1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Panel driver for the Samsung LMS397KF04 480x800 DPI RGB panel.
4 * According to the data sheet the display controller is called DB7430.
5 * Found in the Samsung Galaxy Beam GT-I8350 mobile phone.
6 * Linus Walleij <linus.walleij@linaro.org>
7 */
8 #include <drm/drm_mipi_dbi.h>
9 #include <drm/drm_modes.h>
10 #include <drm/drm_panel.h>
11
12 #include <linux/delay.h>
13 #include <linux/gpio/consumer.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/media-bus-format.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/regulator/consumer.h>
20 #include <linux/spi/spi.h>
21
22 #include <video/mipi_display.h>
23
24 #define DB7430_ACCESS_PROT_OFF 0xb0
25 #define DB7430_UNKNOWN_B4 0xb4
26 #define DB7430_USER_SELECT 0xb5
27 #define DB7430_UNKNOWN_B7 0xb7
28 #define DB7430_UNKNOWN_B8 0xb8
29 #define DB7430_PANEL_DRIVING 0xc0
30 #define DB7430_SOURCE_CONTROL 0xc1
31 #define DB7430_GATE_INTERFACE 0xc4
32 #define DB7430_DISPLAY_H_TIMING 0xc5
33 #define DB7430_RGB_SYNC_OPTION 0xc6
34 #define DB7430_GAMMA_SET_RED 0xc8
35 #define DB7430_GAMMA_SET_GREEN 0xc9
36 #define DB7430_GAMMA_SET_BLUE 0xca
37 #define DB7430_BIAS_CURRENT_CTRL 0xd1
38 #define DB7430_DDV_CTRL 0xd2
39 #define DB7430_GAMMA_CTRL_REF 0xd3
40 #define DB7430_UNKNOWN_D4 0xd4
41 #define DB7430_DCDC_CTRL 0xd5
42 #define DB7430_VCL_CTRL 0xd6
43 #define DB7430_UNKNOWN_F8 0xf8
44 #define DB7430_UNKNOWN_FC 0xfc
45
46 #define DATA_MASK 0x100
47
48 /**
49 * struct db7430 - state container for a panel controlled by the DB7430
50 * controller
51 */
52 struct db7430 {
53 /** @dev: the container device */
54 struct device *dev;
55 /** @dbi: the DBI bus abstraction handle */
56 struct mipi_dbi dbi;
57 /** @panel: the DRM panel instance for this device */
58 struct drm_panel panel;
59 /** @width: the width of this panel in mm */
60 u32 width;
61 /** @height: the height of this panel in mm */
62 u32 height;
63 /** @reset: reset GPIO line */
64 struct gpio_desc *reset;
65 /** @regulators: VCCIO and VIO supply regulators */
66 struct regulator_bulk_data regulators[2];
67 };
68
69 static const struct drm_display_mode db7430_480_800_mode = {
70 /*
71 * 31 ns period min (htotal*vtotal*vrefresh)/1000
72 * gives a Vrefresh of ~71 Hz.
73 */
74 .clock = 32258,
75 .hdisplay = 480,
76 .hsync_start = 480 + 10,
77 .hsync_end = 480 + 10 + 4,
78 .htotal = 480 + 10 + 4 + 40,
79 .vdisplay = 800,
80 .vsync_start = 800 + 6,
81 .vsync_end = 800 + 6 + 1,
82 .vtotal = 800 + 6 + 1 + 7,
83 .width_mm = 53,
84 .height_mm = 87,
85 .flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
86 };
87
to_db7430(struct drm_panel * panel)88 static inline struct db7430 *to_db7430(struct drm_panel *panel)
89 {
90 return container_of(panel, struct db7430, panel);
91 }
92
db7430_power_on(struct db7430 * db)93 static int db7430_power_on(struct db7430 *db)
94 {
95 struct mipi_dbi *dbi = &db->dbi;
96 int ret;
97
98 /* Power up */
99 ret = regulator_bulk_enable(ARRAY_SIZE(db->regulators),
100 db->regulators);
101 if (ret) {
102 dev_err(db->dev, "failed to enable regulators: %d\n", ret);
103 return ret;
104 }
105 msleep(50);
106
107 /* Assert reset >=1 ms */
108 gpiod_set_value_cansleep(db->reset, 1);
109 usleep_range(1000, 5000);
110 /* De-assert reset */
111 gpiod_set_value_cansleep(db->reset, 0);
112 /* Wait >= 10 ms */
113 msleep(10);
114 dev_dbg(db->dev, "de-asserted RESET\n");
115
116 /*
117 * This is set to 0x0a (RGB/BGR order + horizontal flip) in order
118 * to make the display behave normally. If this is not set the displays
119 * normal output behaviour is horizontally flipped and BGR ordered. Do
120 * it twice because the first message doesn't always "take".
121 */
122 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, 0x0a);
123 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, 0x0a);
124 mipi_dbi_command(dbi, DB7430_ACCESS_PROT_OFF, 0x00);
125 mipi_dbi_command(dbi, DB7430_PANEL_DRIVING, 0x28, 0x08);
126 mipi_dbi_command(dbi, DB7430_SOURCE_CONTROL,
127 0x01, 0x30, 0x15, 0x05, 0x22);
128 mipi_dbi_command(dbi, DB7430_GATE_INTERFACE,
129 0x10, 0x01, 0x00);
130 mipi_dbi_command(dbi, DB7430_DISPLAY_H_TIMING,
131 0x06, 0x55, 0x03, 0x07, 0x0b,
132 0x33, 0x00, 0x01, 0x03);
133 /*
134 * 0x00 in datasheet 0x01 in vendor code 0x00, it seems 0x01 means
135 * DE active high and 0x00 means DE active low.
136 */
137 mipi_dbi_command(dbi, DB7430_RGB_SYNC_OPTION, 0x01);
138 mipi_dbi_command(dbi, DB7430_GAMMA_SET_RED,
139 /* R positive gamma */ 0x00,
140 0x0A, 0x31, 0x3B, 0x4E, 0x58, 0x59, 0x5B, 0x58, 0x5E, 0x62,
141 0x60, 0x61, 0x5E, 0x62, 0x55, 0x55, 0x7F, 0x08,
142 /* R negative gamma */ 0x00,
143 0x0A, 0x31, 0x3B, 0x4E, 0x58, 0x59, 0x5B, 0x58, 0x5E, 0x62,
144 0x60, 0x61, 0x5E, 0x62, 0x55, 0x55, 0x7F, 0x08);
145 mipi_dbi_command(dbi, DB7430_GAMMA_SET_GREEN,
146 /* G positive gamma */ 0x00,
147 0x25, 0x15, 0x28, 0x3D, 0x4A, 0x48, 0x4C, 0x4A, 0x52, 0x59,
148 0x59, 0x5B, 0x56, 0x60, 0x5D, 0x55, 0x7F, 0x0A,
149 /* G negative gamma */ 0x00,
150 0x25, 0x15, 0x28, 0x3D, 0x4A, 0x48, 0x4C, 0x4A, 0x52, 0x59,
151 0x59, 0x5B, 0x56, 0x60, 0x5D, 0x55, 0x7F, 0x0A);
152 mipi_dbi_command(dbi, DB7430_GAMMA_SET_BLUE,
153 /* B positive gamma */ 0x00,
154 0x48, 0x10, 0x1F, 0x2F, 0x35, 0x38, 0x3D, 0x3C, 0x45, 0x4D,
155 0x4E, 0x52, 0x51, 0x60, 0x7F, 0x7E, 0x7F, 0x0C,
156 /* B negative gamma */ 0x00,
157 0x48, 0x10, 0x1F, 0x2F, 0x35, 0x38, 0x3D, 0x3C, 0x45, 0x4D,
158 0x4E, 0x52, 0x51, 0x60, 0x7F, 0x7E, 0x7F, 0x0C);
159 mipi_dbi_command(dbi, DB7430_BIAS_CURRENT_CTRL, 0x33, 0x13);
160 mipi_dbi_command(dbi, DB7430_DDV_CTRL, 0x11, 0x00, 0x00);
161 mipi_dbi_command(dbi, DB7430_GAMMA_CTRL_REF, 0x50, 0x50);
162 mipi_dbi_command(dbi, DB7430_DCDC_CTRL, 0x2f, 0x11, 0x1e, 0x46);
163 mipi_dbi_command(dbi, DB7430_VCL_CTRL, 0x11, 0x0a);
164
165 return 0;
166 }
167
db7430_power_off(struct db7430 * db)168 static int db7430_power_off(struct db7430 *db)
169 {
170 /* Go into RESET and disable regulators */
171 gpiod_set_value_cansleep(db->reset, 1);
172 return regulator_bulk_disable(ARRAY_SIZE(db->regulators),
173 db->regulators);
174 }
175
db7430_unprepare(struct drm_panel * panel)176 static int db7430_unprepare(struct drm_panel *panel)
177 {
178 return db7430_power_off(to_db7430(panel));
179 }
180
db7430_disable(struct drm_panel * panel)181 static int db7430_disable(struct drm_panel *panel)
182 {
183 struct db7430 *db = to_db7430(panel);
184 struct mipi_dbi *dbi = &db->dbi;
185
186 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
187 msleep(25);
188 mipi_dbi_command(dbi, MIPI_DCS_ENTER_SLEEP_MODE);
189 msleep(120);
190
191 return 0;
192 }
193
db7430_prepare(struct drm_panel * panel)194 static int db7430_prepare(struct drm_panel *panel)
195 {
196 return db7430_power_on(to_db7430(panel));
197 }
198
db7430_enable(struct drm_panel * panel)199 static int db7430_enable(struct drm_panel *panel)
200 {
201 struct db7430 *db = to_db7430(panel);
202 struct mipi_dbi *dbi = &db->dbi;
203
204 /* Exit sleep mode */
205 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
206 msleep(20);
207
208 /* NVM (non-volatile memory) load sequence */
209 mipi_dbi_command(dbi, DB7430_UNKNOWN_D4, 0x52, 0x5e);
210 mipi_dbi_command(dbi, DB7430_UNKNOWN_F8, 0x01, 0xf5, 0xf2, 0x71, 0x44);
211 mipi_dbi_command(dbi, DB7430_UNKNOWN_FC, 0x00, 0x08);
212 msleep(150);
213
214 /* CABC turn on sequence (BC = backlight control) */
215 mipi_dbi_command(dbi, DB7430_UNKNOWN_B4, 0x0f, 0x00, 0x50);
216 mipi_dbi_command(dbi, DB7430_USER_SELECT, 0x80);
217 mipi_dbi_command(dbi, DB7430_UNKNOWN_B7, 0x24);
218 mipi_dbi_command(dbi, DB7430_UNKNOWN_B8, 0x01);
219
220 /* Turn on display */
221 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
222
223 return 0;
224 }
225
226 /**
227 * db7430_get_modes() - return the mode
228 * @panel: the panel to get the mode for
229 * @connector: reference to the central DRM connector control structure
230 */
db7430_get_modes(struct drm_panel * panel,struct drm_connector * connector)231 static int db7430_get_modes(struct drm_panel *panel,
232 struct drm_connector *connector)
233 {
234 struct db7430 *db = to_db7430(panel);
235 struct drm_display_mode *mode;
236 static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
237
238 mode = drm_mode_duplicate(connector->dev, &db7430_480_800_mode);
239 if (!mode) {
240 dev_err(db->dev, "failed to add mode\n");
241 return -ENOMEM;
242 }
243
244 connector->display_info.bpc = 8;
245 connector->display_info.width_mm = mode->width_mm;
246 connector->display_info.height_mm = mode->height_mm;
247 connector->display_info.bus_flags =
248 DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE;
249 drm_display_info_set_bus_formats(&connector->display_info,
250 &bus_format, 1);
251
252 drm_mode_set_name(mode);
253 mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
254
255 drm_mode_probed_add(connector, mode);
256
257 return 1;
258 }
259
260 static const struct drm_panel_funcs db7430_drm_funcs = {
261 .disable = db7430_disable,
262 .unprepare = db7430_unprepare,
263 .prepare = db7430_prepare,
264 .enable = db7430_enable,
265 .get_modes = db7430_get_modes,
266 };
267
db7430_probe(struct spi_device * spi)268 static int db7430_probe(struct spi_device *spi)
269 {
270 struct device *dev = &spi->dev;
271 struct db7430 *db;
272 int ret;
273
274 db = devm_kzalloc(dev, sizeof(*db), GFP_KERNEL);
275 if (!db)
276 return -ENOMEM;
277 db->dev = dev;
278
279 /*
280 * VCI is the analog voltage supply
281 * VCCIO is the digital I/O voltage supply
282 */
283 db->regulators[0].supply = "vci";
284 db->regulators[1].supply = "vccio";
285 ret = devm_regulator_bulk_get(dev,
286 ARRAY_SIZE(db->regulators),
287 db->regulators);
288 if (ret)
289 return dev_err_probe(dev, ret, "failed to get regulators\n");
290
291 db->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
292 if (IS_ERR(db->reset)) {
293 ret = PTR_ERR(db->reset);
294 return dev_err_probe(dev, ret, "no RESET GPIO\n");
295 }
296
297 ret = mipi_dbi_spi_init(spi, &db->dbi, NULL);
298 if (ret)
299 return dev_err_probe(dev, ret, "MIPI DBI init failed\n");
300
301 drm_panel_init(&db->panel, dev, &db7430_drm_funcs,
302 DRM_MODE_CONNECTOR_DPI);
303
304 /* FIXME: if no external backlight, use internal backlight */
305 ret = drm_panel_of_backlight(&db->panel);
306 if (ret)
307 return dev_err_probe(dev, ret, "failed to add backlight\n");
308
309 spi_set_drvdata(spi, db);
310
311 drm_panel_add(&db->panel);
312 dev_dbg(dev, "added panel\n");
313
314 return 0;
315 }
316
db7430_remove(struct spi_device * spi)317 static void db7430_remove(struct spi_device *spi)
318 {
319 struct db7430 *db = spi_get_drvdata(spi);
320
321 drm_panel_remove(&db->panel);
322 }
323
324 /*
325 * The DB7430 display controller may be used in several display products,
326 * so list the different variants here and add per-variant data if needed.
327 */
328 static const struct of_device_id db7430_match[] = {
329 { .compatible = "samsung,lms397kf04", },
330 {},
331 };
332 MODULE_DEVICE_TABLE(of, db7430_match);
333
334 static struct spi_driver db7430_driver = {
335 .probe = db7430_probe,
336 .remove = db7430_remove,
337 .driver = {
338 .name = "db7430-panel",
339 .of_match_table = db7430_match,
340 },
341 };
342 module_spi_driver(db7430_driver);
343
344 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
345 MODULE_DESCRIPTION("Samsung DB7430 panel driver");
346 MODULE_LICENSE("GPL v2");
347