xref: /dragonfly/sys/dev/drm/i915/intel_dsi_pll.c (revision 279dd846)
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 
53 #ifdef DSI_CLK_FROM_RR
54 
55 static u32 dsi_rr_formula(const struct drm_display_mode *mode,
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;
126 	dsi_clk = dsi_bit_clock_hz / 1000;
127 
128 	if (eotp && video_mode_format == VIDEO_MODE_BURST)
129 		dsi_clk *= 2;
130 
131 	return dsi_clk;
132 }
133 
134 #else
135 
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)
139 {
140 	u32 dsi_clk_khz;
141 	u32 bpp;
142 
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;
155 	}
156 
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);
160 
161 	return dsi_clk_khz;
162 }
163 
164 #endif
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;
172 	int target_dsi_clk;
173 	int calc_dsi_clk;
174 	u32 calc_m;
175 	u32 calc_p;
176 	u32 m_seed;
177 
178 	/* dsi_clk is expected in KHZ */
179 	if (dsi_clk < 300000 || dsi_clk > 1150000) {
180 		DRM_ERROR("DSI CLK Out of Range\n");
181 		return -ECHRNG;
182 	}
183 
184 	ref_clk = 25000;
185 	target_dsi_clk = dsi_clk;
186 	error = 0xFFFFFFFF;
187 	tmp_error = 0xFFFFFFFF;
188 	calc_m = 0;
189 	calc_p = 0;
190 
191 	for (m = 62; m <= 92; m++) {
192 		for (p = 2; p <= 6; p++) {
193 			/* Find the optimal m and p divisors
194 			with minimal error +/- the required clock */
195 			calc_dsi_clk = (m * ref_clk) / p;
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;
208 			}
209 		}
210 
211 		if (error == 0)
212 			break;
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 
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);
232 	const struct drm_display_mode *mode = &intel_crtc->config.adjusted_mode;
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 
238 	dsi_clk = dsi_clk_from_pclk(mode, intel_dsi->pixel_format,
239 						intel_dsi->lane_count);
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 }
301 
302 static void assert_bpp_mismatch(int pixel_format, int pipe_bpp)
303 {
304 	int bpp;
305 
306 	switch (pixel_format) {
307 	default:
308 	case VID_MODE_FORMAT_RGB888:
309 	case VID_MODE_FORMAT_RGB666_LOOSE:
310 		bpp = 24;
311 		break;
312 	case VID_MODE_FORMAT_RGB666:
313 		bpp = 18;
314 		break;
315 	case VID_MODE_FORMAT_RGB565:
316 		bpp = 16;
317 		break;
318 	}
319 
320 	WARN(bpp != pipe_bpp,
321 		"bpp match assertion failure (expected %d, current %d)\n",
322 		bpp, pipe_bpp);
323 }
324 
325 u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp)
326 {
327 	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
328 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
329 	u32 dsi_clock, pclk;
330 	u32 pll_ctl, pll_div;
331 	u32 m = 0, p = 0;
332 	int refclk = 25000;
333 	int i;
334 
335 	DRM_DEBUG_KMS("\n");
336 
337 	mutex_lock(&dev_priv->dpio_lock);
338 	pll_ctl = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
339 	pll_div = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_DIVIDER);
340 	mutex_unlock(&dev_priv->dpio_lock);
341 
342 	/* mask out other bits and extract the P1 divisor */
343 	pll_ctl &= DSI_PLL_P1_POST_DIV_MASK;
344 	pll_ctl = pll_ctl >> (DSI_PLL_P1_POST_DIV_SHIFT - 2);
345 
346 	/* mask out the other bits and extract the M1 divisor */
347 	pll_div &= DSI_PLL_M1_DIV_MASK;
348 	pll_div = pll_div >> DSI_PLL_M1_DIV_SHIFT;
349 
350 	while (pll_ctl) {
351 		pll_ctl = pll_ctl >> 1;
352 		p++;
353 	}
354 	p--;
355 
356 	if (!p) {
357 		DRM_ERROR("wrong P1 divisor\n");
358 		return 0;
359 	}
360 
361 	for (i = 0; i < ARRAY_SIZE(lfsr_converts); i++) {
362 		if (lfsr_converts[i] == pll_div)
363 			break;
364 	}
365 
366 	if (i == ARRAY_SIZE(lfsr_converts)) {
367 		DRM_ERROR("wrong m_seed programmed\n");
368 		return 0;
369 	}
370 
371 	m = i + 62;
372 
373 	dsi_clock = (m * refclk) / p;
374 
375 	/* pixel_format and pipe_bpp should agree */
376 	assert_bpp_mismatch(intel_dsi->pixel_format, pipe_bpp);
377 
378 	pclk = DIV_ROUND_CLOSEST(dsi_clock * intel_dsi->lane_count, pipe_bpp);
379 
380 	return pclk;
381 }
382