ufs-qcom: add support for Qualcomm Technologies Inc platforms

This change adds support for Qualcomm Technologies Inc platforms that
use UFS driver. for example, it adds :
- PM specific operations during hibern8, suspend, resume, clock setup
- qcom-ufs generic phy driver initialization, calibration,
  power-on/off sequence, etc.
- UFS Controller specific configuration
- Rate, Gear, Mode negotiation between device and controller

Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Reviewed-by: Dov Levenglick <dovl@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

4 files changed, 1188 insertions, 0 deletions

diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index 6e07b2afddeb..8a1f4b355416 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -70,3 +70,16 @@ config SCSI_UFSHCD_PLATFORM
 	If you have a controller with this interface, say Y or M here.
 
 	  If unsure, say N.
+
+config SCSI_UFS_QCOM
+	bool "QCOM specific hooks to UFS controller platform driver"
+	depends on SCSI_UFSHCD_PLATFORM && ARCH_MSM
+	select PHY_QCOM_UFS
+	help
+	  This selects the QCOM specific additions to UFSHCD platform driver.
+	  UFS host on QCOM needs some vendor specific configuration before
+	  accessing the hardware which includes PHY configuration and vendor
+	  specific registers.
+
+	  Select this if you have UFS controller on QCOM chipset.
+	  If unsure, say N.
diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index 1e5bd48457d6..8303bcce7a23 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -1,4 +1,5 @@
 # UFSHCD makefile
+obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
 obj-$(CONFIG_SCSI_UFSHCD) += ufshcd.o
 obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o
 obj-$(CONFIG_SCSI_UFSHCD_PLATFORM) += ufshcd-pltfrm.o
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
new file mode 100644
index 000000000000..9217af9bf734
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -0,0 +1,1004 @@
+/*
+ * 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.
+ *
+ */
+
+#include <linux/time.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+
+#include <linux/phy/phy-qcom-ufs.h>
+#include "ufshcd.h"
+#include "unipro.h"
+#include "ufs-qcom.h"
+#include "ufshci.h"
+
+static struct ufs_qcom_host *ufs_qcom_hosts[MAX_UFS_QCOM_HOSTS];
+
+static void ufs_qcom_get_speed_mode(struct ufs_pa_layer_attr *p, char *result);
+static int ufs_qcom_get_bus_vote(struct ufs_qcom_host *host,
+		const char *speed_mode);
+static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote);
+
+static int ufs_qcom_get_connected_tx_lanes(struct ufs_hba *hba, u32 *tx_lanes)
+{
+	int err = 0;
+
+	err = ufshcd_dme_get(hba,
+			UIC_ARG_MIB(PA_CONNECTEDTXDATALANES), tx_lanes);
+	if (err)
+		dev_err(hba->dev, "%s: couldn't read PA_CONNECTEDTXDATALANES %d\n",
+				__func__, err);
+
+	return err;
+}
+
+static int ufs_qcom_host_clk_get(struct device *dev,
+		const char *name, struct clk **clk_out)
+{
+	struct clk *clk;
+	int err = 0;
+
+	clk = devm_clk_get(dev, name);
+	if (IS_ERR(clk)) {
+		err = PTR_ERR(clk);
+		dev_err(dev, "%s: failed to get %s err %d",
+				__func__, name, err);
+	} else {
+		*clk_out = clk;
+	}
+
+	return err;
+}
+
+static int ufs_qcom_host_clk_enable(struct device *dev,
+		const char *name, struct clk *clk)
+{
+	int err = 0;
+
+	err = clk_prepare_enable(clk);
+	if (err)
+		dev_err(dev, "%s: %s enable failed %d\n", __func__, name, err);
+
+	return err;
+}
+
+static void ufs_qcom_disable_lane_clks(struct ufs_qcom_host *host)
+{
+	if (!host->is_lane_clks_enabled)
+		return;
+
+	clk_disable_unprepare(host->tx_l1_sync_clk);
+	clk_disable_unprepare(host->tx_l0_sync_clk);
+	clk_disable_unprepare(host->rx_l1_sync_clk);
+	clk_disable_unprepare(host->rx_l0_sync_clk);
+
+	host->is_lane_clks_enabled = false;
+}
+
+static int ufs_qcom_enable_lane_clks(struct ufs_qcom_host *host)
+{
+	int err = 0;
+	struct device *dev = host->hba->dev;
+
+	if (host->is_lane_clks_enabled)
+		return 0;
+
+	err = ufs_qcom_host_clk_enable(dev, "rx_lane0_sync_clk",
+		host->rx_l0_sync_clk);
+	if (err)
+		goto out;
+
+	err = ufs_qcom_host_clk_enable(dev, "tx_lane0_sync_clk",
+		host->tx_l0_sync_clk);
+	if (err)
+		goto disable_rx_l0;
+
+	err = ufs_qcom_host_clk_enable(dev, "rx_lane1_sync_clk",
+		host->rx_l1_sync_clk);
+	if (err)
+		goto disable_tx_l0;
+
+	err = ufs_qcom_host_clk_enable(dev, "tx_lane1_sync_clk",
+		host->tx_l1_sync_clk);
+	if (err)
+		goto disable_rx_l1;
+
+	host->is_lane_clks_enabled = true;
+	goto out;
+
+disable_rx_l1:
+	clk_disable_unprepare(host->rx_l1_sync_clk);
+disable_tx_l0:
+	clk_disable_unprepare(host->tx_l0_sync_clk);
+disable_rx_l0:
+	clk_disable_unprepare(host->rx_l0_sync_clk);
+out:
+	return err;
+}
+
+static int ufs_qcom_init_lane_clks(struct ufs_qcom_host *host)
+{
+	int err = 0;
+	struct device *dev = host->hba->dev;
+
+	err = ufs_qcom_host_clk_get(dev,
+			"rx_lane0_sync_clk", &host->rx_l0_sync_clk);
+	if (err)
+		goto out;
+
+	err = ufs_qcom_host_clk_get(dev,
+			"tx_lane0_sync_clk", &host->tx_l0_sync_clk);
+	if (err)
+		goto out;
+
+	err = ufs_qcom_host_clk_get(dev, "rx_lane1_sync_clk",
+		&host->rx_l1_sync_clk);
+	if (err)
+		goto out;
+
+	err = ufs_qcom_host_clk_get(dev, "tx_lane1_sync_clk",
+		&host->tx_l1_sync_clk);
+out:
+	return err;
+}
+
+static int ufs_qcom_link_startup_post_change(struct ufs_hba *hba)
+{
+	struct ufs_qcom_host *host = hba->priv;
+	struct phy *phy = host->generic_phy;
+	u32 tx_lanes;
+	int err = 0;
+
+	err = ufs_qcom_get_connected_tx_lanes(hba, &tx_lanes);
+	if (err)
+		goto out;
+
+	err = ufs_qcom_phy_set_tx_lane_enable(phy, tx_lanes);
+	if (err)
+		dev_err(hba->dev, "%s: ufs_qcom_phy_set_tx_lane_enable failed\n",
+			__func__);
+
+out:
+	return err;
+}
+
+static int ufs_qcom_check_hibern8(struct ufs_hba *hba)
+{
+	int err;
+	u32 tx_fsm_val = 0;
+	unsigned long timeout = jiffies + msecs_to_jiffies(HBRN8_POLL_TOUT_MS);
+
+	do {
+		err = ufshcd_dme_get(hba,
+			UIC_ARG_MIB(MPHY_TX_FSM_STATE), &tx_fsm_val);
+		if (err || tx_fsm_val == TX_FSM_HIBERN8)
+			break;
+
+		/* sleep for max. 200us */
+		usleep_range(100, 200);
+	} while (time_before(jiffies, timeout));
+
+	/*
+	 * we might have scheduled out for long during polling so
+	 * check the state again.
+	 */
+	if (time_after(jiffies, timeout))
+		err = ufshcd_dme_get(hba,
+				UIC_ARG_MIB(MPHY_TX_FSM_STATE), &tx_fsm_val);
+
+	if (err) {
+		dev_err(hba->dev, "%s: unable to get TX_FSM_STATE, err %d\n",
+				__func__, err);
+	} else if (tx_fsm_val != TX_FSM_HIBERN8) {
+		err = tx_fsm_val;
+		dev_err(hba->dev, "%s: invalid TX_FSM_STATE = %d\n",
+				__func__, err);
+	}
+
+	return err;
+}
+
+static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
+{
+	struct ufs_qcom_host *host = hba->priv;
+	struct phy *phy = host->generic_phy;
+	int ret = 0;
+	u8 major;
+	u16 minor, step;
+	bool is_rate_B = (UFS_QCOM_LIMIT_HS_RATE == PA_HS_MODE_B)
+							? true : false;
+
+	/* Assert PHY reset and apply PHY calibration values */
+	ufs_qcom_assert_reset(hba);
+	/* provide 1ms delay to let the reset pulse propagate */
+	usleep_range(1000, 1100);
+
+	ufs_qcom_get_controller_revision(hba, &major, &minor, &step);
+	ufs_qcom_phy_save_controller_version(phy, major, minor, step);
+	ret = ufs_qcom_phy_calibrate_phy(phy, is_rate_B);
+	if (ret) {
+		dev_err(hba->dev, "%s: ufs_qcom_phy_calibrate_phy() failed, ret = %d\n",
+			__func__, ret);
+		goto out;
+	}
+
+	/* De-assert PHY reset and start serdes */
+	ufs_qcom_deassert_reset(hba);
+
+	/*
+	 * after reset deassertion, phy will need all ref clocks,
+	 * voltage, current to settle down before starting serdes.
+	 */
+	usleep_range(1000, 1100);
+	ret = ufs_qcom_phy_start_serdes(phy);
+	if (ret) {
+		dev_err(hba->dev, "%s: ufs_qcom_phy_start_serdes() failed, ret = %d\n",
+			__func__, ret);
+		goto out;
+	}
+
+	ret = ufs_qcom_phy_is_pcs_ready(phy);
+	if (ret)
+		dev_err(hba->dev, "%s: is_physical_coding_sublayer_ready() failed, ret = %d\n",
+			__func__, ret);
+
+out:
+	return ret;
+}
+
+/*
+ * The UTP controller has a number of internal clock gating cells (CGCs).
+ * Internal hardware sub-modules within the UTP controller control the CGCs.
+ * Hardware CGCs disable the clock to inactivate UTP sub-modules not involved
+ * in a specific operation, UTP controller CGCs are by default disabled and
+ * this function enables them (after every UFS link startup) to save some power
+ * leakage.
+ */
+static void ufs_qcom_enable_hw_clk_gating(struct ufs_hba *hba)
+{
+	ufshcd_writel(hba,
+		ufshcd_readl(hba, REG_UFS_CFG2) | REG_UFS_CFG2_CGC_EN_ALL,
+		REG_UFS_CFG2);
+
+	/* Ensure that HW clock gating is enabled before next operations */
+	mb();
+}
+
+static int ufs_qcom_hce_enable_notify(struct ufs_hba *hba, bool status)
+{
+	struct ufs_qcom_host *host = hba->priv;
+	int err = 0;
+
+	switch (status) {
+	case PRE_CHANGE:
+		ufs_qcom_power_up_sequence(hba);
+		/*
+		 * The PHY PLL output is the source of tx/rx lane symbol
+		 * clocks, hence, enable the lane clocks only after PHY
+		 * is initialized.
+		 */
+		err = ufs_qcom_enable_lane_clks(host);
+		break;
+	case POST_CHANGE:
+		/* check if UFS PHY moved from DISABLED to HIBERN8 */
+		err = ufs_qcom_check_hibern8(hba);
+		ufs_qcom_enable_hw_clk_gating(hba);
+
+		break;
+	default:
+		dev_err(hba->dev, "%s: invalid status %d\n", __func__, status);
+		err = -EINVAL;
+		break;
+	}
+	return err;
+}
+
+/**
+ * Returns non-zero for success (which rate of core_clk) and 0
+ * in case of a failure
+ */
+static unsigned long
+ufs_qcom_cfg_timers(struct ufs_hba *hba, u32 gear, u32 hs, u32 rate)
+{
+	struct ufs_clk_info *clki;
+	u32 core_clk_period_in_ns;
+	u32 tx_clk_cycles_per_us = 0;
+	unsigned long core_clk_rate = 0;
+	u32 core_clk_cycles_per_us = 0;
+
+	static u32 pwm_fr_table[][2] = {
+		{UFS_PWM_G1, 0x1},
+		{UFS_PWM_G2, 0x1},
+		{UFS_PWM_G3, 0x1},
+		{UFS_PWM_G4, 0x1},
+	};
+
+	static u32 hs_fr_table_rA[][2] = {
+		{UFS_HS_G1, 0x1F},
+		{UFS_HS_G2, 0x3e},
+	};
+
+	static u32 hs_fr_table_rB[][2] = {
+		{UFS_HS_G1, 0x24},
+		{UFS_HS_G2, 0x49},
+	};
+
+	if (gear == 0) {
+		dev_err(hba->dev, "%s: invalid gear = %d\n", __func__, gear);
+		goto out_error;
+	}
+
+	list_for_each_entry(clki, &hba->clk_list_head, list) {
+		if (!strcmp(clki->name, "core_clk"))
+			core_clk_rate = clk_get_rate(clki->clk);
+	}
+
+	/* If frequency is smaller than 1MHz, set to 1MHz */
+	if (core_clk_rate < DEFAULT_CLK_RATE_HZ)
+		core_clk_rate = DEFAULT_CLK_RATE_HZ;
+
+	core_clk_cycles_per_us = core_clk_rate / USEC_PER_SEC;
+	ufshcd_writel(hba, core_clk_cycles_per_us, REG_UFS_SYS1CLK_1US);
+
+	core_clk_period_in_ns = NSEC_PER_SEC / core_clk_rate;
+	core_clk_period_in_ns <<= OFFSET_CLK_NS_REG;
+	core_clk_period_in_ns &= MASK_CLK_NS_REG;
+
+	switch (hs) {
+	case FASTAUTO_MODE:
+	case FAST_MODE:
+		if (rate == PA_HS_MODE_A) {
+			if (gear > ARRAY_SIZE(hs_fr_table_rA)) {
+				dev_err(hba->dev,
+					"%s: index %d exceeds table size %zu\n",
+					__func__, gear,
+					ARRAY_SIZE(hs_fr_table_rA));
+				goto out_error;
+			}
+			tx_clk_cycles_per_us = hs_fr_table_rA[gear-1][1];
+		} else if (rate == PA_HS_MODE_B) {
+			if (gear > ARRAY_SIZE(hs_fr_table_rB)) {
+				dev_err(hba->dev,
+					"%s: index %d exceeds table size %zu\n",
+					__func__, gear,
+					ARRAY_SIZE(hs_fr_table_rB));
+				goto out_error;
+			}
+			tx_clk_cycles_per_us = hs_fr_table_rB[gear-1][1];
+		} else {
+			dev_err(hba->dev, "%s: invalid rate = %d\n",
+				__func__, rate);
+			goto out_error;
+		}
+		break;
+	case SLOWAUTO_MODE:
+	case SLOW_MODE:
+		if (gear > ARRAY_SIZE(pwm_fr_table)) {
+			dev_err(hba->dev,
+					"%s: index %d exceeds table size %zu\n",
+					__func__, gear,
+					ARRAY_SIZE(pwm_fr_table));
+			goto out_error;
+		}
+		tx_clk_cycles_per_us = pwm_fr_table[gear-1][1];
+		break;
+	case UNCHANGED:
+	default:
+		dev_err(hba->dev, "%s: invalid mode = %d\n", __func__, hs);
+		goto out_error;
+	}
+
+	/* this register 2 fields shall be written at once */
+	ufshcd_writel(hba, core_clk_period_in_ns | tx_clk_cycles_per_us,
+						REG_UFS_TX_SYMBOL_CLK_NS_US);
+	goto out;
+
+out_error:
+	core_clk_rate = 0;
+out:
+	return core_clk_rate;
+}
+
+static int ufs_qcom_link_startup_notify(struct ufs_hba *hba, bool status)
+{
+	unsigned long core_clk_rate = 0;
+	u32 core_clk_cycles_per_100ms;
+
+	switch (status) {
+	case PRE_CHANGE:
+		core_clk_rate = ufs_qcom_cfg_timers(hba, UFS_PWM_G1,
+						    SLOWAUTO_MODE, 0);
+		if (!core_clk_rate) {
+			dev_err(hba->dev, "%s: ufs_qcom_cfg_timers() failed\n",
+				__func__);
+			return -EINVAL;
+		}
+		core_clk_cycles_per_100ms =
+			(core_clk_rate / MSEC_PER_SEC) * 100;
+		ufshcd_writel(hba, core_clk_cycles_per_100ms,
+					REG_UFS_PA_LINK_STARTUP_TIMER);
+		break;
+	case POST_CHANGE:
+		ufs_qcom_link_startup_post_change(hba);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int ufs_qcom_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+{
+	struct ufs_qcom_host *host = hba->priv;
+	struct phy *phy = host->generic_phy;
+	int ret = 0;
+
+	if (ufs_qcom_is_link_off(hba)) {
+		/*
+		 * Disable the tx/rx lane symbol clocks before PHY is
+		 * powered down as the PLL source should be disabled
+		 * after downstream clocks are disabled.
+		 */
+		ufs_qcom_disable_lane_clks(host);
+		phy_power_off(phy);
+
+		/* Assert PHY soft reset */
+		ufs_qcom_assert_reset(hba);
+		goto out;
+	}
+
+	/*
+	 * If UniPro link is not active, PHY ref_clk, main PHY analog power
+	 * rail and low noise analog power rail for PLL can be switched off.
+	 */
+	if (!ufs_qcom_is_link_active(hba))
+		phy_power_off(phy);
+
+out:
+	return ret;
+}
+
+static int ufs_qcom_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+{
+	struct ufs_qcom_host *host = hba->priv;
+	struct phy *phy = host->generic_phy;
+	int err;
+
+	err = phy_power_on(phy);
+	if (err) {
+		dev_err(hba->dev, "%s: failed enabling regs, err = %d\n",
+			__func__, err);
+		goto out;
+	}
+
+	hba->is_sys_suspended = false;
+
+out:
+	return err;
+}
+
+struct ufs_qcom_dev_params {
+	u32 pwm_rx_gear;	/* pwm rx gear to work in */
+	u32 pwm_tx_gear;	/* pwm tx gear to work in */
+	u32 hs_rx_gear;		/* hs rx gear to work in */
+	u32 hs_tx_gear;		/* hs tx gear to work in */
+	u32 rx_lanes;		/* number of rx lanes */
+	u32 tx_lanes;		/* number of tx lanes */
+	u32 rx_pwr_pwm;		/* rx pwm working pwr */
+	u32 tx_pwr_pwm;		/* tx pwm working pwr */
+	u32 rx_pwr_hs;		/* rx hs working pwr */
+	u32 tx_pwr_hs;		/* tx hs working pwr */
+	u32 hs_rate;		/* rate A/B to work in HS */
+	u32 desired_working_mode;
+};
+
+static int ufs_qcom_get_pwr_dev_param(struct ufs_qcom_dev_params *qcom_param,
+				      struct ufs_pa_layer_attr *dev_max,
+				      struct ufs_pa_layer_attr *agreed_pwr)
+{
+	int min_qcom_gear;
+	int min_dev_gear;
+	bool is_dev_sup_hs = false;
+	bool is_qcom_max_hs = false;
+
+	if (dev_max->pwr_rx == FAST_MODE)
+		is_dev_sup_hs = true;
+
+	if (qcom_param->desired_working_mode == FAST) {
+		is_qcom_max_hs = true;
+		min_qcom_gear = min_t(u32, qcom_param->hs_rx_gear,
+				      qcom_param->hs_tx_gear);
+	} else {
+		min_qcom_gear = min_t(u32, qcom_param->pwm_rx_gear,
+				      qcom_param->pwm_tx_gear);
+	}
+
+	/*
+	 * device doesn't support HS but qcom_param->desired_working_mode is
+	 * HS, thus device and qcom_param don't agree
+	 */
+	if (!is_dev_sup_hs && is_qcom_max_hs) {
+		pr_err("%s: failed to agree on power mode (device doesn't support HS but requested power is HS)\n",
+			__func__);
+		return -ENOTSUPP;
+	} else if (is_dev_sup_hs && is_qcom_max_hs) {
+		/*
+		 * since device supports HS, it supports FAST_MODE.
+		 * since qcom_param->desired_working_mode is also HS
+		 * then final decision (FAST/FASTAUTO) is done according
+		 * to qcom_params as it is the restricting factor
+		 */
+		agreed_pwr->pwr_rx = agreed_pwr->pwr_tx =
+						qcom_param->rx_pwr_hs;
+	} else {
+		/*
+		 * here qcom_param->desired_working_mode is PWM.
+		 * it doesn't matter whether device supports HS or PWM,
+		 * in both cases qcom_param->desired_working_mode will
+		 * determine the mode
+		 */
+		 agreed_pwr->pwr_rx = agreed_pwr->pwr_tx =
+						qcom_param->rx_pwr_pwm;
+	}
+
+	/*
+	 * we would like tx to work in the minimum number of lanes
+	 * between device capability and vendor preferences.
+	 * the same decision will be made for rx
+	 */
+	agreed_pwr->lane_tx = min_t(u32, dev_max->lane_tx,
+						qcom_param->tx_lanes);
+	agreed_pwr->lane_rx = min_t(u32, dev_max->lane_rx,
+						qcom_param->rx_lanes);
+
+	/* device maximum gear is the minimum between device rx and tx gears */
+	min_dev_gear = min_t(u32, dev_max->gear_rx, dev_max->gear_tx);
+
+	/*
+	 * if both device capabilities and vendor pre-defined preferences are
+	 * both HS or both PWM then set the minimum gear to be the chosen
+	 * working gear.
+	 * if one is PWM and one is HS then the one that is PWM get to decide
+	 * what is the gear, as it is the one that also decided previously what
+	 * pwr the device will be configured to.
+	 */
+	if ((is_dev_sup_hs && is_qcom_max_hs) ||
+	    (!is_dev_sup_hs && !is_qcom_max_hs))
+		agreed_pwr->gear_rx = agreed_pwr->gear_tx =
+			min_t(u32, min_dev_gear, min_qcom_gear);
+	else if (!is_dev_sup_hs)
+		agreed_pwr->gear_rx = agreed_pwr->gear_tx = min_dev_gear;
+	else
+		agreed_pwr->gear_rx = agreed_pwr->gear_tx = min_qcom_gear;
+
+	agreed_pwr->hs_rate = qcom_param->hs_rate;
+	return 0;
+}
+
+static int ufs_qcom_update_bus_bw_vote(struct ufs_qcom_host *host)
+{
+	int vote;
+	int err = 0;
+	char mode[BUS_VECTOR_NAME_LEN];
+
+	ufs_qcom_get_speed_mode(&host->dev_req_params, mode);
+
+	vote = ufs_qcom_get_bus_vote(host, mode);
+	if (vote >= 0)
+		err = ufs_qcom_set_bus_vote(host, vote);
+	else
+		err = vote;
+
+	if (err)
+		dev_err(host->hba->dev, "%s: failed %d\n", __func__, err);
+	else
+		host->bus_vote.saved_vote = vote;
+	return err;
+}
+
+static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
+				bool status,
+				struct ufs_pa_layer_attr *dev_max_params,
+				struct ufs_pa_layer_attr *dev_req_params)
+{
+	u32 val;
+	struct ufs_qcom_host *host = hba->priv;
+	struct phy *phy = host->generic_phy;
+	struct ufs_qcom_dev_params ufs_qcom_cap;
+	int ret = 0;
+	int res = 0;
+
+	if (!dev_req_params) {
+		pr_err("%s: incoming dev_req_params is NULL\n", __func__);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	switch (status) {
+	case PRE_CHANGE:
+		ufs_qcom_cap.tx_lanes = UFS_QCOM_LIMIT_NUM_LANES_TX;
+		ufs_qcom_cap.rx_lanes = UFS_QCOM_LIMIT_NUM_LANES_RX;
+		ufs_qcom_cap.hs_rx_gear = UFS_QCOM_LIMIT_HSGEAR_RX;
+		ufs_qcom_cap.hs_tx_gear = UFS_QCOM_LIMIT_HSGEAR_TX;
+		ufs_qcom_cap.pwm_rx_gear = UFS_QCOM_LIMIT_PWMGEAR_RX;
+		ufs_qcom_cap.pwm_tx_gear = UFS_QCOM_LIMIT_PWMGEAR_TX;
+		ufs_qcom_cap.rx_pwr_pwm = UFS_QCOM_LIMIT_RX_PWR_PWM;
+		ufs_qcom_cap.tx_pwr_pwm = UFS_QCOM_LIMIT_TX_PWR_PWM;
+		ufs_qcom_cap.rx_pwr_hs = UFS_QCOM_LIMIT_RX_PWR_HS;
+		ufs_qcom_cap.tx_pwr_hs = UFS_QCOM_LIMIT_TX_PWR_HS;
+		ufs_qcom_cap.hs_rate = UFS_QCOM_LIMIT_HS_RATE;
+		ufs_qcom_cap.desired_working_mode =
+					UFS_QCOM_LIMIT_DESIRED_MODE;
+
+		ret = ufs_qcom_get_pwr_dev_param(&ufs_qcom_cap,
+						 dev_max_params,
+						 dev_req_params);
+		if (ret) {
+			pr_err("%s: failed to determine capabilities\n",
+					__func__);
+			goto out;
+		}
+
+		break;
+	case POST_CHANGE:
+		if (!ufs_qcom_cfg_timers(hba, dev_req_params->gear_rx,
+					dev_req_params->pwr_rx,
+					dev_req_params->hs_rate)) {
+			dev_err(hba->dev, "%s: ufs_qcom_cfg_timers() failed\n",
+				__func__);
+			/*
+			 * we return error code at the end of the routine,
+			 * but continue to configure UFS_PHY_TX_LANE_ENABLE
+			 * and bus voting as usual
+			 */
+			ret = -EINVAL;
+		}
+
+		val = ~(MAX_U32 << dev_req_params->lane_tx);
+		res = ufs_qcom_phy_set_tx_lane_enable(phy, val);
+		if (res) {
+			dev_err(hba->dev, "%s: ufs_qcom_phy_set_tx_lane_enable() failed res = %d\n",
+				__func__, res);
+			ret = res;
+		}
+
+		/* cache the power mode parameters to use internally */
+		memcpy(&host->dev_req_params,
+				dev_req_params, sizeof(*dev_req_params));
+		ufs_qcom_update_bus_bw_vote(host);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+out:
+	return ret;
+}
+
+/**
+ * ufs_qcom_advertise_quirks - advertise the known QCOM UFS controller quirks
+ * @hba: host controller instance
+ *
+ * QCOM UFS host controller might have some non standard behaviours (quirks)
+ * than what is specified by UFSHCI specification. Advertise all such
+ * quirks to standard UFS host controller driver so standard takes them into
+ * account.
+ */
+static void ufs_qcom_advertise_quirks(struct ufs_hba *hba)
+{
+	u8 major;
+	u16 minor, step;
+
+	ufs_qcom_get_controller_revision(hba, &major, &minor, &step);
+
+	/*
+	 * TBD
+	 * here we should be advertising controller quirks according to
+	 * controller version.
+	 */
+}
+
+static int ufs_qcom_get_bus_vote(struct ufs_qcom_host *host,
+		const char *speed_mode)
+{
+	struct device *dev = host->hba->dev;
+	struct device_node *np = dev->of_node;
+	int err;
+	const char *key = "qcom,bus-vector-names";
+
+	if (!speed_mode) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (host->bus_vote.is_max_bw_needed && !!strcmp(speed_mode, "MIN"))
+		err = of_property_match_string(np, key, "MAX");
+	else
+		err = of_property_match_string(np, key, speed_mode);
+
+out:
+	if (err < 0)
+		dev_err(dev, "%s: Invalid %s mode %d\n",
+				__func__, speed_mode, err);
+	return err;
+}
+
+static int ufs_qcom_set_bus_vote(struct ufs_qcom_host *host, int vote)
+{
+	int err = 0;
+
+	if (vote != host->bus_vote.curr_vote)
+		host->bus_vote.curr_vote = vote;
+
+	return err;
+}
+
+static void ufs_qcom_get_speed_mode(struct ufs_pa_layer_attr *p, char *result)
+{
+	int gear = max_t(u32, p->gear_rx, p->gear_tx);
+	int lanes = max_t(u32, p->lane_rx, p->lane_tx);
+	int pwr;
+
+	/* default to PWM Gear 1, Lane 1 if power mode is not initialized */
+	if (!gear)
+		gear = 1;
+
+	if (!lanes)
+		lanes = 1;
+
+	if (!p->pwr_rx && !p->pwr_tx) {
+		pwr = SLOWAUTO_MODE;
+		snprintf(result, BUS_VECTOR_NAME_LEN, "MIN");
+	} else if (p->pwr_rx == FAST_MODE || p->pwr_rx == FASTAUTO_MODE ||
+		 p->pwr_tx == FAST_MODE || p->pwr_tx == FASTAUTO_MODE) {
+		pwr = FAST_MODE;
+		snprintf(result, BUS_VECTOR_NAME_LEN, "%s_R%s_G%d_L%d", "HS",
+			 p->hs_rate == PA_HS_MODE_B ? "B" : "A", gear, lanes);
+	} else {
+		pwr = SLOW_MODE;
+		snprintf(result, BUS_VECTOR_NAME_LEN, "%s_G%d_L%d",
+			 "PWM", gear, lanes);
+	}
+}
+
+static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on)
+{
+	struct ufs_qcom_host *host = hba->priv;
+	int err = 0;
+	int vote = 0;
+
+	/*
+	 * In case ufs_qcom_init() is not yet done, simply ignore.
+	 * This ufs_qcom_setup_clocks() shall be called from
+	 * ufs_qcom_init() after init is done.
+	 */
+	if (!host)
+		return 0;
+
+	if (on) {
+		err = ufs_qcom_phy_enable_iface_clk(host->generic_phy);
+		if (err)
+			goto out;
+
+		err = ufs_qcom_phy_enable_ref_clk(host->generic_phy);
+		if (err) {
+			dev_err(hba->dev, "%s enable phy ref clock failed, err=%d\n",
+				__func__, err);
+			ufs_qcom_phy_disable_iface_clk(host->generic_phy);
+			goto out;
+		}
+		/* enable the device ref clock */
+		ufs_qcom_phy_enable_dev_ref_clk(host->generic_phy);
+		vote = host->bus_vote.saved_vote;
+		if (vote == host->bus_vote.min_bw_vote)
+			ufs_qcom_update_bus_bw_vote(host);
+	} else {
+		/* M-PHY RMMI interface clocks can be turned off */
+		ufs_qcom_phy_disable_iface_clk(host->generic_phy);
+		if (!ufs_qcom_is_link_active(hba)) {
+			/* turn off UFS local PHY ref_clk */
+			ufs_qcom_phy_disable_ref_clk(host->generic_phy);
+			/* disable device ref_clk */
+			ufs_qcom_phy_disable_dev_ref_clk(host->generic_phy);
+		}
+		vote = host->bus_vote.min_bw_vote;
+	}
+
+	err = ufs_qcom_set_bus_vote(host, vote);
+	if (err)
+		dev_err(hba->dev, "%s: set bus vote failed %d\n",
+				__func__, err);
+
+out:
+	return err;
+}
+
+static ssize_t
+show_ufs_to_mem_max_bus_bw(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	struct ufs_qcom_host *host = hba->priv;
+
+	return snprintf(buf, PAGE_SIZE, "%u\n",
+			host->bus_vote.is_max_bw_needed);
+}
+
+static ssize_t
+store_ufs_to_mem_max_bus_bw(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	struct ufs_qcom_host *host = hba->priv;
+	uint32_t value;
+
+	if (!kstrtou32(buf, 0, &value)) {
+		host->bus_vote.is_max_bw_needed = !!value;
+		ufs_qcom_update_bus_bw_vote(host);
+	}
+
+	return count;
+}
+
+static int ufs_qcom_bus_register(struct ufs_qcom_host *host)
+{
+	int err;
+	struct device *dev = host->hba->dev;
+	struct device_node *np = dev->of_node;
+
+	err = of_property_count_strings(np, "qcom,bus-vector-names");
+	if (err < 0 ) {
+		dev_err(dev, "%s: qcom,bus-vector-names not specified correctly %d\n",
+				__func__, err);
+		goto out;
+	}
+
+	/* cache the vote index for minimum and maximum bandwidth */
+	host->bus_vote.min_bw_vote = ufs_qcom_get_bus_vote(host, "MIN");
+	host->bus_vote.max_bw_vote = ufs_qcom_get_bus_vote(host, "MAX");
+
+	host->bus_vote.max_bus_bw.show = show_ufs_to_mem_max_bus_bw;
+	host->bus_vote.max_bus_bw.store = store_ufs_to_mem_max_bus_bw;
+	sysfs_attr_init(&host->bus_vote.max_bus_bw.attr);
+	host->bus_vote.max_bus_bw.attr.name = "max_bus_bw";
+	host->bus_vote.max_bus_bw.attr.mode = S_IRUGO | S_IWUSR;
+	err = device_create_file(dev, &host->bus_vote.max_bus_bw);
+out:
+	return err;
+}
+
+#define	ANDROID_BOOT_DEV_MAX	30
+static char android_boot_dev[ANDROID_BOOT_DEV_MAX];
+static int get_android_boot_dev(char *str)
+{
+	strlcpy(android_boot_dev, str, ANDROID_BOOT_DEV_MAX);
+	return 1;
+}
+__setup("androidboot.bootdevice=", get_android_boot_dev);
+
+/**
+ * ufs_qcom_init - bind phy with controller
+ * @hba: host controller instance
+ *
+ * Binds PHY with controller and powers up PHY enabling clocks
+ * and regulators.
+ *
+ * Returns -EPROBE_DEFER if binding fails, returns negative error
+ * on phy power up failure and returns zero on success.
+ */
+static int ufs_qcom_init(struct ufs_hba *hba)
+{
+	int err;
+	struct device *dev = hba->dev;
+	struct ufs_qcom_host *host;
+
+	if (strlen(android_boot_dev) && strcmp(android_boot_dev, dev_name(dev)))
+		return -ENODEV;
+
+	host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
+	if (!host) {
+		err = -ENOMEM;
+		dev_err(dev, "%s: no memory for qcom ufs host\n", __func__);
+		goto out;
+	}
+
+	host->hba = hba;
+	hba->priv = (void *)host;
+
+	host->generic_phy = devm_phy_get(dev, "ufsphy");
+
+	if (IS_ERR(host->generic_phy)) {
+		err = PTR_ERR(host->generic_phy);
+		dev_err(dev, "%s: PHY get failed %d\n", __func__, err);
+		goto out;
+	}
+
+	err = ufs_qcom_bus_register(host);
+	if (err)
+		goto out_host_free;
+
+	phy_init(host->generic_phy);
+	err = phy_power_on(host->generic_phy);
+	if (err)
+		goto out_unregister_bus;
+
+	err = ufs_qcom_init_lane_clks(host);
+	if (err)
+		goto out_disable_phy;
+
+	ufs_qcom_advertise_quirks(hba);
+
+	hba->caps |= UFSHCD_CAP_CLK_GATING | UFSHCD_CAP_CLK_SCALING;
+	hba->caps |= UFSHCD_CAP_AUTO_BKOPS_SUSPEND;
+
+	ufs_qcom_setup_clocks(hba, true);
+
+	if (hba->dev->id < MAX_UFS_QCOM_HOSTS)
+		ufs_qcom_hosts[hba->dev->id] = host;
+
+	goto out;
+
+out_disable_phy:
+	phy_power_off(host->generic_phy);
+out_unregister_bus:
+	phy_exit(host->generic_phy);
+out_host_free:
+	devm_kfree(dev, host);
+	hba->priv = NULL;
+out:
+	return err;
+}
+
+static void ufs_qcom_exit(struct ufs_hba *hba)
+{
+	struct ufs_qcom_host *host = hba->priv;
+
+	ufs_qcom_disable_lane_clks(host);
+	phy_power_off(host->generic_phy);
+}
+
+static
+void ufs_qcom_clk_scale_notify(struct ufs_hba *hba)
+{
+	struct ufs_qcom_host *host = hba->priv;
+	struct ufs_pa_layer_attr *dev_req_params = &host->dev_req_params;
+
+	if (!dev_req_params)
+		return;
+
+	ufs_qcom_cfg_timers(hba, dev_req_params->gear_rx,
+				dev_req_params->pwr_rx,
+				dev_req_params->hs_rate);
+}
+
+/**
+ * struct ufs_hba_qcom_vops - UFS QCOM specific variant operations
+ *
+ * The variant operations configure the necessary controller and PHY
+ * handshake during initialization.
+ */
+static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
+	.name                   = "qcom",
+	.init                   = ufs_qcom_init,
+	.exit                   = ufs_qcom_exit,
+	.clk_scale_notify	= ufs_qcom_clk_scale_notify,
+	.setup_clocks           = ufs_qcom_setup_clocks,
+	.hce_enable_notify      = ufs_qcom_hce_enable_notify,
+	.link_startup_notify    = ufs_qcom_link_startup_notify,
+	.pwr_change_notify	= ufs_qcom_pwr_change_notify,
+	.suspend		= ufs_qcom_suspend,
+	.resume			= ufs_qcom_resume,
+};
+EXPORT_SYMBOL(ufs_hba_qcom_vops);
diff --git a/drivers/scsi/ufs/ufs-qcom.h b/drivers/scsi/ufs/ufs-qcom.h
new file mode 100644
index 000000000000..9a6febd007df
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-qcom.h
@@ -0,0 +1,170 @@
+/* Copyright (c) 2013-2015, The 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_H_
+#define UFS_QCOM_H_
+
+#define MAX_UFS_QCOM_HOSTS	1
+#define MAX_U32                 (~(u32)0)
+#define MPHY_TX_FSM_STATE       0x41
+#define TX_FSM_HIBERN8          0x1
+#define HBRN8_POLL_TOUT_MS      100
+#define DEFAULT_CLK_RATE_HZ     1000000
+#define BUS_VECTOR_NAME_LEN     32
+
+#define UFS_HW_VER_MAJOR_SHFT	(28)
+#define UFS_HW_VER_MAJOR_MASK	(0x000F << UFS_HW_VER_MAJOR_SHFT)
+#define UFS_HW_VER_MINOR_SHFT	(16)
+#define UFS_HW_VER_MINOR_MASK	(0x0FFF << UFS_HW_VER_MINOR_SHFT)
+#define UFS_HW_VER_STEP_SHFT	(0)
+#define UFS_HW_VER_STEP_MASK	(0xFFFF << UFS_HW_VER_STEP_SHFT)
+
+/* vendor specific pre-defined parameters */
+#define SLOW 1
+#define FAST 2
+
+#define UFS_QCOM_LIMIT_NUM_LANES_RX	2
+#define UFS_QCOM_LIMIT_NUM_LANES_TX	2
+#define UFS_QCOM_LIMIT_HSGEAR_RX	UFS_HS_G2
+#define UFS_QCOM_LIMIT_HSGEAR_TX	UFS_HS_G2
+#define UFS_QCOM_LIMIT_PWMGEAR_RX	UFS_PWM_G4
+#define UFS_QCOM_LIMIT_PWMGEAR_TX	UFS_PWM_G4
+#define UFS_QCOM_LIMIT_RX_PWR_PWM	SLOW_MODE
+#define UFS_QCOM_LIMIT_TX_PWR_PWM	SLOW_MODE
+#define UFS_QCOM_LIMIT_RX_PWR_HS	FAST_MODE
+#define UFS_QCOM_LIMIT_TX_PWR_HS	FAST_MODE
+#define UFS_QCOM_LIMIT_HS_RATE		PA_HS_MODE_B
+#define UFS_QCOM_LIMIT_DESIRED_MODE	FAST
+
+/* QCOM UFS host controller vendor specific registers */
+enum {
+	REG_UFS_SYS1CLK_1US                 = 0xC0,
+	REG_UFS_TX_SYMBOL_CLK_NS_US         = 0xC4,
+	REG_UFS_LOCAL_PORT_ID_REG           = 0xC8,
+	REG_UFS_PA_ERR_CODE                 = 0xCC,
+	REG_UFS_RETRY_TIMER_REG             = 0xD0,
+	REG_UFS_PA_LINK_STARTUP_TIMER       = 0xD8,
+	REG_UFS_CFG1                        = 0xDC,
+	REG_UFS_CFG2                        = 0xE0,
+	REG_UFS_HW_VERSION                  = 0xE4,
+
+	UFS_DBG_RD_REG_UAWM			= 0x100,
+	UFS_DBG_RD_REG_UARM			= 0x200,
+	UFS_DBG_RD_REG_TXUC			= 0x300,
+	UFS_DBG_RD_REG_RXUC			= 0x400,
+	UFS_DBG_RD_REG_DFC			= 0x500,
+	UFS_DBG_RD_REG_TRLUT			= 0x600,
+	UFS_DBG_RD_REG_TMRLUT			= 0x700,
+	UFS_UFS_DBG_RD_REG_OCSC			= 0x800,
+
+	UFS_UFS_DBG_RD_DESC_RAM			= 0x1500,
+	UFS_UFS_DBG_RD_PRDT_RAM			= 0x1700,
+	UFS_UFS_DBG_RD_RESP_RAM			= 0x1800,
+	UFS_UFS_DBG_RD_EDTL_RAM			= 0x1900,
+};
+
+/* bit definitions for REG_UFS_CFG2 register */
+#define UAWM_HW_CGC_EN		(1 << 0)
+#define UARM_HW_CGC_EN		(1 << 1)
+#define TXUC_HW_CGC_EN		(1 << 2)
+#define RXUC_HW_CGC_EN		(1 << 3)
+#define DFC_HW_CGC_EN		(1 << 4)
+#define TRLUT_HW_CGC_EN		(1 << 5)
+#define TMRLUT_HW_CGC_EN	(1 << 6)
+#define OCSC_HW_CGC_EN		(1 << 7)
+
+#define REG_UFS_CFG2_CGC_EN_ALL (UAWM_HW_CGC_EN | UARM_HW_CGC_EN |\
+				 TXUC_HW_CGC_EN | RXUC_HW_CGC_EN |\
+				 DFC_HW_CGC_EN | TRLUT_HW_CGC_EN |\
+				 TMRLUT_HW_CGC_EN | OCSC_HW_CGC_EN)
+
+/* bit offset */
+enum {
+	OFFSET_UFS_PHY_SOFT_RESET           = 1,
+	OFFSET_CLK_NS_REG                   = 10,
+};
+
+/* bit masks */
+enum {
+	MASK_UFS_PHY_SOFT_RESET             = 0x2,
+	MASK_TX_SYMBOL_CLK_1US_REG          = 0x3FF,
+	MASK_CLK_NS_REG                     = 0xFFFC00,
+};
+
+enum ufs_qcom_phy_init_type {
+	UFS_PHY_INIT_FULL,
+	UFS_PHY_INIT_CFG_RESTORE,
+};
+
+static inline void
+ufs_qcom_get_controller_revision(struct ufs_hba *hba,
+				 u8 *major, u16 *minor, u16 *step)
+{
+	u32 ver = ufshcd_readl(hba, REG_UFS_HW_VERSION);
+
+	*major = (ver & UFS_HW_VER_MAJOR_MASK) >> UFS_HW_VER_MAJOR_SHFT;
+	*minor = (ver & UFS_HW_VER_MINOR_MASK) >> UFS_HW_VER_MINOR_SHFT;
+	*step = (ver & UFS_HW_VER_STEP_MASK) >> UFS_HW_VER_STEP_SHFT;
+};
+
+static inline void ufs_qcom_assert_reset(struct ufs_hba *hba)
+{
+	ufshcd_rmwl(hba, MASK_UFS_PHY_SOFT_RESET,
+			1 << OFFSET_UFS_PHY_SOFT_RESET, REG_UFS_CFG1);
+
+	/*
+	 * Make sure assertion of ufs phy reset is written to
+	 * register before returning
+	 */
+	mb();
+}
+
+static inline void ufs_qcom_deassert_reset(struct ufs_hba *hba)
+{
+	ufshcd_rmwl(hba, MASK_UFS_PHY_SOFT_RESET,
+			0 << OFFSET_UFS_PHY_SOFT_RESET, REG_UFS_CFG1);
+
+	/*
+	 * Make sure de-assertion of ufs phy reset is written to
+	 * register before returning
+	 */
+	mb();
+}
+
+struct ufs_qcom_bus_vote {
+	uint32_t client_handle;
+	uint32_t curr_vote;
+	int min_bw_vote;
+	int max_bw_vote;
+	int saved_vote;
+	bool is_max_bw_needed;
+	struct device_attribute max_bus_bw;
+};
+
+struct ufs_qcom_host {
+	struct phy *generic_phy;
+	struct ufs_hba *hba;
+	struct ufs_qcom_bus_vote bus_vote;
+	struct ufs_pa_layer_attr dev_req_params;
+	struct clk *rx_l0_sync_clk;
+	struct clk *tx_l0_sync_clk;
+	struct clk *rx_l1_sync_clk;
+	struct clk *tx_l1_sync_clk;
+	bool is_lane_clks_enabled;
+};
+
+#define ufs_qcom_is_link_off(hba) ufshcd_is_link_off(hba)
+#define ufs_qcom_is_link_active(hba) ufshcd_is_link_active(hba)
+#define ufs_qcom_is_link_hibern8(hba) ufshcd_is_link_hibern8(hba)
+
+#endif /* UFS_QCOM_H_ */