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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_drv.h>
17#include <drm/drm_edid.h>
18#include <drm/drm_of.h>
19#include <drm/drm_panel.h>
20#include <drm/drm_probe_helper.h>
21#include <drm/drm_simple_kms_helper.h>
22#include <linux/clk.h>
23#include <linux/component.h>
24#include <linux/media-bus-format.h>
25#include <linux/of_graph.h>
26#include <linux/of_platform.h>
27#include "vc4_drv.h"
28#include "vc4_regs.h"
29
30#define DPI_C 0x00
31# define DPI_OUTPUT_ENABLE_MODE BIT(16)
32
33/* The order field takes the incoming 24 bit RGB from the pixel valve
34 * and shuffles the 3 channels.
35 */
36# define DPI_ORDER_MASK VC4_MASK(15, 14)
37# define DPI_ORDER_SHIFT 14
38# define DPI_ORDER_RGB 0
39# define DPI_ORDER_BGR 1
40# define DPI_ORDER_GRB 2
41# define DPI_ORDER_BRG 3
42
43/* The format field takes the ORDER-shuffled pixel valve data and
44 * formats it onto the output lines.
45 */
46# define DPI_FORMAT_MASK VC4_MASK(13, 11)
47# define DPI_FORMAT_SHIFT 11
48/* This define is named in the hardware, but actually just outputs 0. */
49# define DPI_FORMAT_9BIT_666_RGB 0
50/* Outputs 00000000rrrrrggggggbbbbb */
51# define DPI_FORMAT_16BIT_565_RGB_1 1
52/* Outputs 000rrrrr00gggggg000bbbbb */
53# define DPI_FORMAT_16BIT_565_RGB_2 2
54/* Outputs 00rrrrr000gggggg00bbbbb0 */
55# define DPI_FORMAT_16BIT_565_RGB_3 3
56/* Outputs 000000rrrrrrggggggbbbbbb */
57# define DPI_FORMAT_18BIT_666_RGB_1 4
58/* Outputs 00rrrrrr00gggggg00bbbbbb */
59# define DPI_FORMAT_18BIT_666_RGB_2 5
60/* Outputs rrrrrrrrggggggggbbbbbbbb */
61# define DPI_FORMAT_24BIT_888_RGB 6
62
63/* Reverses the polarity of the corresponding signal */
64# define DPI_PIXEL_CLK_INVERT BIT(10)
65# define DPI_HSYNC_INVERT BIT(9)
66# define DPI_VSYNC_INVERT BIT(8)
67# define DPI_OUTPUT_ENABLE_INVERT BIT(7)
68
69/* Outputs the signal the falling clock edge instead of rising. */
70# define DPI_HSYNC_NEGATE BIT(6)
71# define DPI_VSYNC_NEGATE BIT(5)
72# define DPI_OUTPUT_ENABLE_NEGATE BIT(4)
73
74/* Disables the signal */
75# define DPI_HSYNC_DISABLE BIT(3)
76# define DPI_VSYNC_DISABLE BIT(2)
77# define DPI_OUTPUT_ENABLE_DISABLE BIT(1)
78
79/* Power gate to the device, full reset at 0 -> 1 transition */
80# define DPI_ENABLE BIT(0)
81
82/* All other registers besides DPI_C return the ID */
83#define DPI_ID 0x04
84# define DPI_ID_VALUE 0x00647069
85
86/* General DPI hardware state. */
87struct vc4_dpi {
88 struct vc4_encoder encoder;
89
90 struct platform_device *pdev;
91
92 void __iomem *regs;
93
94 struct clk *pixel_clock;
95 struct clk *core_clock;
96
97 struct debugfs_regset32 regset;
98};
99
100static inline struct vc4_dpi *
101to_vc4_dpi(struct drm_encoder *encoder)
102{
103 return container_of(encoder, struct vc4_dpi, encoder.base);
104}
105
106#define DPI_READ(offset) readl(dpi->regs + (offset))
107#define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
108
109static const struct debugfs_reg32 dpi_regs[] = {
110 VC4_REG32(DPI_C),
111 VC4_REG32(DPI_ID),
112};
113
114static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
115{
116 struct drm_device *dev = encoder->dev;
117 struct vc4_dpi *dpi = to_vc4_dpi(encoder);
118 int idx;
119
120 if (!drm_dev_enter(dev, &idx))
121 return;
122
123 clk_disable_unprepare(dpi->pixel_clock);
124
125 drm_dev_exit(idx);
126}
127
128static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
129{
130 struct drm_device *dev = encoder->dev;
131 struct drm_display_mode *mode = &encoder->crtc->mode;
132 struct vc4_dpi *dpi = to_vc4_dpi(encoder);
133 struct drm_connector_list_iter conn_iter;
134 struct drm_connector *connector = NULL, *connector_scan;
135 u32 dpi_c = DPI_ENABLE;
136 int idx;
137 int ret;
138
139 /* Look up the connector attached to DPI so we can get the
140 * bus_format. Ideally the bridge would tell us the
141 * bus_format we want, but it doesn't yet, so assume that it's
142 * uniform throughout the bridge chain.
143 */
144 drm_connector_list_iter_begin(dev, &conn_iter);
145 drm_for_each_connector_iter(connector_scan, &conn_iter) {
146 if (connector_scan->encoder == encoder) {
147 connector = connector_scan;
148 break;
149 }
150 }
151 drm_connector_list_iter_end(&conn_iter);
152
153 /* Default to 24bit if no connector or format found. */
154 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);
155
156 if (connector) {
157 if (connector->display_info.num_bus_formats) {
158 u32 bus_format = connector->display_info.bus_formats[0];
159
160 dpi_c &= ~DPI_FORMAT_MASK;
161
162 switch (bus_format) {
163 case MEDIA_BUS_FMT_RGB888_1X24:
164 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
165 DPI_FORMAT);
166 break;
167 case MEDIA_BUS_FMT_BGR888_1X24:
168 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
169 DPI_FORMAT);
170 dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR,
171 DPI_ORDER);
172 break;
173 case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
174 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
175 DPI_FORMAT);
176 break;
177 case MEDIA_BUS_FMT_RGB666_1X18:
178 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
179 DPI_FORMAT);
180 break;
181 case MEDIA_BUS_FMT_RGB565_1X16:
182 dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
183 DPI_FORMAT);
184 break;
185 default:
186 DRM_ERROR("Unknown media bus format %d\n",
187 bus_format);
188 break;
189 }
190 }
191
192 if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
193 dpi_c |= DPI_PIXEL_CLK_INVERT;
194
195 if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
196 dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
197 }
198
199 if (mode->flags & DRM_MODE_FLAG_CSYNC) {
200 if (mode->flags & DRM_MODE_FLAG_NCSYNC)
201 dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
202 } else {
203 dpi_c |= DPI_OUTPUT_ENABLE_MODE;
204
205 if (mode->flags & DRM_MODE_FLAG_NHSYNC)
206 dpi_c |= DPI_HSYNC_INVERT;
207 else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
208 dpi_c |= DPI_HSYNC_DISABLE;
209
210 if (mode->flags & DRM_MODE_FLAG_NVSYNC)
211 dpi_c |= DPI_VSYNC_INVERT;
212 else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
213 dpi_c |= DPI_VSYNC_DISABLE;
214 }
215
216 if (!drm_dev_enter(dev, &idx))
217 return;
218
219 DPI_WRITE(DPI_C, dpi_c);
220
221 ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
222 if (ret)
223 DRM_ERROR("Failed to set clock rate: %d\n", ret);
224
225 ret = clk_prepare_enable(dpi->pixel_clock);
226 if (ret)
227 DRM_ERROR("Failed to set clock rate: %d\n", ret);
228
229 drm_dev_exit(idx);
230}
231
232static enum drm_mode_status vc4_dpi_encoder_mode_valid(struct drm_encoder *encoder,
233 const struct drm_display_mode *mode)
234{
235 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
236 return MODE_NO_INTERLACE;
237
238 return MODE_OK;
239}
240
241static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
242 .disable = vc4_dpi_encoder_disable,
243 .enable = vc4_dpi_encoder_enable,
244 .mode_valid = vc4_dpi_encoder_mode_valid,
245};
246
247static int vc4_dpi_late_register(struct drm_encoder *encoder)
248{
249 struct drm_device *drm = encoder->dev;
250 struct vc4_dpi *dpi = to_vc4_dpi(encoder);
251 int ret;
252
253 ret = vc4_debugfs_add_regset32(drm->primary, "dpi_regs", &dpi->regset);
254 if (ret)
255 return ret;
256
257 return 0;
258}
259
260static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
261 .late_register = vc4_dpi_late_register,
262};
263
264static const struct of_device_id vc4_dpi_dt_match[] = {
265 { .compatible = "brcm,bcm2835-dpi", .data = NULL },
266 {}
267};
268
269/* Sets up the next link in the display chain, whether it's a panel or
270 * a bridge.
271 */
272static int vc4_dpi_init_bridge(struct vc4_dpi *dpi)
273{
274 struct drm_device *drm = dpi->encoder.base.dev;
275 struct device *dev = &dpi->pdev->dev;
276 struct drm_bridge *bridge;
277
278 bridge = drmm_of_get_bridge(drm, dev->of_node, 0, 0);
279 if (IS_ERR(bridge)) {
280 /* If nothing was connected in the DT, that's not an
281 * error.
282 */
283 if (PTR_ERR(bridge) == -ENODEV)
284 return 0;
285 else
286 return PTR_ERR(bridge);
287 }
288
289 return drm_bridge_attach(&dpi->encoder.base, bridge, NULL, 0);
290}
291
292static void vc4_dpi_disable_clock(void *ptr)
293{
294 struct vc4_dpi *dpi = ptr;
295
296 clk_disable_unprepare(dpi->core_clock);
297}
298
299static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
300{
301 struct platform_device *pdev = to_platform_device(dev);
302 struct drm_device *drm = dev_get_drvdata(master);
303 struct vc4_dpi *dpi;
304 int ret;
305
306 dpi = drmm_kzalloc(drm, sizeof(*dpi), GFP_KERNEL);
307 if (!dpi)
308 return -ENOMEM;
309
310 dpi->encoder.type = VC4_ENCODER_TYPE_DPI;
311 dpi->pdev = pdev;
312 dpi->regs = vc4_ioremap_regs(pdev, 0);
313 if (IS_ERR(dpi->regs))
314 return PTR_ERR(dpi->regs);
315 dpi->regset.base = dpi->regs;
316 dpi->regset.regs = dpi_regs;
317 dpi->regset.nregs = ARRAY_SIZE(dpi_regs);
318
319 if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
320 dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
321 DPI_READ(DPI_ID), DPI_ID_VALUE);
322 return -ENODEV;
323 }
324
325 dpi->core_clock = devm_clk_get(dev, "core");
326 if (IS_ERR(dpi->core_clock)) {
327 ret = PTR_ERR(dpi->core_clock);
328 if (ret != -EPROBE_DEFER)
329 DRM_ERROR("Failed to get core clock: %d\n", ret);
330 return ret;
331 }
332
333 dpi->pixel_clock = devm_clk_get(dev, "pixel");
334 if (IS_ERR(dpi->pixel_clock)) {
335 ret = PTR_ERR(dpi->pixel_clock);
336 if (ret != -EPROBE_DEFER)
337 DRM_ERROR("Failed to get pixel clock: %d\n", ret);
338 return ret;
339 }
340
341 ret = clk_prepare_enable(dpi->core_clock);
342 if (ret) {
343 DRM_ERROR("Failed to turn on core clock: %d\n", ret);
344 return ret;
345 }
346
347 ret = devm_add_action_or_reset(dev, vc4_dpi_disable_clock, dpi);
348 if (ret)
349 return ret;
350
351 ret = drmm_encoder_init(drm, &dpi->encoder.base,
352 &vc4_dpi_encoder_funcs,
353 DRM_MODE_ENCODER_DPI,
354 NULL);
355 if (ret)
356 return ret;
357
358 drm_encoder_helper_add(&dpi->encoder.base, &vc4_dpi_encoder_helper_funcs);
359
360 ret = vc4_dpi_init_bridge(dpi);
361 if (ret)
362 return ret;
363
364 dev_set_drvdata(dev, dpi);
365
366 return 0;
367}
368
369static const struct component_ops vc4_dpi_ops = {
370 .bind = vc4_dpi_bind,
371};
372
373static int vc4_dpi_dev_probe(struct platform_device *pdev)
374{
375 return component_add(&pdev->dev, &vc4_dpi_ops);
376}
377
378static int vc4_dpi_dev_remove(struct platform_device *pdev)
379{
380 component_del(&pdev->dev, &vc4_dpi_ops);
381 return 0;
382}
383
384struct platform_driver vc4_dpi_driver = {
385 .probe = vc4_dpi_dev_probe,
386 .remove = vc4_dpi_dev_remove,
387 .driver = {
388 .name = "vc4_dpi",
389 .of_match_table = vc4_dpi_dt_match,
390 },
391};