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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2016 Broadcom Limited
4 */
5
6/**
7 * DOC: VC4 DPI module
8 *
9 * The VC4 DPI hardware supports MIPI DPI type 4 and Nokia ViSSI
10 * signals. On BCM2835, these can be routed out to GPIO0-27 with the
11 * ALT2 function.
12 */
13
14#include <drm/drm_atomic_helper.h>
15#include <drm/drm_bridge.h>
16#include <drm/drm_edid.h>
17#include <drm/drm_of.h>
18#include <drm/drm_panel.h>
19#include <drm/drm_probe_helper.h>
20#include <linux/clk.h>
21#include <linux/component.h>
22#include <linux/of_graph.h>
23#include <linux/of_platform.h>
24#include "vc4_drv.h"
25#include "vc4_regs.h"
26
27#define DPI_C 0x00
28# define DPI_OUTPUT_ENABLE_MODE BIT(16)
29
30/* The order field takes the incoming 24 bit RGB from the pixel valve
31 * and shuffles the 3 channels.
32 */
33# define DPI_ORDER_MASK VC4_MASK(15, 14)
34# define DPI_ORDER_SHIFT 14
35# define DPI_ORDER_RGB 0
36# define DPI_ORDER_BGR 1
37# define DPI_ORDER_GRB 2
38# define DPI_ORDER_BRG 3
39
40/* The format field takes the ORDER-shuffled pixel valve data and
41 * formats it onto the output lines.
42 */
43# define DPI_FORMAT_MASK VC4_MASK(13, 11)
44# define DPI_FORMAT_SHIFT 11
45/* This define is named in the hardware, but actually just outputs 0. */
46# define DPI_FORMAT_9BIT_666_RGB 0
47/* Outputs 00000000rrrrrggggggbbbbb */
48# define DPI_FORMAT_16BIT_565_RGB_1 1
49/* Outputs 000rrrrr00gggggg000bbbbb */
50# define DPI_FORMAT_16BIT_565_RGB_2 2
51/* Outputs 00rrrrr000gggggg00bbbbb0 */
52# define DPI_FORMAT_16BIT_565_RGB_3 3
53/* Outputs 000000rrrrrrggggggbbbbbb */
54# define DPI_FORMAT_18BIT_666_RGB_1 4
55/* Outputs 00rrrrrr00gggggg00bbbbbb */
56# define DPI_FORMAT_18BIT_666_RGB_2 5
57/* Outputs rrrrrrrrggggggggbbbbbbbb */
58# define DPI_FORMAT_24BIT_888_RGB 6
59
60/* Reverses the polarity of the corresponding signal */
61# define DPI_PIXEL_CLK_INVERT BIT(10)
62# define DPI_HSYNC_INVERT BIT(9)
63# define DPI_VSYNC_INVERT BIT(8)
64# define DPI_OUTPUT_ENABLE_INVERT BIT(7)
65
66/* Outputs the signal the falling clock edge instead of rising. */
67# define DPI_HSYNC_NEGATE BIT(6)
68# define DPI_VSYNC_NEGATE BIT(5)
69# define DPI_OUTPUT_ENABLE_NEGATE BIT(4)
70
71/* Disables the signal */
72# define DPI_HSYNC_DISABLE BIT(3)
73# define DPI_VSYNC_DISABLE BIT(2)
74# define DPI_OUTPUT_ENABLE_DISABLE BIT(1)
75
76/* Power gate to the device, full reset at 0 -> 1 transition */
77# define DPI_ENABLE BIT(0)
78
79/* All other registers besides DPI_C return the ID */
80#define DPI_ID 0x04
81# define DPI_ID_VALUE 0x00647069
82
83/* General DPI hardware state. */
84struct vc4_dpi {
85 struct platform_device *pdev;
86
87 struct drm_encoder *encoder;
88
89 void __iomem *regs;
90
91 struct clk *pixel_clock;
92 struct clk *core_clock;
93
94 struct debugfs_regset32 regset;
95};
96
97#define DPI_READ(offset) readl(dpi->regs + (offset))
98#define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
99
100/* VC4 DPI encoder KMS struct */
101struct vc4_dpi_encoder {
102 struct vc4_encoder base;
103 struct vc4_dpi *dpi;
104};
105
106static inline struct vc4_dpi_encoder *
107to_vc4_dpi_encoder(struct drm_encoder *encoder)
108{
109 return container_of(encoder, struct vc4_dpi_encoder, base.base);
110}
111
112static const struct debugfs_reg32 dpi_regs[] = {
113 VC4_REG32(DPI_C),
114 VC4_REG32(DPI_ID),
115};
116
117static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
118 .destroy = drm_encoder_cleanup,
119};
120
121static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
122{
123 struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
124 struct vc4_dpi *dpi = vc4_encoder->dpi;
125
126 clk_disable_unprepare(dpi->pixel_clock);
127}
128
129static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
130{
131 struct drm_device *dev = encoder->dev;
132 struct drm_display_mode *mode = &encoder->crtc->mode;
133 struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
134 struct vc4_dpi *dpi = vc4_encoder->dpi;
135 struct drm_connector_list_iter conn_iter;
136 struct drm_connector *connector = NULL, *connector_scan;
137 u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
138 int ret;
139
140 /* Look up the connector attached to DPI so we can get the
141 * bus_format. Ideally the bridge would tell us the
142 * bus_format we want, but it doesn't yet, so assume that it's
143 * uniform throughout the bridge chain.
144 */
145 drm_connector_list_iter_begin(dev, &conn_iter);
146 drm_for_each_connector_iter(connector_scan, &conn_iter) {
147 if (connector_scan->encoder == encoder) {
148 connector = connector_scan;
149 break;
150 }
151 }
152 drm_connector_list_iter_end(&conn_iter);
153
154 if (connector && connector->display_info.num_bus_formats) {
155 u32 bus_format = connector->display_info.bus_formats[0];
156
157 switch (bus_format) {
158 case MEDIA_BUS_FMT_RGB888_1X24:
159 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
160 DPI_FORMAT);
161 break;
162 case MEDIA_BUS_FMT_BGR888_1X24:
163 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
164 DPI_FORMAT);
165 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
166 break;
167 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
168 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
169 DPI_FORMAT);
170 break;
171 case MEDIA_BUS_FMT_RGB666_1X18:
172 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
173 DPI_FORMAT);
174 break;
175 case MEDIA_BUS_FMT_RGB565_1X16:
176 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
177 DPI_FORMAT);
178 break;
179 default:
180 DRM_ERROR("Unknown media bus format %d\n", bus_format);
181 break;
182 }
183 } else {
184 /* Default to 24bit if no connector found. */
185 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
186 }
187
188 if (mode->flags & DRM_MODE_FLAG_NHSYNC)
189 dpi_c |= DPI_HSYNC_INVERT;
190 else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
191 dpi_c |= DPI_HSYNC_DISABLE;
192
193 if (mode->flags & DRM_MODE_FLAG_NVSYNC)
194 dpi_c |= DPI_VSYNC_INVERT;
195 else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
196 dpi_c |= DPI_VSYNC_DISABLE;
197
198 DPI_WRITE(DPI_C, dpi_c);
199
200 ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
201 if (ret)
202 DRM_ERROR("Failed to set clock rate: %d\n", ret);
203
204 ret = clk_prepare_enable(dpi->pixel_clock);
205 if (ret)
206 DRM_ERROR("Failed to set clock rate: %d\n", ret);
207}
208
209static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
210 const struct drm_display_mode *mode)
211{
212 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
213 return MODE_NO_INTERLACE;
214
215 return MODE_OK;
216}
217
218static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
219 .disable = vc4_dpi_encoder_disable,
220 .enable = vc4_dpi_encoder_enable,
221 .mode_valid = vc4_dpi_encoder_mode_valid,
222};
223
224static const struct of_device_id vc4_dpi_dt_match[] = {
225 { .compatible = "brcm,bcm2835-dpi", .data = NULL },
226 {}
227};
228
229/* Sets up the next link in the display chain, whether it's a panel or
230 * a bridge.
231 */
232static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
233{
234 struct device *dev = &dpi->pdev->dev;
235 struct drm_panel *panel;
236 struct drm_bridge *bridge;
237 int ret;
238
239 ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
240 &panel, &bridge);
241 if (ret) {
242 /* If nothing was connected in the DT, that's not an
243 * error.
244 */
245 if (ret == -ENODEV)
246 return 0;
247 else
248 return ret;
249 }
250
251 if (panel)
252 bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DPI);
253
254 return drm_bridge_attach(dpi->encoder, bridge, NULL);
255}
256
257static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
258{
259 struct platform_device *pdev = to_platform_device(dev);
260 struct drm_device *drm = dev_get_drvdata(master);
261 struct vc4_dev *vc4 = to_vc4_dev(drm);
262 struct vc4_dpi *dpi;
263 struct vc4_dpi_encoder *vc4_dpi_encoder;
264 int ret;
265
266 dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
267 if (!dpi)
268 return -ENOMEM;
269
270 vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
271 GFP_KERNEL);
272 if (!vc4_dpi_encoder)
273 return -ENOMEM;
274 vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
275 vc4_dpi_encoder->dpi = dpi;
276 dpi->encoder = &vc4_dpi_encoder->base.base;
277
278 dpi->pdev = pdev;
279 dpi->regs = vc4_ioremap_regs(pdev, 0);
280 if (IS_ERR(dpi->regs))
281 return PTR_ERR(dpi->regs);
282 dpi->regset.base = dpi->regs;
283 dpi->regset.regs = dpi_regs;
284 dpi->regset.nregs = ARRAY_SIZE(dpi_regs);
285
286 if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
287 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
288 DPI_READ(DPI_ID), DPI_ID_VALUE);
289 return -ENODEV;
290 }
291
292 dpi->core_clock = devm_clk_get(dev, "core");
293 if (IS_ERR(dpi->core_clock)) {
294 ret = PTR_ERR(dpi->core_clock);
295 if (ret != -EPROBE_DEFER)
296 DRM_ERROR("Failed to get core clock: %d\n", ret);
297 return ret;
298 }
299 dpi->pixel_clock = devm_clk_get(dev, "pixel");
300 if (IS_ERR(dpi->pixel_clock)) {
301 ret = PTR_ERR(dpi->pixel_clock);
302 if (ret != -EPROBE_DEFER)
303 DRM_ERROR("Failed to get pixel clock: %d\n", ret);
304 return ret;
305 }
306
307 ret = clk_prepare_enable(dpi->core_clock);
308 if (ret)
309 DRM_ERROR("Failed to turn on core clock: %d\n", ret);
310
311 drm_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
312 DRM_MODE_ENCODER_DPI, NULL);
313 drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
314
315 ret = vc4_dpi_init_bridge(dpi);
316 if (ret)
317 goto err_destroy_encoder;
318
319 dev_set_drvdata(dev, dpi);
320
321 vc4->dpi = dpi;
322
323 vc4_debugfs_add_regset32(drm, "dpi_regs", &dpi->regset);
324
325 return 0;
326
327err_destroy_encoder:
328 drm_encoder_cleanup(dpi->encoder);
329 clk_disable_unprepare(dpi->core_clock);
330 return ret;
331}
332
333static void vc4_dpi_unbind(struct device *dev, struct device *master,
334 void *data)
335{
336 struct drm_device *drm = dev_get_drvdata(master);
337 struct vc4_dev *vc4 = to_vc4_dev(drm);
338 struct vc4_dpi *dpi = dev_get_drvdata(dev);
339
340 drm_of_panel_bridge_remove(dev->of_node, 0, 0);
341
342 drm_encoder_cleanup(dpi->encoder);
343
344 clk_disable_unprepare(dpi->core_clock);
345
346 vc4->dpi = NULL;
347}
348
349static const struct component_ops vc4_dpi_ops = {
350 .bind = vc4_dpi_bind,
351 .unbind = vc4_dpi_unbind,
352};
353
354static int vc4_dpi_dev_probe(struct platform_device *pdev)
355{
356 return component_add(&pdev->dev, &vc4_dpi_ops);
357}
358
359static int vc4_dpi_dev_remove(struct platform_device *pdev)
360{
361 component_del(&pdev->dev, &vc4_dpi_ops);
362 return 0;
363}
364
365struct platform_driver vc4_dpi_driver = {
366 .probe = vc4_dpi_dev_probe,
367 .remove = vc4_dpi_dev_remove,
368 .driver = {
369 .name = "vc4_dpi",
370 .of_match_table = vc4_dpi_dt_match,
371 },
372};