path: root/drivers/gpu/drm/i915/intel_dsi.c

/*
 * Copyright © 2013 Intel Corporation
 *
 * 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 AUTHORS OR COPYRIGHT HOLDERS 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.
 *
 * Author: Jani Nikula <jani.nikula@intel.com>
 */

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_edid.h>
#include <drm/i915_drm.h>
#include <linux/slab.h>
#include "i915_drv.h"
#include "intel_drv.h"
#include "intel_dsi.h"
#include "intel_dsi_cmd.h"

/* the sub-encoders aka panel drivers */
static const struct intel_dsi_device intel_dsi_devices[] = {
	{
		.panel_id = MIPI_DSI_GENERIC_PANEL_ID,
		.name = "vbt-generic-dsi-vid-mode-display",
		.dev_ops = &vbt_generic_dsi_display_ops,
	},
};

static void band_gap_reset(struct drm_i915_private *dev_priv)
{
	mutex_lock(&dev_priv->dpio_lock);

	vlv_flisdsi_write(dev_priv, 0x08, 0x0001);
	vlv_flisdsi_write(dev_priv, 0x0F, 0x0005);
	vlv_flisdsi_write(dev_priv, 0x0F, 0x0025);
	udelay(150);
	vlv_flisdsi_write(dev_priv, 0x0F, 0x0000);
	vlv_flisdsi_write(dev_priv, 0x08, 0x0000);

	mutex_unlock(&dev_priv->dpio_lock);
}

static struct intel_dsi *intel_attached_dsi(struct drm_connector *connector)
{
	return container_of(intel_attached_encoder(connector),
			    struct intel_dsi, base);
}

static inline bool is_vid_mode(struct intel_dsi *intel_dsi)
{
	return intel_dsi->operation_mode == INTEL_DSI_VIDEO_MODE;
}

static inline bool is_cmd_mode(struct intel_dsi *intel_dsi)
{
	return intel_dsi->operation_mode == INTEL_DSI_COMMAND_MODE;
}

static void intel_dsi_hot_plug(struct intel_encoder *encoder)
{
	DRM_DEBUG_KMS("\n");
}

static bool intel_dsi_compute_config(struct intel_encoder *encoder,
				     struct intel_crtc_config *config)
{
	struct intel_dsi *intel_dsi = container_of(encoder, struct intel_dsi,
						   base);
	struct intel_connector *intel_connector = intel_dsi->attached_connector;
	struct drm_display_mode *fixed_mode = intel_connector->panel.fixed_mode;
	struct drm_display_mode *adjusted_mode = &config->adjusted_mode;
	struct drm_display_mode *mode = &config->requested_mode;

	DRM_DEBUG_KMS("\n");

	if (fixed_mode)
		intel_fixed_panel_mode(fixed_mode, adjusted_mode);

	/* DSI uses short packets for sync events, so clear mode flags for DSI */
	adjusted_mode->flags = 0;

	if (intel_dsi->dev.dev_ops->mode_fixup)
		return intel_dsi->dev.dev_ops->mode_fixup(&intel_dsi->dev,
							  mode, adjusted_mode);

	return true;
}

static void intel_dsi_device_ready(struct intel_encoder *encoder)
{
	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
	int pipe = intel_crtc->pipe;
	u32 val;

	DRM_DEBUG_KMS("\n");

	mutex_lock(&dev_priv->dpio_lock);
	/* program rcomp for compliance, reduce from 50 ohms to 45 ohms
	 * needed everytime after power gate */
	vlv_flisdsi_write(dev_priv, 0x04, 0x0004);
	mutex_unlock(&dev_priv->dpio_lock);

	/* bandgap reset is needed after everytime we do power gate */
	band_gap_reset(dev_priv);

	I915_WRITE(MIPI_DEVICE_READY(pipe), ULPS_STATE_ENTER);
	usleep_range(2500, 3000);

	val = I915_READ(MIPI_PORT_CTRL(pipe));
	I915_WRITE(MIPI_PORT_CTRL(pipe), val | LP_OUTPUT_HOLD);
	usleep_range(1000, 1500);

	I915_WRITE(MIPI_DEVICE_READY(pipe), ULPS_STATE_EXIT);
	usleep_range(2500, 3000);

	I915_WRITE(MIPI_DEVICE_READY(pipe), DEVICE_READY);
	usleep_range(2500, 3000);
}

static void intel_dsi_enable(struct intel_encoder *encoder)
{
	struct drm_device *dev = encoder->base.dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
	int pipe = intel_crtc->pipe;
	u32 temp;

	DRM_DEBUG_KMS("\n");

	if (is_cmd_mode(intel_dsi))
		I915_WRITE(MIPI_MAX_RETURN_PKT_SIZE(pipe), 8 * 4);
	else {
		msleep(20); /* XXX */
		dpi_send_cmd(intel_dsi, TURN_ON, DPI_LP_MODE_EN);
		msleep(100);

		if (intel_dsi->dev.dev_ops->enable)
			intel_dsi->dev.dev_ops->enable(&intel_dsi->dev);

		wait_for_dsi_fifo_empty(intel_dsi);

		/* assert ip_tg_enable signal */
		temp = I915_READ(MIPI_PORT_CTRL(pipe)) & ~LANE_CONFIGURATION_MASK;
		temp = temp | intel_dsi->port_bits;
		I915_WRITE(MIPI_PORT_CTRL(pipe), temp | DPI_ENABLE);
		POSTING_READ(MIPI_PORT_CTRL(pipe));
	}
}

static void intel_dsi_pre_enable(struct intel_encoder *encoder)
{
	struct drm_device *dev = encoder->base.dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
	enum pipe pipe = intel_crtc->pipe;
	u32 tmp;

	DRM_DEBUG_KMS("\n");

	/* Disable DPOunit clock gating, can stall pipe
	 * and we need DPLL REFA always enabled */
	tmp = I915_READ(DPLL(pipe));
	tmp |= DPLL_REFA_CLK_ENABLE_VLV;
	I915_WRITE(DPLL(pipe), tmp);

	/* update the hw state for DPLL */
	intel_crtc->config.dpll_hw_state.dpll = DPLL_INTEGRATED_CLOCK_VLV |
		DPLL_REFA_CLK_ENABLE_VLV;

	tmp = I915_READ(DSPCLK_GATE_D);
	tmp |= DPOUNIT_CLOCK_GATE_DISABLE;
	I915_WRITE(DSPCLK_GATE_D, tmp);

	/* put device in ready state */
	intel_dsi_device_ready(encoder);

	msleep(intel_dsi->panel_on_delay);

	if (intel_dsi->dev.dev_ops->panel_reset)
		intel_dsi->dev.dev_ops->panel_reset(&intel_dsi->dev);

	if (intel_dsi->dev.dev_ops->send_otp_cmds)
		intel_dsi->dev.dev_ops->send_otp_cmds(&intel_dsi->dev);

	wait_for_dsi_fifo_empty(intel_dsi);

	/* Enable port in pre-enable phase itself because as per hw team
	 * recommendation, port should be enabled befor plane & pipe */
	intel_dsi_enable(encoder);
}

static void intel_dsi_enable_nop(struct intel_encoder *encoder)
{
	DRM_DEBUG_KMS("\n");

	/* for DSI port enable has to be done before pipe
	 * and plane enable, so port enable is done in
	 * pre_enable phase itself unlike other encoders
	 */
}

static void intel_dsi_pre_disable(struct intel_encoder *encoder)
{
	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);

	DRM_DEBUG_KMS("\n");

	if (is_vid_mode(intel_dsi)) {
		/* Send Shutdown command to the panel in LP mode */
		dpi_send_cmd(intel_dsi, SHUTDOWN, DPI_LP_MODE_EN);
		msleep(10);
	}
}

static void intel_dsi_disable(struct intel_encoder *encoder)
{
	struct drm_device *dev = encoder->base.dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
	int pipe = intel_crtc->pipe;
	u32 temp;

	DRM_DEBUG_KMS("\n");

	if (is_vid_mode(intel_dsi)) {
		wait_for_dsi_fifo_empty(intel_dsi);

		/* de-assert ip_tg_enable signal */
		temp = I915_READ(MIPI_PORT_CTRL(pipe));
		I915_WRITE(MIPI_PORT_CTRL(pipe), temp & ~DPI_ENABLE);
		POSTING_READ(MIPI_PORT_CTRL(pipe));

		msleep(2);
	}

	/* Panel commands can be sent when clock is in LP11 */
	I915_WRITE(MIPI_DEVICE_READY(pipe), 0x0);

	temp = I915_READ(MIPI_CTRL(pipe));
	temp &= ~ESCAPE_CLOCK_DIVIDER_MASK;
	I915_WRITE(MIPI_CTRL(pipe), temp |
		   intel_dsi->escape_clk_div <<
		   ESCAPE_CLOCK_DIVIDER_SHIFT);

	I915_WRITE(MIPI_EOT_DISABLE(pipe), CLOCKSTOP);

	temp = I915_READ(MIPI_DSI_FUNC_PRG(pipe));
	temp &= ~VID_MODE_FORMAT_MASK;
	I915_WRITE(MIPI_DSI_FUNC_PRG(pipe), temp);

	I915_WRITE(MIPI_DEVICE_READY(pipe), 0x1);

	/* if disable packets are sent before sending shutdown packet then in
	 * some next enable sequence send turn on packet error is observed */
	if (intel_dsi->dev.dev_ops->disable)
		intel_dsi->dev.dev_ops->disable(&intel_dsi->dev);

	wait_for_dsi_fifo_empty(intel_dsi);
}

static void intel_dsi_clear_device_ready(struct intel_encoder *encoder)
{
	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
	int pipe = intel_crtc->pipe;
	u32 val;

	DRM_DEBUG_KMS("\n");

	I915_WRITE(MIPI_DEVICE_READY(pipe), DEVICE_READY | ULPS_STATE_ENTER);
	usleep_range(2000, 2500);

	I915_WRITE(MIPI_DEVICE_READY(pipe), DEVICE_READY | ULPS_STATE_EXIT);
	usleep_range(2000, 2500);

	I915_WRITE(MIPI_DEVICE_READY(pipe), DEVICE_READY | ULPS_STATE_ENTER);
	usleep_range(2000, 2500);

	if (wait_for(((I915_READ(MIPI_PORT_CTRL(pipe)) & AFE_LATCHOUT)
		      == 0x00000), 30))
		DRM_ERROR("DSI LP not going Low\n");

	val = I915_READ(MIPI_PORT_CTRL(pipe));
	I915_WRITE(MIPI_PORT_CTRL(pipe), val & ~LP_OUTPUT_HOLD);
	usleep_range(1000, 1500);

	I915_WRITE(MIPI_DEVICE_READY(pipe), 0x00);
	usleep_range(2000, 2500);

	vlv_disable_dsi_pll(encoder);
}

static void intel_dsi_post_disable(struct intel_encoder *encoder)
{
	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
	u32 val;

	DRM_DEBUG_KMS("\n");

	intel_dsi_disable(encoder);

	intel_dsi_clear_device_ready(encoder);

	val = I915_READ(DSPCLK_GATE_D);
	val &= ~DPOUNIT_CLOCK_GATE_DISABLE;
	I915_WRITE(DSPCLK_GATE_D, val);

	if (intel_dsi->dev.dev_ops->disable_panel_power)
		intel_dsi->dev.dev_ops->disable_panel_power(&intel_dsi->dev);

	msleep(intel_dsi->panel_off_delay);
	msleep(intel_dsi->panel_pwr_cycle_delay);
}

static bool intel_dsi_get_hw_state(struct intel_encoder *encoder,
				   enum pipe *pipe)
{
	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	enum intel_display_power_domain power_domain;
	u32 port, func;
	enum pipe p;

	DRM_DEBUG_KMS("\n");

	power_domain = intel_display_port_power_domain(encoder);
	if (!intel_display_power_enabled(dev_priv, power_domain))
		return false;

	/* XXX: this only works for one DSI output */
	for (p = PIPE_A; p <= PIPE_B; p++) {
		port = I915_READ(MIPI_PORT_CTRL(p));
		func = I915_READ(MIPI_DSI_FUNC_PRG(p));

		if ((port & DPI_ENABLE) || (func & CMD_MODE_DATA_WIDTH_MASK)) {
			if (I915_READ(MIPI_DEVICE_READY(p)) & DEVICE_READY) {
				*pipe = p;
				return true;
			}
		}
	}

	return false;
}

static void intel_dsi_get_config(struct intel_encoder *encoder,
				 struct intel_crtc_config *pipe_config)
{
	u32 pclk;
	DRM_DEBUG_KMS("\n");

	/*
	 * DPLL_MD is not used in case of DSI, reading will get some default value
	 * set dpll_md = 0
	 */
	pipe_config->dpll_hw_state.dpll_md = 0;

	pclk = vlv_get_dsi_pclk(encoder, pipe_config->pipe_bpp);
	if (!pclk)
		return;

	pipe_config->adjusted_mode.crtc_clock = pclk;
	pipe_config->port_clock = pclk;
}

static enum drm_mode_status
intel_dsi_mode_valid(struct drm_connector *connector,
		     struct drm_display_mode *mode)
{
	struct intel_connector *intel_connector = to_intel_connector(connector);
	struct drm_display_mode *fixed_mode = intel_connector->panel.fixed_mode;
	struct intel_dsi *intel_dsi = intel_attached_dsi(connector);

	DRM_DEBUG_KMS("\n");

	if (mode->flags & DRM_MODE_FLAG_DBLSCAN) {
		DRM_DEBUG_KMS("MODE_NO_DBLESCAN\n");
		return MODE_NO_DBLESCAN;
	}

	if (fixed_mode) {
		if (mode->hdisplay > fixed_mode->hdisplay)
			return MODE_PANEL;
		if (mode->vdisplay > fixed_mode->vdisplay)
			return MODE_PANEL;
	}

	return intel_dsi->dev.dev_ops->mode_valid(&intel_dsi->dev, mode);
}

/* return txclkesc cycles in terms of divider and duration in us */
static u16 txclkesc(u32 divider, unsigned int us)
{
	switch (divider) {
	case ESCAPE_CLOCK_DIVIDER_1:
	default:
		return 20 * us;
	case ESCAPE_CLOCK_DIVIDER_2:
		return 10 * us;
	case ESCAPE_CLOCK_DIVIDER_4:
		return 5 * us;
	}
}

/* return pixels in terms of txbyteclkhs */
static u16 txbyteclkhs(u16 pixels, int bpp, int lane_count,
		       u16 burst_mode_ratio)
{
	return DIV_ROUND_UP(DIV_ROUND_UP(pixels * bpp * burst_mode_ratio,
					 8 * 100), lane_count);
}

static void set_dsi_timings(struct drm_encoder *encoder,
			    const struct drm_display_mode *mode)
{
	struct drm_device *dev = encoder->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
	int pipe = intel_crtc->pipe;
	unsigned int bpp = intel_crtc->config.pipe_bpp;
	unsigned int lane_count = intel_dsi->lane_count;

	u16 hactive, hfp, hsync, hbp, vfp, vsync, vbp;

	hactive = mode->hdisplay;
	hfp = mode->hsync_start - mode->hdisplay;
	hsync = mode->hsync_end - mode->hsync_start;
	hbp = mode->htotal - mode->hsync_end;

	vfp = mode->vsync_start - mode->vdisplay;
	vsync = mode->vsync_end - mode->vsync_start;
	vbp = mode->vtotal - mode->vsync_end;

	/* horizontal values are in terms of high speed byte clock */
	hactive = txbyteclkhs(hactive, bpp, lane_count,
			      intel_dsi->burst_mode_ratio);
	hfp = txbyteclkhs(hfp, bpp, lane_count, intel_dsi->burst_mode_ratio);
	hsync = txbyteclkhs(hsync, bpp, lane_count,
			    intel_dsi->burst_mode_ratio);
	hbp = txbyteclkhs(hbp, bpp, lane_count, intel_dsi->burst_mode_ratio);

	I915_WRITE(MIPI_HACTIVE_AREA_COUNT(pipe), hactive);
	I915_WRITE(MIPI_HFP_COUNT(pipe), hfp);

	/* meaningful for video mode non-burst sync pulse mode only, can be zero
	 * for non-burst sync events and burst modes */
	I915_WRITE(MIPI_HSYNC_PADDING_COUNT(pipe), hsync);
	I915_WRITE(MIPI_HBP_COUNT(pipe), hbp);

	/* vertical values are in terms of lines */
	I915_WRITE(MIPI_VFP_COUNT(pipe), vfp);
	I915_WRITE(MIPI_VSYNC_PADDING_COUNT(pipe), vsync);
	I915_WRITE(MIPI_VBP_COUNT(pipe), vbp);
}

static void intel_dsi_prepare(struct intel_encoder *intel_encoder)
{
	struct drm_encoder *encoder = &intel_encoder->base;
	struct drm_device *dev = encoder->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
	struct drm_display_mode *adjusted_mode =
		&intel_crtc->config.adjusted_mode;
	int pipe = intel_crtc->pipe;
	unsigned int bpp = intel_crtc->config.pipe_bpp;
	u32 val, tmp;

	DRM_DEBUG_KMS("pipe %c\n", pipe_name(pipe));

	/* escape clock divider, 20MHz, shared for A and C. device ready must be
	 * off when doing this! txclkesc? */
	tmp = I915_READ(MIPI_CTRL(0));
	tmp &= ~ESCAPE_CLOCK_DIVIDER_MASK;
	I915_WRITE(MIPI_CTRL(0), tmp | ESCAPE_CLOCK_DIVIDER_1);

	/* read request priority is per pipe */
	tmp = I915_READ(MIPI_CTRL(pipe));
	tmp &= ~READ_REQUEST_PRIORITY_MASK;
	I915_WRITE(MIPI_CTRL(pipe), tmp | READ_REQUEST_PRIORITY_HIGH);

	/* XXX: why here, why like this? handling in irq handler?! */
	I915_WRITE(MIPI_INTR_STAT(pipe), 0xffffffff);
	I915_WRITE(MIPI_INTR_EN(pipe), 0xffffffff);

	I915_WRITE(MIPI_DPHY_PARAM(pipe), intel_dsi->dphy_reg);

	I915_WRITE(MIPI_DPI_RESOLUTION(pipe),
		   adjusted_mode->vdisplay << VERTICAL_ADDRESS_SHIFT |
		   adjusted_mode->hdisplay << HORIZONTAL_ADDRESS_SHIFT);

	set_dsi_timings(encoder, adjusted_mode);

	val = intel_dsi->lane_count << DATA_LANES_PRG_REG_SHIFT;
	if (is_cmd_mode(intel_dsi)) {
		val |= intel_dsi->channel << CMD_MODE_CHANNEL_NUMBER_SHIFT;
		val |= CMD_MODE_DATA_WIDTH_8_BIT; /* XXX */
	} else {
		val |= intel_dsi->channel << VID_MODE_CHANNEL_NUMBER_SHIFT;

		/* XXX: cross-check bpp vs. pixel format? */
		val |= intel_dsi->pixel_format;
	}
	I915_WRITE(MIPI_DSI_FUNC_PRG(pipe), val);

	/* timeouts for recovery. one frame IIUC. if counter expires, EOT and
	 * stop state. */

	/*
	 * In burst mode, value greater than one DPI line Time in byte clock
	 * (txbyteclkhs) To timeout this timer 1+ of the above said value is
	 * recommended.
	 *
	 * In non-burst mode, Value greater than one DPI frame time in byte
	 * clock(txbyteclkhs) To timeout this timer 1+ of the above said value
	 * is recommended.
	 *
	 * In DBI only mode, value greater than one DBI frame time in byte
	 * clock(txbyteclkhs) To timeout this timer 1+ of the above said value
	 * is recommended.
	 */

	if (is_vid_mode(intel_dsi) &&
	    intel_dsi->video_mode_format == VIDEO_MODE_BURST) {
		I915_WRITE(MIPI_HS_TX_TIMEOUT(pipe),
			   txbyteclkhs(adjusted_mode->htotal, bpp,
				       intel_dsi->lane_count,
				       intel_dsi->burst_mode_ratio) + 1);
	} else {
		I915_WRITE(MIPI_HS_TX_TIMEOUT(pipe),
			   txbyteclkhs(adjusted_mode->vtotal *
				       adjusted_mode->htotal,
				       bpp, intel_dsi->lane_count,
				       intel_dsi->burst_mode_ratio) + 1);
	}
	I915_WRITE(MIPI_LP_RX_TIMEOUT(pipe), intel_dsi->lp_rx_timeout);
	I915_WRITE(MIPI_TURN_AROUND_TIMEOUT(pipe), intel_dsi->turn_arnd_val);
	I915_WRITE(MIPI_DEVICE_RESET_TIMER(pipe), intel_dsi->rst_timer_val);

	/* dphy stuff */

	/* in terms of low power clock */
	I915_WRITE(MIPI_INIT_COUNT(pipe), txclkesc(intel_dsi->escape_clk_div, 100));

	val = 0;
	if (intel_dsi->eotp_pkt == 0)
		val |= EOT_DISABLE;

	if (intel_dsi->clock_stop)
		val |= CLOCKSTOP;

	/* recovery disables */
	I915_WRITE(MIPI_EOT_DISABLE(pipe), val);

	/* in terms of low power clock */
	I915_WRITE(MIPI_INIT_COUNT(pipe), intel_dsi->init_count);

	/* in terms of txbyteclkhs. actual high to low switch +
	 * MIPI_STOP_STATE_STALL * MIPI_LP_BYTECLK.
	 *
	 * XXX: write MIPI_STOP_STATE_STALL?
	 */
	I915_WRITE(MIPI_HIGH_LOW_SWITCH_COUNT(pipe),
		   intel_dsi->hs_to_lp_count);

	/* XXX: low power clock equivalence in terms of byte clock. the number
	 * of byte clocks occupied in one low power clock. based on txbyteclkhs
	 * and txclkesc. txclkesc time / txbyteclk time * (105 +
	 * MIPI_STOP_STATE_STALL) / 105.???
	 */
	I915_WRITE(MIPI_LP_BYTECLK(pipe), intel_dsi->lp_byte_clk);

	/* the bw essential for transmitting 16 long packets containing 252
	 * bytes meant for dcs write memory command is programmed in this
	 * register in terms of byte clocks. based on dsi transfer rate and the
	 * number of lanes configured the time taken to transmit 16 long packets
	 * in a dsi stream varies. */
	I915_WRITE(MIPI_DBI_BW_CTRL(pipe), intel_dsi->bw_timer);

	I915_WRITE(MIPI_CLK_LANE_SWITCH_TIME_CNT(pipe),
		   intel_dsi->clk_lp_to_hs_count << LP_HS_SSW_CNT_SHIFT |
		   intel_dsi->clk_hs_to_lp_count << HS_LP_PWR_SW_CNT_SHIFT);

	if (is_vid_mode(intel_dsi))
		/* Some panels might have resolution which is not a multiple of
		 * 64 like 1366 x 768. Enable RANDOM resolution support for such
		 * panels by default */
		I915_WRITE(MIPI_VIDEO_MODE_FORMAT(pipe),
			   intel_dsi->video_frmt_cfg_bits |
			   intel_dsi->video_mode_format |
			   IP_TG_CONFIG |
			   RANDOM_DPI_DISPLAY_RESOLUTION);
}

static void intel_dsi_pre_pll_enable(struct intel_encoder *encoder)
{
	DRM_DEBUG_KMS("\n");

	intel_dsi_prepare(encoder);

	vlv_enable_dsi_pll(encoder);
}

static enum drm_connector_status
intel_dsi_detect(struct drm_connector *connector, bool force)
{
	struct intel_dsi *intel_dsi = intel_attached_dsi(connector);
	struct intel_encoder *intel_encoder = &intel_dsi->base;
	enum intel_display_power_domain power_domain;
	enum drm_connector_status connector_status;
	struct drm_i915_private *dev_priv = intel_encoder->base.dev->dev_private;

	DRM_DEBUG_KMS("\n");
	power_domain = intel_display_port_power_domain(intel_encoder);

	intel_display_power_get(dev_priv, power_domain);
	connector_status = intel_dsi->dev.dev_ops->detect(&intel_dsi->dev);
	intel_display_power_put(dev_priv, power_domain);

	return connector_status;
}

static int intel_dsi_get_modes(struct drm_connector *connector)
{
	struct intel_connector *intel_connector = to_intel_connector(connector);
	struct drm_display_mode *mode;

	DRM_DEBUG_KMS("\n");

	if (!intel_connector->panel.fixed_mode) {
		DRM_DEBUG_KMS("no fixed mode\n");
		return 0;
	}

	mode = drm_mode_duplicate(connector->dev,
				  intel_connector->panel.fixed_mode);
	if (!mode) {
		DRM_DEBUG_KMS("drm_mode_duplicate failed\n");
		return 0;
	}

	drm_mode_probed_add(connector, mode);
	return 1;
}

static void intel_dsi_destroy(struct drm_connector *connector)
{
	struct intel_connector *intel_connector = to_intel_connector(connector);

	DRM_DEBUG_KMS("\n");
	intel_panel_fini(&intel_connector->panel);
	drm_connector_cleanup(connector);
	kfree(connector);
}

static const struct drm_encoder_funcs intel_dsi_funcs = {
	.destroy = intel_encoder_destroy,
};

static const struct drm_connector_helper_funcs intel_dsi_connector_helper_funcs = {
	.get_modes = intel_dsi_get_modes,
	.mode_valid = intel_dsi_mode_valid,
	.best_encoder = intel_best_encoder,
};

static const struct drm_connector_funcs intel_dsi_connector_funcs = {
	.dpms = intel_connector_dpms,
	.detect = intel_dsi_detect,
	.destroy = intel_dsi_destroy,
	.fill_modes = drm_helper_probe_single_connector_modes,
};

void intel_dsi_init(struct drm_device *dev)
{
	struct intel_dsi *intel_dsi;
	struct intel_encoder *intel_encoder;
	struct drm_encoder *encoder;
	struct intel_connector *intel_connector;
	struct drm_connector *connector;
	struct drm_display_mode *fixed_mode = NULL;
	struct drm_i915_private *dev_priv = dev->dev_private;
	const struct intel_dsi_device *dsi;
	unsigned int i;

	DRM_DEBUG_KMS("\n");

	/* There is no detection method for MIPI so rely on VBT */
	if (!dev_priv->vbt.has_mipi)
		return;

	if (IS_VALLEYVIEW(dev)) {
		dev_priv->mipi_mmio_base = VLV_MIPI_BASE;
	} else {
		DRM_ERROR("Unsupported Mipi device to reg base");
		return;
	}

	intel_dsi = kzalloc(sizeof(*intel_dsi), GFP_KERNEL);
	if (!intel_dsi)
		return;

	intel_connector = kzalloc(sizeof(*intel_connector), GFP_KERNEL);
	if (!intel_connector) {
		kfree(intel_dsi);
		return;
	}

	intel_encoder = &intel_dsi->base;
	encoder = &intel_encoder->base;
	intel_dsi->attached_connector = intel_connector;

	connector = &intel_connector->base;

	drm_encoder_init(dev, encoder, &intel_dsi_funcs, DRM_MODE_ENCODER_DSI);

	/* XXX: very likely not all of these are needed */
	intel_encoder->hot_plug = intel_dsi_hot_plug;
	intel_encoder->compute_config = intel_dsi_compute_config;
	intel_encoder->pre_pll_enable = intel_dsi_pre_pll_enable;
	intel_encoder->pre_enable = intel_dsi_pre_enable;
	intel_encoder->enable = intel_dsi_enable_nop;
	intel_encoder->disable = intel_dsi_pre_disable;
	intel_encoder->post_disable = intel_dsi_post_disable;
	intel_encoder->get_hw_state = intel_dsi_get_hw_state;
	intel_encoder->get_config = intel_dsi_get_config;

	intel_connector->get_hw_state = intel_connector_get_hw_state;
	intel_connector->unregister = intel_connector_unregister;

	for (i = 0; i < ARRAY_SIZE(intel_dsi_devices); i++) {
		dsi = &intel_dsi_devices[i];
		intel_dsi->dev = *dsi;

		if (dsi->dev_ops->init(&intel_dsi->dev))
			break;
	}

	if (i == ARRAY_SIZE(intel_dsi_devices)) {
		DRM_DEBUG_KMS("no device found\n");
		goto err;
	}

	intel_encoder->type = INTEL_OUTPUT_DSI;
	intel_encoder->crtc_mask = (1 << 0); /* XXX */

	intel_encoder->cloneable = 0;
	drm_connector_init(dev, connector, &intel_dsi_connector_funcs,
			   DRM_MODE_CONNECTOR_DSI);

	drm_connector_helper_add(connector, &intel_dsi_connector_helper_funcs);

	connector->display_info.subpixel_order = SubPixelHorizontalRGB; /*XXX*/
	connector->interlace_allowed = false;
	connector->doublescan_allowed = false;

	intel_connector_attach_encoder(intel_connector, intel_encoder);

	drm_connector_register(connector);

	fixed_mode = dsi->dev_ops->get_modes(&intel_dsi->dev);
	if (!fixed_mode) {
		DRM_DEBUG_KMS("no fixed mode\n");
		goto err;
	}

	fixed_mode->type |= DRM_MODE_TYPE_PREFERRED;
	intel_panel_init(&intel_connector->panel, fixed_mode, NULL);

	return;

err:
	drm_encoder_cleanup(&intel_encoder->base);
	kfree(intel_dsi);
	kfree(intel_connector);
}