xref: /openbmc/linux/drivers/gpu/drm/omapdrm/dss/sdi.c (revision 5ef12cb4a3a78ffb331c03a795a15eea4ae35155)
1 /*
2  * Copyright (C) 2009 Nokia Corporation
3  * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #define DSS_SUBSYS_NAME "SDI"
19 
20 #include <linux/kernel.h>
21 #include <linux/delay.h>
22 #include <linux/err.h>
23 #include <linux/regulator/consumer.h>
24 #include <linux/export.h>
25 #include <linux/platform_device.h>
26 #include <linux/string.h>
27 #include <linux/of.h>
28 
29 #include "omapdss.h"
30 #include "dss.h"
31 
32 struct sdi_device {
33 	struct platform_device *pdev;
34 	struct dss_device *dss;
35 
36 	bool update_enabled;
37 	struct regulator *vdds_sdi_reg;
38 
39 	struct dss_lcd_mgr_config mgr_config;
40 	struct videomode vm;
41 	int datapairs;
42 
43 	struct omap_dss_device output;
44 };
45 
46 #define dssdev_to_sdi(dssdev) container_of(dssdev, struct sdi_device, output)
47 
48 struct sdi_clk_calc_ctx {
49 	struct sdi_device *sdi;
50 	unsigned long pck_min, pck_max;
51 
52 	unsigned long fck;
53 	struct dispc_clock_info dispc_cinfo;
54 };
55 
56 static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
57 		unsigned long pck, void *data)
58 {
59 	struct sdi_clk_calc_ctx *ctx = data;
60 
61 	ctx->dispc_cinfo.lck_div = lckd;
62 	ctx->dispc_cinfo.pck_div = pckd;
63 	ctx->dispc_cinfo.lck = lck;
64 	ctx->dispc_cinfo.pck = pck;
65 
66 	return true;
67 }
68 
69 static bool dpi_calc_dss_cb(unsigned long fck, void *data)
70 {
71 	struct sdi_clk_calc_ctx *ctx = data;
72 
73 	ctx->fck = fck;
74 
75 	return dispc_div_calc(ctx->sdi->dss->dispc, fck,
76 			      ctx->pck_min, ctx->pck_max,
77 			      dpi_calc_dispc_cb, ctx);
78 }
79 
80 static int sdi_calc_clock_div(struct sdi_device *sdi, unsigned long pclk,
81 			      unsigned long *fck,
82 			      struct dispc_clock_info *dispc_cinfo)
83 {
84 	int i;
85 	struct sdi_clk_calc_ctx ctx = { .sdi = sdi };
86 
87 	/*
88 	 * DSS fclk gives us very few possibilities, so finding a good pixel
89 	 * clock may not be possible. We try multiple times to find the clock,
90 	 * each time widening the pixel clock range we look for, up to
91 	 * +/- 1MHz.
92 	 */
93 
94 	for (i = 0; i < 10; ++i) {
95 		bool ok;
96 
97 		memset(&ctx, 0, sizeof(ctx));
98 		if (pclk > 1000 * i * i * i)
99 			ctx.pck_min = max(pclk - 1000 * i * i * i, 0lu);
100 		else
101 			ctx.pck_min = 0;
102 		ctx.pck_max = pclk + 1000 * i * i * i;
103 
104 		ok = dss_div_calc(sdi->dss, pclk, ctx.pck_min,
105 				  dpi_calc_dss_cb, &ctx);
106 		if (ok) {
107 			*fck = ctx.fck;
108 			*dispc_cinfo = ctx.dispc_cinfo;
109 			return 0;
110 		}
111 	}
112 
113 	return -EINVAL;
114 }
115 
116 static void sdi_config_lcd_manager(struct sdi_device *sdi)
117 {
118 	sdi->mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
119 
120 	sdi->mgr_config.stallmode = false;
121 	sdi->mgr_config.fifohandcheck = false;
122 
123 	sdi->mgr_config.video_port_width = 24;
124 	sdi->mgr_config.lcden_sig_polarity = 1;
125 
126 	dss_mgr_set_lcd_config(&sdi->output, &sdi->mgr_config);
127 }
128 
129 static int sdi_display_enable(struct omap_dss_device *dssdev)
130 {
131 	struct sdi_device *sdi = dssdev_to_sdi(dssdev);
132 	struct videomode *vm = &sdi->vm;
133 	unsigned long fck;
134 	struct dispc_clock_info dispc_cinfo;
135 	unsigned long pck;
136 	int r;
137 
138 	if (!sdi->output.dispc_channel_connected) {
139 		DSSERR("failed to enable display: no output/manager\n");
140 		return -ENODEV;
141 	}
142 
143 	r = regulator_enable(sdi->vdds_sdi_reg);
144 	if (r)
145 		goto err_reg_enable;
146 
147 	r = dispc_runtime_get(sdi->dss->dispc);
148 	if (r)
149 		goto err_get_dispc;
150 
151 	/* 15.5.9.1.2 */
152 	vm->flags |= DISPLAY_FLAGS_PIXDATA_POSEDGE | DISPLAY_FLAGS_SYNC_POSEDGE;
153 
154 	r = sdi_calc_clock_div(sdi, vm->pixelclock, &fck, &dispc_cinfo);
155 	if (r)
156 		goto err_calc_clock_div;
157 
158 	sdi->mgr_config.clock_info = dispc_cinfo;
159 
160 	pck = fck / dispc_cinfo.lck_div / dispc_cinfo.pck_div;
161 
162 	if (pck != vm->pixelclock) {
163 		DSSWARN("Could not find exact pixel clock. Requested %lu Hz, got %lu Hz\n",
164 			vm->pixelclock, pck);
165 
166 		vm->pixelclock = pck;
167 	}
168 
169 
170 	dss_mgr_set_timings(&sdi->output, vm);
171 
172 	r = dss_set_fck_rate(sdi->dss, fck);
173 	if (r)
174 		goto err_set_dss_clock_div;
175 
176 	sdi_config_lcd_manager(sdi);
177 
178 	/*
179 	 * LCLK and PCLK divisors are located in shadow registers, and we
180 	 * normally write them to DISPC registers when enabling the output.
181 	 * However, SDI uses pck-free as source clock for its PLL, and pck-free
182 	 * is affected by the divisors. And as we need the PLL before enabling
183 	 * the output, we need to write the divisors early.
184 	 *
185 	 * It seems just writing to the DISPC register is enough, and we don't
186 	 * need to care about the shadow register mechanism for pck-free. The
187 	 * exact reason for this is unknown.
188 	 */
189 	dispc_mgr_set_clock_div(sdi->dss->dispc, sdi->output.dispc_channel,
190 				&sdi->mgr_config.clock_info);
191 
192 	dss_sdi_init(sdi->dss, sdi->datapairs);
193 	r = dss_sdi_enable(sdi->dss);
194 	if (r)
195 		goto err_sdi_enable;
196 	mdelay(2);
197 
198 	r = dss_mgr_enable(&sdi->output);
199 	if (r)
200 		goto err_mgr_enable;
201 
202 	return 0;
203 
204 err_mgr_enable:
205 	dss_sdi_disable(sdi->dss);
206 err_sdi_enable:
207 err_set_dss_clock_div:
208 err_calc_clock_div:
209 	dispc_runtime_put(sdi->dss->dispc);
210 err_get_dispc:
211 	regulator_disable(sdi->vdds_sdi_reg);
212 err_reg_enable:
213 	return r;
214 }
215 
216 static void sdi_display_disable(struct omap_dss_device *dssdev)
217 {
218 	struct sdi_device *sdi = dssdev_to_sdi(dssdev);
219 
220 	dss_mgr_disable(&sdi->output);
221 
222 	dss_sdi_disable(sdi->dss);
223 
224 	dispc_runtime_put(sdi->dss->dispc);
225 
226 	regulator_disable(sdi->vdds_sdi_reg);
227 }
228 
229 static void sdi_set_timings(struct omap_dss_device *dssdev,
230 			    struct videomode *vm)
231 {
232 	struct sdi_device *sdi = dssdev_to_sdi(dssdev);
233 
234 	sdi->vm = *vm;
235 }
236 
237 static void sdi_get_timings(struct omap_dss_device *dssdev,
238 			    struct videomode *vm)
239 {
240 	struct sdi_device *sdi = dssdev_to_sdi(dssdev);
241 
242 	*vm = sdi->vm;
243 }
244 
245 static int sdi_check_timings(struct omap_dss_device *dssdev,
246 			     struct videomode *vm)
247 {
248 	struct sdi_device *sdi = dssdev_to_sdi(dssdev);
249 	enum omap_channel channel = dssdev->dispc_channel;
250 
251 	if (!dispc_mgr_timings_ok(sdi->dss->dispc, channel, vm))
252 		return -EINVAL;
253 
254 	if (vm->pixelclock == 0)
255 		return -EINVAL;
256 
257 	return 0;
258 }
259 
260 static int sdi_init_regulator(struct sdi_device *sdi)
261 {
262 	struct regulator *vdds_sdi;
263 
264 	if (sdi->vdds_sdi_reg)
265 		return 0;
266 
267 	vdds_sdi = devm_regulator_get(&sdi->pdev->dev, "vdds_sdi");
268 	if (IS_ERR(vdds_sdi)) {
269 		if (PTR_ERR(vdds_sdi) != -EPROBE_DEFER)
270 			DSSERR("can't get VDDS_SDI regulator\n");
271 		return PTR_ERR(vdds_sdi);
272 	}
273 
274 	sdi->vdds_sdi_reg = vdds_sdi;
275 
276 	return 0;
277 }
278 
279 static int sdi_connect(struct omap_dss_device *dssdev,
280 		struct omap_dss_device *dst)
281 {
282 	struct sdi_device *sdi = dssdev_to_sdi(dssdev);
283 	int r;
284 
285 	r = sdi_init_regulator(sdi);
286 	if (r)
287 		return r;
288 
289 	r = dss_mgr_connect(&sdi->output, dssdev);
290 	if (r)
291 		return r;
292 
293 	r = omapdss_output_set_device(dssdev, dst);
294 	if (r) {
295 		DSSERR("failed to connect output to new device: %s\n",
296 				dst->name);
297 		dss_mgr_disconnect(&sdi->output, dssdev);
298 		return r;
299 	}
300 
301 	return 0;
302 }
303 
304 static void sdi_disconnect(struct omap_dss_device *dssdev,
305 		struct omap_dss_device *dst)
306 {
307 	struct sdi_device *sdi = dssdev_to_sdi(dssdev);
308 
309 	WARN_ON(dst != dssdev->dst);
310 
311 	if (dst != dssdev->dst)
312 		return;
313 
314 	omapdss_output_unset_device(dssdev);
315 
316 	dss_mgr_disconnect(&sdi->output, dssdev);
317 }
318 
319 static const struct omapdss_sdi_ops sdi_ops = {
320 	.connect = sdi_connect,
321 	.disconnect = sdi_disconnect,
322 
323 	.enable = sdi_display_enable,
324 	.disable = sdi_display_disable,
325 
326 	.check_timings = sdi_check_timings,
327 	.set_timings = sdi_set_timings,
328 	.get_timings = sdi_get_timings,
329 };
330 
331 static void sdi_init_output(struct sdi_device *sdi)
332 {
333 	struct omap_dss_device *out = &sdi->output;
334 
335 	out->dev = &sdi->pdev->dev;
336 	out->id = OMAP_DSS_OUTPUT_SDI;
337 	out->output_type = OMAP_DISPLAY_TYPE_SDI;
338 	out->name = "sdi.0";
339 	out->dispc_channel = OMAP_DSS_CHANNEL_LCD;
340 	/* We have SDI only on OMAP3, where it's on port 1 */
341 	out->port_num = 1;
342 	out->ops.sdi = &sdi_ops;
343 	out->owner = THIS_MODULE;
344 
345 	omapdss_register_output(out);
346 }
347 
348 static void sdi_uninit_output(struct sdi_device *sdi)
349 {
350 	omapdss_unregister_output(&sdi->output);
351 }
352 
353 int sdi_init_port(struct dss_device *dss, struct platform_device *pdev,
354 		  struct device_node *port)
355 {
356 	struct sdi_device *sdi;
357 	struct device_node *ep;
358 	u32 datapairs;
359 	int r;
360 
361 	sdi = kzalloc(sizeof(*sdi), GFP_KERNEL);
362 	if (!sdi)
363 		return -ENOMEM;
364 
365 	ep = of_get_next_child(port, NULL);
366 	if (!ep) {
367 		r = 0;
368 		goto err_free;
369 	}
370 
371 	r = of_property_read_u32(ep, "datapairs", &datapairs);
372 	if (r) {
373 		DSSERR("failed to parse datapairs\n");
374 		goto err_datapairs;
375 	}
376 
377 	sdi->datapairs = datapairs;
378 	sdi->dss = dss;
379 
380 	of_node_put(ep);
381 
382 	sdi->pdev = pdev;
383 	port->data = sdi;
384 
385 	sdi_init_output(sdi);
386 
387 	return 0;
388 
389 err_datapairs:
390 	of_node_put(ep);
391 err_free:
392 	kfree(sdi);
393 
394 	return r;
395 }
396 
397 void sdi_uninit_port(struct device_node *port)
398 {
399 	struct sdi_device *sdi = port->data;
400 
401 	if (!sdi)
402 		return;
403 
404 	sdi_uninit_output(sdi);
405 	kfree(sdi);
406 }
407