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  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
 24struct 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
 42struct 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
 50static 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
 63static 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
 74static 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
113static 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
130static 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
142static enum drm_mode_status
143sdi_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
163static 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
190static 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
199static 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
252err_mgr_enable:
253	dss_sdi_disable(sdi->dss);
254err_sdi_enable:
255err_set_dss_clock_div:
256err_calc_clock_div:
257	dispc_runtime_put(sdi->dss->dispc);
258err_get_dispc:
259	regulator_disable(sdi->vdds_sdi_reg);
260}
261
262static 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
275static 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
284static 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
293static void sdi_bridge_cleanup(struct sdi_device *sdi)
294{
295	drm_bridge_remove(&sdi->bridge);
296}
297
298/* -----------------------------------------------------------------------------
299 * Initialisation and Cleanup
300 */
301
302static 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
330static 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
338int 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
383err_free:
384	kfree(sdi);
385
386	return r;
387}
388
389void 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}