rate(rk_phy->emmcclk); > + unsigned long ideal_rate; > + unsigned long diff; > + > + switch (rate) { > + case 0 ... 74999999: > + ideal_rate = 50000000; > + freqsel = PHYCTRL_FREQSEL_50M; > + break; > + case 75000000 ... 124999999: > + ideal_rate = 100000000; > + freqsel = PHYCTRL_FREQSEL_100M; > + break; > + case 125000000 ... 174999999: > + ideal_rate = 150000000; > + freqsel = PHYCTRL_FREQSEL_150M; > + break; > + default: > + ideal_rate = 200000000; > + break; > + }; > + > + diff = (rate > ideal_rate) ? > + rate - ideal_rate : ideal_rate - rate; > + > + /* > + * In order for tuning delays to be accurate we need to be > + * pretty spot on for the DLL range, so warn if we're too > + * far off. Also warn if we're above the 200 MHz max. Don't > + * warn for really slow rates since we won't be tuning then. > + */ > + if ((rate > 50000000 && diff > 15000000) || (rate > 200000000)) > + dev_warn(&phy->dev, "Unsupported rate: %lu\n", rate); > + } > + > + /* > * Keep phyctrl_pdb and phyctrl_endll low to allow > * initialization of CALIO state M/C DFFs > */ > @@ -132,6 +190,13 @@ static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy, > return -ETIMEDOUT; > } > > + /* Set the frequency of the DLL operation */ > + regmap_write(rk_phy->reg_base, > + rk_phy->reg_offset + GRF_EMMCPHY_CON0, > + HIWORD_UPDATE(freqsel, PHYCTRL_FREQSEL_MASK, > + PHYCTRL_FREQSEL_SHIFT)); > + > + /* Turn on the DLL */ > regmap_write(rk_phy->reg_base, > rk_phy->reg_offset + GRF_EMMCPHY_CON6, > HIWORD_UPDATE(PHYCTRL_ENDLL_ENABLE, > @@ -168,23 +233,14 @@ static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy, > > static int rockchip_emmc_phy_power_off(struct phy *phy) > { > - struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy); > - > /* Power down emmc phy analog blocks */ > - return rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_OFF); > + return rockchip_emmc_phy_power(phy, PHYCTRL_PDB_PWR_OFF); > } > > static int rockchip_emmc_phy_power_on(struct phy *phy) > { > struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy); > > - /* 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, > @@ -207,7 +263,7 @@ static int rockchip_emmc_phy_power_on(struct phy *phy) > PHYCTRL_OTAPDLYSEL_SHIFT)); > > /* Power up emmc phy analog blocks */ > - return rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_ON); > + return rockchip_emmc_phy_power(phy, PHYCTRL_PDB_PWR_ON); > } > > static const struct phy_ops ops = { > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html