1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020 Marek Vasut <marex@denx.de>
4 *
5 * Based on tc358764.c by
6 * Andrzej Hajda <a.hajda@samsung.com>
7 * Maciej Purski <m.purski@samsung.com>
8 *
9 * Based on rpi_touchscreen.c by
10 * Eric Anholt <eric@anholt.net>
11 */
12
13 #include <linux/delay.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/module.h>
17 #include <linux/of_graph.h>
18 #include <linux/regulator/consumer.h>
19
20 #include <video/mipi_display.h>
21
22 #include <drm/drm_atomic_helper.h>
23 #include <drm/drm_bridge.h>
24 #include <drm/drm_crtc.h>
25 #include <drm/drm_mipi_dsi.h>
26 #include <drm/drm_of.h>
27 #include <drm/drm_print.h>
28 #include <drm/drm_probe_helper.h>
29
30 /* PPI layer registers */
31 #define PPI_STARTPPI 0x0104 /* START control bit */
32 #define PPI_LPTXTIMECNT 0x0114 /* LPTX timing signal */
33 #define PPI_D0S_ATMR 0x0144
34 #define PPI_D1S_ATMR 0x0148
35 #define PPI_D0S_CLRSIPOCOUNT 0x0164 /* Assertion timer for Lane 0 */
36 #define PPI_D1S_CLRSIPOCOUNT 0x0168 /* Assertion timer for Lane 1 */
37 #define PPI_START_FUNCTION 1
38
39 /* DSI layer registers */
40 #define DSI_STARTDSI 0x0204 /* START control bit of DSI-TX */
41 #define DSI_LANEENABLE 0x0210 /* Enables each lane */
42 #define DSI_RX_START 1
43
44 /* LCDC/DPI Host Registers, based on guesswork that this matches TC358764 */
45 #define LCDCTRL 0x0420 /* Video Path Control */
46 #define LCDCTRL_MSF BIT(0) /* Magic square in RGB666 */
47 #define LCDCTRL_VTGEN BIT(4)/* Use chip clock for timing */
48 #define LCDCTRL_UNK6 BIT(6) /* Unknown */
49 #define LCDCTRL_EVTMODE BIT(5) /* Event mode */
50 #define LCDCTRL_RGB888 BIT(8) /* RGB888 mode */
51 #define LCDCTRL_HSPOL BIT(17) /* Polarity of HSYNC signal */
52 #define LCDCTRL_DEPOL BIT(18) /* Polarity of DE signal */
53 #define LCDCTRL_VSPOL BIT(19) /* Polarity of VSYNC signal */
54 #define LCDCTRL_VSDELAY(v) (((v) & 0xfff) << 20) /* VSYNC delay */
55
56 /* SPI Master Registers */
57 #define SPICMR 0x0450
58 #define SPITCR 0x0454
59
60 /* System Controller Registers */
61 #define SYSCTRL 0x0464
62
63 /* System registers */
64 #define LPX_PERIOD 3
65
66 /* Lane enable PPI and DSI register bits */
67 #define LANEENABLE_CLEN BIT(0)
68 #define LANEENABLE_L0EN BIT(1)
69 #define LANEENABLE_L1EN BIT(2)
70
71 struct tc358762 {
72 struct device *dev;
73 struct drm_bridge bridge;
74 struct regulator *regulator;
75 struct drm_bridge *panel_bridge;
76 struct gpio_desc *reset_gpio;
77 struct drm_display_mode mode;
78 bool pre_enabled;
79 int error;
80 };
81
tc358762_clear_error(struct tc358762 * ctx)82 static int tc358762_clear_error(struct tc358762 *ctx)
83 {
84 int ret = ctx->error;
85
86 ctx->error = 0;
87 return ret;
88 }
89
tc358762_write(struct tc358762 * ctx,u16 addr,u32 val)90 static void tc358762_write(struct tc358762 *ctx, u16 addr, u32 val)
91 {
92 struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
93 ssize_t ret;
94 u8 data[6];
95
96 if (ctx->error)
97 return;
98
99 data[0] = addr;
100 data[1] = addr >> 8;
101 data[2] = val;
102 data[3] = val >> 8;
103 data[4] = val >> 16;
104 data[5] = val >> 24;
105
106 ret = mipi_dsi_generic_write(dsi, data, sizeof(data));
107 if (ret < 0)
108 ctx->error = ret;
109 }
110
bridge_to_tc358762(struct drm_bridge * bridge)111 static inline struct tc358762 *bridge_to_tc358762(struct drm_bridge *bridge)
112 {
113 return container_of(bridge, struct tc358762, bridge);
114 }
115
tc358762_init(struct tc358762 * ctx)116 static int tc358762_init(struct tc358762 *ctx)
117 {
118 u32 lcdctrl;
119
120 tc358762_write(ctx, DSI_LANEENABLE,
121 LANEENABLE_L0EN | LANEENABLE_CLEN);
122 tc358762_write(ctx, PPI_D0S_CLRSIPOCOUNT, 5);
123 tc358762_write(ctx, PPI_D1S_CLRSIPOCOUNT, 5);
124 tc358762_write(ctx, PPI_D0S_ATMR, 0);
125 tc358762_write(ctx, PPI_D1S_ATMR, 0);
126 tc358762_write(ctx, PPI_LPTXTIMECNT, LPX_PERIOD);
127
128 tc358762_write(ctx, SPICMR, 0x00);
129
130 lcdctrl = LCDCTRL_VSDELAY(1) | LCDCTRL_RGB888 |
131 LCDCTRL_UNK6 | LCDCTRL_VTGEN;
132
133 if (ctx->mode.flags & DRM_MODE_FLAG_NHSYNC)
134 lcdctrl |= LCDCTRL_HSPOL;
135
136 if (ctx->mode.flags & DRM_MODE_FLAG_NVSYNC)
137 lcdctrl |= LCDCTRL_VSPOL;
138
139 tc358762_write(ctx, LCDCTRL, lcdctrl);
140
141 tc358762_write(ctx, SYSCTRL, 0x040f);
142 msleep(100);
143
144 tc358762_write(ctx, PPI_STARTPPI, PPI_START_FUNCTION);
145 tc358762_write(ctx, DSI_STARTDSI, DSI_RX_START);
146
147 msleep(100);
148
149 return tc358762_clear_error(ctx);
150 }
151
tc358762_post_disable(struct drm_bridge * bridge,struct drm_atomic_state * state)152 static void tc358762_post_disable(struct drm_bridge *bridge,
153 struct drm_atomic_state *state)
154 {
155 struct tc358762 *ctx = bridge_to_tc358762(bridge);
156 int ret;
157
158 /*
159 * The post_disable hook might be called multiple times.
160 * We want to avoid regulator imbalance below.
161 */
162 if (!ctx->pre_enabled)
163 return;
164
165 ctx->pre_enabled = false;
166
167 if (ctx->reset_gpio)
168 gpiod_set_value_cansleep(ctx->reset_gpio, 0);
169
170 ret = regulator_disable(ctx->regulator);
171 if (ret < 0)
172 dev_err(ctx->dev, "error disabling regulators (%d)\n", ret);
173 }
174
tc358762_pre_enable(struct drm_bridge * bridge,struct drm_atomic_state * state)175 static void tc358762_pre_enable(struct drm_bridge *bridge,
176 struct drm_atomic_state *state)
177 {
178 struct tc358762 *ctx = bridge_to_tc358762(bridge);
179 int ret;
180
181 ret = regulator_enable(ctx->regulator);
182 if (ret < 0)
183 dev_err(ctx->dev, "error enabling regulators (%d)\n", ret);
184
185 if (ctx->reset_gpio) {
186 gpiod_set_value_cansleep(ctx->reset_gpio, 1);
187 usleep_range(5000, 10000);
188 }
189
190 ctx->pre_enabled = true;
191 }
192
tc358762_enable(struct drm_bridge * bridge,struct drm_atomic_state * state)193 static void tc358762_enable(struct drm_bridge *bridge,
194 struct drm_atomic_state *state)
195 {
196 struct tc358762 *ctx = bridge_to_tc358762(bridge);
197 int ret;
198
199 ret = tc358762_init(ctx);
200 if (ret < 0)
201 dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
202 }
203
tc358762_attach(struct drm_bridge * bridge,enum drm_bridge_attach_flags flags)204 static int tc358762_attach(struct drm_bridge *bridge,
205 enum drm_bridge_attach_flags flags)
206 {
207 struct tc358762 *ctx = bridge_to_tc358762(bridge);
208
209 return drm_bridge_attach(bridge->encoder, ctx->panel_bridge,
210 bridge, flags);
211 }
212
tc358762_bridge_mode_set(struct drm_bridge * bridge,const struct drm_display_mode * mode,const struct drm_display_mode * adj)213 static void tc358762_bridge_mode_set(struct drm_bridge *bridge,
214 const struct drm_display_mode *mode,
215 const struct drm_display_mode *adj)
216 {
217 struct tc358762 *ctx = bridge_to_tc358762(bridge);
218
219 drm_mode_copy(&ctx->mode, mode);
220 }
221
222 static const struct drm_bridge_funcs tc358762_bridge_funcs = {
223 .atomic_post_disable = tc358762_post_disable,
224 .atomic_pre_enable = tc358762_pre_enable,
225 .atomic_enable = tc358762_enable,
226 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
227 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
228 .atomic_reset = drm_atomic_helper_bridge_reset,
229 .attach = tc358762_attach,
230 .mode_set = tc358762_bridge_mode_set,
231 };
232
tc358762_parse_dt(struct tc358762 * ctx)233 static int tc358762_parse_dt(struct tc358762 *ctx)
234 {
235 struct drm_bridge *panel_bridge;
236 struct device *dev = ctx->dev;
237
238 panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
239 if (IS_ERR(panel_bridge))
240 return PTR_ERR(panel_bridge);
241
242 ctx->panel_bridge = panel_bridge;
243
244 /* Reset GPIO is optional */
245 ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
246 if (IS_ERR(ctx->reset_gpio))
247 return PTR_ERR(ctx->reset_gpio);
248
249 return 0;
250 }
251
tc358762_configure_regulators(struct tc358762 * ctx)252 static int tc358762_configure_regulators(struct tc358762 *ctx)
253 {
254 ctx->regulator = devm_regulator_get(ctx->dev, "vddc");
255 if (IS_ERR(ctx->regulator))
256 return PTR_ERR(ctx->regulator);
257
258 return 0;
259 }
260
tc358762_probe(struct mipi_dsi_device * dsi)261 static int tc358762_probe(struct mipi_dsi_device *dsi)
262 {
263 struct device *dev = &dsi->dev;
264 struct tc358762 *ctx;
265 int ret;
266
267 ctx = devm_kzalloc(dev, sizeof(struct tc358762), GFP_KERNEL);
268 if (!ctx)
269 return -ENOMEM;
270
271 mipi_dsi_set_drvdata(dsi, ctx);
272
273 ctx->dev = dev;
274 ctx->pre_enabled = false;
275
276 /* TODO: Find out how to get dual-lane mode working */
277 dsi->lanes = 1;
278 dsi->format = MIPI_DSI_FMT_RGB888;
279 dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
280 MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_VIDEO_HSE;
281
282 ret = tc358762_parse_dt(ctx);
283 if (ret < 0)
284 return ret;
285
286 ret = tc358762_configure_regulators(ctx);
287 if (ret < 0)
288 return ret;
289
290 ctx->bridge.funcs = &tc358762_bridge_funcs;
291 ctx->bridge.type = DRM_MODE_CONNECTOR_DPI;
292 ctx->bridge.of_node = dev->of_node;
293 ctx->bridge.pre_enable_prev_first = true;
294
295 drm_bridge_add(&ctx->bridge);
296
297 ret = mipi_dsi_attach(dsi);
298 if (ret < 0) {
299 drm_bridge_remove(&ctx->bridge);
300 dev_err(dev, "failed to attach dsi\n");
301 }
302
303 return ret;
304 }
305
tc358762_remove(struct mipi_dsi_device * dsi)306 static void tc358762_remove(struct mipi_dsi_device *dsi)
307 {
308 struct tc358762 *ctx = mipi_dsi_get_drvdata(dsi);
309
310 mipi_dsi_detach(dsi);
311 drm_bridge_remove(&ctx->bridge);
312 }
313
314 static const struct of_device_id tc358762_of_match[] = {
315 { .compatible = "toshiba,tc358762" },
316 { }
317 };
318 MODULE_DEVICE_TABLE(of, tc358762_of_match);
319
320 static struct mipi_dsi_driver tc358762_driver = {
321 .probe = tc358762_probe,
322 .remove = tc358762_remove,
323 .driver = {
324 .name = "tc358762",
325 .of_match_table = tc358762_of_match,
326 },
327 };
328 module_mipi_dsi_driver(tc358762_driver);
329
330 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
331 MODULE_DESCRIPTION("MIPI-DSI based Driver for TC358762 DSI/DPI Bridge");
332 MODULE_LICENSE("GPL v2");
333