/* * 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");