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-rw-r--r--drivers/phy/rockchip/phy-rockchip-emmc.c399
1 files changed, 399 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..a005fc58b
--- /dev/null
+++ b/drivers/phy/rockchip/phy-rockchip-emmc.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Rockchip emmc PHY driver
+ *
+ * Copyright (C) 2016 Shawn Lin <shawn.lin@rock-chips.com>
+ * Copyright (C) 2016 ROCKCHIP, Inc.
+ */
+
+#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;
+ unsigned int drive_impedance;
+};
+
+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, using clk_get_optional() to get the clock
+ * and do error processing if the return value != 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_optional(&phy->dev, "emmcclk");
+ if (IS_ERR(rk_phy->emmcclk)) {
+ ret = PTR_ERR(rk_phy->emmcclk);
+ dev_err(&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: from DTS */
+ regmap_write(rk_phy->reg_base,
+ rk_phy->reg_offset + GRF_EMMCPHY_CON6,
+ HIWORD_UPDATE(rk_phy->drive_impedance,
+ 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 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;
+ struct rockchip_emmc_phy *rk_phy;
+ struct phy *generic_phy;
+ struct phy_provider *phy_provider;
+ struct regmap *grf;
+ unsigned int reg_offset;
+ u32 val;
+
+ 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", &reg_offset)) {
+ dev_err(dev, "missing reg property in node %pOFn\n",
+ dev->of_node);
+ return -EINVAL;
+ }
+
+ 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)) {
+ 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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 07:21:45 +0000