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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/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
 23struct 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
 41struct 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
 49static 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
 62static 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
 73static 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
112static 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
129static 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
141static enum drm_mode_status
142sdi_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
162static 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
189static 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
198static 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
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			       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
276static 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
285static 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
294static void sdi_bridge_cleanup(struct sdi_device *sdi)
295{
296	drm_bridge_remove(&sdi->bridge);
297}
298
299/* -----------------------------------------------------------------------------
300 * Initialisation and Cleanup
301 */
302
303static 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
332static 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
340int 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
385err_free:
386	kfree(sdi);
387
388	return r;
389}
390
391void 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}