xref: /openbmc/linux/drivers/gpu/drm/bridge/tc358762.c (revision d2f4a190)
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/mod_devicetable.h>
15 #include <linux/module.h>
16 #include <linux/of_graph.h>
17 #include <linux/regulator/consumer.h>
18 
19 #include <video/mipi_display.h>
20 
21 #include <drm/drm_atomic_helper.h>
22 #include <drm/drm_crtc.h>
23 #include <drm/drm_mipi_dsi.h>
24 #include <drm/drm_of.h>
25 #include <drm/drm_panel.h>
26 #include <drm/drm_print.h>
27 #include <drm/drm_probe_helper.h>
28 
29 /* PPI layer registers */
30 #define PPI_STARTPPI		0x0104 /* START control bit */
31 #define PPI_LPTXTIMECNT		0x0114 /* LPTX timing signal */
32 #define PPI_D0S_ATMR		0x0144
33 #define PPI_D1S_ATMR		0x0148
34 #define PPI_D0S_CLRSIPOCOUNT	0x0164 /* Assertion timer for Lane 0 */
35 #define PPI_D1S_CLRSIPOCOUNT	0x0168 /* Assertion timer for Lane 1 */
36 #define PPI_START_FUNCTION	1
37 
38 /* DSI layer registers */
39 #define DSI_STARTDSI		0x0204 /* START control bit of DSI-TX */
40 #define DSI_LANEENABLE		0x0210 /* Enables each lane */
41 #define DSI_RX_START		1
42 
43 /* LCDC/DPI Host Registers */
44 #define LCDCTRL			0x0420
45 
46 /* SPI Master Registers */
47 #define SPICMR			0x0450
48 #define SPITCR			0x0454
49 
50 /* System Controller Registers */
51 #define SYSCTRL			0x0464
52 
53 /* System registers */
54 #define LPX_PERIOD		3
55 
56 /* Lane enable PPI and DSI register bits */
57 #define LANEENABLE_CLEN		BIT(0)
58 #define LANEENABLE_L0EN		BIT(1)
59 #define LANEENABLE_L1EN		BIT(2)
60 
61 struct tc358762 {
62 	struct device *dev;
63 	struct drm_bridge bridge;
64 	struct regulator *regulator;
65 	struct drm_bridge *panel_bridge;
66 	bool pre_enabled;
67 	int error;
68 };
69 
70 static int tc358762_clear_error(struct tc358762 *ctx)
71 {
72 	int ret = ctx->error;
73 
74 	ctx->error = 0;
75 	return ret;
76 }
77 
78 static void tc358762_write(struct tc358762 *ctx, u16 addr, u32 val)
79 {
80 	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
81 	ssize_t ret;
82 	u8 data[6];
83 
84 	if (ctx->error)
85 		return;
86 
87 	data[0] = addr;
88 	data[1] = addr >> 8;
89 	data[2] = val;
90 	data[3] = val >> 8;
91 	data[4] = val >> 16;
92 	data[5] = val >> 24;
93 
94 	ret = mipi_dsi_generic_write(dsi, data, sizeof(data));
95 	if (ret < 0)
96 		ctx->error = ret;
97 }
98 
99 static inline struct tc358762 *bridge_to_tc358762(struct drm_bridge *bridge)
100 {
101 	return container_of(bridge, struct tc358762, bridge);
102 }
103 
104 static int tc358762_init(struct tc358762 *ctx)
105 {
106 	tc358762_write(ctx, DSI_LANEENABLE,
107 		       LANEENABLE_L0EN | LANEENABLE_CLEN);
108 	tc358762_write(ctx, PPI_D0S_CLRSIPOCOUNT, 5);
109 	tc358762_write(ctx, PPI_D1S_CLRSIPOCOUNT, 5);
110 	tc358762_write(ctx, PPI_D0S_ATMR, 0);
111 	tc358762_write(ctx, PPI_D1S_ATMR, 0);
112 	tc358762_write(ctx, PPI_LPTXTIMECNT, LPX_PERIOD);
113 
114 	tc358762_write(ctx, SPICMR, 0x00);
115 	tc358762_write(ctx, LCDCTRL, 0x00100150);
116 	tc358762_write(ctx, SYSCTRL, 0x040f);
117 	msleep(100);
118 
119 	tc358762_write(ctx, PPI_STARTPPI, PPI_START_FUNCTION);
120 	tc358762_write(ctx, DSI_STARTDSI, DSI_RX_START);
121 
122 	msleep(100);
123 
124 	return tc358762_clear_error(ctx);
125 }
126 
127 static void tc358762_post_disable(struct drm_bridge *bridge)
128 {
129 	struct tc358762 *ctx = bridge_to_tc358762(bridge);
130 	int ret;
131 
132 	/*
133 	 * The post_disable hook might be called multiple times.
134 	 * We want to avoid regulator imbalance below.
135 	 */
136 	if (!ctx->pre_enabled)
137 		return;
138 
139 	ctx->pre_enabled = false;
140 
141 	ret = regulator_disable(ctx->regulator);
142 	if (ret < 0)
143 		dev_err(ctx->dev, "error disabling regulators (%d)\n", ret);
144 }
145 
146 static void tc358762_pre_enable(struct drm_bridge *bridge)
147 {
148 	struct tc358762 *ctx = bridge_to_tc358762(bridge);
149 	int ret;
150 
151 	ret = regulator_enable(ctx->regulator);
152 	if (ret < 0)
153 		dev_err(ctx->dev, "error enabling regulators (%d)\n", ret);
154 
155 	ret = tc358762_init(ctx);
156 	if (ret < 0)
157 		dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
158 
159 	ctx->pre_enabled = true;
160 }
161 
162 static int tc358762_attach(struct drm_bridge *bridge,
163 			   enum drm_bridge_attach_flags flags)
164 {
165 	struct tc358762 *ctx = bridge_to_tc358762(bridge);
166 
167 	return drm_bridge_attach(bridge->encoder, ctx->panel_bridge,
168 				 bridge, flags);
169 }
170 
171 static const struct drm_bridge_funcs tc358762_bridge_funcs = {
172 	.post_disable = tc358762_post_disable,
173 	.pre_enable = tc358762_pre_enable,
174 	.attach = tc358762_attach,
175 };
176 
177 static int tc358762_parse_dt(struct tc358762 *ctx)
178 {
179 	struct drm_bridge *panel_bridge;
180 	struct device *dev = ctx->dev;
181 
182 	panel_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
183 	if (IS_ERR(panel_bridge))
184 		return PTR_ERR(panel_bridge);
185 
186 	ctx->panel_bridge = panel_bridge;
187 
188 	return 0;
189 }
190 
191 static int tc358762_configure_regulators(struct tc358762 *ctx)
192 {
193 	ctx->regulator = devm_regulator_get(ctx->dev, "vddc");
194 	if (IS_ERR(ctx->regulator))
195 		return PTR_ERR(ctx->regulator);
196 
197 	return 0;
198 }
199 
200 static int tc358762_probe(struct mipi_dsi_device *dsi)
201 {
202 	struct device *dev = &dsi->dev;
203 	struct tc358762 *ctx;
204 	int ret;
205 
206 	ctx = devm_kzalloc(dev, sizeof(struct tc358762), GFP_KERNEL);
207 	if (!ctx)
208 		return -ENOMEM;
209 
210 	mipi_dsi_set_drvdata(dsi, ctx);
211 
212 	ctx->dev = dev;
213 	ctx->pre_enabled = false;
214 
215 	/* TODO: Find out how to get dual-lane mode working */
216 	dsi->lanes = 1;
217 	dsi->format = MIPI_DSI_FMT_RGB888;
218 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
219 			  MIPI_DSI_MODE_LPM;
220 
221 	ret = tc358762_parse_dt(ctx);
222 	if (ret < 0)
223 		return ret;
224 
225 	ret = tc358762_configure_regulators(ctx);
226 	if (ret < 0)
227 		return ret;
228 
229 	ctx->bridge.funcs = &tc358762_bridge_funcs;
230 	ctx->bridge.type = DRM_MODE_CONNECTOR_DPI;
231 	ctx->bridge.of_node = dev->of_node;
232 	ctx->bridge.pre_enable_prev_first = true;
233 
234 	drm_bridge_add(&ctx->bridge);
235 
236 	ret = mipi_dsi_attach(dsi);
237 	if (ret < 0) {
238 		drm_bridge_remove(&ctx->bridge);
239 		dev_err(dev, "failed to attach dsi\n");
240 	}
241 
242 	return ret;
243 }
244 
245 static void tc358762_remove(struct mipi_dsi_device *dsi)
246 {
247 	struct tc358762 *ctx = mipi_dsi_get_drvdata(dsi);
248 
249 	mipi_dsi_detach(dsi);
250 	drm_bridge_remove(&ctx->bridge);
251 }
252 
253 static const struct of_device_id tc358762_of_match[] = {
254 	{ .compatible = "toshiba,tc358762" },
255 	{ }
256 };
257 MODULE_DEVICE_TABLE(of, tc358762_of_match);
258 
259 static struct mipi_dsi_driver tc358762_driver = {
260 	.probe = tc358762_probe,
261 	.remove = tc358762_remove,
262 	.driver = {
263 		.name = "tc358762",
264 		.of_match_table = tc358762_of_match,
265 	},
266 };
267 module_mipi_dsi_driver(tc358762_driver);
268 
269 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
270 MODULE_DESCRIPTION("MIPI-DSI based Driver for TC358762 DSI/DPI Bridge");
271 MODULE_LICENSE("GPL v2");
272