/*
 * Copyright (C) 2013 NVIDIA Corporation
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/host1x.h>
#include <linux/io.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include "dev.h"

#define MIPI_CAL_CTRL                   0x00
#define MIPI_CAL_CTRL_NOISE_FILTER(x)   (((x) & 0xf) << 26)
#define MIPI_CAL_CTRL_PRESCALE(x)       (((x) & 0x3) << 24)
#define MIPI_CAL_CTRL_CLKEN_OVR         (1 << 4)
#define MIPI_CAL_CTRL_START             (1 << 0)

#define MIPI_CAL_AUTOCAL_CTRL           0x01

#define MIPI_CAL_STATUS                 0x02
#define MIPI_CAL_STATUS_DONE            (1 << 16)
#define MIPI_CAL_STATUS_ACTIVE          (1 <<  0)

#define MIPI_CAL_CONFIG_CSIA            0x05
#define MIPI_CAL_CONFIG_CSIB            0x06
#define MIPI_CAL_CONFIG_CSIC            0x07
#define MIPI_CAL_CONFIG_CSID            0x08
#define MIPI_CAL_CONFIG_CSIE            0x09
#define MIPI_CAL_CONFIG_CSIF            0x0a
#define MIPI_CAL_CONFIG_DSIA            0x0e
#define MIPI_CAL_CONFIG_DSIB            0x0f
#define MIPI_CAL_CONFIG_DSIC            0x10
#define MIPI_CAL_CONFIG_DSID            0x11

#define MIPI_CAL_CONFIG_DSIA_CLK        0x19
#define MIPI_CAL_CONFIG_DSIB_CLK        0x1a
#define MIPI_CAL_CONFIG_CSIAB_CLK       0x1b
#define MIPI_CAL_CONFIG_DSIC_CLK        0x1c
#define MIPI_CAL_CONFIG_CSICD_CLK       0x1c
#define MIPI_CAL_CONFIG_DSID_CLK        0x1d
#define MIPI_CAL_CONFIG_CSIE_CLK        0x1d

/* for data and clock lanes */
#define MIPI_CAL_CONFIG_SELECT          (1 << 21)

/* for data lanes */
#define MIPI_CAL_CONFIG_HSPDOS(x)       (((x) & 0x1f) << 16)
#define MIPI_CAL_CONFIG_HSPUOS(x)       (((x) & 0x1f) <<  8)
#define MIPI_CAL_CONFIG_TERMOS(x)       (((x) & 0x1f) <<  0)

/* for clock lanes */
#define MIPI_CAL_CONFIG_HSCLKPDOSD(x)   (((x) & 0x1f) <<  8)
#define MIPI_CAL_CONFIG_HSCLKPUOSD(x)   (((x) & 0x1f) <<  0)

#define MIPI_CAL_BIAS_PAD_CFG0          0x16
#define MIPI_CAL_BIAS_PAD_PDVCLAMP      (1 << 1)
#define MIPI_CAL_BIAS_PAD_E_VCLAMP_REF  (1 << 0)

#define MIPI_CAL_BIAS_PAD_CFG1          0x17
#define MIPI_CAL_BIAS_PAD_DRV_DN_REF(x) (((x) & 0x7) << 16)
#define MIPI_CAL_BIAS_PAD_DRV_UP_REF(x) (((x) & 0x7) << 8)

#define MIPI_CAL_BIAS_PAD_CFG2          0x18
#define MIPI_CAL_BIAS_PAD_VCLAMP(x)     (((x) & 0x7) << 16)
#define MIPI_CAL_BIAS_PAD_VAUXP(x)      (((x) & 0x7) << 4)
#define MIPI_CAL_BIAS_PAD_PDVREG        (1 << 1)

struct tegra_mipi_pad {
        unsigned long data;
        unsigned long clk;
};

struct tegra_mipi_soc {
        bool has_clk_lane;
        const struct tegra_mipi_pad *pads;
        unsigned int num_pads;

        bool clock_enable_override;
        bool needs_vclamp_ref;

        /* bias pad configuration settings */
        u8 pad_drive_down_ref;
        u8 pad_drive_up_ref;

        u8 pad_vclamp_level;
        u8 pad_vauxp_level;

        /* calibration settings for data lanes */
        u8 hspdos;
        u8 hspuos;
        u8 termos;

        /* calibration settings for clock lanes */
        u8 hsclkpdos;
        u8 hsclkpuos;
};

struct tegra_mipi {
        const struct tegra_mipi_soc *soc;
        struct device *dev;
        void __iomem *regs;
        struct mutex lock;
        struct clk *clk;

        unsigned long usage_count;
};

struct tegra_mipi_device {
        struct platform_device *pdev;
        struct tegra_mipi *mipi;
        struct device *device;
        unsigned long pads;
};

static inline u32 tegra_mipi_readl(struct tegra_mipi *mipi,
                                   unsigned long offset)
{
        return readl(mipi->regs + (offset << 2));
}

static inline void tegra_mipi_writel(struct tegra_mipi *mipi, u32 value,
                                     unsigned long offset)
{
        writel(value, mipi->regs + (offset << 2));
}

static int tegra_mipi_power_up(struct tegra_mipi *mipi)
{
        u32 value;
        int err;

        err = clk_enable(mipi->clk);
        if (err < 0)
                return err;

        value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG0);
        value &= ~MIPI_CAL_BIAS_PAD_PDVCLAMP;

        if (mipi->soc->needs_vclamp_ref)
                value |= MIPI_CAL_BIAS_PAD_E_VCLAMP_REF;

        tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG0);

        value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG2);
        value &= ~MIPI_CAL_BIAS_PAD_PDVREG;
        tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG2);

        clk_disable(mipi->clk);

        return 0;
}

static int tegra_mipi_power_down(struct tegra_mipi *mipi)
{
        u32 value;
        int err;

        err = clk_enable(mipi->clk);
        if (err < 0)
                return err;

        /*
         * The MIPI_CAL_BIAS_PAD_PDVREG controls a voltage regulator that
         * supplies the DSI pads. This must be kept enabled until none of the
         * DSI lanes are used anymore.
         */
        value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG2);
        value |= MIPI_CAL_BIAS_PAD_PDVREG;
        tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG2);

        /*
         * MIPI_CAL_BIAS_PAD_PDVCLAMP and MIPI_CAL_BIAS_PAD_E_VCLAMP_REF
         * control a regulator that supplies current to the pre-driver logic.
         * Powering down this regulator causes DSI to fail, so it must remain
         * powered on until none of the DSI lanes are used anymore.
         */
        value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG0);

        if (mipi->soc->needs_vclamp_ref)
                value &= ~MIPI_CAL_BIAS_PAD_E_VCLAMP_REF;

        value |= MIPI_CAL_BIAS_PAD_PDVCLAMP;
        tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG0);

        return 0;
}

struct tegra_mipi_device *tegra_mipi_request(struct device *device)
{
        struct device_node *np = device->of_node;
        struct tegra_mipi_device *dev;
        struct of_phandle_args args;
        int err;

        err = of_parse_phandle_with_args(np, "nvidia,mipi-calibrate",
                                         "#nvidia,mipi-calibrate-cells", 0,
                                         &args);
        if (err < 0)
                return ERR_PTR(err);

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

        dev->pdev = of_find_device_by_node(args.np);
        if (!dev->pdev) {
                err = -ENODEV;
                goto free;
        }

        dev->mipi = platform_get_drvdata(dev->pdev);
        if (!dev->mipi) {
                err = -EPROBE_DEFER;
                goto put;
        }

        of_node_put(args.np);

        dev->pads = args.args[0];
        dev->device = device;

        mutex_lock(&dev->mipi->lock);

        if (dev->mipi->usage_count++ == 0) {
                err = tegra_mipi_power_up(dev->mipi);
                if (err < 0) {
                        dev_err(dev->mipi->dev,
                                "failed to power up MIPI bricks: %d\n",
                                err);
                        return ERR_PTR(err);
                }
        }

        mutex_unlock(&dev->mipi->lock);

        return dev;

put:
        platform_device_put(dev->pdev);
free:
        kfree(dev);
out:
        of_node_put(args.np);
        return ERR_PTR(err);
}
EXPORT_SYMBOL(tegra_mipi_request);

void tegra_mipi_free(struct tegra_mipi_device *device)
{
        int err;

        mutex_lock(&device->mipi->lock);

        if (--device->mipi->usage_count == 0) {
                err = tegra_mipi_power_down(device->mipi);
                if (err < 0) {
                        /*
                         * Not much that can be done here, so an error message
                         * will have to do.
                         */
                        dev_err(device->mipi->dev,
                                "failed to power down MIPI bricks: %d\n",
                                err);
                }
        }

        mutex_unlock(&device->mipi->lock);

        platform_device_put(device->pdev);
        kfree(device);
}
EXPORT_SYMBOL(tegra_mipi_free);

static int tegra_mipi_wait(struct tegra_mipi *mipi)
{
        unsigned long timeout = jiffies + msecs_to_jiffies(250);
        u32 value;

        while (time_before(jiffies, timeout)) {
                value = tegra_mipi_readl(mipi, MIPI_CAL_STATUS);
                if ((value & MIPI_CAL_STATUS_ACTIVE) == 0 &&
                    (value & MIPI_CAL_STATUS_DONE) != 0)
                        return 0;

                usleep_range(10, 50);
        }

        return -ETIMEDOUT;
}

int tegra_mipi_calibrate(struct tegra_mipi_device *device)
{
        const struct tegra_mipi_soc *soc = device->mipi->soc;
        unsigned int i;
        u32 value;
        int err;

        err = clk_enable(device->mipi->clk);
        if (err < 0)
                return err;

        mutex_lock(&device->mipi->lock);

        value = MIPI_CAL_BIAS_PAD_DRV_DN_REF(soc->pad_drive_down_ref) |
                MIPI_CAL_BIAS_PAD_DRV_UP_REF(soc->pad_drive_up_ref);
        tegra_mipi_writel(device->mipi, value, MIPI_CAL_BIAS_PAD_CFG1);

        value = tegra_mipi_readl(device->mipi, MIPI_CAL_BIAS_PAD_CFG2);
        value &= ~MIPI_CAL_BIAS_PAD_VCLAMP(0x7);
        value &= ~MIPI_CAL_BIAS_PAD_VAUXP(0x7);
        value |= MIPI_CAL_BIAS_PAD_VCLAMP(soc->pad_vclamp_level);
        value |= MIPI_CAL_BIAS_PAD_VAUXP(soc->pad_vauxp_level);
        tegra_mipi_writel(device->mipi, value, MIPI_CAL_BIAS_PAD_CFG2);

        for (i = 0; i < soc->num_pads; i++) {
                u32 clk = 0, data = 0;

                if (device->pads & BIT(i)) {
                        data = MIPI_CAL_CONFIG_SELECT |
                               MIPI_CAL_CONFIG_HSPDOS(soc->hspdos) |
                               MIPI_CAL_CONFIG_HSPUOS(soc->hspuos) |
                               MIPI_CAL_CONFIG_TERMOS(soc->termos);
                        clk = MIPI_CAL_CONFIG_SELECT |
                              MIPI_CAL_CONFIG_HSCLKPDOSD(soc->hsclkpdos) |
                              MIPI_CAL_CONFIG_HSCLKPUOSD(soc->hsclkpuos);
                }

                tegra_mipi_writel(device->mipi, data, soc->pads[i].data);

                if (soc->has_clk_lane && soc->pads[i].clk != 0)
                        tegra_mipi_writel(device->mipi, clk, soc->pads[i].clk);
        }

        value = tegra_mipi_readl(device->mipi, MIPI_CAL_CTRL);
        value &= ~MIPI_CAL_CTRL_NOISE_FILTER(0xf);
        value &= ~MIPI_CAL_CTRL_PRESCALE(0x3);
        value |= MIPI_CAL_CTRL_NOISE_FILTER(0xa);
        value |= MIPI_CAL_CTRL_PRESCALE(0x2);

        if (!soc->clock_enable_override)
                value &= ~MIPI_CAL_CTRL_CLKEN_OVR;
        else
                value |= MIPI_CAL_CTRL_CLKEN_OVR;

        tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL);

        /* clear any pending status bits */
        value = tegra_mipi_readl(device->mipi, MIPI_CAL_STATUS);
        tegra_mipi_writel(device->mipi, value, MIPI_CAL_STATUS);

        value = tegra_mipi_readl(device->mipi, MIPI_CAL_CTRL);
        value |= MIPI_CAL_CTRL_START;
        tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL);

        err = tegra_mipi_wait(device->mipi);

        mutex_unlock(&device->mipi->lock);
        clk_disable(device->mipi->clk);

        return err;
}
EXPORT_SYMBOL(tegra_mipi_calibrate);

static const struct tegra_mipi_pad tegra114_mipi_pads[] = {
        { .data = MIPI_CAL_CONFIG_CSIA },
        { .data = MIPI_CAL_CONFIG_CSIB },
        { .data = MIPI_CAL_CONFIG_CSIC },
        { .data = MIPI_CAL_CONFIG_CSID },
        { .data = MIPI_CAL_CONFIG_CSIE },
        { .data = MIPI_CAL_CONFIG_DSIA },
        { .data = MIPI_CAL_CONFIG_DSIB },
        { .data = MIPI_CAL_CONFIG_DSIC },
        { .data = MIPI_CAL_CONFIG_DSID },
};

static const struct tegra_mipi_soc tegra114_mipi_soc = {
        .has_clk_lane = false,
        .pads = tegra114_mipi_pads,
        .num_pads = ARRAY_SIZE(tegra114_mipi_pads),
        .clock_enable_override = true,
        .needs_vclamp_ref = true,
        .pad_drive_down_ref = 0x2,
        .pad_drive_up_ref = 0x0,
        .pad_vclamp_level = 0x0,
        .pad_vauxp_level = 0x0,
        .hspdos = 0x0,
        .hspuos = 0x4,
        .termos = 0x5,
        .hsclkpdos = 0x0,
        .hsclkpuos = 0x4,
};

static const struct tegra_mipi_pad tegra124_mipi_pads[] = {
        { .data = MIPI_CAL_CONFIG_CSIA, .clk = MIPI_CAL_CONFIG_CSIAB_CLK },
        { .data = MIPI_CAL_CONFIG_CSIB, .clk = MIPI_CAL_CONFIG_CSIAB_CLK },
        { .data = MIPI_CAL_CONFIG_CSIC, .clk = MIPI_CAL_CONFIG_CSICD_CLK },
        { .data = MIPI_CAL_CONFIG_CSID, .clk = MIPI_CAL_CONFIG_CSICD_CLK },
        { .data = MIPI_CAL_CONFIG_CSIE, .clk = MIPI_CAL_CONFIG_CSIE_CLK  },
        { .data = MIPI_CAL_CONFIG_DSIA, .clk = MIPI_CAL_CONFIG_DSIA_CLK  },
        { .data = MIPI_CAL_CONFIG_DSIB, .clk = MIPI_CAL_CONFIG_DSIB_CLK  },
};

static const struct tegra_mipi_soc tegra124_mipi_soc = {
        .has_clk_lane = true,
        .pads = tegra124_mipi_pads,
        .num_pads = ARRAY_SIZE(tegra124_mipi_pads),
        .clock_enable_override = true,
        .needs_vclamp_ref = true,
        .pad_drive_down_ref = 0x2,
        .pad_drive_up_ref = 0x0,
        .pad_vclamp_level = 0x0,
        .pad_vauxp_level = 0x0,
        .hspdos = 0x0,
        .hspuos = 0x0,
        .termos = 0x0,
        .hsclkpdos = 0x1,
        .hsclkpuos = 0x2,
};

static const struct tegra_mipi_soc tegra132_mipi_soc = {
        .has_clk_lane = true,
        .pads = tegra124_mipi_pads,
        .num_pads = ARRAY_SIZE(tegra124_mipi_pads),
        .clock_enable_override = false,
        .needs_vclamp_ref = false,
        .pad_drive_down_ref = 0x0,
        .pad_drive_up_ref = 0x3,
        .pad_vclamp_level = 0x0,
        .pad_vauxp_level = 0x0,
        .hspdos = 0x0,
        .hspuos = 0x0,
        .termos = 0x0,
        .hsclkpdos = 0x3,
        .hsclkpuos = 0x2,
};

static const struct tegra_mipi_pad tegra210_mipi_pads[] = {
        { .data = MIPI_CAL_CONFIG_CSIA, .clk = 0 },
        { .data = MIPI_CAL_CONFIG_CSIB, .clk = 0 },
        { .data = MIPI_CAL_CONFIG_CSIC, .clk = 0 },
        { .data = MIPI_CAL_CONFIG_CSID, .clk = 0 },
        { .data = MIPI_CAL_CONFIG_CSIE, .clk = 0 },
        { .data = MIPI_CAL_CONFIG_CSIF, .clk = 0 },
        { .data = MIPI_CAL_CONFIG_DSIA, .clk = MIPI_CAL_CONFIG_DSIA_CLK },
        { .data = MIPI_CAL_CONFIG_DSIB, .clk = MIPI_CAL_CONFIG_DSIB_CLK },
        { .data = MIPI_CAL_CONFIG_DSIC, .clk = MIPI_CAL_CONFIG_DSIC_CLK },
        { .data = MIPI_CAL_CONFIG_DSID, .clk = MIPI_CAL_CONFIG_DSID_CLK },
};

static const struct tegra_mipi_soc tegra210_mipi_soc = {
        .has_clk_lane = true,
        .pads = tegra210_mipi_pads,
        .num_pads = ARRAY_SIZE(tegra210_mipi_pads),
        .clock_enable_override = true,
        .needs_vclamp_ref = false,
        .pad_drive_down_ref = 0x0,
        .pad_drive_up_ref = 0x3,
        .pad_vclamp_level = 0x1,
        .pad_vauxp_level = 0x1,
        .hspdos = 0x0,
        .hspuos = 0x2,
        .termos = 0x0,
        .hsclkpdos = 0x0,
        .hsclkpuos = 0x2,
};

static const struct of_device_id tegra_mipi_of_match[] = {
        { .compatible = "nvidia,tegra114-mipi", .data = &tegra114_mipi_soc },
        { .compatible = "nvidia,tegra124-mipi", .data = &tegra124_mipi_soc },
        { .compatible = "nvidia,tegra132-mipi", .data = &tegra132_mipi_soc },
        { .compatible = "nvidia,tegra210-mipi", .data = &tegra210_mipi_soc },
        { },
};

static int tegra_mipi_probe(struct platform_device *pdev)
{
        const struct of_device_id *match;
        struct tegra_mipi *mipi;
        struct resource *res;
        int err;

        match = of_match_node(tegra_mipi_of_match, pdev->dev.of_node);
        if (!match)
                return -ENODEV;

        mipi = devm_kzalloc(&pdev->dev, sizeof(*mipi), GFP_KERNEL);
        if (!mipi)
                return -ENOMEM;

        mipi->soc = match->data;
        mipi->dev = &pdev->dev;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        mipi->regs = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(mipi->regs))
                return PTR_ERR(mipi->regs);

        mutex_init(&mipi->lock);

        mipi->clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(mipi->clk)) {
                dev_err(&pdev->dev, "failed to get clock\n");
                return PTR_ERR(mipi->clk);
        }

        err = clk_prepare(mipi->clk);
        if (err < 0)
                return err;

        platform_set_drvdata(pdev, mipi);

        return 0;
}

static int tegra_mipi_remove(struct platform_device *pdev)
{
        struct tegra_mipi *mipi = platform_get_drvdata(pdev);

        clk_unprepare(mipi->clk);

        return 0;
}

struct platform_driver tegra_mipi_driver = {
        .driver = {
                .name = "tegra-mipi",
                .of_match_table = tegra_mipi_of_match,
        },
        .probe = tegra_mipi_probe,
        .remove = tegra_mipi_remove,
};