sil164_drv.c

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/*
 * 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/drmP.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_encoder_slave.h>
#include <drm/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_slave(x)->slave_priv)

#define sil164_dbg(client, format, ...) do {                \
        if (drm_debug & 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(drm_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(drm_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(drm_i2c_encoder_get_client(encoder),
                 priv->saved_state);

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

static bool
sil164_encoder_mode_fixup(struct drm_encoder *encoder,
              const struct drm_display_mode *mode,
              struct drm_display_mode *adjusted_mode)
{
    return true;
}

static int
sil164_encoder_mode_valid(struct drm_encoder *encoder,
              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(drm_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 = drm_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);

    if (priv->duallink_slave)
        i2c_unregister_device(priv->duallink_slave);

    kfree(priv);
    drm_i2c_encoder_destroy(encoder);
}

static struct drm_encoder_slave_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_fixup = sil164_encoder_mode_fixup,
    .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, const struct i2c_device_id *id)
{
    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 int
sil164_remove(struct i2c_client *client)
{
    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_device(adap, &info);
}

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

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

    encoder->slave_priv = priv;
    encoder->slave_funcs = &sil164_encoder_funcs;

    priv->duallink_slave = sil164_detect_slave(client);

    return 0;
}

static struct i2c_device_id sil164_ids[] = {
    { "sil164", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, sil164_ids);

static struct drm_i2c_encoder_driver sil164_driver = {
    .i2c_driver = {
        .probe = sil164_probe,
        .remove = sil164_remove,
        .driver = {
            .name = "sil164",
        },
        .id_table = sil164_ids,
    },
    .encoder_init = sil164_encoder_init,
};

/* Module initialization */

static int __init
sil164_init(void)
{
    return drm_i2c_encoder_register(THIS_MODULE, &sil164_driver);
}

static void __exit
sil164_exit(void)
{
    drm_i2c_encoder_unregister(&sil164_driver);
}

MODULE_AUTHOR("Francisco Jerez <[email protected]>");
MODULE_DESCRIPTION("Silicon Image sil164 TMDS transmitter driver");
MODULE_LICENSE("GPL and additional rights");

module_init(sil164_init);
module_exit(sil164_exit);