diff options
Diffstat (limited to 'drivers/phy/rockchip/phy-rockchip-emmc.c')
| -rw-r--r-- | drivers/phy/rockchip/phy-rockchip-emmc.c | 379 |
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c b/drivers/phy/rockchip/phy-rockchip-emmc.c new file mode 100644 index 000000000..b237360f9 --- /dev/null +++ b/drivers/phy/rockchip/phy-rockchip-emmc.c @@ -0,0 +1,379 @@ +/* + * Rockchip emmc PHY driver + * + * Copyright (C) 2016 Shawn Lin <shawn.lin@rock-chips.com> + * Copyright (C) 2016 ROCKCHIP, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +/* + * The higher 16-bit of this register is used for write protection + * only if BIT(x + 16) set to 1 the BIT(x) can be written. + */ +#define HIWORD_UPDATE(val, mask, shift) \ + ((val) << (shift) | (mask) << ((shift) + 16)) + +/* Register definition */ +#define GRF_EMMCPHY_CON0 0x0 +#define GRF_EMMCPHY_CON1 0x4 +#define GRF_EMMCPHY_CON2 0x8 +#define GRF_EMMCPHY_CON3 0xc +#define GRF_EMMCPHY_CON4 0x10 +#define GRF_EMMCPHY_CON5 0x14 +#define GRF_EMMCPHY_CON6 0x18 +#define GRF_EMMCPHY_STATUS 0x20 + +#define PHYCTRL_PDB_MASK 0x1 +#define PHYCTRL_PDB_SHIFT 0x0 +#define PHYCTRL_PDB_PWR_ON 0x1 +#define PHYCTRL_PDB_PWR_OFF 0x0 +#define PHYCTRL_ENDLL_MASK 0x1 +#define PHYCTRL_ENDLL_SHIFT 0x1 +#define PHYCTRL_ENDLL_ENABLE 0x1 +#define PHYCTRL_ENDLL_DISABLE 0x0 +#define PHYCTRL_CALDONE_MASK 0x1 +#define PHYCTRL_CALDONE_SHIFT 0x6 +#define PHYCTRL_CALDONE_DONE 0x1 +#define PHYCTRL_CALDONE_GOING 0x0 +#define PHYCTRL_DLLRDY_MASK 0x1 +#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 +#define PHYCTRL_OTAPDLYENA 0x1 +#define PHYCTRL_OTAPDLYENA_MASK 0x1 +#define PHYCTRL_OTAPDLYENA_SHIFT 0xb +#define PHYCTRL_OTAPDLYSEL_MASK 0xf +#define PHYCTRL_OTAPDLYSEL_SHIFT 0x7 + +#define PHYCTRL_IS_CALDONE(x) \ + ((((x) >> PHYCTRL_CALDONE_SHIFT) & \ + PHYCTRL_CALDONE_MASK) == PHYCTRL_CALDONE_DONE) +#define PHYCTRL_IS_DLLRDY(x) \ + ((((x) >> PHYCTRL_DLLRDY_SHIFT) & \ + PHYCTRL_DLLRDY_MASK) == PHYCTRL_DLLRDY_DONE) + +struct rockchip_emmc_phy { + unsigned int reg_offset; + struct regmap *reg_base; + struct clk *emmcclk; +}; + +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 rate; + int ret; + + /* + * Keep phyctrl_pdb and phyctrl_endll low to allow + * initialization of CALIO state M/C DFFs + */ + regmap_write(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_CON6, + HIWORD_UPDATE(PHYCTRL_PDB_PWR_OFF, + PHYCTRL_PDB_MASK, + PHYCTRL_PDB_SHIFT)); + regmap_write(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_CON6, + HIWORD_UPDATE(PHYCTRL_ENDLL_DISABLE, + PHYCTRL_ENDLL_MASK, + PHYCTRL_ENDLL_SHIFT)); + + /* Already finish power_off above */ + if (on_off == PHYCTRL_PDB_PWR_OFF) + return 0; + + rate = clk_get_rate(rk_phy->emmcclk); + + if (rate != 0) { + unsigned long ideal_rate; + unsigned long diff; + + switch (rate) { + case 1 ... 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); + } + + /* + * According to the user manual, calpad calibration + * cycle takes more than 2us without the minimal recommended + * value, so we may need a little margin here + */ + udelay(3); + regmap_write(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_CON6, + HIWORD_UPDATE(PHYCTRL_PDB_PWR_ON, + PHYCTRL_PDB_MASK, + PHYCTRL_PDB_SHIFT)); + + /* + * According to the user manual, it asks driver to wait 5us for + * calpad busy trimming. However it is documented that this value is + * PVT(A.K.A process,voltage and temperature) relevant, so some + * failure cases are found which indicates we should be more tolerant + * to calpad busy trimming. + */ + ret = regmap_read_poll_timeout(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_STATUS, + caldone, PHYCTRL_IS_CALDONE(caldone), + 0, 50); + if (ret) { + pr_err("%s: caldone failed, ret=%d\n", __func__, ret); + return ret; + } + + /* 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, + PHYCTRL_ENDLL_MASK, + PHYCTRL_ENDLL_SHIFT)); + + /* + * We turned on the DLL even though the rate was 0 because we the + * clock might be turned on later. ...but we can't wait for the DLL + * to lock when the rate is 0 because it will never lock with no + * input clock. + * + * Technically we should be checking the lock later when the clock + * is turned on, but for now we won't. + */ + if (rate == 0) + return 0; + + /* + * After enabling analog DLL circuits docs say that we need 10.2 us if + * our source clock is at 50 MHz and that lock time scales linearly + * with clock speed. If we are powering on the PHY and the card clock + * is super slow (like 100 kHZ) this could take as long as 5.1 ms as + * per the math: 10.2 us * (50000000 Hz / 100000 Hz) => 5.1 ms + * Hopefully we won't be running at 100 kHz, but we should still make + * sure we wait long enough. + * + * NOTE: There appear to be corner cases where the DLL seems to take + * extra long to lock for reasons that aren't understood. In some + * extreme cases we've seen it take up to over 10ms (!). We'll be + * generous and give it 50ms. + */ + ret = regmap_read_poll_timeout(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_STATUS, + dllrdy, PHYCTRL_IS_DLLRDY(dllrdy), + 0, 50 * USEC_PER_MSEC); + if (ret) { + pr_err("%s: dllrdy failed. ret=%d\n", __func__, ret); + return ret; + } + + return 0; +} + +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(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); + + /* 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)); + + /* Output tap delay: enable */ + regmap_write(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_CON0, + HIWORD_UPDATE(PHYCTRL_OTAPDLYENA, + PHYCTRL_OTAPDLYENA_MASK, + PHYCTRL_OTAPDLYENA_SHIFT)); + + /* Output tap delay */ + regmap_write(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_CON0, + HIWORD_UPDATE(4, + PHYCTRL_OTAPDLYSEL_MASK, + PHYCTRL_OTAPDLYSEL_SHIFT)); + + /* Power up emmc phy analog blocks */ + 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, +}; + +static int rockchip_emmc_phy_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rockchip_emmc_phy *rk_phy; + struct phy *generic_phy; + struct phy_provider *phy_provider; + struct regmap *grf; + unsigned int reg_offset; + + if (!dev->parent || !dev->parent->of_node) + return -ENODEV; + + grf = syscon_node_to_regmap(dev->parent->of_node); + if (IS_ERR(grf)) { + dev_err(dev, "Missing rockchip,grf property\n"); + return PTR_ERR(grf); + } + + rk_phy = devm_kzalloc(dev, sizeof(*rk_phy), GFP_KERNEL); + if (!rk_phy) + return -ENOMEM; + + if (of_property_read_u32(dev->of_node, "reg", ®_offset)) { + dev_err(dev, "missing reg property in node %s\n", + dev->of_node->name); + return -EINVAL; + } + + rk_phy->reg_offset = reg_offset; + rk_phy->reg_base = grf; + + generic_phy = devm_phy_create(dev, dev->of_node, &ops); + if (IS_ERR(generic_phy)) { + dev_err(dev, "failed to create PHY\n"); + return PTR_ERR(generic_phy); + } + + phy_set_drvdata(generic_phy, rk_phy); + phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); + + return PTR_ERR_OR_ZERO(phy_provider); +} + +static const struct of_device_id rockchip_emmc_phy_dt_ids[] = { + { .compatible = "rockchip,rk3399-emmc-phy" }, + {} +}; + +MODULE_DEVICE_TABLE(of, rockchip_emmc_phy_dt_ids); + +static struct platform_driver rockchip_emmc_driver = { + .probe = rockchip_emmc_phy_probe, + .driver = { + .name = "rockchip-emmc-phy", + .of_match_table = rockchip_emmc_phy_dt_ids, + }, +}; + +module_platform_driver(rockchip_emmc_driver); + +MODULE_AUTHOR("Shawn Lin <shawn.lin@rock-chips.com>"); +MODULE_DESCRIPTION("Rockchip EMMC PHY driver"); +MODULE_LICENSE("GPL v2"); |