diff options
Diffstat (limited to 'drivers/phy/phy-rockchip-emmc.c')
| -rw-r--r-- | drivers/phy/phy-rockchip-emmc.c | 101 |
1 files changed, 89 insertions, 12 deletions
diff --git a/drivers/phy/phy-rockchip-emmc.c b/drivers/phy/phy-rockchip-emmc.c index 23fe50864526..9dce958233a0 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> @@ -78,15 +79,53 @@ 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; + if (rk_phy->emmcclk != NULL) { + 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 +171,13 @@ 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, @@ -166,25 +212,54 @@ static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy, return 0; } -static int rockchip_emmc_phy_power_off(struct phy *phy) +static int rockchip_emmc_phy_init(struct phy *phy) +{ + struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy); + int ret = 0; + + /* + * 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 init the PHY + * + * The clock is optional, so upon any error we just set to NULL. + * + * NOTE: we don't do anything special for EPROBE_DEFER here. Given the + * above expected use case, EPROBE_DEFER isn't sensible to expect, so + * it's just like any other error. + */ + rk_phy->emmcclk = clk_get(&phy->dev, "emmcclk"); + if (IS_ERR(rk_phy->emmcclk)) { + dev_dbg(&phy->dev, "Error getting emmcclk: %d\n", ret); + rk_phy->emmcclk = NULL; + } + + return ret; +} + +static int rockchip_emmc_phy_exit(struct phy *phy) { struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy); + clk_put(rk_phy->emmcclk); + + return 0; +} + +static int rockchip_emmc_phy_power_off(struct phy *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, @@ -207,10 +282,12 @@ 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 = { + .init = rockchip_emmc_phy_init, + .exit = rockchip_emmc_phy_exit, .power_on = rockchip_emmc_phy_power_on, .power_off = rockchip_emmc_phy_power_off, .owner = THIS_MODULE, |
