[PATCH v3 2/2] phy: add a driver for the Rockchip SoC internal eMMC PHY

From: Shawn Lin
Date: Wed Feb 03 2016 - 02:27:08 EST


This patch to add a generic PHY driver for ROCKCHIP eMMC PHY.
Access the PHY via registers provided by GRF (general register
files) module.

Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>

---

Changes in v3:
- remove empty init/exit
- fix copyright timestamp
- add comment for delay

Changes in v2:
- remove phy from rockchip_emmc_phy
- remove state from rockchip_emmc_phy
- remove on/off from init/exit

drivers/phy/Kconfig | 7 ++
drivers/phy/Makefile | 1 +
drivers/phy/phy-rockchip-emmc.c | 229 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 237 insertions(+)
create mode 100644 drivers/phy/phy-rockchip-emmc.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index e7e117d..d90e798 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -336,6 +336,13 @@ config PHY_ROCKCHIP_USB
help
Enable this to support the Rockchip USB 2.0 PHY.

+config PHY_ROCKCHIP_EMMC
+ tristate "Rockchip EMMC PHY Driver"
+ depends on ARCH_ROCKCHIP && OF
+ select GENERIC_PHY
+ help
+ Enable this to support the Rockchip EMMC PHY.
+
config PHY_ST_SPEAR1310_MIPHY
tristate "ST SPEAR1310-MIPHY driver"
select GENERIC_PHY
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index c80f09d..50260b4 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -37,6 +37,7 @@ phy-exynos-usb2-$(CONFIG_PHY_S5PV210_USB2) += phy-s5pv210-usb2.o
obj-$(CONFIG_PHY_EXYNOS5_USBDRD) += phy-exynos5-usbdrd.o
obj-$(CONFIG_PHY_QCOM_APQ8064_SATA) += phy-qcom-apq8064-sata.o
obj-$(CONFIG_PHY_ROCKCHIP_USB) += phy-rockchip-usb.o
+obj-$(CONFIG_PHY_ROCKCHIP_EMMC) += phy-rockchip-emmc.o
obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA) += phy-qcom-ipq806x-sata.o
obj-$(CONFIG_PHY_ST_SPEAR1310_MIPHY) += phy-spear1310-miphy.o
obj-$(CONFIG_PHY_ST_SPEAR1340_MIPHY) += phy-spear1340-miphy.o
diff --git a/drivers/phy/phy-rockchip-emmc.c b/drivers/phy/phy-rockchip-emmc.c
new file mode 100644
index 0000000..887b4c2
--- /dev/null
+++ b/drivers/phy/phy-rockchip-emmc.c
@@ -0,0 +1,229 @@
+/*
+ * Rockchip emmc PHY driver
+ *
+ * Copyright (C) 2016 Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
+ * 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/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
+
+struct rockchip_emmc_phy {
+ unsigned int reg_offset;
+ struct regmap *reg_base;
+};
+
+static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy,
+ bool on_off)
+{
+ unsigned int caldone;
+ unsigned int dllrdy;
+
+ /*
+ * 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;
+
+ /*
+ * 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
+ */
+ udelay(5);
+ regmap_read(rk_phy->reg_base,
+ rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
+ &caldone);
+ caldone = (caldone >> PHYCTRL_CALDONE_SHIFT) & PHYCTRL_CALDONE_MASK;
+ if (caldone != PHYCTRL_CALDONE_DONE) {
+ pr_err("rockchip_emmc_phy_power: caldone timeout.\n");
+ return -ETIMEDOUT;
+ }
+
+ regmap_write(rk_phy->reg_base,
+ rk_phy->reg_offset + GRF_EMMCPHY_CON6,
+ HIWORD_UPDATE(PHYCTRL_ENDLL_ENABLE,
+ PHYCTRL_ENDLL_MASK,
+ PHYCTRL_ENDLL_SHIFT));
+ /*
+ * After enable analog DLL circuits, we need extra 10.2us
+ * for dll to be ready for work.
+ */
+ udelay(11);
+ regmap_read(rk_phy->reg_base,
+ rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
+ &dllrdy);
+ dllrdy = (dllrdy >> PHYCTRL_DLLRDY_SHIFT) & PHYCTRL_DLLRDY_MASK;
+ if (dllrdy != PHYCTRL_DLLRDY_DONE) {
+ pr_err("rockchip_emmc_phy_power: dllrdy timeout.\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static int rockchip_emmc_phy_power_off(struct phy *phy)
+{
+ struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy);
+ int ret = 0;
+
+ /* Power down emmc phy analog blocks */
+ ret = rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_OFF);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int rockchip_emmc_phy_power_on(struct phy *phy)
+{
+ struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy);
+ int ret = 0;
+
+ /* Power up emmc phy analog blocks */
+ ret = rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_ON);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static const struct phy_ops ops = {
+ .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;
+
+ grf = syscon_regmap_lookup_by_phandle(dev->of_node, "rockchip,grf");
+ 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 %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@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Rockchip EMMC PHY driver");
+MODULE_LICENSE("GPL v2");
--
2.3.7