// SPDX-License-Identifier: GPL-2.0+
/**
 * PCIe SERDES driver for AM654x SoC
 *
 * Copyright (C) 2018 Texas Instruments
 * Author: Kishon Vijay Abraham I <kishon@ti.com>
 */

#include <common.h>
#include <clk-uclass.h>
#include <dm.h>
#include <log.h>
#include <dm/device.h>
#include <dm/device_compat.h>
#include <dm/lists.h>
#include <dt-bindings/phy/phy.h>
#include <generic-phy.h>
#include <asm/io.h>
#include <asm/arch/sys_proto.h>
#include <power-domain.h>
#include <regmap.h>
#include <syscon.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/err.h>

#define CMU_R07C                0x7c
#define CMU_MASTER_CDN_O        BIT(24)

#define COMLANE_R138            0xb38
#define CONFIG_VERSION_REG_MASK GENMASK(23, 16)
#define CONFIG_VERSION_REG_SHIFT 16
#define VERSION                 0x70

#define COMLANE_R190            0xb90
#define L1_MASTER_CDN_O         BIT(9)

#define COMLANE_R194            0xb94
#define CMU_OK_I_0              BIT(19)

#define SERDES_CTRL             0x1fd0
#define POR_EN                  BIT(29)

#define WIZ_LANEXCTL_STS        0x1fe0
#define TX0_ENABLE_OVL          BIT(31)
#define TX0_ENABLE_MASK         GENMASK(30, 29)
#define TX0_ENABLE_SHIFT        29
#define TX0_DISABLE_STATE       0x0
#define TX0_SLEEP_STATE         0x1
#define TX0_SNOOZE_STATE        0x2
#define TX0_ENABLE_STATE        0x3
#define RX0_ENABLE_OVL          BIT(15)
#define RX0_ENABLE_MASK         GENMASK(14, 13)
#define RX0_ENABLE_SHIFT        13
#define RX0_DISABLE_STATE       0x0
#define RX0_SLEEP_STATE         0x1
#define RX0_SNOOZE_STATE        0x2
#define RX0_ENABLE_STATE        0x3

#define WIZ_PLL_CTRL            0x1ff4
#define PLL_ENABLE_OVL          BIT(31)
#define PLL_ENABLE_MASK         GENMASK(30, 29)
#define PLL_ENABLE_SHIFT        29
#define PLL_DISABLE_STATE       0x0
#define PLL_SLEEP_STATE         0x1
#define PLL_SNOOZE_STATE        0x2
#define PLL_ENABLE_STATE        0x3
#define PLL_OK                  BIT(28)

#define PLL_LOCK_TIME           1000    /* in milliseconds */
#define SLEEP_TIME              100     /* in microseconds */

#define LANE_USB3               0x0
#define LANE_PCIE0_LANE0        0x1

#define LANE_PCIE1_LANE0        0x0
#define LANE_PCIE0_LANE1        0x1

#define SERDES_NUM_CLOCKS       3

/* SERDES control MMR bit offsets */
#define SERDES_CTL_LANE_FUNC_SEL_SHIFT  0
#define SERDES_CTL_LANE_FUNC_SEL_MASK   GENMASK(1, 0)
#define SERDES_CTL_CLK_SEL_SHIFT        4
#define SERDES_CTL_CLK_SEL_MASK         GENMASK(7, 4)

/**
 * struct serdes_am654_mux_clk_data - clock controller information structure
 */
struct serdes_am654_mux_clk_data {
        struct regmap *regmap;
        struct clk_bulk parents;
};

static int serdes_am654_mux_clk_probe(struct udevice *dev)
{
        struct serdes_am654_mux_clk_data *data = dev_get_priv(dev);
        struct udevice *syscon;
        struct regmap *regmap;
        int ret;

        debug("%s(dev=%s)\n", __func__, dev->name);

        if (!data)
                return -ENOMEM;

        ret = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
                                           "ti,serdes-clk", &syscon);
        if (ret) {
                dev_err(dev, "unable to find syscon device\n");
                return ret;
        }

        regmap = syscon_get_regmap(syscon);
        if (IS_ERR(regmap)) {
                dev_err(dev, "Fail to get Syscon regmap\n");
                return PTR_ERR(regmap);
        }

        data->regmap = regmap;

        ret = clk_get_bulk(dev, &data->parents);
        if (ret) {
                dev_err(dev, "Failed to obtain parent clocks\n");
                return ret;
        }

        return 0;
}

static int mux_table[SERDES_NUM_CLOCKS][3] = {
        /*
         * The entries represent values for selecting between
         * {left input, external reference clock, right input}
         * Only one of Left Output or Right Output should be used since
         * both left and right output clock uses the same bits and modifying
         * one clock will impact the other.
         */
        { BIT(2),               0, BIT(0) }, /* Mux of CMU refclk */
        {     -1,          BIT(3), BIT(1) }, /* Mux of Left Output */
        { BIT(1), BIT(3) | BIT(1),     -1 }, /* Mux of Right Output */
};

static int serdes_am654_mux_clk_set_parent(struct clk *clk, struct clk *parent)
{
        struct serdes_am654_mux_clk_data *data = dev_get_priv(clk->dev);
        u32 val;
        int i;

        debug("%s(clk=%s, parent=%s)\n", __func__, clk->dev->name,
              parent->dev->name);

        /*
         * Since we have the same device-tree node represent both the
         * clock and serdes device, we have two devices associated with
         * the serdes node. assigned-clocks for this node is processed twice,
         * once for the clock device and another time for the serdes
         * device. When it is processed for the clock device, it is before
         * the probe for clock device has been called. We ignore this case
         * and rely on assigned-clocks to be processed correctly for the
         * serdes case.
         */
        if (!data->regmap)
                return 0;

        for (i = 0; i < data->parents.count; i++) {
                if (clk_is_match(&data->parents.clks[i], parent))
                        break;
        }

        if (i >= data->parents.count)
                return -EINVAL;

        val = mux_table[clk->id][i];
        val <<= SERDES_CTL_CLK_SEL_SHIFT;

        regmap_update_bits(data->regmap, 0, SERDES_CTL_CLK_SEL_MASK, val);

        return 0;
}

static struct clk_ops serdes_am654_mux_clk_ops = {
        .set_parent = serdes_am654_mux_clk_set_parent,
};

U_BOOT_DRIVER(serdes_am654_mux_clk) = {
        .name = "ti-serdes-am654-mux-clk",
        .id = UCLASS_CLK,
        .probe = serdes_am654_mux_clk_probe,
        .priv_auto_alloc_size = sizeof(struct serdes_am654_mux_clk_data),
        .ops = &serdes_am654_mux_clk_ops,
};

struct serdes_am654 {
        struct regmap *regmap;
        struct regmap *serdes_ctl;
};

static int serdes_am654_enable_pll(struct serdes_am654 *phy)
{
        u32 mask = PLL_ENABLE_OVL | PLL_ENABLE_MASK;
        u32 val = PLL_ENABLE_OVL | (PLL_ENABLE_STATE << PLL_ENABLE_SHIFT);

        regmap_update_bits(phy->regmap, WIZ_PLL_CTRL, mask, val);

        return regmap_read_poll_timeout(phy->regmap, WIZ_PLL_CTRL, val,
                                        val & PLL_OK, 1000, PLL_LOCK_TIME);
}

static void serdes_am654_disable_pll(struct serdes_am654 *phy)
{
        u32 mask = PLL_ENABLE_OVL | PLL_ENABLE_MASK;

        regmap_update_bits(phy->regmap, WIZ_PLL_CTRL, mask, 0);
}

static int serdes_am654_enable_txrx(struct serdes_am654 *phy)
{
        u32 mask;
        u32 val;

        /* Enable TX */
        mask = TX0_ENABLE_OVL | TX0_ENABLE_MASK;
        val = TX0_ENABLE_OVL | (TX0_ENABLE_STATE << TX0_ENABLE_SHIFT);
        regmap_update_bits(phy->regmap, WIZ_LANEXCTL_STS, mask, val);

        /* Enable RX */
        mask = RX0_ENABLE_OVL | RX0_ENABLE_MASK;
        val = RX0_ENABLE_OVL | (RX0_ENABLE_STATE << RX0_ENABLE_SHIFT);
        regmap_update_bits(phy->regmap, WIZ_LANEXCTL_STS, mask, val);

        return 0;
}

static int serdes_am654_disable_txrx(struct serdes_am654 *phy)
{
        u32 mask;

        /* Disable TX */
        mask = TX0_ENABLE_OVL | TX0_ENABLE_MASK;
        regmap_update_bits(phy->regmap, WIZ_LANEXCTL_STS, mask, 0);

        /* Disable RX */
        mask = RX0_ENABLE_OVL | RX0_ENABLE_MASK;
        regmap_update_bits(phy->regmap, WIZ_LANEXCTL_STS, mask, 0);

        return 0;
}

static int serdes_am654_power_on(struct phy *x)
{
        struct serdes_am654 *phy = dev_get_priv(x->dev);
        int ret;
        u32 val;

        ret = serdes_am654_enable_pll(phy);
        if (ret) {
                dev_err(x->dev, "Failed to enable PLL\n");
                return ret;
        }

        ret = serdes_am654_enable_txrx(phy);
        if (ret) {
                dev_err(x->dev, "Failed to enable TX RX\n");
                return ret;
        }

        return regmap_read_poll_timeout(phy->regmap, COMLANE_R194, val,
                                        val & CMU_OK_I_0, SLEEP_TIME,
                                        PLL_LOCK_TIME);
}

static int serdes_am654_power_off(struct phy *x)
{
        struct serdes_am654 *phy = dev_get_priv(x->dev);

        serdes_am654_disable_txrx(phy);
        serdes_am654_disable_pll(phy);

        return 0;
}

static int serdes_am654_init(struct phy *x)
{
        struct serdes_am654 *phy = dev_get_priv(x->dev);
        u32 mask;
        u32 val;

        mask = CONFIG_VERSION_REG_MASK;
        val = VERSION << CONFIG_VERSION_REG_SHIFT;
        regmap_update_bits(phy->regmap, COMLANE_R138, mask, val);

        val = CMU_MASTER_CDN_O;
        regmap_update_bits(phy->regmap, CMU_R07C, val, val);

        val = L1_MASTER_CDN_O;
        regmap_update_bits(phy->regmap, COMLANE_R190, val, val);

        return 0;
}

static int serdes_am654_reset(struct phy *x)
{
        struct serdes_am654 *phy = dev_get_priv(x->dev);
        u32 val;

        val = POR_EN;
        regmap_update_bits(phy->regmap, SERDES_CTRL, val, val);
        mdelay(1);
        regmap_update_bits(phy->regmap, SERDES_CTRL, val, 0);

        return 0;
}

static int serdes_am654_of_xlate(struct phy *x,
                                 struct ofnode_phandle_args *args)
{
        struct serdes_am654 *phy = dev_get_priv(x->dev);

        if (args->args_count != 2) {
                dev_err(x->dev, "Invalid DT PHY argument count: %d\n",
                        args->args_count);
                return -EINVAL;
        }

        if (args->args[0] != PHY_TYPE_PCIE) {
                dev_err(x->dev, "Unrecognized PHY type: %d\n",
                        args->args[0]);
                return -EINVAL;
        }

        x->id = args->args[0] | (args->args[1] << 16);

        /* Setup mux mode using second argument */
        regmap_update_bits(phy->serdes_ctl, 0, SERDES_CTL_LANE_FUNC_SEL_MASK,
                           args->args[1]);

        return 0;
}

static int serdes_am654_bind(struct udevice *dev)
{
        int ret;

        ret = device_bind_driver_to_node(dev->parent,
                                         "ti-serdes-am654-mux-clk",
                                         dev_read_name(dev), dev->node,
                                         NULL);
        if (ret) {
                dev_err(dev, "%s: not able to bind clock driver\n", __func__);
                return ret;
        }

        return 0;
}

static int serdes_am654_probe(struct udevice *dev)
{
        struct serdes_am654 *phy = dev_get_priv(dev);
        struct power_domain serdes_pwrdmn;
        struct regmap *serdes_ctl;
        struct regmap *map;
        int ret;

        ret = regmap_init_mem(dev_ofnode(dev), &map);
        if (ret)
                return ret;

        phy->regmap = map;

        serdes_ctl = syscon_regmap_lookup_by_phandle(dev, "ti,serdes-clk");
        if (IS_ERR(serdes_ctl)) {
                dev_err(dev, "unable to find syscon device\n");
                return PTR_ERR(serdes_ctl);
        }

        phy->serdes_ctl = serdes_ctl;

        ret = power_domain_get_by_index(dev, &serdes_pwrdmn, 0);
        if (ret) {
                dev_err(dev, "failed to get power domain\n");
                return ret;
        }

        ret = power_domain_on(&serdes_pwrdmn);
        if (ret) {
                dev_err(dev, "Power domain on failed\n");
                return ret;
        }

        return 0;
}

static const struct udevice_id serdes_am654_phy_ids[] = {
        {
                .compatible = "ti,phy-am654-serdes",
        },
};

static const struct phy_ops serdes_am654_phy_ops = {
        .reset          = serdes_am654_reset,
        .init           = serdes_am654_init,
        .power_on       = serdes_am654_power_on,
        .power_off      = serdes_am654_power_off,
        .of_xlate       = serdes_am654_of_xlate,
};

U_BOOT_DRIVER(am654_serdes_phy) = {
        .name   = "am654_serdes_phy",
        .id     = UCLASS_PHY,
        .of_match = serdes_am654_phy_ids,
        .bind = serdes_am654_bind,
        .ops = &serdes_am654_phy_ops,
        .probe = serdes_am654_probe,
        .priv_auto_alloc_size = sizeof(struct serdes_am654),
};