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  1/*
  2 * linux/drivers/video/omap2/dss/sdi.c
  3 *
  4 * Copyright (C) 2009 Nokia Corporation
  5 * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
  6 *
  7 * This program is free software; you can redistribute it and/or modify it
  8 * under the terms of the GNU General Public License version 2 as published by
  9 * the Free Software Foundation.
 10 *
 11 * This program is distributed in the hope that it will be useful, but WITHOUT
 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 14 * more details.
 15 *
 16 * You should have received a copy of the GNU General Public License along with
 17 * this program.  If not, see <http://www.gnu.org/licenses/>.
 18 */
 19
 20#define DSS_SUBSYS_NAME "SDI"
 21
 22#include <linux/kernel.h>
 23#include <linux/delay.h>
 24#include <linux/err.h>
 25#include <linux/regulator/consumer.h>
 26#include <linux/export.h>
 27#include <linux/platform_device.h>
 28#include <linux/string.h>
 29#include <linux/of.h>
 30#include <linux/component.h>
 31
 32#include <video/omapdss.h>
 33#include "dss.h"
 34
 35static struct {
 36	struct platform_device *pdev;
 37
 38	bool update_enabled;
 39	struct regulator *vdds_sdi_reg;
 40
 41	struct dss_lcd_mgr_config mgr_config;
 42	struct omap_video_timings timings;
 43	int datapairs;
 44
 45	struct omap_dss_device output;
 46
 47	bool port_initialized;
 48} sdi;
 49
 50struct sdi_clk_calc_ctx {
 51	unsigned long pck_min, pck_max;
 52
 53	unsigned long fck;
 54	struct dispc_clock_info dispc_cinfo;
 55};
 56
 57static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
 58		unsigned long pck, void *data)
 59{
 60	struct sdi_clk_calc_ctx *ctx = data;
 61
 62	ctx->dispc_cinfo.lck_div = lckd;
 63	ctx->dispc_cinfo.pck_div = pckd;
 64	ctx->dispc_cinfo.lck = lck;
 65	ctx->dispc_cinfo.pck = pck;
 66
 67	return true;
 68}
 69
 70static bool dpi_calc_dss_cb(unsigned long fck, void *data)
 71{
 72	struct sdi_clk_calc_ctx *ctx = data;
 73
 74	ctx->fck = fck;
 75
 76	return dispc_div_calc(fck, ctx->pck_min, ctx->pck_max,
 77			dpi_calc_dispc_cb, ctx);
 78}
 79
 80static int sdi_calc_clock_div(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;
 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(pclk, ctx.pck_min, dpi_calc_dss_cb, &ctx);
105		if (ok) {
106			*fck = ctx.fck;
107			*dispc_cinfo = ctx.dispc_cinfo;
108			return 0;
109		}
110	}
111
112	return -EINVAL;
113}
114
115static void sdi_config_lcd_manager(struct omap_dss_device *dssdev)
116{
117	enum omap_channel channel = dssdev->dispc_channel;
118
119	sdi.mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
120
121	sdi.mgr_config.stallmode = false;
122	sdi.mgr_config.fifohandcheck = false;
123
124	sdi.mgr_config.video_port_width = 24;
125	sdi.mgr_config.lcden_sig_polarity = 1;
126
127	dss_mgr_set_lcd_config(channel, &sdi.mgr_config);
128}
129
130static int sdi_display_enable(struct omap_dss_device *dssdev)
131{
132	struct omap_dss_device *out = &sdi.output;
133	enum omap_channel channel = dssdev->dispc_channel;
134	struct omap_video_timings *t = &sdi.timings;
135	unsigned long fck;
136	struct dispc_clock_info dispc_cinfo;
137	unsigned long pck;
138	int r;
139
140	if (!out->dispc_channel_connected) {
141		DSSERR("failed to enable display: no output/manager\n");
142		return -ENODEV;
143	}
144
145	r = regulator_enable(sdi.vdds_sdi_reg);
146	if (r)
147		goto err_reg_enable;
148
149	r = dispc_runtime_get();
150	if (r)
151		goto err_get_dispc;
152
153	/* 15.5.9.1.2 */
154	t->data_pclk_edge = OMAPDSS_DRIVE_SIG_RISING_EDGE;
155	t->sync_pclk_edge = OMAPDSS_DRIVE_SIG_RISING_EDGE;
156
157	r = sdi_calc_clock_div(t->pixelclock, &fck, &dispc_cinfo);
158	if (r)
159		goto err_calc_clock_div;
160
161	sdi.mgr_config.clock_info = dispc_cinfo;
162
163	pck = fck / dispc_cinfo.lck_div / dispc_cinfo.pck_div;
164
165	if (pck != t->pixelclock) {
166		DSSWARN("Could not find exact pixel clock. Requested %d Hz, got %lu Hz\n",
167			t->pixelclock, pck);
168
169		t->pixelclock = pck;
170	}
171
172
173	dss_mgr_set_timings(channel, t);
174
175	r = dss_set_fck_rate(fck);
176	if (r)
177		goto err_set_dss_clock_div;
178
179	sdi_config_lcd_manager(dssdev);
180
181	/*
182	 * LCLK and PCLK divisors are located in shadow registers, and we
183	 * normally write them to DISPC registers when enabling the output.
184	 * However, SDI uses pck-free as source clock for its PLL, and pck-free
185	 * is affected by the divisors. And as we need the PLL before enabling
186	 * the output, we need to write the divisors early.
187	 *
188	 * It seems just writing to the DISPC register is enough, and we don't
189	 * need to care about the shadow register mechanism for pck-free. The
190	 * exact reason for this is unknown.
191	 */
192	dispc_mgr_set_clock_div(channel, &sdi.mgr_config.clock_info);
193
194	dss_sdi_init(sdi.datapairs);
195	r = dss_sdi_enable();
196	if (r)
197		goto err_sdi_enable;
198	mdelay(2);
199
200	r = dss_mgr_enable(channel);
201	if (r)
202		goto err_mgr_enable;
203
204	return 0;
205
206err_mgr_enable:
207	dss_sdi_disable();
208err_sdi_enable:
209err_set_dss_clock_div:
210err_calc_clock_div:
211	dispc_runtime_put();
212err_get_dispc:
213	regulator_disable(sdi.vdds_sdi_reg);
214err_reg_enable:
215	return r;
216}
217
218static void sdi_display_disable(struct omap_dss_device *dssdev)
219{
220	enum omap_channel channel = dssdev->dispc_channel;
221
222	dss_mgr_disable(channel);
223
224	dss_sdi_disable();
225
226	dispc_runtime_put();
227
228	regulator_disable(sdi.vdds_sdi_reg);
229}
230
231static void sdi_set_timings(struct omap_dss_device *dssdev,
232		struct omap_video_timings *timings)
233{
234	sdi.timings = *timings;
235}
236
237static void sdi_get_timings(struct omap_dss_device *dssdev,
238		struct omap_video_timings *timings)
239{
240	*timings = sdi.timings;
241}
242
243static int sdi_check_timings(struct omap_dss_device *dssdev,
244			struct omap_video_timings *timings)
245{
246	enum omap_channel channel = dssdev->dispc_channel;
247
248	if (!dispc_mgr_timings_ok(channel, timings))
249		return -EINVAL;
250
251	if (timings->pixelclock == 0)
252		return -EINVAL;
253
254	return 0;
255}
256
257static void sdi_set_datapairs(struct omap_dss_device *dssdev, int datapairs)
258{
259	sdi.datapairs = datapairs;
260}
261
262static int sdi_init_regulator(void)
263{
264	struct regulator *vdds_sdi;
265
266	if (sdi.vdds_sdi_reg)
267		return 0;
268
269	vdds_sdi = devm_regulator_get(&sdi.pdev->dev, "vdds_sdi");
270	if (IS_ERR(vdds_sdi)) {
271		if (PTR_ERR(vdds_sdi) != -EPROBE_DEFER)
272			DSSERR("can't get VDDS_SDI regulator\n");
273		return PTR_ERR(vdds_sdi);
274	}
275
276	sdi.vdds_sdi_reg = vdds_sdi;
277
278	return 0;
279}
280
281static int sdi_connect(struct omap_dss_device *dssdev,
282		struct omap_dss_device *dst)
283{
284	enum omap_channel channel = dssdev->dispc_channel;
285	int r;
286
287	r = sdi_init_regulator();
288	if (r)
289		return r;
290
291	r = dss_mgr_connect(channel, dssdev);
292	if (r)
293		return r;
294
295	r = omapdss_output_set_device(dssdev, dst);
296	if (r) {
297		DSSERR("failed to connect output to new device: %s\n",
298				dst->name);
299		dss_mgr_disconnect(channel, dssdev);
300		return r;
301	}
302
303	return 0;
304}
305
306static void sdi_disconnect(struct omap_dss_device *dssdev,
307		struct omap_dss_device *dst)
308{
309	enum omap_channel channel = dssdev->dispc_channel;
310
311	WARN_ON(dst != dssdev->dst);
312
313	if (dst != dssdev->dst)
314		return;
315
316	omapdss_output_unset_device(dssdev);
317
318	dss_mgr_disconnect(channel, dssdev);
319}
320
321static const struct omapdss_sdi_ops sdi_ops = {
322	.connect = sdi_connect,
323	.disconnect = sdi_disconnect,
324
325	.enable = sdi_display_enable,
326	.disable = sdi_display_disable,
327
328	.check_timings = sdi_check_timings,
329	.set_timings = sdi_set_timings,
330	.get_timings = sdi_get_timings,
331
332	.set_datapairs = sdi_set_datapairs,
333};
334
335static void sdi_init_output(struct platform_device *pdev)
336{
337	struct omap_dss_device *out = &sdi.output;
338
339	out->dev = &pdev->dev;
340	out->id = OMAP_DSS_OUTPUT_SDI;
341	out->output_type = OMAP_DISPLAY_TYPE_SDI;
342	out->name = "sdi.0";
343	out->dispc_channel = OMAP_DSS_CHANNEL_LCD;
344	/* We have SDI only on OMAP3, where it's on port 1 */
345	out->port_num = 1;
346	out->ops.sdi = &sdi_ops;
347	out->owner = THIS_MODULE;
348
349	omapdss_register_output(out);
350}
351
352static void sdi_uninit_output(struct platform_device *pdev)
353{
354	struct omap_dss_device *out = &sdi.output;
355
356	omapdss_unregister_output(out);
357}
358
359static int sdi_bind(struct device *dev, struct device *master, void *data)
360{
361	struct platform_device *pdev = to_platform_device(dev);
362
363	sdi.pdev = pdev;
364
365	sdi_init_output(pdev);
366
367	return 0;
368}
369
370static void sdi_unbind(struct device *dev, struct device *master, void *data)
371{
372	struct platform_device *pdev = to_platform_device(dev);
373
374	sdi_uninit_output(pdev);
375}
376
377static const struct component_ops sdi_component_ops = {
378	.bind	= sdi_bind,
379	.unbind	= sdi_unbind,
380};
381
382static int sdi_probe(struct platform_device *pdev)
383{
384	return component_add(&pdev->dev, &sdi_component_ops);
385}
386
387static int sdi_remove(struct platform_device *pdev)
388{
389	component_del(&pdev->dev, &sdi_component_ops);
390	return 0;
391}
392
393static struct platform_driver omap_sdi_driver = {
394	.probe		= sdi_probe,
395	.remove         = sdi_remove,
396	.driver         = {
397		.name   = "omapdss_sdi",
398		.suppress_bind_attrs = true,
399	},
400};
401
402int __init sdi_init_platform_driver(void)
403{
404	return platform_driver_register(&omap_sdi_driver);
405}
406
407void sdi_uninit_platform_driver(void)
408{
409	platform_driver_unregister(&omap_sdi_driver);
410}
411
412int sdi_init_port(struct platform_device *pdev, struct device_node *port)
413{
414	struct device_node *ep;
415	u32 datapairs;
416	int r;
417
418	ep = omapdss_of_get_next_endpoint(port, NULL);
419	if (!ep)
420		return 0;
421
422	r = of_property_read_u32(ep, "datapairs", &datapairs);
423	if (r) {
424		DSSERR("failed to parse datapairs\n");
425		goto err_datapairs;
426	}
427
428	sdi.datapairs = datapairs;
429
430	of_node_put(ep);
431
432	sdi.pdev = pdev;
433
434	sdi_init_output(pdev);
435
436	sdi.port_initialized = true;
437
438	return 0;
439
440err_datapairs:
441	of_node_put(ep);
442
443	return r;
444}
445
446void sdi_uninit_port(struct device_node *port)
447{
448	if (!sdi.port_initialized)
449		return;
450
451	sdi_uninit_output(sdi.pdev);
452}