// SPDX-License-Identifier: GPL-2.0
/*
 * Meson AXG MIPI DPHY driver
 *
 * Copyright (C) 2018 Amlogic, Inc. All rights reserved
 * Copyright (C) 2020 BayLibre, SAS
 * Author: Neil Armstrong <narmstrong@baylibre.com>
 */

#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>

/* [31] soft reset for the phy.
 *              1: reset. 0: dessert the reset.
 * [30] clock lane soft reset.
 * [29] data byte lane 3 soft reset.
 * [28] data byte lane 2 soft reset.
 * [27] data byte lane 1 soft reset.
 * [26] data byte lane 0 soft reset.
 * [25] mipi dsi pll clock selection.
 *              1:  clock from fixed 850Mhz clock source. 0: from VID2 PLL.
 * [12] mipi HSbyteclk enable.
 * [11] mipi divider clk selection.
 *              1: select the mipi DDRCLKHS from clock divider.
 *              0: from PLL clock.
 * [10] mipi clock divider control.
 *              1: /4. 0: /2.
 * [9]  mipi divider output enable.
 * [8]  mipi divider counter enable.
 * [7]  PLL clock enable.
 * [5]  LPDT data endian.
 *              1 = transfer the high bit first. 0 : transfer the low bit first.
 * [4]  HS data endian.
 * [3]  force data byte lane in stop mode.
 * [2]  force data byte lane 0 in receiver mode.
 * [1]  write 1 to sync the txclkesc input. the internal logic have to
 *      use txclkesc to decide Txvalid and Txready.
 * [0]  enalbe the MIPI DPHY TxDDRClk.
 */
#define MIPI_DSI_PHY_CTRL                               0x0

/* [31] clk lane tx_hs_en control selection.
 *              1: from register. 0: use clk lane state machine.
 * [30] register bit for clock lane tx_hs_en.
 * [29] clk lane tx_lp_en contrl selection.
 *              1: from register. 0: from clk lane state machine.
 * [28] register bit for clock lane tx_lp_en.
 * [27] chan0 tx_hs_en control selection.
 *              1: from register. 0: from chan0 state machine.
 * [26] register bit for chan0 tx_hs_en.
 * [25] chan0 tx_lp_en control selection.
 *              1: from register. 0: from chan0 state machine.
 * [24] register bit from chan0 tx_lp_en.
 * [23] chan0 rx_lp_en control selection.
 *              1: from register. 0: from chan0 state machine.
 * [22] register bit from chan0 rx_lp_en.
 * [21] chan0 contention detection enable control selection.
 *              1: from register. 0: from chan0 state machine.
 * [20] register bit from chan0 contention dectection enable.
 * [19] chan1 tx_hs_en control selection.
 *              1: from register. 0: from chan0 state machine.
 * [18] register bit for chan1 tx_hs_en.
 * [17] chan1 tx_lp_en control selection.
 *              1: from register. 0: from chan0 state machine.
 * [16] register bit from chan1 tx_lp_en.
 * [15] chan2 tx_hs_en control selection.
 *              1: from register. 0: from chan0 state machine.
 * [14] register bit for chan2 tx_hs_en.
 * [13] chan2 tx_lp_en control selection.
 *              1: from register. 0: from chan0 state machine.
 * [12] register bit from chan2 tx_lp_en.
 * [11] chan3 tx_hs_en control selection.
 *              1: from register. 0: from chan0 state machine.
 * [10] register bit for chan3 tx_hs_en.
 * [9]  chan3 tx_lp_en control selection.
 *              1: from register. 0: from chan0 state machine.
 * [8]  register bit from chan3 tx_lp_en.
 * [4]  clk chan power down. this bit is also used as the power down
 *      of the whole MIPI_DSI_PHY.
 * [3]  chan3 power down.
 * [2]  chan2 power down.
 * [1]  chan1 power down.
 * [0]  chan0 power down.
 */
#define MIPI_DSI_CHAN_CTRL                              0x4

/* [24]   rx turn watch dog triggered.
 * [23]   rx esc watchdog  triggered.
 * [22]   mbias ready.
 * [21]   txclkesc  synced and ready.
 * [20:17] clk lane state. {mbias_ready, tx_stop, tx_ulps, tx_hs_active}
 * [16:13] chan3 state{0, tx_stop, tx_ulps, tx_hs_active}
 * [12:9]  chan2 state.{0, tx_stop, tx_ulps, tx_hs_active}
 * [8:5]   chan1 state. {0, tx_stop, tx_ulps, tx_hs_active}
 * [4:0]   chan0 state. {TX_STOP, tx_ULPS, hs_active, direction, rxulpsesc}
 */
#define MIPI_DSI_CHAN_STS                               0x8

/* [31:24] TCLK_PREPARE.
 * [23:16] TCLK_ZERO.
 * [15:8]  TCLK_POST.
 * [7:0]   TCLK_TRAIL.
 */
#define MIPI_DSI_CLK_TIM                                0xc

/* [31:24] THS_PREPARE.
 * [23:16] THS_ZERO.
 * [15:8]  THS_TRAIL.
 * [7:0]   THS_EXIT.
 */
#define MIPI_DSI_HS_TIM                                 0x10

/* [31:24] tTA_GET.
 * [23:16] tTA_GO.
 * [15:8]  tTA_SURE.
 * [7:0]   tLPX.
 */
#define MIPI_DSI_LP_TIM                                 0x14

/* wait time to  MIPI DIS analog ready. */
#define MIPI_DSI_ANA_UP_TIM                             0x18

/* TINIT. */
#define MIPI_DSI_INIT_TIM                               0x1c

/* TWAKEUP. */
#define MIPI_DSI_WAKEUP_TIM                             0x20

/* when in RxULPS check state, after the logic enable the analog,
 *      how long we should wait to check the lP state .
 */
#define MIPI_DSI_LPOK_TIM                               0x24

/* Watchdog for RX low power state no finished. */
#define MIPI_DSI_LP_WCHDOG                              0x28

/* tMBIAS,  after send power up signals to analog,
 *      how long we should wait for analog powered up.
 */
#define MIPI_DSI_ANA_CTRL                               0x2c

/* [31:8]  reserved for future.
 * [7:0]   tCLK_PRE.
 */
#define MIPI_DSI_CLK_TIM1                               0x30

/* watchdog for turn around waiting time. */
#define MIPI_DSI_TURN_WCHDOG                            0x34

/* When in RxULPS state, how frequency we should to check
 *      if the TX side out of ULPS state.
 */
#define MIPI_DSI_ULPS_CHECK                             0x38
#define MIPI_DSI_TEST_CTRL0                             0x3c
#define MIPI_DSI_TEST_CTRL1                             0x40

struct phy_meson_axg_mipi_dphy_priv {
        struct device                           *dev;
        struct regmap                           *regmap;
        struct clk                              *clk;
        struct reset_control                    *reset;
        struct phy                              *analog;
        struct phy_configure_opts_mipi_dphy     config;
};

static const struct regmap_config phy_meson_axg_mipi_dphy_regmap_conf = {
        .reg_bits = 8,
        .val_bits = 32,
        .reg_stride = 4,
        .max_register = MIPI_DSI_TEST_CTRL1,
};

static int phy_meson_axg_mipi_dphy_init(struct phy *phy)
{
        struct phy_meson_axg_mipi_dphy_priv *priv = phy_get_drvdata(phy);
        int ret;

        ret = phy_init(priv->analog);
        if (ret)
                return ret;

        ret = reset_control_reset(priv->reset);
        if (ret)
                return ret;

        return 0;
}

static int phy_meson_axg_mipi_dphy_configure(struct phy *phy,
                                              union phy_configure_opts *opts)
{
        struct phy_meson_axg_mipi_dphy_priv *priv = phy_get_drvdata(phy);
        int ret;

        ret = phy_mipi_dphy_config_validate(&opts->mipi_dphy);
        if (ret)
                return ret;

        ret = phy_configure(priv->analog, opts);
        if (ret)
                return ret;

        memcpy(&priv->config, opts, sizeof(priv->config));

        return 0;
}

static int phy_meson_axg_mipi_dphy_power_on(struct phy *phy)
{
        struct phy_meson_axg_mipi_dphy_priv *priv = phy_get_drvdata(phy);
        int ret;
        unsigned long temp;

        ret = phy_power_on(priv->analog);
        if (ret)
                return ret;

        /* enable phy clock */
        regmap_write(priv->regmap, MIPI_DSI_PHY_CTRL,  0x1);
        regmap_write(priv->regmap, MIPI_DSI_PHY_CTRL,
                     BIT(0) | /* enable the DSI PLL clock . */
                     BIT(7) | /* enable pll clock which connected to DDR clock path */
                     BIT(8)); /* enable the clock divider counter */

        /* enable the divider clock out */
        regmap_update_bits(priv->regmap, MIPI_DSI_PHY_CTRL, BIT(9), BIT(9));

        /* enable the byte clock generation. */
        regmap_update_bits(priv->regmap, MIPI_DSI_PHY_CTRL, BIT(12), BIT(12));
        regmap_update_bits(priv->regmap, MIPI_DSI_PHY_CTRL, BIT(31), BIT(31));
        regmap_update_bits(priv->regmap, MIPI_DSI_PHY_CTRL, BIT(31), 0);

        /* Calculate lanebyteclk period in ps */
        temp = (1000000 * 100) / (priv->config.hs_clk_rate / 1000);
        temp = temp * 8 * 10;

        regmap_write(priv->regmap, MIPI_DSI_CLK_TIM,
                     DIV_ROUND_UP(priv->config.clk_trail, temp) |
                     (DIV_ROUND_UP(priv->config.clk_post +
                                   priv->config.hs_trail, temp) << 8) |
                     (DIV_ROUND_UP(priv->config.clk_zero, temp) << 16) |
                     (DIV_ROUND_UP(priv->config.clk_prepare, temp) << 24));
        regmap_write(priv->regmap, MIPI_DSI_CLK_TIM1,
                     DIV_ROUND_UP(priv->config.clk_pre, BITS_PER_BYTE));

        regmap_write(priv->regmap, MIPI_DSI_HS_TIM,
                     DIV_ROUND_UP(priv->config.hs_exit, temp) |
                     (DIV_ROUND_UP(priv->config.hs_trail, temp) << 8) |
                     (DIV_ROUND_UP(priv->config.hs_zero, temp) << 16) |
                     (DIV_ROUND_UP(priv->config.hs_prepare, temp) << 24));

        regmap_write(priv->regmap, MIPI_DSI_LP_TIM,
                     DIV_ROUND_UP(priv->config.lpx, temp) |
                     (DIV_ROUND_UP(priv->config.ta_sure, temp) << 8) |
                     (DIV_ROUND_UP(priv->config.ta_go, temp) << 16) |
                     (DIV_ROUND_UP(priv->config.ta_get, temp) << 24));

        regmap_write(priv->regmap, MIPI_DSI_ANA_UP_TIM, 0x0100);
        regmap_write(priv->regmap, MIPI_DSI_INIT_TIM,
                     DIV_ROUND_UP(priv->config.init * NSEC_PER_MSEC, temp));
        regmap_write(priv->regmap, MIPI_DSI_WAKEUP_TIM,
                     DIV_ROUND_UP(priv->config.wakeup * NSEC_PER_MSEC, temp));
        regmap_write(priv->regmap, MIPI_DSI_LPOK_TIM, 0x7C);
        regmap_write(priv->regmap, MIPI_DSI_ULPS_CHECK, 0x927C);
        regmap_write(priv->regmap, MIPI_DSI_LP_WCHDOG, 0x1000);
        regmap_write(priv->regmap, MIPI_DSI_TURN_WCHDOG, 0x1000);

        /* Powerup the analog circuit */
        switch (priv->config.lanes) {
        case 1:
                regmap_write(priv->regmap, MIPI_DSI_CHAN_CTRL, 0xe);
                break;
        case 2:
                regmap_write(priv->regmap, MIPI_DSI_CHAN_CTRL, 0xc);
                break;
        case 3:
                regmap_write(priv->regmap, MIPI_DSI_CHAN_CTRL, 0x8);
                break;
        case 4:
        default:
                regmap_write(priv->regmap, MIPI_DSI_CHAN_CTRL, 0);
                break;
        }

        /* Trigger a sync active for esc_clk */
        regmap_update_bits(priv->regmap, MIPI_DSI_PHY_CTRL, BIT(1), BIT(1));

        return 0;
}

static int phy_meson_axg_mipi_dphy_power_off(struct phy *phy)
{
        struct phy_meson_axg_mipi_dphy_priv *priv = phy_get_drvdata(phy);

        regmap_write(priv->regmap, MIPI_DSI_CHAN_CTRL, 0xf);
        regmap_write(priv->regmap, MIPI_DSI_PHY_CTRL, BIT(31));

        phy_power_off(priv->analog);

        return 0;
}

static int phy_meson_axg_mipi_dphy_exit(struct phy *phy)
{
        struct phy_meson_axg_mipi_dphy_priv *priv = phy_get_drvdata(phy);
        int ret;

        ret = phy_exit(priv->analog);
        if (ret)
                return ret;

        return reset_control_reset(priv->reset);
}

static const struct phy_ops phy_meson_axg_mipi_dphy_ops = {
        .configure      = phy_meson_axg_mipi_dphy_configure,
        .init           = phy_meson_axg_mipi_dphy_init,
        .exit           = phy_meson_axg_mipi_dphy_exit,
        .power_on       = phy_meson_axg_mipi_dphy_power_on,
        .power_off      = phy_meson_axg_mipi_dphy_power_off,
        .owner          = THIS_MODULE,
};

static int phy_meson_axg_mipi_dphy_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct phy_provider *phy_provider;
        struct phy_meson_axg_mipi_dphy_priv *priv;
        struct phy *phy;
        void __iomem *base;
        int ret;

        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        priv->dev = dev;
        platform_set_drvdata(pdev, priv);

        base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(base))
                return PTR_ERR(base);

        priv->regmap = devm_regmap_init_mmio(dev, base,
                                        &phy_meson_axg_mipi_dphy_regmap_conf);
        if (IS_ERR(priv->regmap))
                return PTR_ERR(priv->regmap);

        priv->clk = devm_clk_get(dev, "pclk");
        if (IS_ERR(priv->clk))
                return PTR_ERR(priv->clk);

        priv->reset = devm_reset_control_get(dev, "phy");
        if (IS_ERR(priv->reset))
                return PTR_ERR(priv->reset);

        priv->analog = devm_phy_get(dev, "analog");
        if (IS_ERR(priv->analog))
                return PTR_ERR(priv->analog);

        ret = clk_prepare_enable(priv->clk);
        if (ret)
                return ret;

        ret = reset_control_deassert(priv->reset);
        if (ret)
                return ret;

        phy = devm_phy_create(dev, NULL, &phy_meson_axg_mipi_dphy_ops);
        if (IS_ERR(phy))
                return dev_err_probe(dev, PTR_ERR(phy),
                                     "failed to create PHY\n");

        phy_set_drvdata(phy, priv);

        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 phy_meson_axg_mipi_dphy_of_match[] = {
        { .compatible = "amlogic,axg-mipi-dphy", },
        { },
};
MODULE_DEVICE_TABLE(of, phy_meson_axg_mipi_dphy_of_match);

static struct platform_driver phy_meson_axg_mipi_dphy_driver = {
        .probe  = phy_meson_axg_mipi_dphy_probe,
        .driver = {
                .name           = "phy-meson-axg-mipi-dphy",
                .of_match_table = phy_meson_axg_mipi_dphy_of_match,
        },
};
module_platform_driver(phy_meson_axg_mipi_dphy_driver);

MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_DESCRIPTION("Meson AXG MIPI DPHY driver");
MODULE_LICENSE("GPL v2");