xref: /linux/drivers/gpu/drm/omapdrm/dss/sdi.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2009 Nokia Corporation
4  * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
5  */
6 
7 #define DSS_SUBSYS_NAME "SDI"
8 
9 #include <linux/delay.h>
10 #include <linux/err.h>
11 #include <linux/export.h>
12 #include <linux/kernel.h>
13 #include <linux/of.h>
14 #include <linux/of_graph.h>
15 #include <linux/platform_device.h>
16 #include <linux/regulator/consumer.h>
17 #include <linux/string.h>
18 
19 #include <drm/drm_atomic_state_helper.h>
20 #include <drm/drm_bridge.h>
21 
22 #include "dss.h"
23 #include "omapdss.h"
24 
25 struct sdi_device {
26 	struct platform_device *pdev;
27 	struct dss_device *dss;
28 
29 	bool update_enabled;
30 	struct regulator *vdds_sdi_reg;
31 
32 	struct dss_lcd_mgr_config mgr_config;
33 	unsigned long pixelclock;
34 	int datapairs;
35 
36 	struct omap_dss_device output;
37 	struct drm_bridge bridge;
38 };
39 
40 #define drm_bridge_to_sdi(bridge) \
41 	container_of(bridge, struct sdi_device, bridge)
42 
43 struct sdi_clk_calc_ctx {
44 	struct sdi_device *sdi;
45 	unsigned long pck_min, pck_max;
46 
47 	unsigned long fck;
48 	struct dispc_clock_info dispc_cinfo;
49 };
50 
51 static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
52 		unsigned long pck, void *data)
53 {
54 	struct sdi_clk_calc_ctx *ctx = data;
55 
56 	ctx->dispc_cinfo.lck_div = lckd;
57 	ctx->dispc_cinfo.pck_div = pckd;
58 	ctx->dispc_cinfo.lck = lck;
59 	ctx->dispc_cinfo.pck = pck;
60 
61 	return true;
62 }
63 
64 static bool dpi_calc_dss_cb(unsigned long fck, void *data)
65 {
66 	struct sdi_clk_calc_ctx *ctx = data;
67 
68 	ctx->fck = fck;
69 
70 	return dispc_div_calc(ctx->sdi->dss->dispc, fck,
71 			      ctx->pck_min, ctx->pck_max,
72 			      dpi_calc_dispc_cb, ctx);
73 }
74 
75 static int sdi_calc_clock_div(struct sdi_device *sdi, unsigned long pclk,
76 			      unsigned long *fck,
77 			      struct dispc_clock_info *dispc_cinfo)
78 {
79 	int i;
80 	struct sdi_clk_calc_ctx ctx;
81 
82 	/*
83 	 * DSS fclk gives us very few possibilities, so finding a good pixel
84 	 * clock may not be possible. We try multiple times to find the clock,
85 	 * each time widening the pixel clock range we look for, up to
86 	 * +/- 1MHz.
87 	 */
88 
89 	for (i = 0; i < 10; ++i) {
90 		bool ok;
91 
92 		memset(&ctx, 0, sizeof(ctx));
93 
94 		ctx.sdi = sdi;
95 
96 		if (pclk > 1000 * i * i * i)
97 			ctx.pck_min = max(pclk - 1000 * i * i * i, 0lu);
98 		else
99 			ctx.pck_min = 0;
100 		ctx.pck_max = pclk + 1000 * i * i * i;
101 
102 		ok = dss_div_calc(sdi->dss, pclk, ctx.pck_min,
103 				  dpi_calc_dss_cb, &ctx);
104 		if (ok) {
105 			*fck = ctx.fck;
106 			*dispc_cinfo = ctx.dispc_cinfo;
107 			return 0;
108 		}
109 	}
110 
111 	return -EINVAL;
112 }
113 
114 static void sdi_config_lcd_manager(struct sdi_device *sdi)
115 {
116 	sdi->mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
117 
118 	sdi->mgr_config.stallmode = false;
119 	sdi->mgr_config.fifohandcheck = false;
120 
121 	sdi->mgr_config.video_port_width = 24;
122 	sdi->mgr_config.lcden_sig_polarity = 1;
123 
124 	dss_mgr_set_lcd_config(&sdi->output, &sdi->mgr_config);
125 }
126 
127 /* -----------------------------------------------------------------------------
128  * DRM Bridge Operations
129  */
130 
131 static int sdi_bridge_attach(struct drm_bridge *bridge,
132 			     struct drm_encoder *encoder,
133 			     enum drm_bridge_attach_flags flags)
134 {
135 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
136 
137 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
138 		return -EINVAL;
139 
140 	return drm_bridge_attach(encoder, sdi->output.next_bridge,
141 				 bridge, flags);
142 }
143 
144 static enum drm_mode_status
145 sdi_bridge_mode_valid(struct drm_bridge *bridge,
146 		      const struct drm_display_info *info,
147 		      const struct drm_display_mode *mode)
148 {
149 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
150 	unsigned long pixelclock = mode->clock * 1000;
151 	struct dispc_clock_info dispc_cinfo;
152 	unsigned long fck;
153 	int ret;
154 
155 	if (pixelclock == 0)
156 		return MODE_NOCLOCK;
157 
158 	ret = sdi_calc_clock_div(sdi, pixelclock, &fck, &dispc_cinfo);
159 	if (ret < 0)
160 		return MODE_CLOCK_RANGE;
161 
162 	return MODE_OK;
163 }
164 
165 static bool sdi_bridge_mode_fixup(struct drm_bridge *bridge,
166 				  const struct drm_display_mode *mode,
167 				  struct drm_display_mode *adjusted_mode)
168 {
169 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
170 	unsigned long pixelclock = mode->clock * 1000;
171 	struct dispc_clock_info dispc_cinfo;
172 	unsigned long fck;
173 	unsigned long pck;
174 	int ret;
175 
176 	ret = sdi_calc_clock_div(sdi, pixelclock, &fck, &dispc_cinfo);
177 	if (ret < 0)
178 		return false;
179 
180 	pck = fck / dispc_cinfo.lck_div / dispc_cinfo.pck_div;
181 
182 	if (pck != pixelclock)
183 		dev_dbg(&sdi->pdev->dev,
184 			"pixel clock adjusted from %lu Hz to %lu Hz\n",
185 			pixelclock, pck);
186 
187 	adjusted_mode->clock = pck / 1000;
188 
189 	return true;
190 }
191 
192 static void sdi_bridge_mode_set(struct drm_bridge *bridge,
193 				const struct drm_display_mode *mode,
194 				const struct drm_display_mode *adjusted_mode)
195 {
196 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
197 
198 	sdi->pixelclock = adjusted_mode->clock * 1000;
199 }
200 
201 static void sdi_bridge_enable(struct drm_bridge *bridge,
202 			      struct drm_atomic_commit *commit)
203 {
204 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
205 	struct dispc_clock_info dispc_cinfo;
206 	unsigned long fck;
207 	int r;
208 
209 	r = regulator_enable(sdi->vdds_sdi_reg);
210 	if (r)
211 		return;
212 
213 	r = dispc_runtime_get(sdi->dss->dispc);
214 	if (r)
215 		goto err_get_dispc;
216 
217 	r = sdi_calc_clock_div(sdi, sdi->pixelclock, &fck, &dispc_cinfo);
218 	if (r)
219 		goto err_calc_clock_div;
220 
221 	sdi->mgr_config.clock_info = dispc_cinfo;
222 
223 	r = dss_set_fck_rate(sdi->dss, fck);
224 	if (r)
225 		goto err_set_dss_clock_div;
226 
227 	sdi_config_lcd_manager(sdi);
228 
229 	/*
230 	 * LCLK and PCLK divisors are located in shadow registers, and we
231 	 * normally write them to DISPC registers when enabling the output.
232 	 * However, SDI uses pck-free as source clock for its PLL, and pck-free
233 	 * is affected by the divisors. And as we need the PLL before enabling
234 	 * the output, we need to write the divisors early.
235 	 *
236 	 * It seems just writing to the DISPC register is enough, and we don't
237 	 * need to care about the shadow register mechanism for pck-free. The
238 	 * exact reason for this is unknown.
239 	 */
240 	dispc_mgr_set_clock_div(sdi->dss->dispc, sdi->output.dispc_channel,
241 				&sdi->mgr_config.clock_info);
242 
243 	dss_sdi_init(sdi->dss, sdi->datapairs);
244 	r = dss_sdi_enable(sdi->dss);
245 	if (r)
246 		goto err_sdi_enable;
247 	mdelay(2);
248 
249 	r = dss_mgr_enable(&sdi->output);
250 	if (r)
251 		goto err_mgr_enable;
252 
253 	return;
254 
255 err_mgr_enable:
256 	dss_sdi_disable(sdi->dss);
257 err_sdi_enable:
258 err_set_dss_clock_div:
259 err_calc_clock_div:
260 	dispc_runtime_put(sdi->dss->dispc);
261 err_get_dispc:
262 	regulator_disable(sdi->vdds_sdi_reg);
263 }
264 
265 static void sdi_bridge_disable(struct drm_bridge *bridge,
266 			       struct drm_atomic_commit *commit)
267 {
268 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
269 
270 	dss_mgr_disable(&sdi->output);
271 
272 	dss_sdi_disable(sdi->dss);
273 
274 	dispc_runtime_put(sdi->dss->dispc);
275 
276 	regulator_disable(sdi->vdds_sdi_reg);
277 }
278 
279 static const struct drm_bridge_funcs sdi_bridge_funcs = {
280 	.atomic_create_state = drm_atomic_helper_bridge_create_state,
281 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
282 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
283 	.attach = sdi_bridge_attach,
284 	.mode_valid = sdi_bridge_mode_valid,
285 	.mode_fixup = sdi_bridge_mode_fixup,
286 	.mode_set = sdi_bridge_mode_set,
287 	.atomic_enable = sdi_bridge_enable,
288 	.atomic_disable = sdi_bridge_disable,
289 };
290 
291 static void sdi_bridge_init(struct sdi_device *sdi)
292 {
293 	sdi->bridge.of_node = sdi->pdev->dev.of_node;
294 	sdi->bridge.type = DRM_MODE_CONNECTOR_LVDS;
295 
296 	drm_bridge_add(&sdi->bridge);
297 }
298 
299 static void sdi_bridge_cleanup(struct sdi_device *sdi)
300 {
301 	drm_bridge_remove(&sdi->bridge);
302 }
303 
304 /* -----------------------------------------------------------------------------
305  * Initialisation and Cleanup
306  */
307 
308 static int sdi_init_output(struct sdi_device *sdi)
309 {
310 	struct omap_dss_device *out = &sdi->output;
311 	int r;
312 
313 	sdi_bridge_init(sdi);
314 
315 	out->dev = &sdi->pdev->dev;
316 	out->id = OMAP_DSS_OUTPUT_SDI;
317 	out->type = OMAP_DISPLAY_TYPE_SDI;
318 	out->name = "sdi.0";
319 	out->dispc_channel = OMAP_DSS_CHANNEL_LCD;
320 	/* We have SDI only on OMAP3, where it's on port 1 */
321 	out->of_port = 1;
322 	out->bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE	/* 15.5.9.1.2 */
323 		       | DRM_BUS_FLAG_SYNC_DRIVE_POSEDGE;
324 
325 	r = omapdss_device_init_output(out, &sdi->bridge);
326 	if (r < 0) {
327 		sdi_bridge_cleanup(sdi);
328 		return r;
329 	}
330 
331 	omapdss_device_register(out);
332 
333 	return 0;
334 }
335 
336 static void sdi_uninit_output(struct sdi_device *sdi)
337 {
338 	omapdss_device_unregister(&sdi->output);
339 	omapdss_device_cleanup_output(&sdi->output);
340 
341 	sdi_bridge_cleanup(sdi);
342 }
343 
344 int sdi_init_port(struct dss_device *dss, struct platform_device *pdev,
345 		  struct device_node *port)
346 {
347 	struct sdi_device *sdi;
348 	struct device_node *ep;
349 	u32 datapairs;
350 	int r;
351 
352 	sdi = devm_drm_bridge_alloc(&pdev->dev, struct sdi_device, bridge, &sdi_bridge_funcs);
353 	if (IS_ERR(sdi))
354 		return PTR_ERR(sdi);
355 
356 	ep = of_graph_get_next_port_endpoint(port, NULL);
357 	if (!ep)
358 		return 0;
359 
360 	r = of_property_read_u32(ep, "datapairs", &datapairs);
361 	of_node_put(ep);
362 	if (r) {
363 		DSSERR("failed to parse datapairs\n");
364 		return r;
365 	}
366 
367 	sdi->datapairs = datapairs;
368 	sdi->dss = dss;
369 
370 	sdi->pdev = pdev;
371 	port->data = sdi;
372 
373 	sdi->vdds_sdi_reg = devm_regulator_get(&pdev->dev, "vdds_sdi");
374 	if (IS_ERR(sdi->vdds_sdi_reg)) {
375 		r = PTR_ERR(sdi->vdds_sdi_reg);
376 		if (r != -EPROBE_DEFER)
377 			DSSERR("can't get VDDS_SDI regulator\n");
378 		return r;
379 	}
380 
381 	r = sdi_init_output(sdi);
382 	if (r)
383 		return r;
384 
385 	return 0;
386 }
387 
388 void sdi_uninit_port(struct device_node *port)
389 {
390 	struct sdi_device *sdi = port->data;
391 
392 	if (!sdi)
393 		return;
394 
395 	sdi_uninit_output(sdi);
396 }
397