phy: qcom-ufs: add support for QUALCOMM Technologies UFS PHY drivers

This change adds a generic and common API support for ufs phy QUALCOMM
Technologies. This support provides common code and also points
to specific phy callbacks to differentiate between different behaviors
of frequent use-cases (like power on, power off, phy calibration etc).
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Reviewed-by: Dov Levenglick <dovl@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/phy/Kconfig

@@ -277,4 +277,11 @@ config PHY_STIH41X_USB
 	  Enable this to support the USB transceiver that is part of
 	  STMicroelectronics STiH41x SoC series.
 
+config PHY_QCOM_UFS
+	tristate "Qualcomm UFS PHY driver"
+	depends on OF && ARCH_MSM
+	select GENERIC_PHY
+	help
+	  Support for UFS PHY on QCOM chipsets.
+
 endmenu

drivers/phy/Makefile

@@ -34,3 +34,4 @@ obj-$(CONFIG_PHY_ST_SPEAR1340_MIPHY)	+= phy-spear1340-miphy.o
 obj-$(CONFIG_PHY_XGENE)			+= phy-xgene.o
 obj-$(CONFIG_PHY_STIH407_USB)		+= phy-stih407-usb.o
 obj-$(CONFIG_PHY_STIH41X_USB)		+= phy-stih41x-usb.o
+obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs.o

drivers/phy/phy-qcom-ufs-i.h

+/*
+ * Copyright (c) 2013-2015, Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#ifndef UFS_QCOM_PHY_I_H_
+#define UFS_QCOM_PHY_I_H_
+
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+
+#define UFS_QCOM_PHY_NAME_LEN	30
+
+struct ufs_qcom_phy_calibration {
+	u32 reg_offset;
+	u32 cfg_value;
+};
+
+struct ufs_qcom_phy_vreg {
+	const char *name;
+	struct regulator *reg;
+	int max_uA;
+	int min_uV;
+	int max_uV;
+	bool enabled;
+	bool is_always_on;
+};
+
+struct ufs_qcom_phy {
+	struct list_head list;
+	struct device *dev;
+	void __iomem *mmio;
+	void __iomem *dev_ref_clk_ctrl_mmio;
+	struct clk *tx_iface_clk;
+	struct clk *rx_iface_clk;
+	bool is_iface_clk_enabled;
+	struct clk *ref_clk_src;
+	struct clk *ref_clk_parent;
+	struct clk *ref_clk;
+	bool is_ref_clk_enabled;
+	bool is_dev_ref_clk_enabled;
+	struct ufs_qcom_phy_vreg vdda_pll;
+	struct ufs_qcom_phy_vreg vdda_phy;
+	struct ufs_qcom_phy_vreg vddp_ref_clk;
+	unsigned int quirks;
+
+	/*
+	* If UFS link is put into Hibern8 and if UFS PHY analog hardware is
+	* power collapsed (by clearing UFS_PHY_POWER_DOWN_CONTROL), Hibern8
+	* exit might fail even after powering on UFS PHY analog hardware.
+	* Enabling this quirk will help to solve above issue by doing
+	* custom PHY settings just before PHY analog power collapse.
+	*/
+	#define UFS_QCOM_PHY_QUIRK_HIBERN8_EXIT_AFTER_PHY_PWR_COLLAPSE	BIT(0)
+
+	u8 host_ctrl_rev_major;
+	u16 host_ctrl_rev_minor;
+	u16 host_ctrl_rev_step;
+
+	char name[UFS_QCOM_PHY_NAME_LEN];
+	struct ufs_qcom_phy_calibration *cached_regs;
+	int cached_regs_table_size;
+	bool is_powered_on;
+	struct ufs_qcom_phy_specific_ops *phy_spec_ops;
+};
+
+/**
+ * struct ufs_qcom_phy_specific_ops - set of pointers to functions which have a
+ * specific implementation per phy. Each UFS phy, should implement
+ * those functions according to its spec and requirements
+ * @calibrate_phy: pointer to a function that calibrate the phy
+ * @start_serdes: pointer to a function that starts the serdes
+ * @is_physical_coding_sublayer_ready: pointer to a function that
+ * checks pcs readiness. returns 0 for success and non-zero for error.
+ * @set_tx_lane_enable: pointer to a function that enable tx lanes
+ * @power_control: pointer to a function that controls analog rail of phy
+ * and writes to QSERDES_RX_SIGDET_CNTRL attribute
+ */
+struct ufs_qcom_phy_specific_ops {
+	int (*calibrate_phy)(struct ufs_qcom_phy *phy, bool is_rate_B);
+	void (*start_serdes)(struct ufs_qcom_phy *phy);
+	int (*is_physical_coding_sublayer_ready)(struct ufs_qcom_phy *phy);
+	void (*set_tx_lane_enable)(struct ufs_qcom_phy *phy, u32 val);
+	void (*power_control)(struct ufs_qcom_phy *phy, bool val);
+};
+
+struct ufs_qcom_phy *get_ufs_qcom_phy(struct phy *generic_phy);
+int ufs_qcom_phy_power_on(struct phy *generic_phy);
+int ufs_qcom_phy_power_off(struct phy *generic_phy);
+int ufs_qcom_phy_exit(struct phy *generic_phy);
+int ufs_qcom_phy_init_clks(struct phy *generic_phy,
+			struct ufs_qcom_phy *phy_common);
+int ufs_qcom_phy_init_vregulators(struct phy *generic_phy,
+			struct ufs_qcom_phy *phy_common);
+int ufs_qcom_phy_remove(struct phy *generic_phy,
+		       struct ufs_qcom_phy *ufs_qcom_phy);
+struct phy *ufs_qcom_phy_generic_probe(struct platform_device *pdev,
+			struct ufs_qcom_phy *common_cfg,
+			struct phy_ops *ufs_qcom_phy_gen_ops,
+			struct ufs_qcom_phy_specific_ops *phy_spec_ops);
+int ufs_qcom_phy_calibrate(struct ufs_qcom_phy *ufs_qcom_phy,
+			struct ufs_qcom_phy_calibration *tbl_A, int tbl_size_A,
+			struct ufs_qcom_phy_calibration *tbl_B, int tbl_size_B,
+			bool is_rate_B);
+#endif