xref: /linux/drivers/gpu/drm/omapdrm/dss/sdi.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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_bridge.h>
20 
21 #include "dss.h"
22 #include "omapdss.h"
23 
24 struct sdi_device {
25 	struct platform_device *pdev;
26 	struct dss_device *dss;
27 
28 	bool update_enabled;
29 	struct regulator *vdds_sdi_reg;
30 
31 	struct dss_lcd_mgr_config mgr_config;
32 	unsigned long pixelclock;
33 	int datapairs;
34 
35 	struct omap_dss_device output;
36 	struct drm_bridge bridge;
37 };
38 
39 #define drm_bridge_to_sdi(bridge) \
40 	container_of(bridge, struct sdi_device, bridge)
41 
42 struct sdi_clk_calc_ctx {
43 	struct sdi_device *sdi;
44 	unsigned long pck_min, pck_max;
45 
46 	unsigned long fck;
47 	struct dispc_clock_info dispc_cinfo;
48 };
49 
50 static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
51 		unsigned long pck, void *data)
52 {
53 	struct sdi_clk_calc_ctx *ctx = data;
54 
55 	ctx->dispc_cinfo.lck_div = lckd;
56 	ctx->dispc_cinfo.pck_div = pckd;
57 	ctx->dispc_cinfo.lck = lck;
58 	ctx->dispc_cinfo.pck = pck;
59 
60 	return true;
61 }
62 
63 static bool dpi_calc_dss_cb(unsigned long fck, void *data)
64 {
65 	struct sdi_clk_calc_ctx *ctx = data;
66 
67 	ctx->fck = fck;
68 
69 	return dispc_div_calc(ctx->sdi->dss->dispc, fck,
70 			      ctx->pck_min, ctx->pck_max,
71 			      dpi_calc_dispc_cb, ctx);
72 }
73 
74 static int sdi_calc_clock_div(struct sdi_device *sdi, unsigned long pclk,
75 			      unsigned long *fck,
76 			      struct dispc_clock_info *dispc_cinfo)
77 {
78 	int i;
79 	struct sdi_clk_calc_ctx ctx;
80 
81 	/*
82 	 * DSS fclk gives us very few possibilities, so finding a good pixel
83 	 * clock may not be possible. We try multiple times to find the clock,
84 	 * each time widening the pixel clock range we look for, up to
85 	 * +/- 1MHz.
86 	 */
87 
88 	for (i = 0; i < 10; ++i) {
89 		bool ok;
90 
91 		memset(&ctx, 0, sizeof(ctx));
92 
93 		ctx.sdi = sdi;
94 
95 		if (pclk > 1000 * i * i * i)
96 			ctx.pck_min = max(pclk - 1000 * i * i * i, 0lu);
97 		else
98 			ctx.pck_min = 0;
99 		ctx.pck_max = pclk + 1000 * i * i * i;
100 
101 		ok = dss_div_calc(sdi->dss, pclk, ctx.pck_min,
102 				  dpi_calc_dss_cb, &ctx);
103 		if (ok) {
104 			*fck = ctx.fck;
105 			*dispc_cinfo = ctx.dispc_cinfo;
106 			return 0;
107 		}
108 	}
109 
110 	return -EINVAL;
111 }
112 
113 static void sdi_config_lcd_manager(struct sdi_device *sdi)
114 {
115 	sdi->mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
116 
117 	sdi->mgr_config.stallmode = false;
118 	sdi->mgr_config.fifohandcheck = false;
119 
120 	sdi->mgr_config.video_port_width = 24;
121 	sdi->mgr_config.lcden_sig_polarity = 1;
122 
123 	dss_mgr_set_lcd_config(&sdi->output, &sdi->mgr_config);
124 }
125 
126 /* -----------------------------------------------------------------------------
127  * DRM Bridge Operations
128  */
129 
130 static int sdi_bridge_attach(struct drm_bridge *bridge,
131 			     enum drm_bridge_attach_flags flags)
132 {
133 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
134 
135 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
136 		return -EINVAL;
137 
138 	return drm_bridge_attach(bridge->encoder, sdi->output.next_bridge,
139 				 bridge, flags);
140 }
141 
142 static enum drm_mode_status
143 sdi_bridge_mode_valid(struct drm_bridge *bridge,
144 		      const struct drm_display_info *info,
145 		      const struct drm_display_mode *mode)
146 {
147 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
148 	unsigned long pixelclock = mode->clock * 1000;
149 	struct dispc_clock_info dispc_cinfo;
150 	unsigned long fck;
151 	int ret;
152 
153 	if (pixelclock == 0)
154 		return MODE_NOCLOCK;
155 
156 	ret = sdi_calc_clock_div(sdi, pixelclock, &fck, &dispc_cinfo);
157 	if (ret < 0)
158 		return MODE_CLOCK_RANGE;
159 
160 	return MODE_OK;
161 }
162 
163 static bool sdi_bridge_mode_fixup(struct drm_bridge *bridge,
164 				  const struct drm_display_mode *mode,
165 				  struct drm_display_mode *adjusted_mode)
166 {
167 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
168 	unsigned long pixelclock = mode->clock * 1000;
169 	struct dispc_clock_info dispc_cinfo;
170 	unsigned long fck;
171 	unsigned long pck;
172 	int ret;
173 
174 	ret = sdi_calc_clock_div(sdi, pixelclock, &fck, &dispc_cinfo);
175 	if (ret < 0)
176 		return false;
177 
178 	pck = fck / dispc_cinfo.lck_div / dispc_cinfo.pck_div;
179 
180 	if (pck != pixelclock)
181 		dev_dbg(&sdi->pdev->dev,
182 			"pixel clock adjusted from %lu Hz to %lu Hz\n",
183 			pixelclock, pck);
184 
185 	adjusted_mode->clock = pck / 1000;
186 
187 	return true;
188 }
189 
190 static void sdi_bridge_mode_set(struct drm_bridge *bridge,
191 				const struct drm_display_mode *mode,
192 				const struct drm_display_mode *adjusted_mode)
193 {
194 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
195 
196 	sdi->pixelclock = adjusted_mode->clock * 1000;
197 }
198 
199 static void sdi_bridge_enable(struct drm_bridge *bridge)
200 {
201 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
202 	struct dispc_clock_info dispc_cinfo;
203 	unsigned long fck;
204 	int r;
205 
206 	r = regulator_enable(sdi->vdds_sdi_reg);
207 	if (r)
208 		return;
209 
210 	r = dispc_runtime_get(sdi->dss->dispc);
211 	if (r)
212 		goto err_get_dispc;
213 
214 	r = sdi_calc_clock_div(sdi, sdi->pixelclock, &fck, &dispc_cinfo);
215 	if (r)
216 		goto err_calc_clock_div;
217 
218 	sdi->mgr_config.clock_info = dispc_cinfo;
219 
220 	r = dss_set_fck_rate(sdi->dss, fck);
221 	if (r)
222 		goto err_set_dss_clock_div;
223 
224 	sdi_config_lcd_manager(sdi);
225 
226 	/*
227 	 * LCLK and PCLK divisors are located in shadow registers, and we
228 	 * normally write them to DISPC registers when enabling the output.
229 	 * However, SDI uses pck-free as source clock for its PLL, and pck-free
230 	 * is affected by the divisors. And as we need the PLL before enabling
231 	 * the output, we need to write the divisors early.
232 	 *
233 	 * It seems just writing to the DISPC register is enough, and we don't
234 	 * need to care about the shadow register mechanism for pck-free. The
235 	 * exact reason for this is unknown.
236 	 */
237 	dispc_mgr_set_clock_div(sdi->dss->dispc, sdi->output.dispc_channel,
238 				&sdi->mgr_config.clock_info);
239 
240 	dss_sdi_init(sdi->dss, sdi->datapairs);
241 	r = dss_sdi_enable(sdi->dss);
242 	if (r)
243 		goto err_sdi_enable;
244 	mdelay(2);
245 
246 	r = dss_mgr_enable(&sdi->output);
247 	if (r)
248 		goto err_mgr_enable;
249 
250 	return;
251 
252 err_mgr_enable:
253 	dss_sdi_disable(sdi->dss);
254 err_sdi_enable:
255 err_set_dss_clock_div:
256 err_calc_clock_div:
257 	dispc_runtime_put(sdi->dss->dispc);
258 err_get_dispc:
259 	regulator_disable(sdi->vdds_sdi_reg);
260 }
261 
262 static void sdi_bridge_disable(struct drm_bridge *bridge)
263 {
264 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
265 
266 	dss_mgr_disable(&sdi->output);
267 
268 	dss_sdi_disable(sdi->dss);
269 
270 	dispc_runtime_put(sdi->dss->dispc);
271 
272 	regulator_disable(sdi->vdds_sdi_reg);
273 }
274 
275 static const struct drm_bridge_funcs sdi_bridge_funcs = {
276 	.attach = sdi_bridge_attach,
277 	.mode_valid = sdi_bridge_mode_valid,
278 	.mode_fixup = sdi_bridge_mode_fixup,
279 	.mode_set = sdi_bridge_mode_set,
280 	.enable = sdi_bridge_enable,
281 	.disable = sdi_bridge_disable,
282 };
283 
284 static void sdi_bridge_init(struct sdi_device *sdi)
285 {
286 	sdi->bridge.funcs = &sdi_bridge_funcs;
287 	sdi->bridge.of_node = sdi->pdev->dev.of_node;
288 	sdi->bridge.type = DRM_MODE_CONNECTOR_LVDS;
289 
290 	drm_bridge_add(&sdi->bridge);
291 }
292 
293 static void sdi_bridge_cleanup(struct sdi_device *sdi)
294 {
295 	drm_bridge_remove(&sdi->bridge);
296 }
297 
298 /* -----------------------------------------------------------------------------
299  * Initialisation and Cleanup
300  */
301 
302 static int sdi_init_output(struct sdi_device *sdi)
303 {
304 	struct omap_dss_device *out = &sdi->output;
305 	int r;
306 
307 	sdi_bridge_init(sdi);
308 
309 	out->dev = &sdi->pdev->dev;
310 	out->id = OMAP_DSS_OUTPUT_SDI;
311 	out->type = OMAP_DISPLAY_TYPE_SDI;
312 	out->name = "sdi.0";
313 	out->dispc_channel = OMAP_DSS_CHANNEL_LCD;
314 	/* We have SDI only on OMAP3, where it's on port 1 */
315 	out->of_port = 1;
316 	out->bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE	/* 15.5.9.1.2 */
317 		       | DRM_BUS_FLAG_SYNC_DRIVE_POSEDGE;
318 
319 	r = omapdss_device_init_output(out, &sdi->bridge);
320 	if (r < 0) {
321 		sdi_bridge_cleanup(sdi);
322 		return r;
323 	}
324 
325 	omapdss_device_register(out);
326 
327 	return 0;
328 }
329 
330 static void sdi_uninit_output(struct sdi_device *sdi)
331 {
332 	omapdss_device_unregister(&sdi->output);
333 	omapdss_device_cleanup_output(&sdi->output);
334 
335 	sdi_bridge_cleanup(sdi);
336 }
337 
338 int sdi_init_port(struct dss_device *dss, struct platform_device *pdev,
339 		  struct device_node *port)
340 {
341 	struct sdi_device *sdi;
342 	struct device_node *ep;
343 	u32 datapairs;
344 	int r;
345 
346 	sdi = kzalloc(sizeof(*sdi), GFP_KERNEL);
347 	if (!sdi)
348 		return -ENOMEM;
349 
350 	ep = of_graph_get_next_port_endpoint(port, NULL);
351 	if (!ep) {
352 		r = 0;
353 		goto err_free;
354 	}
355 
356 	r = of_property_read_u32(ep, "datapairs", &datapairs);
357 	of_node_put(ep);
358 	if (r) {
359 		DSSERR("failed to parse datapairs\n");
360 		goto err_free;
361 	}
362 
363 	sdi->datapairs = datapairs;
364 	sdi->dss = dss;
365 
366 	sdi->pdev = pdev;
367 	port->data = sdi;
368 
369 	sdi->vdds_sdi_reg = devm_regulator_get(&pdev->dev, "vdds_sdi");
370 	if (IS_ERR(sdi->vdds_sdi_reg)) {
371 		r = PTR_ERR(sdi->vdds_sdi_reg);
372 		if (r != -EPROBE_DEFER)
373 			DSSERR("can't get VDDS_SDI regulator\n");
374 		goto err_free;
375 	}
376 
377 	r = sdi_init_output(sdi);
378 	if (r)
379 		goto err_free;
380 
381 	return 0;
382 
383 err_free:
384 	kfree(sdi);
385 
386 	return r;
387 }
388 
389 void sdi_uninit_port(struct device_node *port)
390 {
391 	struct sdi_device *sdi = port->data;
392 
393 	if (!sdi)
394 		return;
395 
396 	sdi_uninit_output(sdi);
397 	kfree(sdi);
398 }
399