xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/sdi.c (revision 29c37341)
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/platform_device.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/string.h>
17 
18 #include <drm/drm_bridge.h>
19 
20 #include "dss.h"
21 #include "omapdss.h"
22 
23 struct sdi_device {
24 	struct platform_device *pdev;
25 	struct dss_device *dss;
26 
27 	bool update_enabled;
28 	struct regulator *vdds_sdi_reg;
29 
30 	struct dss_lcd_mgr_config mgr_config;
31 	unsigned long pixelclock;
32 	int datapairs;
33 
34 	struct omap_dss_device output;
35 	struct drm_bridge bridge;
36 };
37 
38 #define drm_bridge_to_sdi(bridge) \
39 	container_of(bridge, struct sdi_device, bridge)
40 
41 struct sdi_clk_calc_ctx {
42 	struct sdi_device *sdi;
43 	unsigned long pck_min, pck_max;
44 
45 	unsigned long fck;
46 	struct dispc_clock_info dispc_cinfo;
47 };
48 
49 static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
50 		unsigned long pck, void *data)
51 {
52 	struct sdi_clk_calc_ctx *ctx = data;
53 
54 	ctx->dispc_cinfo.lck_div = lckd;
55 	ctx->dispc_cinfo.pck_div = pckd;
56 	ctx->dispc_cinfo.lck = lck;
57 	ctx->dispc_cinfo.pck = pck;
58 
59 	return true;
60 }
61 
62 static bool dpi_calc_dss_cb(unsigned long fck, void *data)
63 {
64 	struct sdi_clk_calc_ctx *ctx = data;
65 
66 	ctx->fck = fck;
67 
68 	return dispc_div_calc(ctx->sdi->dss->dispc, fck,
69 			      ctx->pck_min, ctx->pck_max,
70 			      dpi_calc_dispc_cb, ctx);
71 }
72 
73 static int sdi_calc_clock_div(struct sdi_device *sdi, unsigned long pclk,
74 			      unsigned long *fck,
75 			      struct dispc_clock_info *dispc_cinfo)
76 {
77 	int i;
78 	struct sdi_clk_calc_ctx ctx;
79 
80 	/*
81 	 * DSS fclk gives us very few possibilities, so finding a good pixel
82 	 * clock may not be possible. We try multiple times to find the clock,
83 	 * each time widening the pixel clock range we look for, up to
84 	 * +/- 1MHz.
85 	 */
86 
87 	for (i = 0; i < 10; ++i) {
88 		bool ok;
89 
90 		memset(&ctx, 0, sizeof(ctx));
91 
92 		ctx.sdi = sdi;
93 
94 		if (pclk > 1000 * i * i * i)
95 			ctx.pck_min = max(pclk - 1000 * i * i * i, 0lu);
96 		else
97 			ctx.pck_min = 0;
98 		ctx.pck_max = pclk + 1000 * i * i * i;
99 
100 		ok = dss_div_calc(sdi->dss, pclk, ctx.pck_min,
101 				  dpi_calc_dss_cb, &ctx);
102 		if (ok) {
103 			*fck = ctx.fck;
104 			*dispc_cinfo = ctx.dispc_cinfo;
105 			return 0;
106 		}
107 	}
108 
109 	return -EINVAL;
110 }
111 
112 static void sdi_config_lcd_manager(struct sdi_device *sdi)
113 {
114 	sdi->mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
115 
116 	sdi->mgr_config.stallmode = false;
117 	sdi->mgr_config.fifohandcheck = false;
118 
119 	sdi->mgr_config.video_port_width = 24;
120 	sdi->mgr_config.lcden_sig_polarity = 1;
121 
122 	dss_mgr_set_lcd_config(&sdi->output, &sdi->mgr_config);
123 }
124 
125 /* -----------------------------------------------------------------------------
126  * DRM Bridge Operations
127  */
128 
129 static int sdi_bridge_attach(struct drm_bridge *bridge,
130 			     enum drm_bridge_attach_flags flags)
131 {
132 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
133 
134 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
135 		return -EINVAL;
136 
137 	return drm_bridge_attach(bridge->encoder, sdi->output.next_bridge,
138 				 bridge, flags);
139 }
140 
141 static enum drm_mode_status
142 sdi_bridge_mode_valid(struct drm_bridge *bridge,
143 		      const struct drm_display_info *info,
144 		      const struct drm_display_mode *mode)
145 {
146 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
147 	unsigned long pixelclock = mode->clock * 1000;
148 	struct dispc_clock_info dispc_cinfo;
149 	unsigned long fck;
150 	int ret;
151 
152 	if (pixelclock == 0)
153 		return MODE_NOCLOCK;
154 
155 	ret = sdi_calc_clock_div(sdi, pixelclock, &fck, &dispc_cinfo);
156 	if (ret < 0)
157 		return MODE_CLOCK_RANGE;
158 
159 	return MODE_OK;
160 }
161 
162 static bool sdi_bridge_mode_fixup(struct drm_bridge *bridge,
163 				  const struct drm_display_mode *mode,
164 				  struct drm_display_mode *adjusted_mode)
165 {
166 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
167 	unsigned long pixelclock = mode->clock * 1000;
168 	struct dispc_clock_info dispc_cinfo;
169 	unsigned long fck;
170 	unsigned long pck;
171 	int ret;
172 
173 	ret = sdi_calc_clock_div(sdi, pixelclock, &fck, &dispc_cinfo);
174 	if (ret < 0)
175 		return false;
176 
177 	pck = fck / dispc_cinfo.lck_div / dispc_cinfo.pck_div;
178 
179 	if (pck != pixelclock)
180 		dev_dbg(&sdi->pdev->dev,
181 			"pixel clock adjusted from %lu Hz to %lu Hz\n",
182 			pixelclock, pck);
183 
184 	adjusted_mode->clock = pck / 1000;
185 
186 	return true;
187 }
188 
189 static void sdi_bridge_mode_set(struct drm_bridge *bridge,
190 				const struct drm_display_mode *mode,
191 				const struct drm_display_mode *adjusted_mode)
192 {
193 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
194 
195 	sdi->pixelclock = adjusted_mode->clock * 1000;
196 }
197 
198 static void sdi_bridge_enable(struct drm_bridge *bridge,
199 			      struct drm_bridge_state *bridge_state)
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 			       struct drm_bridge_state *bridge_state)
264 {
265 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
266 
267 	dss_mgr_disable(&sdi->output);
268 
269 	dss_sdi_disable(sdi->dss);
270 
271 	dispc_runtime_put(sdi->dss->dispc);
272 
273 	regulator_disable(sdi->vdds_sdi_reg);
274 }
275 
276 static const struct drm_bridge_funcs sdi_bridge_funcs = {
277 	.attach = sdi_bridge_attach,
278 	.mode_valid = sdi_bridge_mode_valid,
279 	.mode_fixup = sdi_bridge_mode_fixup,
280 	.mode_set = sdi_bridge_mode_set,
281 	.atomic_enable = sdi_bridge_enable,
282 	.atomic_disable = sdi_bridge_disable,
283 };
284 
285 static void sdi_bridge_init(struct sdi_device *sdi)
286 {
287 	sdi->bridge.funcs = &sdi_bridge_funcs;
288 	sdi->bridge.of_node = sdi->pdev->dev.of_node;
289 	sdi->bridge.type = DRM_MODE_CONNECTOR_LVDS;
290 
291 	drm_bridge_add(&sdi->bridge);
292 }
293 
294 static void sdi_bridge_cleanup(struct sdi_device *sdi)
295 {
296 	drm_bridge_remove(&sdi->bridge);
297 }
298 
299 /* -----------------------------------------------------------------------------
300  * Initialisation and Cleanup
301  */
302 
303 static int sdi_init_output(struct sdi_device *sdi)
304 {
305 	struct omap_dss_device *out = &sdi->output;
306 	int r;
307 
308 	sdi_bridge_init(sdi);
309 
310 	out->dev = &sdi->pdev->dev;
311 	out->id = OMAP_DSS_OUTPUT_SDI;
312 	out->type = OMAP_DISPLAY_TYPE_SDI;
313 	out->name = "sdi.0";
314 	out->dispc_channel = OMAP_DSS_CHANNEL_LCD;
315 	/* We have SDI only on OMAP3, where it's on port 1 */
316 	out->of_port = 1;
317 	out->owner = THIS_MODULE;
318 	out->bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE	/* 15.5.9.1.2 */
319 		       | DRM_BUS_FLAG_SYNC_DRIVE_POSEDGE;
320 
321 	r = omapdss_device_init_output(out, &sdi->bridge);
322 	if (r < 0) {
323 		sdi_bridge_cleanup(sdi);
324 		return r;
325 	}
326 
327 	omapdss_device_register(out);
328 
329 	return 0;
330 }
331 
332 static void sdi_uninit_output(struct sdi_device *sdi)
333 {
334 	omapdss_device_unregister(&sdi->output);
335 	omapdss_device_cleanup_output(&sdi->output);
336 
337 	sdi_bridge_cleanup(sdi);
338 }
339 
340 int sdi_init_port(struct dss_device *dss, struct platform_device *pdev,
341 		  struct device_node *port)
342 {
343 	struct sdi_device *sdi;
344 	struct device_node *ep;
345 	u32 datapairs;
346 	int r;
347 
348 	sdi = kzalloc(sizeof(*sdi), GFP_KERNEL);
349 	if (!sdi)
350 		return -ENOMEM;
351 
352 	ep = of_get_next_child(port, NULL);
353 	if (!ep) {
354 		r = 0;
355 		goto err_free;
356 	}
357 
358 	r = of_property_read_u32(ep, "datapairs", &datapairs);
359 	of_node_put(ep);
360 	if (r) {
361 		DSSERR("failed to parse datapairs\n");
362 		goto err_free;
363 	}
364 
365 	sdi->datapairs = datapairs;
366 	sdi->dss = dss;
367 
368 	sdi->pdev = pdev;
369 	port->data = sdi;
370 
371 	sdi->vdds_sdi_reg = devm_regulator_get(&pdev->dev, "vdds_sdi");
372 	if (IS_ERR(sdi->vdds_sdi_reg)) {
373 		r = PTR_ERR(sdi->vdds_sdi_reg);
374 		if (r != -EPROBE_DEFER)
375 			DSSERR("can't get VDDS_SDI regulator\n");
376 		goto err_free;
377 	}
378 
379 	r = sdi_init_output(sdi);
380 	if (r)
381 		goto err_free;
382 
383 	return 0;
384 
385 err_free:
386 	kfree(sdi);
387 
388 	return r;
389 }
390 
391 void sdi_uninit_port(struct device_node *port)
392 {
393 	struct sdi_device *sdi = port->data;
394 
395 	if (!sdi)
396 		return;
397 
398 	sdi_uninit_output(sdi);
399 	kfree(sdi);
400 }
401