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