xref: /openbmc/linux/drivers/gpu/drm/bridge/tc358762.c (revision 80382226)
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_crtc.h>
24 #include <drm/drm_mipi_dsi.h>
25 #include <drm/drm_of.h>
26 #include <drm/drm_panel.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 	bool pre_enabled;
78 	int error;
79 };
80 
81 static int tc358762_clear_error(struct tc358762 *ctx)
82 {
83 	int ret = ctx->error;
84 
85 	ctx->error = 0;
86 	return ret;
87 }
88 
89 static void tc358762_write(struct tc358762 *ctx, u16 addr, u32 val)
90 {
91 	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
92 	ssize_t ret;
93 	u8 data[6];
94 
95 	if (ctx->error)
96 		return;
97 
98 	data[0] = addr;
99 	data[1] = addr >> 8;
100 	data[2] = val;
101 	data[3] = val >> 8;
102 	data[4] = val >> 16;
103 	data[5] = val >> 24;
104 
105 	ret = mipi_dsi_generic_write(dsi, data, sizeof(data));
106 	if (ret < 0)
107 		ctx->error = ret;
108 }
109 
110 static inline struct tc358762 *bridge_to_tc358762(struct drm_bridge *bridge)
111 {
112 	return container_of(bridge, struct tc358762, bridge);
113 }
114 
115 static int tc358762_init(struct tc358762 *ctx)
116 {
117 	tc358762_write(ctx, DSI_LANEENABLE,
118 		       LANEENABLE_L0EN | LANEENABLE_CLEN);
119 	tc358762_write(ctx, PPI_D0S_CLRSIPOCOUNT, 5);
120 	tc358762_write(ctx, PPI_D1S_CLRSIPOCOUNT, 5);
121 	tc358762_write(ctx, PPI_D0S_ATMR, 0);
122 	tc358762_write(ctx, PPI_D1S_ATMR, 0);
123 	tc358762_write(ctx, PPI_LPTXTIMECNT, LPX_PERIOD);
124 
125 	tc358762_write(ctx, SPICMR, 0x00);
126 	tc358762_write(ctx, LCDCTRL, LCDCTRL_VSDELAY(1) | LCDCTRL_RGB888 |
127 				     LCDCTRL_UNK6 | LCDCTRL_VTGEN);
128 	tc358762_write(ctx, SYSCTRL, 0x040f);
129 	msleep(100);
130 
131 	tc358762_write(ctx, PPI_STARTPPI, PPI_START_FUNCTION);
132 	tc358762_write(ctx, DSI_STARTDSI, DSI_RX_START);
133 
134 	msleep(100);
135 
136 	return tc358762_clear_error(ctx);
137 }
138 
139 static void tc358762_post_disable(struct drm_bridge *bridge, struct drm_bridge_state *state)
140 {
141 	struct tc358762 *ctx = bridge_to_tc358762(bridge);
142 	int ret;
143 
144 	/*
145 	 * The post_disable hook might be called multiple times.
146 	 * We want to avoid regulator imbalance below.
147 	 */
148 	if (!ctx->pre_enabled)
149 		return;
150 
151 	ctx->pre_enabled = false;
152 
153 	if (ctx->reset_gpio)
154 		gpiod_set_value_cansleep(ctx->reset_gpio, 0);
155 
156 	ret = regulator_disable(ctx->regulator);
157 	if (ret < 0)
158 		dev_err(ctx->dev, "error disabling regulators (%d)\n", ret);
159 }
160 
161 static void tc358762_pre_enable(struct drm_bridge *bridge, struct drm_bridge_state *state)
162 {
163 	struct tc358762 *ctx = bridge_to_tc358762(bridge);
164 	int ret;
165 
166 	ret = regulator_enable(ctx->regulator);
167 	if (ret < 0)
168 		dev_err(ctx->dev, "error enabling regulators (%d)\n", ret);
169 
170 	if (ctx->reset_gpio) {
171 		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
172 		usleep_range(5000, 10000);
173 	}
174 
175 	ctx->pre_enabled = true;
176 }
177 
178 static void tc358762_enable(struct drm_bridge *bridge, struct drm_bridge_state *state)
179 {
180 	struct tc358762 *ctx = bridge_to_tc358762(bridge);
181 	int ret;
182 
183 	ret = tc358762_init(ctx);
184 	if (ret < 0)
185 		dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
186 }
187 
188 static int tc358762_attach(struct drm_bridge *bridge,
189 			   enum drm_bridge_attach_flags flags)
190 {
191 	struct tc358762 *ctx = bridge_to_tc358762(bridge);
192 
193 	return drm_bridge_attach(bridge->encoder, ctx->panel_bridge,
194 				 bridge, flags);
195 }
196 
197 static const struct drm_bridge_funcs tc358762_bridge_funcs = {
198 	.atomic_post_disable = tc358762_post_disable,
199 	.atomic_pre_enable = tc358762_pre_enable,
200 	.atomic_enable = tc358762_enable,
201 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
202 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
203 	.atomic_reset = drm_atomic_helper_bridge_reset,
204 	.attach = tc358762_attach,
205 };
206 
207 static int tc358762_parse_dt(struct tc358762 *ctx)
208 {
209 	struct drm_bridge *panel_bridge;
210 	struct device *dev = ctx->dev;
211 
212 	panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
213 	if (IS_ERR(panel_bridge))
214 		return PTR_ERR(panel_bridge);
215 
216 	ctx->panel_bridge = panel_bridge;
217 
218 	/* Reset GPIO is optional */
219 	ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
220 	if (IS_ERR(ctx->reset_gpio))
221 		return PTR_ERR(ctx->reset_gpio);
222 
223 	return 0;
224 }
225 
226 static int tc358762_configure_regulators(struct tc358762 *ctx)
227 {
228 	ctx->regulator = devm_regulator_get(ctx->dev, "vddc");
229 	if (IS_ERR(ctx->regulator))
230 		return PTR_ERR(ctx->regulator);
231 
232 	return 0;
233 }
234 
235 static int tc358762_probe(struct mipi_dsi_device *dsi)
236 {
237 	struct device *dev = &dsi->dev;
238 	struct tc358762 *ctx;
239 	int ret;
240 
241 	ctx = devm_kzalloc(dev, sizeof(struct tc358762), GFP_KERNEL);
242 	if (!ctx)
243 		return -ENOMEM;
244 
245 	mipi_dsi_set_drvdata(dsi, ctx);
246 
247 	ctx->dev = dev;
248 	ctx->pre_enabled = false;
249 
250 	/* TODO: Find out how to get dual-lane mode working */
251 	dsi->lanes = 1;
252 	dsi->format = MIPI_DSI_FMT_RGB888;
253 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
254 			  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_VIDEO_HSE;
255 
256 	ret = tc358762_parse_dt(ctx);
257 	if (ret < 0)
258 		return ret;
259 
260 	ret = tc358762_configure_regulators(ctx);
261 	if (ret < 0)
262 		return ret;
263 
264 	ctx->bridge.funcs = &tc358762_bridge_funcs;
265 	ctx->bridge.type = DRM_MODE_CONNECTOR_DPI;
266 	ctx->bridge.of_node = dev->of_node;
267 	ctx->bridge.pre_enable_prev_first = true;
268 
269 	drm_bridge_add(&ctx->bridge);
270 
271 	ret = mipi_dsi_attach(dsi);
272 	if (ret < 0) {
273 		drm_bridge_remove(&ctx->bridge);
274 		dev_err(dev, "failed to attach dsi\n");
275 	}
276 
277 	return ret;
278 }
279 
280 static void tc358762_remove(struct mipi_dsi_device *dsi)
281 {
282 	struct tc358762 *ctx = mipi_dsi_get_drvdata(dsi);
283 
284 	mipi_dsi_detach(dsi);
285 	drm_bridge_remove(&ctx->bridge);
286 }
287 
288 static const struct of_device_id tc358762_of_match[] = {
289 	{ .compatible = "toshiba,tc358762" },
290 	{ }
291 };
292 MODULE_DEVICE_TABLE(of, tc358762_of_match);
293 
294 static struct mipi_dsi_driver tc358762_driver = {
295 	.probe = tc358762_probe,
296 	.remove = tc358762_remove,
297 	.driver = {
298 		.name = "tc358762",
299 		.of_match_table = tc358762_of_match,
300 	},
301 };
302 module_mipi_dsi_driver(tc358762_driver);
303 
304 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
305 MODULE_DESCRIPTION("MIPI-DSI based Driver for TC358762 DSI/DPI Bridge");
306 MODULE_LICENSE("GPL v2");
307