text: /*
   * 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 "drmP.h"
  #include "drm_crtc_helper.h"
  #include "drm_encoder_slave.h"
  #include "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,
  			  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 <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);
  