/*
 * Copyright (C) 2010 Francisco Jerez.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial
 * portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include <linux/module.h>

#include <drm/drm_drv.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>

#include <dispnv04/i2c/encoder_i2c.h>
#include <dispnv04/i2c/sil164.h>

struct sil164_priv {
        struct sil164_encoder_params config;
        struct i2c_client *duallink_slave;

        uint8_t saved_state[0x10];
        uint8_t saved_slave_state[0x10];
};

#define to_sil164_priv(x) \
        ((struct sil164_priv *)to_encoder_i2c(x)->encoder_i2c_priv)

#define sil164_dbg(client, format, ...) do {                            \
                if (drm_debug_enabled(DRM_UT_KMS))                      \
                        dev_printk(KERN_DEBUG, &client->dev,            \
                                   "%s: " format, __func__, ## __VA_ARGS__); \
        } while (0)
#define sil164_info(client, format, ...)                \
        dev_info(&client->dev, format, __VA_ARGS__)
#define sil164_err(client, format, ...)                 \
        dev_err(&client->dev, format, __VA_ARGS__)

#define SIL164_I2C_ADDR_MASTER                  0x38
#define SIL164_I2C_ADDR_SLAVE                   0x39

/* HW register definitions */

#define SIL164_VENDOR_LO                        0x0
#define SIL164_VENDOR_HI                        0x1
#define SIL164_DEVICE_LO                        0x2
#define SIL164_DEVICE_HI                        0x3
#define SIL164_REVISION                         0x4
#define SIL164_FREQ_MIN                         0x6
#define SIL164_FREQ_MAX                         0x7
#define SIL164_CONTROL0                         0x8
#  define SIL164_CONTROL0_POWER_ON              0x01
#  define SIL164_CONTROL0_EDGE_RISING           0x02
#  define SIL164_CONTROL0_INPUT_24BIT           0x04
#  define SIL164_CONTROL0_DUAL_EDGE             0x08
#  define SIL164_CONTROL0_HSYNC_ON              0x10
#  define SIL164_CONTROL0_VSYNC_ON              0x20
#define SIL164_DETECT                           0x9
#  define SIL164_DETECT_INTR_STAT               0x01
#  define SIL164_DETECT_HOTPLUG_STAT            0x02
#  define SIL164_DETECT_RECEIVER_STAT           0x04
#  define SIL164_DETECT_INTR_MODE_RECEIVER      0x00
#  define SIL164_DETECT_INTR_MODE_HOTPLUG       0x08
#  define SIL164_DETECT_OUT_MODE_HIGH           0x00
#  define SIL164_DETECT_OUT_MODE_INTR           0x10
#  define SIL164_DETECT_OUT_MODE_RECEIVER       0x20
#  define SIL164_DETECT_OUT_MODE_HOTPLUG        0x30
#  define SIL164_DETECT_VSWING_STAT             0x80
#define SIL164_CONTROL1                         0xa
#  define SIL164_CONTROL1_DESKEW_ENABLE         0x10
#  define SIL164_CONTROL1_DESKEW_INCR_SHIFT     5
#define SIL164_GPIO                             0xb
#define SIL164_CONTROL2                         0xc
#  define SIL164_CONTROL2_FILTER_ENABLE         0x01
#  define SIL164_CONTROL2_FILTER_SETTING_SHIFT  1
#  define SIL164_CONTROL2_DUALLINK_MASTER       0x40
#  define SIL164_CONTROL2_SYNC_CONT             0x80
#define SIL164_DUALLINK                         0xd
#  define SIL164_DUALLINK_ENABLE                0x10
#  define SIL164_DUALLINK_SKEW_SHIFT            5
#define SIL164_PLLZONE                          0xe
#  define SIL164_PLLZONE_STAT                   0x08
#  define SIL164_PLLZONE_FORCE_ON               0x10
#  define SIL164_PLLZONE_FORCE_HIGH             0x20

/* HW access functions */

static void
sil164_write(struct i2c_client *client, uint8_t addr, uint8_t val)
{
        uint8_t buf[] = {addr, val};
        int ret;

        ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
        if (ret < 0)
                sil164_err(client, "Error %d writing to subaddress 0x%x\n",
                           ret, addr);
}

static uint8_t
sil164_read(struct i2c_client *client, uint8_t addr)
{
        uint8_t val;
        int ret;

        ret = i2c_master_send(client, &addr, sizeof(addr));
        if (ret < 0)
                goto fail;

        ret = i2c_master_recv(client, &val, sizeof(val));
        if (ret < 0)
                goto fail;

        return val;

fail:
        sil164_err(client, "Error %d reading from subaddress 0x%x\n",
                   ret, addr);
        return 0;
}

static void
sil164_save_state(struct i2c_client *client, uint8_t *state)
{
        int i;

        for (i = 0x8; i <= 0xe; i++)
                state[i] = sil164_read(client, i);
}

static void
sil164_restore_state(struct i2c_client *client, uint8_t *state)
{
        int i;

        for (i = 0x8; i <= 0xe; i++)
                sil164_write(client, i, state[i]);
}

static void
sil164_set_power_state(struct i2c_client *client, bool on)
{
        uint8_t control0 = sil164_read(client, SIL164_CONTROL0);

        if (on)
                control0 |= SIL164_CONTROL0_POWER_ON;
        else
                control0 &= ~SIL164_CONTROL0_POWER_ON;

        sil164_write(client, SIL164_CONTROL0, control0);
}

static void
sil164_init_state(struct i2c_client *client,
                  struct sil164_encoder_params *config,
                  bool duallink)
{
        sil164_write(client, SIL164_CONTROL0,
                     SIL164_CONTROL0_HSYNC_ON |
                     SIL164_CONTROL0_VSYNC_ON |
                     (config->input_edge ? SIL164_CONTROL0_EDGE_RISING : 0) |
                     (config->input_width ? SIL164_CONTROL0_INPUT_24BIT : 0) |
                     (config->input_dual ? SIL164_CONTROL0_DUAL_EDGE : 0));

        sil164_write(client, SIL164_DETECT,
                     SIL164_DETECT_INTR_STAT |
                     SIL164_DETECT_OUT_MODE_RECEIVER);

        sil164_write(client, SIL164_CONTROL1,
                     (config->input_skew ? SIL164_CONTROL1_DESKEW_ENABLE : 0) |
                     (((config->input_skew + 4) & 0x7)
                      << SIL164_CONTROL1_DESKEW_INCR_SHIFT));

        sil164_write(client, SIL164_CONTROL2,
                     SIL164_CONTROL2_SYNC_CONT |
                     (config->pll_filter ? 0 : SIL164_CONTROL2_FILTER_ENABLE) |
                     (4 << SIL164_CONTROL2_FILTER_SETTING_SHIFT));

        sil164_write(client, SIL164_PLLZONE, 0);

        if (duallink)
                sil164_write(client, SIL164_DUALLINK,
                             SIL164_DUALLINK_ENABLE |
                             (((config->duallink_skew + 4) & 0x7)
                              << SIL164_DUALLINK_SKEW_SHIFT));
        else
                sil164_write(client, SIL164_DUALLINK, 0);
}

/* DRM encoder functions */

static void
sil164_encoder_set_config(struct drm_encoder *encoder, void *params)
{
        struct sil164_priv *priv = to_sil164_priv(encoder);

        priv->config = *(struct sil164_encoder_params *)params;
}

static void
sil164_encoder_dpms(struct drm_encoder *encoder, int mode)
{
        struct sil164_priv *priv = to_sil164_priv(encoder);
        bool on = (mode == DRM_MODE_DPMS_ON);
        bool duallink = (on && encoder->crtc->mode.clock > 165000);

        sil164_set_power_state(nouveau_i2c_encoder_get_client(encoder), on);

        if (priv->duallink_slave)
                sil164_set_power_state(priv->duallink_slave, duallink);
}

static void
sil164_encoder_save(struct drm_encoder *encoder)
{
        struct sil164_priv *priv = to_sil164_priv(encoder);

        sil164_save_state(nouveau_i2c_encoder_get_client(encoder),
                          priv->saved_state);

        if (priv->duallink_slave)
                sil164_save_state(priv->duallink_slave,
                                  priv->saved_slave_state);
}

static void
sil164_encoder_restore(struct drm_encoder *encoder)
{
        struct sil164_priv *priv = to_sil164_priv(encoder);

        sil164_restore_state(nouveau_i2c_encoder_get_client(encoder),
                             priv->saved_state);

        if (priv->duallink_slave)
                sil164_restore_state(priv->duallink_slave,
                                     priv->saved_slave_state);
}

static int
sil164_encoder_mode_valid(struct drm_encoder *encoder,
                          const struct drm_display_mode *mode)
{
        struct sil164_priv *priv = to_sil164_priv(encoder);

        if (mode->clock < 32000)
                return MODE_CLOCK_LOW;

        if (mode->clock > 330000 ||
            (mode->clock > 165000 && !priv->duallink_slave))
                return MODE_CLOCK_HIGH;

        return MODE_OK;
}

static void
sil164_encoder_mode_set(struct drm_encoder *encoder,
                        struct drm_display_mode *mode,
                        struct drm_display_mode *adjusted_mode)
{
        struct sil164_priv *priv = to_sil164_priv(encoder);
        bool duallink = adjusted_mode->clock > 165000;

        sil164_init_state(nouveau_i2c_encoder_get_client(encoder),
                          &priv->config, duallink);

        if (priv->duallink_slave)
                sil164_init_state(priv->duallink_slave,
                                  &priv->config, duallink);

        sil164_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
}

static enum drm_connector_status
sil164_encoder_detect(struct drm_encoder *encoder,
                      struct drm_connector *connector)
{
        struct i2c_client *client = nouveau_i2c_encoder_get_client(encoder);

        if (sil164_read(client, SIL164_DETECT) & SIL164_DETECT_HOTPLUG_STAT)
                return connector_status_connected;
        else
                return connector_status_disconnected;
}

static int
sil164_encoder_get_modes(struct drm_encoder *encoder,
                         struct drm_connector *connector)
{
        return 0;
}

static int
sil164_encoder_create_resources(struct drm_encoder *encoder,
                                struct drm_connector *connector)
{
        return 0;
}

static int
sil164_encoder_set_property(struct drm_encoder *encoder,
                            struct drm_connector *connector,
                            struct drm_property *property,
                            uint64_t val)
{
        return 0;
}

static void
sil164_encoder_destroy(struct drm_encoder *encoder)
{
        struct sil164_priv *priv = to_sil164_priv(encoder);

        i2c_unregister_device(priv->duallink_slave);

        kfree(priv);
        nouveau_i2c_encoder_destroy(encoder);
}

static const struct nouveau_i2c_encoder_funcs sil164_encoder_funcs = {
        .set_config = sil164_encoder_set_config,
        .destroy = sil164_encoder_destroy,
        .dpms = sil164_encoder_dpms,
        .save = sil164_encoder_save,
        .restore = sil164_encoder_restore,
        .mode_valid = sil164_encoder_mode_valid,
        .mode_set = sil164_encoder_mode_set,
        .detect = sil164_encoder_detect,
        .get_modes = sil164_encoder_get_modes,
        .create_resources = sil164_encoder_create_resources,
        .set_property = sil164_encoder_set_property,
};

/* I2C driver functions */

static int
sil164_probe(struct i2c_client *client)
{
        int vendor = sil164_read(client, SIL164_VENDOR_HI) << 8 |
                sil164_read(client, SIL164_VENDOR_LO);
        int device = sil164_read(client, SIL164_DEVICE_HI) << 8 |
                sil164_read(client, SIL164_DEVICE_LO);
        int rev = sil164_read(client, SIL164_REVISION);

        if (vendor != 0x1 || device != 0x6) {
                sil164_dbg(client, "Unknown device %x:%x.%x\n",
                           vendor, device, rev);
                return -ENODEV;
        }

        sil164_info(client, "Detected device %x:%x.%x\n",
                    vendor, device, rev);

        return 0;
}

static struct i2c_client *
sil164_detect_slave(struct i2c_client *client)
{
        struct i2c_adapter *adap = client->adapter;
        struct i2c_msg msg = {
                .addr = SIL164_I2C_ADDR_SLAVE,
                .len = 0,
        };
        const struct i2c_board_info info = {
                I2C_BOARD_INFO("sil164", SIL164_I2C_ADDR_SLAVE)
        };

        if (i2c_transfer(adap, &msg, 1) != 1) {
                sil164_dbg(adap, "No dual-link slave found.");
                return NULL;
        }

        return i2c_new_client_device(adap, &info);
}

static int
sil164_encoder_init(struct i2c_client *client,
                    struct drm_device *dev,
                    struct nouveau_i2c_encoder *encoder)
{
        struct sil164_priv *priv;
        struct i2c_client *slave_client;

        priv = kzalloc_obj(*priv);
        if (!priv)
                return -ENOMEM;

        encoder->encoder_i2c_priv = priv;
        encoder->encoder_i2c_funcs = &sil164_encoder_funcs;

        slave_client = sil164_detect_slave(client);
        if (!IS_ERR(slave_client))
                priv->duallink_slave = slave_client;

        return 0;
}

static const struct i2c_device_id sil164_ids[] = {
        { "sil164" },
        { }
};
MODULE_DEVICE_TABLE(i2c, sil164_ids);

static struct nouveau_i2c_encoder_driver sil164_driver = {
        .i2c_driver = {
                .probe = sil164_probe,
                .driver = {
                        .name = "sil164",
                },
                .id_table = sil164_ids,
        },
        .encoder_init = sil164_encoder_init,
};

/* Module initialization */

static int __init
sil164_init(void)
{
        return i2c_add_driver(&sil164_driver.i2c_driver);
}

static void __exit
sil164_exit(void)
{
        i2c_del_driver(&sil164_driver.i2c_driver);
}

MODULE_AUTHOR("Francisco Jerez <currojerez@riseup.net>");
MODULE_DESCRIPTION("Silicon Image sil164 TMDS transmitter driver");
MODULE_LICENSE("GPL and additional rights");

module_init(sil164_init);
module_exit(sil164_exit);