[deliverable/linux.git] / drivers / gpu / drm / i915 / intel_dsi_pll.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.
 *
 * Authors:
 *	Shobhit Kumar <shobhit.kumar@intel.com>
 *	Yogesh Mohan Marimuthu <yogesh.mohan.marimuthu@intel.com>
 */

#include <linux/kernel.h>
#include "intel_drv.h"
#include "i915_drv.h"
#include "intel_dsi.h"

#define DSI_HSS_PACKET_SIZE		4
#define DSI_HSE_PACKET_SIZE		4
#define DSI_HSA_PACKET_EXTRA_SIZE	6
#define DSI_HBP_PACKET_EXTRA_SIZE	6
#define DSI_HACTIVE_PACKET_EXTRA_SIZE	6
#define DSI_HFP_PACKET_EXTRA_SIZE	6
#define DSI_EOTP_PACKET_SIZE		4

struct dsi_mnp {
	u32 dsi_pll_ctrl;
	u32 dsi_pll_div;
};

static const u32 lfsr_converts[] = {
	426, 469, 234, 373, 442, 221, 110, 311, 411,		/* 62 - 70 */
	461, 486, 243, 377, 188, 350, 175, 343, 427, 213,	/* 71 - 80 */
	106, 53, 282, 397, 354, 227, 113, 56, 284, 142,		/* 81 - 90 */
	71, 35							/* 91 - 92 */
};

#ifdef DSI_CLK_FROM_RR

static u32 dsi_rr_formula(const struct drm_display_mode *mode,
			  int pixel_format, int video_mode_format,
			  int lane_count, bool eotp)
{
	u32 bpp;
	u32 hactive, vactive, hfp, hsync, hbp, vfp, vsync, vbp;
	u32 hsync_bytes, hbp_bytes, hactive_bytes, hfp_bytes;
	u32 bytes_per_line, bytes_per_frame;
	u32 num_frames;
	u32 bytes_per_x_frames, bytes_per_x_frames_x_lanes;
	u32 dsi_bit_clock_hz;
	u32 dsi_clk;

	switch (pixel_format) {
	default:
	case VID_MODE_FORMAT_RGB888:
	case VID_MODE_FORMAT_RGB666_LOOSE:
		bpp = 24;
		break;
	case VID_MODE_FORMAT_RGB666:
		bpp = 18;
		break;
	case VID_MODE_FORMAT_RGB565:
		bpp = 16;
		break;
	}

	hactive = mode->hdisplay;
	vactive = mode->vdisplay;
	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;

	hsync_bytes = DIV_ROUND_UP(hsync * bpp, 8);
	hbp_bytes = DIV_ROUND_UP(hbp * bpp, 8);
	hactive_bytes = DIV_ROUND_UP(hactive * bpp, 8);
	hfp_bytes = DIV_ROUND_UP(hfp * bpp, 8);

	bytes_per_line = DSI_HSS_PACKET_SIZE + hsync_bytes +
		DSI_HSA_PACKET_EXTRA_SIZE + DSI_HSE_PACKET_SIZE +
		hbp_bytes + DSI_HBP_PACKET_EXTRA_SIZE +
		hactive_bytes + DSI_HACTIVE_PACKET_EXTRA_SIZE +
		hfp_bytes + DSI_HFP_PACKET_EXTRA_SIZE;

	/*
	 * XXX: Need to accurately calculate LP to HS transition timeout and add
	 * it to bytes_per_line/bytes_per_frame.
	 */

	if (eotp && video_mode_format == VIDEO_MODE_BURST)
		bytes_per_line += DSI_EOTP_PACKET_SIZE;

	bytes_per_frame = vsync * bytes_per_line + vbp * bytes_per_line +
		vactive * bytes_per_line + vfp * bytes_per_line;

	if (eotp &&
	    (video_mode_format == VIDEO_MODE_NON_BURST_WITH_SYNC_PULSE ||
	     video_mode_format == VIDEO_MODE_NON_BURST_WITH_SYNC_EVENTS))
		bytes_per_frame += DSI_EOTP_PACKET_SIZE;

	num_frames = drm_mode_vrefresh(mode);
	bytes_per_x_frames = num_frames * bytes_per_frame;

	bytes_per_x_frames_x_lanes = bytes_per_x_frames / lane_count;

	/* the dsi clock is divided by 2 in the hardware to get dsi ddr clock */
	dsi_bit_clock_hz = bytes_per_x_frames_x_lanes * 8;
	dsi_clk = dsi_bit_clock_hz / 1000;

	if (eotp && video_mode_format == VIDEO_MODE_BURST)
		dsi_clk *= 2;

	return dsi_clk;
}

#else

/* Get DSI clock from pixel clock */
static u32 dsi_clk_from_pclk(const struct drm_display_mode *mode,
			  int pixel_format, int lane_count)
{
	u32 dsi_clk_khz;
	u32 bpp;

	switch (pixel_format) {
	default:
	case VID_MODE_FORMAT_RGB888:
	case VID_MODE_FORMAT_RGB666_LOOSE:
		bpp = 24;
		break;
	case VID_MODE_FORMAT_RGB666:
		bpp = 18;
		break;
	case VID_MODE_FORMAT_RGB565:
		bpp = 16;
		break;
	}

	/* DSI data rate = pixel clock * bits per pixel / lane count
	   pixel clock is converted from KHz to Hz */
	dsi_clk_khz = DIV_ROUND_CLOSEST(mode->clock * bpp, lane_count);

	return dsi_clk_khz;
}

#endif

static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
{
	u32 m, n, p;
	u32 ref_clk;
	u32 error;
	u32 tmp_error;
	int target_dsi_clk;
	int calc_dsi_clk;
	u32 calc_m;
	u32 calc_p;
	u32 m_seed;

	/* dsi_clk is expected in KHZ */
	if (dsi_clk < 300000 || dsi_clk > 1150000) {
		DRM_ERROR("DSI CLK Out of Range\n");
		return -ECHRNG;
	}

	ref_clk = 25000;
	target_dsi_clk = dsi_clk;
	error = 0xFFFFFFFF;
	tmp_error = 0xFFFFFFFF;
	calc_m = 0;
	calc_p = 0;

	for (m = 62; m <= 92; m++) {
		for (p = 2; p <= 6; p++) {
			/* Find the optimal m and p divisors
			with minimal error +/- the required clock */
			calc_dsi_clk = (m * ref_clk) / p;
			if (calc_dsi_clk == target_dsi_clk) {
				calc_m = m;
				calc_p = p;
				error = 0;
				break;
			} else
				tmp_error = abs(target_dsi_clk - calc_dsi_clk);

			if (tmp_error < error) {
				error = tmp_error;
				calc_m = m;
				calc_p = p;
			}
		}

		if (error == 0)
			break;
	}

	m_seed = lfsr_converts[calc_m - 62];
	n = 1;
	dsi_mnp->dsi_pll_ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + calc_p - 2);
	dsi_mnp->dsi_pll_div = (n - 1) << DSI_PLL_N1_DIV_SHIFT |
		m_seed << DSI_PLL_M1_DIV_SHIFT;

	return 0;
}

/*
 * XXX: The muxing and gating is hard coded for now. Need to add support for
 * sharing PLLs with two DSI outputs.
 */
static void vlv_configure_dsi_pll(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);
	const struct drm_display_mode *mode = &intel_crtc->config.adjusted_mode;
	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
	int ret;
	struct dsi_mnp dsi_mnp;
	u32 dsi_clk;

	dsi_clk = dsi_clk_from_pclk(mode, intel_dsi->pixel_format,
						intel_dsi->lane_count);

	ret = dsi_calc_mnp(dsi_clk, &dsi_mnp);
	if (ret) {
		DRM_DEBUG_KMS("dsi_calc_mnp failed\n");
		return;
	}

	dsi_mnp.dsi_pll_ctrl |= DSI_PLL_CLK_GATE_DSI0_DSIPLL;

	DRM_DEBUG_KMS("dsi pll div %08x, ctrl %08x\n",
		      dsi_mnp.dsi_pll_div, dsi_mnp.dsi_pll_ctrl);

	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, 0);
	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_DIVIDER, dsi_mnp.dsi_pll_div);
	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, dsi_mnp.dsi_pll_ctrl);
}

void vlv_enable_dsi_pll(struct intel_encoder *encoder)
{
	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	u32 tmp;

	DRM_DEBUG_KMS("\n");

	mutex_lock(&dev_priv->dpio_lock);

	vlv_configure_dsi_pll(encoder);

	/* wait at least 0.5 us after ungating before enabling VCO */
	usleep_range(1, 10);

	tmp = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
	tmp |= DSI_PLL_VCO_EN;
	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, tmp);

	mutex_unlock(&dev_priv->dpio_lock);

	if (wait_for(I915_READ(PIPECONF(PIPE_A)) & PIPECONF_DSI_PLL_LOCKED, 20)) {
		DRM_ERROR("DSI PLL lock failed\n");
		return;
	}

	DRM_DEBUG_KMS("DSI PLL locked\n");
}

void vlv_disable_dsi_pll(struct intel_encoder *encoder)
{
	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	u32 tmp;

	DRM_DEBUG_KMS("\n");

	mutex_lock(&dev_priv->dpio_lock);

	tmp = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
	tmp &= ~DSI_PLL_VCO_EN;
	tmp |= DSI_PLL_LDO_GATE;
	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, tmp);

	mutex_unlock(&dev_priv->dpio_lock);
}
Commit	Line	Data
be4fc046	1	/*
	2	* Copyright © 2013 Intel Corporation
	3	*
	4	* Permission is hereby granted, free of charge, to any person obtaining a
	5	* copy of this software and associated documentation files (the "Software"),
	6	* to deal in the Software without restriction, including without limitation
	7	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	8	* and/or sell copies of the Software, and to permit persons to whom the
	9	* Software is furnished to do so, subject to the following conditions:
	10	*
	11	* The above copyright notice and this permission notice (including the next
	12	* paragraph) shall be included in all copies or substantial portions of the
	13	* Software.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	16	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	18	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	19	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	20	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
	21	* DEALINGS IN THE SOFTWARE.
	22	*
	23	* Authors:
	24	* Shobhit Kumar <shobhit.kumar@intel.com>
	25	* Yogesh Mohan Marimuthu <yogesh.mohan.marimuthu@intel.com>
	26	*/
	27
	28	#include <linux/kernel.h>
	29	#include "intel_drv.h"
	30	#include "i915_drv.h"
	31	#include "intel_dsi.h"
	32
	33	#define DSI_HSS_PACKET_SIZE 4
	34	#define DSI_HSE_PACKET_SIZE 4
	35	#define DSI_HSA_PACKET_EXTRA_SIZE 6
	36	#define DSI_HBP_PACKET_EXTRA_SIZE 6
	37	#define DSI_HACTIVE_PACKET_EXTRA_SIZE 6
	38	#define DSI_HFP_PACKET_EXTRA_SIZE 6
	39	#define DSI_EOTP_PACKET_SIZE 4
	40
	41	struct dsi_mnp {
	42	u32 dsi_pll_ctrl;
	43	u32 dsi_pll_div;
	44	};
	45
	46	static const u32 lfsr_converts[] = {
	47	426, 469, 234, 373, 442, 221, 110, 311, 411, /* 62 - 70 */
	48	461, 486, 243, 377, 188, 350, 175, 343, 427, 213, /* 71 - 80 */
	49	106, 53, 282, 397, 354, 227, 113, 56, 284, 142, /* 81 - 90 */
	50	71, 35 /* 91 - 92 */
	51	};
	52
44d4c6ee SK	53	#ifdef DSI_CLK_FROM_RR
44d4c6ee SK	54
a7482145	55	static u32 dsi_rr_formula(const struct drm_display_mode *mode,
be4fc046	56	int pixel_format, int video_mode_format,
	57	int lane_count, bool eotp)
	58	{
	59	u32 bpp;
	60	u32 hactive, vactive, hfp, hsync, hbp, vfp, vsync, vbp;
	61	u32 hsync_bytes, hbp_bytes, hactive_bytes, hfp_bytes;
	62	u32 bytes_per_line, bytes_per_frame;
	63	u32 num_frames;
	64	u32 bytes_per_x_frames, bytes_per_x_frames_x_lanes;
	65	u32 dsi_bit_clock_hz;
	66	u32 dsi_clk;
	67
	68	switch (pixel_format) {
	69	default:
	70	case VID_MODE_FORMAT_RGB888:
	71	case VID_MODE_FORMAT_RGB666_LOOSE:
	72	bpp = 24;
	73	break;
	74	case VID_MODE_FORMAT_RGB666:
	75	bpp = 18;
	76	break;
	77	case VID_MODE_FORMAT_RGB565:
	78	bpp = 16;
	79	break;
	80	}
	81
	82	hactive = mode->hdisplay;
	83	vactive = mode->vdisplay;
	84	hfp = mode->hsync_start - mode->hdisplay;
	85	hsync = mode->hsync_end - mode->hsync_start;
	86	hbp = mode->htotal - mode->hsync_end;
	87
	88	vfp = mode->vsync_start - mode->vdisplay;
	89	vsync = mode->vsync_end - mode->vsync_start;
	90	vbp = mode->vtotal - mode->vsync_end;
	91
	92	hsync_bytes = DIV_ROUND_UP(hsync * bpp, 8);
	93	hbp_bytes = DIV_ROUND_UP(hbp * bpp, 8);
	94	hactive_bytes = DIV_ROUND_UP(hactive * bpp, 8);
	95	hfp_bytes = DIV_ROUND_UP(hfp * bpp, 8);
	96
	97	bytes_per_line = DSI_HSS_PACKET_SIZE + hsync_bytes +
	98	DSI_HSA_PACKET_EXTRA_SIZE + DSI_HSE_PACKET_SIZE +
	99	hbp_bytes + DSI_HBP_PACKET_EXTRA_SIZE +
	100	hactive_bytes + DSI_HACTIVE_PACKET_EXTRA_SIZE +
	101	hfp_bytes + DSI_HFP_PACKET_EXTRA_SIZE;
	102
	103	/*
	104	* XXX: Need to accurately calculate LP to HS transition timeout and add
	105	* it to bytes_per_line/bytes_per_frame.
	106	*/
	107
	108	if (eotp && video_mode_format == VIDEO_MODE_BURST)
	109	bytes_per_line += DSI_EOTP_PACKET_SIZE;
	110
	111	bytes_per_frame = vsync * bytes_per_line + vbp * bytes_per_line +
	112	vactive * bytes_per_line + vfp * bytes_per_line;
	113
	114	if (eotp &&
	115	(video_mode_format == VIDEO_MODE_NON_BURST_WITH_SYNC_PULSE \|\|
	116	video_mode_format == VIDEO_MODE_NON_BURST_WITH_SYNC_EVENTS))
	117	bytes_per_frame += DSI_EOTP_PACKET_SIZE;
	118
	119	num_frames = drm_mode_vrefresh(mode);
120	bytes_per_x_frames = num_frames * bytes_per_frame;
121
122	bytes_per_x_frames_x_lanes = bytes_per_x_frames / lane_count;
123
124	/* the dsi clock is divided by 2 in the hardware to get dsi ddr clock */
125	dsi_bit_clock_hz = bytes_per_x_frames_x_lanes * 8;
44d4c6ee	126	dsi_clk = dsi_bit_clock_hz / 1000;
be4fc046	127
	128	if (eotp && video_mode_format == VIDEO_MODE_BURST)
	129	dsi_clk *= 2;
	130
	131	return dsi_clk;
	132	}
	133
44d4c6ee	134	#else
be4fc046	135
44d4c6ee SK	136	/* Get DSI clock from pixel clock */
	137	static u32 dsi_clk_from_pclk(const struct drm_display_mode *mode,
	138	int pixel_format, int lane_count)
be4fc046	139	{
44d4c6ee SK	140	u32 dsi_clk_khz;
44d4c6ee SK	141	u32 bpp;
be4fc046	142
44d4c6ee SK	143	switch (pixel_format) {
	144	default:
	145	case VID_MODE_FORMAT_RGB888:
	146	case VID_MODE_FORMAT_RGB666_LOOSE:
	147	bpp = 24;
	148	break;
	149	case VID_MODE_FORMAT_RGB666:
	150	bpp = 18;
	151	break;
	152	case VID_MODE_FORMAT_RGB565:
	153	bpp = 16;
	154	break;
be4fc046	155	}
be4fc046	156
44d4c6ee SK	157	/* DSI data rate = pixel clock * bits per pixel / lane count
	158	pixel clock is converted from KHz to Hz */
	159	dsi_clk_khz = DIV_ROUND_CLOSEST(mode->clock * bpp, lane_count);
be4fc046	160
44d4c6ee	161	return dsi_clk_khz;
be4fc046	162	}
be4fc046	163
44d4c6ee	164	#endif
be4fc046	165
	166	static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
	167	{
	168	u32 m, n, p;
	169	u32 ref_clk;
	170	u32 error;
	171	u32 tmp_error;
8e1eed5a SK	172	int target_dsi_clk;
8e1eed5a SK	173	int calc_dsi_clk;
be4fc046	174	u32 calc_m;
	175	u32 calc_p;
	176	u32 m_seed;
	177
44d4c6ee SK	178	/* dsi_clk is expected in KHZ */
44d4c6ee SK	179	if (dsi_clk < 300000 \|\| dsi_clk > 1150000) {
be4fc046	180	DRM_ERROR("DSI CLK Out of Range\n");
	181	return -ECHRNG;
	182	}
	183
	184	ref_clk = 25000;
44d4c6ee	185	target_dsi_clk = dsi_clk;
be4fc046	186	error = 0xFFFFFFFF;
8e1eed5a	187	tmp_error = 0xFFFFFFFF;
be4fc046	188	calc_m = 0;
	189	calc_p = 0;
	190
	191	for (m = 62; m <= 92; m++) {
	192	for (p = 2; p <= 6; p++) {
8e1eed5a SK	193	/* Find the optimal m and p divisors
8e1eed5a SK	194	with minimal error +/- the required clock */
be4fc046	195	calc_dsi_clk = (m * ref_clk) / p;
8e1eed5a SK	196	if (calc_dsi_clk == target_dsi_clk) {
	197	calc_m = m;
	198	calc_p = p;
	199	error = 0;
	200	break;
	201	} else
	202	tmp_error = abs(target_dsi_clk - calc_dsi_clk);
	203
	204	if (tmp_error < error) {
	205	error = tmp_error;
	206	calc_m = m;
	207	calc_p = p;
be4fc046	208	}
be4fc046	209	}
8e1eed5a SK	210
	211	if (error == 0)
	212	break;
be4fc046	213	}
	214
	215	m_seed = lfsr_converts[calc_m - 62];
	216	n = 1;
	217	dsi_mnp->dsi_pll_ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + calc_p - 2);
	218	dsi_mnp->dsi_pll_div = (n - 1) << DSI_PLL_N1_DIV_SHIFT \|
	219	m_seed << DSI_PLL_M1_DIV_SHIFT;
	220
	221	return 0;
	222	}
	223
be4fc046	224	/*
	225	* XXX: The muxing and gating is hard coded for now. Need to add support for
	226	* sharing PLLs with two DSI outputs.
	227	*/
	228	static void vlv_configure_dsi_pll(struct intel_encoder *encoder)
	229	{
	230	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	231	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
a7482145	232	const struct drm_display_mode *mode = &intel_crtc->config.adjusted_mode;
be4fc046	233	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
	234	int ret;
	235	struct dsi_mnp dsi_mnp;
	236	u32 dsi_clk;
	237
44d4c6ee SK	238	dsi_clk = dsi_clk_from_pclk(mode, intel_dsi->pixel_format,
44d4c6ee SK	239	intel_dsi->lane_count);
be4fc046	240
	241	ret = dsi_calc_mnp(dsi_clk, &dsi_mnp);
	242	if (ret) {
	243	DRM_DEBUG_KMS("dsi_calc_mnp failed\n");
	244	return;
	245	}
	246
	247	dsi_mnp.dsi_pll_ctrl \|= DSI_PLL_CLK_GATE_DSI0_DSIPLL;
	248
	249	DRM_DEBUG_KMS("dsi pll div %08x, ctrl %08x\n",
	250	dsi_mnp.dsi_pll_div, dsi_mnp.dsi_pll_ctrl);
	251
	252	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, 0);
	253	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_DIVIDER, dsi_mnp.dsi_pll_div);
	254	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, dsi_mnp.dsi_pll_ctrl);
	255	}
	256
	257	void vlv_enable_dsi_pll(struct intel_encoder *encoder)
	258	{
	259	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	260	u32 tmp;
	261
	262	DRM_DEBUG_KMS("\n");
	263
	264	mutex_lock(&dev_priv->dpio_lock);
	265
	266	vlv_configure_dsi_pll(encoder);
	267
	268	/* wait at least 0.5 us after ungating before enabling VCO */
	269	usleep_range(1, 10);
	270
	271	tmp = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
	272	tmp \|= DSI_PLL_VCO_EN;
	273	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, tmp);
	274
	275	mutex_unlock(&dev_priv->dpio_lock);
	276
	277	if (wait_for(I915_READ(PIPECONF(PIPE_A)) & PIPECONF_DSI_PLL_LOCKED, 20)) {
	278	DRM_ERROR("DSI PLL lock failed\n");
	279	return;
	280	}
	281
	282	DRM_DEBUG_KMS("DSI PLL locked\n");
	283	}
	284
	285	void vlv_disable_dsi_pll(struct intel_encoder *encoder)
	286	{
	287	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
	288	u32 tmp;
	289
	290	DRM_DEBUG_KMS("\n");
	291
	292	mutex_lock(&dev_priv->dpio_lock);
	293
	294	tmp = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
	295	tmp &= ~DSI_PLL_VCO_EN;
	296	tmp \|= DSI_PLL_LDO_GATE;
	297	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, tmp);
	298
	299	mutex_unlock(&dev_priv->dpio_lock);
	300	}