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1/*
2 * Copyright (C) 2016 Broadcom Limited
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 as published by
6 * the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16
17/**
18 * DOC: VC4 DPI module
19 *
20 * The VC4 DPI hardware supports MIPI DPI type 4 and Nokia ViSSI
21 * signals. On BCM2835, these can be routed out to GPIO0-27 with the
22 * ALT2 function.
23 */
24
25#include <drm/drm_atomic_helper.h>
26#include <drm/drm_bridge.h>
27#include <drm/drm_crtc_helper.h>
28#include <drm/drm_edid.h>
29#include <drm/drm_of.h>
30#include <drm/drm_panel.h>
31#include <linux/clk.h>
32#include <linux/component.h>
33#include <linux/of_graph.h>
34#include <linux/of_platform.h>
35#include "vc4_drv.h"
36#include "vc4_regs.h"
37
38#define DPI_C 0x00
39# define DPI_OUTPUT_ENABLE_MODE BIT(16)
40
41/* The order field takes the incoming 24 bit RGB from the pixel valve
42 * and shuffles the 3 channels.
43 */
44# define DPI_ORDER_MASK VC4_MASK(15, 14)
45# define DPI_ORDER_SHIFT 14
46# define DPI_ORDER_RGB 0
47# define DPI_ORDER_BGR 1
48# define DPI_ORDER_GRB 2
49# define DPI_ORDER_BRG 3
50
51/* The format field takes the ORDER-shuffled pixel valve data and
52 * formats it onto the output lines.
53 */
54# define DPI_FORMAT_MASK VC4_MASK(13, 11)
55# define DPI_FORMAT_SHIFT 11
56/* This define is named in the hardware, but actually just outputs 0. */
57# define DPI_FORMAT_9BIT_666_RGB 0
58/* Outputs 00000000rrrrrggggggbbbbb */
59# define DPI_FORMAT_16BIT_565_RGB_1 1
60/* Outputs 000rrrrr00gggggg000bbbbb */
61# define DPI_FORMAT_16BIT_565_RGB_2 2
62/* Outputs 00rrrrr000gggggg00bbbbb0 */
63# define DPI_FORMAT_16BIT_565_RGB_3 3
64/* Outputs 000000rrrrrrggggggbbbbbb */
65# define DPI_FORMAT_18BIT_666_RGB_1 4
66/* Outputs 00rrrrrr00gggggg00bbbbbb */
67# define DPI_FORMAT_18BIT_666_RGB_2 5
68/* Outputs rrrrrrrrggggggggbbbbbbbb */
69# define DPI_FORMAT_24BIT_888_RGB 6
70
71/* Reverses the polarity of the corresponding signal */
72# define DPI_PIXEL_CLK_INVERT BIT(10)
73# define DPI_HSYNC_INVERT BIT(9)
74# define DPI_VSYNC_INVERT BIT(8)
75# define DPI_OUTPUT_ENABLE_INVERT BIT(7)
76
77/* Outputs the signal the falling clock edge instead of rising. */
78# define DPI_HSYNC_NEGATE BIT(6)
79# define DPI_VSYNC_NEGATE BIT(5)
80# define DPI_OUTPUT_ENABLE_NEGATE BIT(4)
81
82/* Disables the signal */
83# define DPI_HSYNC_DISABLE BIT(3)
84# define DPI_VSYNC_DISABLE BIT(2)
85# define DPI_OUTPUT_ENABLE_DISABLE BIT(1)
86
87/* Power gate to the device, full reset at 0 -> 1 transition */
88# define DPI_ENABLE BIT(0)
89
90/* All other registers besides DPI_C return the ID */
91#define DPI_ID 0x04
92# define DPI_ID_VALUE 0x00647069
93
94/* General DPI hardware state. */
95struct vc4_dpi {
96 struct platform_device *pdev;
97
98 struct drm_encoder *encoder;
99
100 void __iomem *regs;
101
102 struct clk *pixel_clock;
103 struct clk *core_clock;
104};
105
106#define DPI_READ(offset) readl(dpi->regs + (offset))
107#define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
108
109/* VC4 DPI encoder KMS struct */
110struct vc4_dpi_encoder {
111 struct vc4_encoder base;
112 struct vc4_dpi *dpi;
113};
114
115static inline struct vc4_dpi_encoder *
116to_vc4_dpi_encoder(struct drm_encoder *encoder)
117{
118 return container_of(encoder, struct vc4_dpi_encoder, base.base);
119}
120
121#define DPI_REG(reg) { reg, #reg }
122static const struct {
123 u32 reg;
124 const char *name;
125} dpi_regs[] = {
126 DPI_REG(DPI_C),
127 DPI_REG(DPI_ID),
128};
129
130#ifdef CONFIG_DEBUG_FS
131int vc4_dpi_debugfs_regs(struct seq_file *m, void *unused)
132{
133 struct drm_info_node *node = (struct drm_info_node *)m->private;
134 struct drm_device *dev = node->minor->dev;
135 struct vc4_dev *vc4 = to_vc4_dev(dev);
136 struct vc4_dpi *dpi = vc4->dpi;
137 int i;
138
139 if (!dpi)
140 return 0;
141
142 for (i = 0; i < ARRAY_SIZE(dpi_regs); i++) {
143 seq_printf(m, "%s (0x%04x): 0x%08x\n",
144 dpi_regs[i].name, dpi_regs[i].reg,
145 DPI_READ(dpi_regs[i].reg));
146 }
147
148 return 0;
149}
150#endif
151
152static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
153 .destroy = drm_encoder_cleanup,
154};
155
156static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
157{
158 struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
159 struct vc4_dpi *dpi = vc4_encoder->dpi;
160
161 clk_disable_unprepare(dpi->pixel_clock);
162}
163
164static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
165{
166 struct drm_device *dev = encoder->dev;
167 struct drm_display_mode *mode = &encoder->crtc->mode;
168 struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
169 struct vc4_dpi *dpi = vc4_encoder->dpi;
170 struct drm_connector_list_iter conn_iter;
171 struct drm_connector *connector = NULL, *connector_scan;
172 u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
173 int ret;
174
175 /* Look up the connector attached to DPI so we can get the
176 * bus_format. Ideally the bridge would tell us the
177 * bus_format we want, but it doesn't yet, so assume that it's
178 * uniform throughout the bridge chain.
179 */
180 drm_connector_list_iter_begin(dev, &conn_iter);
181 drm_for_each_connector_iter(connector_scan, &conn_iter) {
182 if (connector_scan->encoder == encoder) {
183 connector = connector_scan;
184 break;
185 }
186 }
187 drm_connector_list_iter_end(&conn_iter);
188
189 if (connector && connector->display_info.num_bus_formats) {
190 u32 bus_format = connector->display_info.bus_formats[0];
191
192 switch (bus_format) {
193 case MEDIA_BUS_FMT_RGB888_1X24:
194 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
195 DPI_FORMAT);
196 break;
197 case MEDIA_BUS_FMT_BGR888_1X24:
198 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
199 DPI_FORMAT);
200 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
201 break;
202 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
203 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
204 DPI_FORMAT);
205 break;
206 case MEDIA_BUS_FMT_RGB666_1X18:
207 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
208 DPI_FORMAT);
209 break;
210 case MEDIA_BUS_FMT_RGB565_1X16:
211 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
212 DPI_FORMAT);
213 break;
214 default:
215 DRM_ERROR("Unknown media bus format %d\n", bus_format);
216 break;
217 }
218 } else {
219 /* Default to 24bit if no connector found. */
220 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
221 }
222
223 if (mode->flags & DRM_MODE_FLAG_NHSYNC)
224 dpi_c |= DPI_HSYNC_INVERT;
225 else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
226 dpi_c |= DPI_HSYNC_DISABLE;
227
228 if (mode->flags & DRM_MODE_FLAG_NVSYNC)
229 dpi_c |= DPI_VSYNC_INVERT;
230 else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
231 dpi_c |= DPI_VSYNC_DISABLE;
232
233 DPI_WRITE(DPI_C, dpi_c);
234
235 ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
236 if (ret)
237 DRM_ERROR("Failed to set clock rate: %d\n", ret);
238
239 ret = clk_prepare_enable(dpi->pixel_clock);
240 if (ret)
241 DRM_ERROR("Failed to set clock rate: %d\n", ret);
242}
243
244static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
245 const struct drm_display_mode *mode)
246{
247 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
248 return MODE_NO_INTERLACE;
249
250 return MODE_OK;
251}
252
253static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
254 .disable = vc4_dpi_encoder_disable,
255 .enable = vc4_dpi_encoder_enable,
256 .mode_valid = vc4_dpi_encoder_mode_valid,
257};
258
259static const struct of_device_id vc4_dpi_dt_match[] = {
260 { .compatible = "brcm,bcm2835-dpi", .data = NULL },
261 {}
262};
263
264/* Sets up the next link in the display chain, whether it's a panel or
265 * a bridge.
266 */
267static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
268{
269 struct device *dev = &dpi->pdev->dev;
270 struct drm_panel *panel;
271 struct drm_bridge *bridge;
272 int ret;
273
274 ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
275 &panel, &bridge);
276 if (ret) {
277 /* If nothing was connected in the DT, that's not an
278 * error.
279 */
280 if (ret == -ENODEV)
281 return 0;
282 else
283 return ret;
284 }
285
286 if (panel)
287 bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DPI);
288
289 return drm_bridge_attach(dpi->encoder, bridge, NULL);
290}
291
292static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
293{
294 struct platform_device *pdev = to_platform_device(dev);
295 struct drm_device *drm = dev_get_drvdata(master);
296 struct vc4_dev *vc4 = to_vc4_dev(drm);
297 struct vc4_dpi *dpi;
298 struct vc4_dpi_encoder *vc4_dpi_encoder;
299 int ret;
300
301 dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
302 if (!dpi)
303 return -ENOMEM;
304
305 vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
306 GFP_KERNEL);
307 if (!vc4_dpi_encoder)
308 return -ENOMEM;
309 vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
310 vc4_dpi_encoder->dpi = dpi;
311 dpi->encoder = &vc4_dpi_encoder->base.base;
312
313 dpi->pdev = pdev;
314 dpi->regs = vc4_ioremap_regs(pdev, 0);
315 if (IS_ERR(dpi->regs))
316 return PTR_ERR(dpi->regs);
317
318 if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
319 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
320 DPI_READ(DPI_ID), DPI_ID_VALUE);
321 return -ENODEV;
322 }
323
324 dpi->core_clock = devm_clk_get(dev, "core");
325 if (IS_ERR(dpi->core_clock)) {
326 ret = PTR_ERR(dpi->core_clock);
327 if (ret != -EPROBE_DEFER)
328 DRM_ERROR("Failed to get core clock: %d\n", ret);
329 return ret;
330 }
331 dpi->pixel_clock = devm_clk_get(dev, "pixel");
332 if (IS_ERR(dpi->pixel_clock)) {
333 ret = PTR_ERR(dpi->pixel_clock);
334 if (ret != -EPROBE_DEFER)
335 DRM_ERROR("Failed to get pixel clock: %d\n", ret);
336 return ret;
337 }
338
339 ret = clk_prepare_enable(dpi->core_clock);
340 if (ret)
341 DRM_ERROR("Failed to turn on core clock: %d\n", ret);
342
343 drm_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
344 DRM_MODE_ENCODER_DPI, NULL);
345 drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
346
347 ret = vc4_dpi_init_bridge(dpi);
348 if (ret)
349 goto err_destroy_encoder;
350
351 dev_set_drvdata(dev, dpi);
352
353 vc4->dpi = dpi;
354
355 return 0;
356
357err_destroy_encoder:
358 drm_encoder_cleanup(dpi->encoder);
359 clk_disable_unprepare(dpi->core_clock);
360 return ret;
361}
362
363static void vc4_dpi_unbind(struct device *dev, struct device *master,
364 void *data)
365{
366 struct drm_device *drm = dev_get_drvdata(master);
367 struct vc4_dev *vc4 = to_vc4_dev(drm);
368 struct vc4_dpi *dpi = dev_get_drvdata(dev);
369
370 drm_of_panel_bridge_remove(dev->of_node, 0, 0);
371
372 drm_encoder_cleanup(dpi->encoder);
373
374 clk_disable_unprepare(dpi->core_clock);
375
376 vc4->dpi = NULL;
377}
378
379static const struct component_ops vc4_dpi_ops = {
380 .bind = vc4_dpi_bind,
381 .unbind = vc4_dpi_unbind,
382};
383
384static int vc4_dpi_dev_probe(struct platform_device *pdev)
385{
386 return component_add(&pdev->dev, &vc4_dpi_ops);
387}
388
389static int vc4_dpi_dev_remove(struct platform_device *pdev)
390{
391 component_del(&pdev->dev, &vc4_dpi_ops);
392 return 0;
393}
394
395struct platform_driver vc4_dpi_driver = {
396 .probe = vc4_dpi_dev_probe,
397 .remove = vc4_dpi_dev_remove,
398 .driver = {
399 .name = "vc4_dpi",
400 .of_match_table = vc4_dpi_dt_match,
401 },
402};