root/drivers/phy/samsung/phy-samsung-ufs.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * UFS PHY driver for Samsung SoC
 *
 * Copyright (C) 2020 Samsung Electronics Co., Ltd.
 * Author: Seungwon Jeon <essuuj@gmail.com>
 * Author: Alim Akhtar <alim.akhtar@samsung.com>
 *
 */
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#include "phy-samsung-ufs.h"

#define for_each_phy_lane(phy, i) \
        for (i = 0; i < (phy)->lane_cnt; i++)
#define for_each_phy_cfg(cfg) \
        for (; (cfg)->id; (cfg)++)

#define PHY_DEF_LANE_CNT        1

void samsung_ufs_phy_config(struct samsung_ufs_phy *phy,
                            const struct samsung_ufs_phy_cfg *cfg,
                            u8 lane)
{
        enum {LANE_0, LANE_1}; /* lane index */

        switch (lane) {
        case LANE_0:
                writel(cfg->val, (phy)->reg_pma + cfg->off_0);
                break;
        case LANE_1:
                if (cfg->id == PHY_TRSV_BLK)
                        writel(cfg->val, (phy)->reg_pma + cfg->off_1);
                break;
        }
}

int samsung_ufs_phy_wait_for_lock_acq(struct phy *phy, u8 lane)
{
        struct samsung_ufs_phy *ufs_phy = get_samsung_ufs_phy(phy);
        const unsigned int timeout_us = 100000;
        const unsigned int sleep_us = 10;
        u32 val;
        int err;

        err = readl_poll_timeout(
                        ufs_phy->reg_pma + PHY_APB_ADDR(PHY_PLL_LOCK_STATUS),
                        val, (val & PHY_PLL_LOCK_BIT), sleep_us, timeout_us);
        if (err) {
                dev_err(ufs_phy->dev,
                        "failed to get phy pll lock acquisition %d\n", err);
                goto out;
        }

        err = readl_poll_timeout(
                        ufs_phy->reg_pma +
                        PHY_APB_ADDR(ufs_phy->drvdata->cdr_lock_status_offset),
                        val, (val & PHY_CDR_LOCK_BIT), sleep_us, timeout_us);
        if (err)
                dev_err(ufs_phy->dev,
                        "failed to get phy cdr lock acquisition %d\n", err);
out:
        return err;
}

static int samsung_ufs_phy_calibrate(struct phy *phy)
{
        struct samsung_ufs_phy *ufs_phy = get_samsung_ufs_phy(phy);
        const struct samsung_ufs_phy_cfg * const *cfgs = ufs_phy->cfgs;
        const struct samsung_ufs_phy_cfg *cfg;
        int err = 0;
        int i;

        if (unlikely(ufs_phy->ufs_phy_state < CFG_PRE_INIT ||
                     ufs_phy->ufs_phy_state >= CFG_TAG_MAX)) {
                dev_err(ufs_phy->dev, "invalid phy config index %d\n", ufs_phy->ufs_phy_state);
                return -EINVAL;
        }

        cfg = cfgs[ufs_phy->ufs_phy_state];
        if (!cfg)
                goto out;

        for_each_phy_cfg(cfg) {
                for_each_phy_lane(ufs_phy, i) {
                        samsung_ufs_phy_config(ufs_phy, cfg, i);
                }
        }

        for_each_phy_lane(ufs_phy, i) {
                if (ufs_phy->ufs_phy_state == CFG_PRE_INIT &&
                    ufs_phy->drvdata->wait_for_cal) {
                        err = ufs_phy->drvdata->wait_for_cal(phy, i);
                        if (err)
                                goto out;
                }

                if (ufs_phy->ufs_phy_state == CFG_POST_PWR_HS &&
                    ufs_phy->drvdata->wait_for_cdr) {
                        err = ufs_phy->drvdata->wait_for_cdr(phy, i);
                        if (err)
                                goto out;
                }
        }

        /**
         * In Samsung ufshci, PHY need to be calibrated at different
         * stages / state mainly before Linkstartup, after Linkstartup,
         * before power mode change and after power mode change.
         * Below state machine to make sure to calibrate PHY in each
         * state. Here after configuring PHY in a given state, will
         * change the state to next state so that next state phy
         * calibration value can be programed
         */
out:
        switch (ufs_phy->ufs_phy_state) {
        case CFG_PRE_INIT:
                ufs_phy->ufs_phy_state = CFG_POST_INIT;
                break;
        case CFG_POST_INIT:
                ufs_phy->ufs_phy_state = CFG_PRE_PWR_HS;
                break;
        case CFG_PRE_PWR_HS:
                ufs_phy->ufs_phy_state = CFG_POST_PWR_HS;
                break;
        case CFG_POST_PWR_HS:
                /* Change back to INIT state */
                ufs_phy->ufs_phy_state = CFG_PRE_INIT;
                break;
        default:
                dev_err(ufs_phy->dev, "wrong state for phy calibration\n");
        }

        return err;
}

static int samsung_ufs_phy_clks_init(struct samsung_ufs_phy *phy)
{
        int i;
        const struct samsung_ufs_phy_drvdata *drvdata = phy->drvdata;
        int num_clks = drvdata->num_clks;

        phy->clks = devm_kcalloc(phy->dev, num_clks, sizeof(*phy->clks),
                                 GFP_KERNEL);
        if (!phy->clks)
                return -ENOMEM;

        for (i = 0; i < num_clks; i++)
                phy->clks[i].id = drvdata->clk_list[i];

        return devm_clk_bulk_get(phy->dev, num_clks, phy->clks);
}

static int samsung_ufs_phy_init(struct phy *phy)
{
        struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(phy);

        ss_phy->lane_cnt = phy->attrs.bus_width;
        ss_phy->ufs_phy_state = CFG_PRE_INIT;

        return 0;
}

static int samsung_ufs_phy_power_on(struct phy *phy)
{
        struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(phy);
        int ret;

        samsung_ufs_phy_ctrl_isol(ss_phy, false);

        ret = clk_bulk_prepare_enable(ss_phy->drvdata->num_clks, ss_phy->clks);
        if (ret) {
                dev_err(ss_phy->dev, "failed to enable ufs phy clocks\n");
                return ret;
        }

        if (ss_phy->ufs_phy_state == CFG_PRE_INIT) {
                ret = samsung_ufs_phy_calibrate(phy);
                if (ret)
                        dev_err(ss_phy->dev, "ufs phy calibration failed\n");
        }

        return ret;
}

static int samsung_ufs_phy_power_off(struct phy *phy)
{
        struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(phy);

        clk_bulk_disable_unprepare(ss_phy->drvdata->num_clks, ss_phy->clks);

        samsung_ufs_phy_ctrl_isol(ss_phy, true);

        return 0;
}

static int samsung_ufs_phy_set_mode(struct phy *generic_phy,
                                    enum phy_mode mode, int submode)
{
        struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(generic_phy);

        ss_phy->mode = PHY_MODE_INVALID;

        if (mode > 0)
                ss_phy->mode = mode;

        return 0;
}

static int samsung_ufs_phy_notify_state(struct phy *phy,
                                        union phy_notify state)
{
        struct samsung_ufs_phy *ufs_phy = get_samsung_ufs_phy(phy);
        const struct samsung_ufs_phy_cfg *cfg;
        int i, err = -EINVAL;

        if (!ufs_phy->cfgs_hibern8)
                return 0;

        if (state.ufs_state == PHY_UFS_HIBERN8_ENTER)
                cfg = ufs_phy->cfgs_hibern8[CFG_POST_HIBERN8_ENTER];
        else if (state.ufs_state == PHY_UFS_HIBERN8_EXIT)
                cfg = ufs_phy->cfgs_hibern8[CFG_PRE_HIBERN8_EXIT];
        else
                goto err_out;

        for_each_phy_cfg(cfg) {
                for_each_phy_lane(ufs_phy, i) {
                        samsung_ufs_phy_config(ufs_phy, cfg, i);
                }
        }

        if (state.ufs_state == PHY_UFS_HIBERN8_EXIT) {
                for_each_phy_lane(ufs_phy, i) {
                        if (ufs_phy->drvdata->wait_for_cdr) {
                                err = ufs_phy->drvdata->wait_for_cdr(phy, i);
                                if (err)
                                        goto err_out;
                        }
                }
        }

        return 0;
err_out:
        return err;
}

static int samsung_ufs_phy_exit(struct phy *phy)
{
        struct samsung_ufs_phy *ss_phy = get_samsung_ufs_phy(phy);

        ss_phy->ufs_phy_state = CFG_TAG_MAX;

        return 0;
}

static const struct phy_ops samsung_ufs_phy_ops = {
        .init           = samsung_ufs_phy_init,
        .exit           = samsung_ufs_phy_exit,
        .power_on       = samsung_ufs_phy_power_on,
        .power_off      = samsung_ufs_phy_power_off,
        .calibrate      = samsung_ufs_phy_calibrate,
        .set_mode       = samsung_ufs_phy_set_mode,
        .notify_phystate = samsung_ufs_phy_notify_state,
        .owner          = THIS_MODULE,
};

static const struct of_device_id samsung_ufs_phy_match[];

static int samsung_ufs_phy_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        const struct of_device_id *match;
        struct samsung_ufs_phy *phy;
        struct phy *gen_phy;
        struct phy_provider *phy_provider;
        const struct samsung_ufs_phy_drvdata *drvdata;
        u32 isol_offset;
        int err = 0;

        match = of_match_node(samsung_ufs_phy_match, dev->of_node);
        if (!match) {
                err = -EINVAL;
                dev_err(dev, "failed to get match_node\n");
                goto out;
        }

        phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
        if (!phy) {
                err = -ENOMEM;
                goto out;
        }

        phy->reg_pma = devm_platform_ioremap_resource_byname(pdev, "phy-pma");
        if (IS_ERR(phy->reg_pma)) {
                err = PTR_ERR(phy->reg_pma);
                goto out;
        }

        phy->reg_pmu = syscon_regmap_lookup_by_phandle(dev->of_node,
                                                       "samsung,pmu-syscon");
        if (IS_ERR(phy->reg_pmu)) {
                err = PTR_ERR(phy->reg_pmu);
                dev_err(dev, "failed syscon remap for pmu\n");
                goto out;
        }

        gen_phy = devm_phy_create(dev, NULL, &samsung_ufs_phy_ops);
        if (IS_ERR(gen_phy)) {
                err = PTR_ERR(gen_phy);
                dev_err(dev, "failed to create PHY for ufs-phy\n");
                goto out;
        }

        drvdata = match->data;
        phy->dev = dev;
        phy->drvdata = drvdata;
        phy->cfgs = drvdata->cfgs;
        phy->cfgs_hibern8 = drvdata->cfgs_hibern8;
        memcpy(&phy->isol, &drvdata->isol, sizeof(phy->isol));

        if (!of_property_read_u32_index(dev->of_node, "samsung,pmu-syscon", 1,
                                        &isol_offset))
                phy->isol.offset = isol_offset;

        phy->lane_cnt = PHY_DEF_LANE_CNT;

        err = samsung_ufs_phy_clks_init(phy);
        if (err) {
                dev_err(dev, "failed to get phy clocks\n");
                goto out;
        }

        phy_set_drvdata(gen_phy, phy);

        phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
        if (IS_ERR(phy_provider)) {
                err = PTR_ERR(phy_provider);
                dev_err(dev, "failed to register phy-provider\n");
                goto out;
        }
out:
        return err;
}

static const struct of_device_id samsung_ufs_phy_match[] = {
        {
                .compatible = "google,gs101-ufs-phy",
                .data = &tensor_gs101_ufs_phy,
        }, {
                .compatible = "samsung,exynos7-ufs-phy",
                .data = &exynos7_ufs_phy,
        }, {
                .compatible = "samsung,exynosautov9-ufs-phy",
                .data = &exynosautov9_ufs_phy,
        }, {
                .compatible = "samsung,exynosautov920-ufs-phy",
                .data = &exynosautov920_ufs_phy,
        }, {
                .compatible = "tesla,fsd-ufs-phy",
                .data = &fsd_ufs_phy,
        },
        {},
};
MODULE_DEVICE_TABLE(of, samsung_ufs_phy_match);

static struct platform_driver samsung_ufs_phy_driver = {
        .probe  = samsung_ufs_phy_probe,
        .driver = {
                .name = "samsung-ufs-phy",
                .of_match_table = samsung_ufs_phy_match,
        },
};
module_platform_driver(samsung_ufs_phy_driver);
MODULE_DESCRIPTION("Samsung SoC UFS PHY Driver");
MODULE_AUTHOR("Seungwon Jeon <essuuj@gmail.com>");
MODULE_AUTHOR("Alim Akhtar <alim.akhtar@samsung.com>");
MODULE_LICENSE("GPL v2");