xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/sdi.c (revision b8265621)
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_mode *mode)
144 {
145 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
146 	unsigned long pixelclock = mode->clock * 1000;
147 	struct dispc_clock_info dispc_cinfo;
148 	unsigned long fck;
149 	int ret;
150 
151 	if (pixelclock == 0)
152 		return MODE_NOCLOCK;
153 
154 	ret = sdi_calc_clock_div(sdi, pixelclock, &fck, &dispc_cinfo);
155 	if (ret < 0)
156 		return MODE_CLOCK_RANGE;
157 
158 	return MODE_OK;
159 }
160 
161 static bool sdi_bridge_mode_fixup(struct drm_bridge *bridge,
162 				  const struct drm_display_mode *mode,
163 				  struct drm_display_mode *adjusted_mode)
164 {
165 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
166 	unsigned long pixelclock = mode->clock * 1000;
167 	struct dispc_clock_info dispc_cinfo;
168 	unsigned long fck;
169 	unsigned long pck;
170 	int ret;
171 
172 	ret = sdi_calc_clock_div(sdi, pixelclock, &fck, &dispc_cinfo);
173 	if (ret < 0)
174 		return false;
175 
176 	pck = fck / dispc_cinfo.lck_div / dispc_cinfo.pck_div;
177 
178 	if (pck != pixelclock)
179 		dev_dbg(&sdi->pdev->dev,
180 			"pixel clock adjusted from %lu Hz to %lu Hz\n",
181 			pixelclock, pck);
182 
183 	adjusted_mode->clock = pck / 1000;
184 
185 	return true;
186 }
187 
188 static void sdi_bridge_mode_set(struct drm_bridge *bridge,
189 				const struct drm_display_mode *mode,
190 				const struct drm_display_mode *adjusted_mode)
191 {
192 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
193 
194 	sdi->pixelclock = adjusted_mode->clock * 1000;
195 }
196 
197 static void sdi_bridge_enable(struct drm_bridge *bridge,
198 			      struct drm_bridge_state *bridge_state)
199 {
200 	struct sdi_device *sdi = drm_bridge_to_sdi(bridge);
201 	struct dispc_clock_info dispc_cinfo;
202 	unsigned long fck;
203 	int r;
204 
205 	r = regulator_enable(sdi->vdds_sdi_reg);
206 	if (r)
207 		return;
208 
209 	r = dispc_runtime_get(sdi->dss->dispc);
210 	if (r)
211 		goto err_get_dispc;
212 
213 	r = sdi_calc_clock_div(sdi, sdi->pixelclock, &fck, &dispc_cinfo);
214 	if (r)
215 		goto err_calc_clock_div;
216 
217 	sdi->mgr_config.clock_info = dispc_cinfo;
218 
219 	r = dss_set_fck_rate(sdi->dss, fck);
220 	if (r)
221 		goto err_set_dss_clock_div;
222 
223 	sdi_config_lcd_manager(sdi);
224 
225 	/*
226 	 * LCLK and PCLK divisors are located in shadow registers, and we
227 	 * normally write them to DISPC registers when enabling the output.
228 	 * However, SDI uses pck-free as source clock for its PLL, and pck-free
229 	 * is affected by the divisors. And as we need the PLL before enabling
230 	 * the output, we need to write the divisors early.
231 	 *
232 	 * It seems just writing to the DISPC register is enough, and we don't
233 	 * need to care about the shadow register mechanism for pck-free. The
234 	 * exact reason for this is unknown.
235 	 */
236 	dispc_mgr_set_clock_div(sdi->dss->dispc, sdi->output.dispc_channel,
237 				&sdi->mgr_config.clock_info);
238 
239 	dss_sdi_init(sdi->dss, sdi->datapairs);
240 	r = dss_sdi_enable(sdi->dss);
241 	if (r)
242 		goto err_sdi_enable;
243 	mdelay(2);
244 
245 	r = dss_mgr_enable(&sdi->output);
246 	if (r)
247 		goto err_mgr_enable;
248 
249 	return;
250 
251 err_mgr_enable:
252 	dss_sdi_disable(sdi->dss);
253 err_sdi_enable:
254 err_set_dss_clock_div:
255 err_calc_clock_div:
256 	dispc_runtime_put(sdi->dss->dispc);
257 err_get_dispc:
258 	regulator_disable(sdi->vdds_sdi_reg);
259 }
260 
261 static void sdi_bridge_disable(struct drm_bridge *bridge,
262 			       struct drm_bridge_state *bridge_state)
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 	.atomic_enable = sdi_bridge_enable,
281 	.atomic_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->owner = THIS_MODULE;
317 	out->bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE	/* 15.5.9.1.2 */
318 		       | DRM_BUS_FLAG_SYNC_DRIVE_POSEDGE;
319 
320 	r = omapdss_device_init_output(out, &sdi->bridge);
321 	if (r < 0) {
322 		sdi_bridge_cleanup(sdi);
323 		return r;
324 	}
325 
326 	omapdss_device_register(out);
327 
328 	return 0;
329 }
330 
331 static void sdi_uninit_output(struct sdi_device *sdi)
332 {
333 	omapdss_device_unregister(&sdi->output);
334 	omapdss_device_cleanup_output(&sdi->output);
335 
336 	sdi_bridge_cleanup(sdi);
337 }
338 
339 int sdi_init_port(struct dss_device *dss, struct platform_device *pdev,
340 		  struct device_node *port)
341 {
342 	struct sdi_device *sdi;
343 	struct device_node *ep;
344 	u32 datapairs;
345 	int r;
346 
347 	sdi = kzalloc(sizeof(*sdi), GFP_KERNEL);
348 	if (!sdi)
349 		return -ENOMEM;
350 
351 	ep = of_get_next_child(port, NULL);
352 	if (!ep) {
353 		r = 0;
354 		goto err_free;
355 	}
356 
357 	r = of_property_read_u32(ep, "datapairs", &datapairs);
358 	of_node_put(ep);
359 	if (r) {
360 		DSSERR("failed to parse datapairs\n");
361 		goto err_free;
362 	}
363 
364 	sdi->datapairs = datapairs;
365 	sdi->dss = dss;
366 
367 	sdi->pdev = pdev;
368 	port->data = sdi;
369 
370 	sdi->vdds_sdi_reg = devm_regulator_get(&pdev->dev, "vdds_sdi");
371 	if (IS_ERR(sdi->vdds_sdi_reg)) {
372 		r = PTR_ERR(sdi->vdds_sdi_reg);
373 		if (r != -EPROBE_DEFER)
374 			DSSERR("can't get VDDS_SDI regulator\n");
375 		goto err_free;
376 	}
377 
378 	r = sdi_init_output(sdi);
379 	if (r)
380 		goto err_free;
381 
382 	return 0;
383 
384 err_free:
385 	kfree(sdi);
386 
387 	return r;
388 }
389 
390 void sdi_uninit_port(struct device_node *port)
391 {
392 	struct sdi_device *sdi = port->data;
393 
394 	if (!sdi)
395 		return;
396 
397 	sdi_uninit_output(sdi);
398 	kfree(sdi);
399 }
400