1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Novatek NT39016 TFT LCD panel driver |
4 | * |
5 | * Copyright (C) 2017, Maarten ter Huurne <maarten@treewalker.org> |
6 | * Copyright (C) 2019, Paul Cercueil <paul@crapouillou.net> |
7 | */ |
8 | |
9 | #include <linux/delay.h> |
10 | #include <linux/device.h> |
11 | #include <linux/gpio/consumer.h> |
12 | #include <linux/media-bus-format.h> |
13 | #include <linux/module.h> |
14 | #include <linux/of.h> |
15 | #include <linux/regmap.h> |
16 | #include <linux/regulator/consumer.h> |
17 | #include <linux/spi/spi.h> |
18 | |
19 | #include <drm/drm_modes.h> |
20 | #include <drm/drm_panel.h> |
21 | |
22 | enum nt39016_regs { |
23 | NT39016_REG_SYSTEM, |
24 | NT39016_REG_TIMING, |
25 | NT39016_REG_OP, |
26 | NT39016_REG_DATA_IN, |
27 | NT39016_REG_SRC_TIMING_DELAY, |
28 | NT39016_REG_GATE_TIMING_DELAY, |
29 | NT39016_REG_RESERVED, |
30 | NT39016_REG_INITIAL_FUNC, |
31 | NT39016_REG_CONTRAST, |
32 | NT39016_REG_BRIGHTNESS, |
33 | NT39016_REG_HUE_SATURATION, |
34 | NT39016_REG_RB_SUBCONTRAST, |
35 | NT39016_REG_R_SUBBRIGHTNESS, |
36 | NT39016_REG_B_SUBBRIGHTNESS, |
37 | NT39016_REG_VCOMDC, |
38 | NT39016_REG_VCOMAC, |
39 | NT39016_REG_VGAM2, |
40 | NT39016_REG_VGAM34, |
41 | NT39016_REG_VGAM56, |
42 | NT39016_REG_VCOMDC_TRIM = 0x1e, |
43 | NT39016_REG_DISPLAY_MODE = 0x20, |
44 | }; |
45 | |
46 | #define NT39016_SYSTEM_RESET_N BIT(0) |
47 | #define NT39016_SYSTEM_STANDBY BIT(1) |
48 | |
49 | struct nt39016_panel_info { |
50 | const struct drm_display_mode *display_modes; |
51 | unsigned int num_modes; |
52 | u16 width_mm, height_mm; |
53 | u32 bus_format, bus_flags; |
54 | }; |
55 | |
56 | struct nt39016 { |
57 | struct drm_panel drm_panel; |
58 | struct regmap *map; |
59 | struct regulator *supply; |
60 | const struct nt39016_panel_info *panel_info; |
61 | |
62 | struct gpio_desc *reset_gpio; |
63 | }; |
64 | |
65 | static inline struct nt39016 *to_nt39016(struct drm_panel *panel) |
66 | { |
67 | return container_of(panel, struct nt39016, drm_panel); |
68 | } |
69 | |
70 | #define RV(REG, VAL) { .reg = (REG), .def = (VAL), .delay_us = 2 } |
71 | static const struct reg_sequence nt39016_panel_regs[] = { |
72 | RV(NT39016_REG_SYSTEM, 0x00), |
73 | RV(NT39016_REG_TIMING, 0x00), |
74 | RV(NT39016_REG_OP, 0x03), |
75 | RV(NT39016_REG_DATA_IN, 0xCC), |
76 | RV(NT39016_REG_SRC_TIMING_DELAY, 0x46), |
77 | RV(NT39016_REG_GATE_TIMING_DELAY, 0x05), |
78 | RV(NT39016_REG_RESERVED, 0x00), |
79 | RV(NT39016_REG_INITIAL_FUNC, 0x00), |
80 | RV(NT39016_REG_CONTRAST, 0x08), |
81 | RV(NT39016_REG_BRIGHTNESS, 0x40), |
82 | RV(NT39016_REG_HUE_SATURATION, 0x88), |
83 | RV(NT39016_REG_RB_SUBCONTRAST, 0x88), |
84 | RV(NT39016_REG_R_SUBBRIGHTNESS, 0x20), |
85 | RV(NT39016_REG_B_SUBBRIGHTNESS, 0x20), |
86 | RV(NT39016_REG_VCOMDC, 0x67), |
87 | RV(NT39016_REG_VCOMAC, 0xA4), |
88 | RV(NT39016_REG_VGAM2, 0x04), |
89 | RV(NT39016_REG_VGAM34, 0x24), |
90 | RV(NT39016_REG_VGAM56, 0x24), |
91 | RV(NT39016_REG_DISPLAY_MODE, 0x00), |
92 | }; |
93 | |
94 | #undef RV |
95 | |
96 | static const struct regmap_range nt39016_regmap_no_ranges[] = { |
97 | regmap_reg_range(0x13, 0x1D), |
98 | regmap_reg_range(0x1F, 0x1F), |
99 | }; |
100 | |
101 | static const struct regmap_access_table nt39016_regmap_access_table = { |
102 | .no_ranges = nt39016_regmap_no_ranges, |
103 | .n_no_ranges = ARRAY_SIZE(nt39016_regmap_no_ranges), |
104 | }; |
105 | |
106 | static const struct regmap_config nt39016_regmap_config = { |
107 | .reg_bits = 6, |
108 | .pad_bits = 2, |
109 | .val_bits = 8, |
110 | |
111 | .max_register = NT39016_REG_DISPLAY_MODE, |
112 | .wr_table = &nt39016_regmap_access_table, |
113 | .write_flag_mask = 0x02, |
114 | |
115 | .cache_type = REGCACHE_FLAT, |
116 | }; |
117 | |
118 | static int nt39016_prepare(struct drm_panel *drm_panel) |
119 | { |
120 | struct nt39016 *panel = to_nt39016(panel: drm_panel); |
121 | int err; |
122 | |
123 | err = regulator_enable(regulator: panel->supply); |
124 | if (err) { |
125 | dev_err(drm_panel->dev, "Failed to enable power supply: %d\n" , err); |
126 | return err; |
127 | } |
128 | |
129 | /* |
130 | * Reset the NT39016. |
131 | * The documentation says the reset pulse should be at least 40 us to |
132 | * pass the glitch filter, but when testing I see some resets fail and |
133 | * some succeed when using a 70 us delay, so we use 100 us instead. |
134 | */ |
135 | gpiod_set_value_cansleep(desc: panel->reset_gpio, value: 1); |
136 | usleep_range(min: 100, max: 1000); |
137 | gpiod_set_value_cansleep(desc: panel->reset_gpio, value: 0); |
138 | udelay(2); |
139 | |
140 | /* Init all registers. */ |
141 | err = regmap_multi_reg_write(map: panel->map, regs: nt39016_panel_regs, |
142 | ARRAY_SIZE(nt39016_panel_regs)); |
143 | if (err) { |
144 | dev_err(drm_panel->dev, "Failed to init registers: %d\n" , err); |
145 | goto err_disable_regulator; |
146 | } |
147 | |
148 | return 0; |
149 | |
150 | err_disable_regulator: |
151 | regulator_disable(regulator: panel->supply); |
152 | return err; |
153 | } |
154 | |
155 | static int nt39016_unprepare(struct drm_panel *drm_panel) |
156 | { |
157 | struct nt39016 *panel = to_nt39016(panel: drm_panel); |
158 | |
159 | gpiod_set_value_cansleep(desc: panel->reset_gpio, value: 1); |
160 | |
161 | regulator_disable(regulator: panel->supply); |
162 | |
163 | return 0; |
164 | } |
165 | |
166 | static int nt39016_enable(struct drm_panel *drm_panel) |
167 | { |
168 | struct nt39016 *panel = to_nt39016(panel: drm_panel); |
169 | int ret; |
170 | |
171 | ret = regmap_write(map: panel->map, reg: NT39016_REG_SYSTEM, |
172 | NT39016_SYSTEM_RESET_N | NT39016_SYSTEM_STANDBY); |
173 | if (ret) { |
174 | dev_err(drm_panel->dev, "Unable to enable panel: %d\n" , ret); |
175 | return ret; |
176 | } |
177 | |
178 | if (drm_panel->backlight) { |
179 | /* Wait for the picture to be ready before enabling backlight */ |
180 | msleep(msecs: 150); |
181 | } |
182 | |
183 | return 0; |
184 | } |
185 | |
186 | static int nt39016_disable(struct drm_panel *drm_panel) |
187 | { |
188 | struct nt39016 *panel = to_nt39016(panel: drm_panel); |
189 | int err; |
190 | |
191 | err = regmap_write(map: panel->map, reg: NT39016_REG_SYSTEM, |
192 | NT39016_SYSTEM_RESET_N); |
193 | if (err) { |
194 | dev_err(drm_panel->dev, "Unable to disable panel: %d\n" , err); |
195 | return err; |
196 | } |
197 | |
198 | return 0; |
199 | } |
200 | |
201 | static int nt39016_get_modes(struct drm_panel *drm_panel, |
202 | struct drm_connector *connector) |
203 | { |
204 | struct nt39016 *panel = to_nt39016(panel: drm_panel); |
205 | const struct nt39016_panel_info *panel_info = panel->panel_info; |
206 | struct drm_display_mode *mode; |
207 | unsigned int i; |
208 | |
209 | for (i = 0; i < panel_info->num_modes; i++) { |
210 | mode = drm_mode_duplicate(dev: connector->dev, |
211 | mode: &panel_info->display_modes[i]); |
212 | if (!mode) |
213 | return -ENOMEM; |
214 | |
215 | drm_mode_set_name(mode); |
216 | |
217 | mode->type = DRM_MODE_TYPE_DRIVER; |
218 | if (panel_info->num_modes == 1) |
219 | mode->type |= DRM_MODE_TYPE_PREFERRED; |
220 | |
221 | drm_mode_probed_add(connector, mode); |
222 | } |
223 | |
224 | connector->display_info.bpc = 8; |
225 | connector->display_info.width_mm = panel_info->width_mm; |
226 | connector->display_info.height_mm = panel_info->height_mm; |
227 | |
228 | drm_display_info_set_bus_formats(info: &connector->display_info, |
229 | formats: &panel_info->bus_format, num_formats: 1); |
230 | connector->display_info.bus_flags = panel_info->bus_flags; |
231 | |
232 | return panel_info->num_modes; |
233 | } |
234 | |
235 | static const struct drm_panel_funcs nt39016_funcs = { |
236 | .prepare = nt39016_prepare, |
237 | .unprepare = nt39016_unprepare, |
238 | .enable = nt39016_enable, |
239 | .disable = nt39016_disable, |
240 | .get_modes = nt39016_get_modes, |
241 | }; |
242 | |
243 | static int nt39016_probe(struct spi_device *spi) |
244 | { |
245 | struct device *dev = &spi->dev; |
246 | struct nt39016 *panel; |
247 | int err; |
248 | |
249 | panel = devm_kzalloc(dev, size: sizeof(*panel), GFP_KERNEL); |
250 | if (!panel) |
251 | return -ENOMEM; |
252 | |
253 | spi_set_drvdata(spi, data: panel); |
254 | |
255 | panel->panel_info = of_device_get_match_data(dev); |
256 | if (!panel->panel_info) |
257 | return -EINVAL; |
258 | |
259 | panel->supply = devm_regulator_get(dev, id: "power" ); |
260 | if (IS_ERR(ptr: panel->supply)) |
261 | return dev_err_probe(dev, err: PTR_ERR(ptr: panel->supply), |
262 | fmt: "Failed to get power supply\n" ); |
263 | |
264 | panel->reset_gpio = devm_gpiod_get(dev, con_id: "reset" , flags: GPIOD_OUT_HIGH); |
265 | if (IS_ERR(ptr: panel->reset_gpio)) |
266 | return dev_err_probe(dev, err: PTR_ERR(ptr: panel->reset_gpio), fmt: "Failed to get reset GPIO\n" ); |
267 | |
268 | spi->bits_per_word = 8; |
269 | spi->mode = SPI_MODE_3 | SPI_3WIRE; |
270 | err = spi_setup(spi); |
271 | if (err) { |
272 | dev_err(dev, "Failed to setup SPI\n" ); |
273 | return err; |
274 | } |
275 | |
276 | panel->map = devm_regmap_init_spi(spi, &nt39016_regmap_config); |
277 | if (IS_ERR(ptr: panel->map)) { |
278 | dev_err(dev, "Failed to init regmap\n" ); |
279 | return PTR_ERR(ptr: panel->map); |
280 | } |
281 | |
282 | drm_panel_init(panel: &panel->drm_panel, dev, funcs: &nt39016_funcs, |
283 | DRM_MODE_CONNECTOR_DPI); |
284 | |
285 | err = drm_panel_of_backlight(panel: &panel->drm_panel); |
286 | if (err) |
287 | return dev_err_probe(dev, err, fmt: "Failed to get backlight handle\n" ); |
288 | |
289 | drm_panel_add(panel: &panel->drm_panel); |
290 | |
291 | return 0; |
292 | } |
293 | |
294 | static void nt39016_remove(struct spi_device *spi) |
295 | { |
296 | struct nt39016 *panel = spi_get_drvdata(spi); |
297 | |
298 | drm_panel_remove(panel: &panel->drm_panel); |
299 | |
300 | nt39016_disable(drm_panel: &panel->drm_panel); |
301 | nt39016_unprepare(drm_panel: &panel->drm_panel); |
302 | } |
303 | |
304 | static const struct drm_display_mode kd035g6_display_modes[] = { |
305 | { /* 60 Hz */ |
306 | .clock = 6000, |
307 | .hdisplay = 320, |
308 | .hsync_start = 320 + 10, |
309 | .hsync_end = 320 + 10 + 50, |
310 | .htotal = 320 + 10 + 50 + 20, |
311 | .vdisplay = 240, |
312 | .vsync_start = 240 + 5, |
313 | .vsync_end = 240 + 5 + 1, |
314 | .vtotal = 240 + 5 + 1 + 4, |
315 | .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, |
316 | }, |
317 | { /* 50 Hz */ |
318 | .clock = 5400, |
319 | .hdisplay = 320, |
320 | .hsync_start = 320 + 42, |
321 | .hsync_end = 320 + 42 + 50, |
322 | .htotal = 320 + 42 + 50 + 20, |
323 | .vdisplay = 240, |
324 | .vsync_start = 240 + 5, |
325 | .vsync_end = 240 + 5 + 1, |
326 | .vtotal = 240 + 5 + 1 + 4, |
327 | .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC, |
328 | }, |
329 | }; |
330 | |
331 | static const struct nt39016_panel_info kd035g6_info = { |
332 | .display_modes = kd035g6_display_modes, |
333 | .num_modes = ARRAY_SIZE(kd035g6_display_modes), |
334 | .width_mm = 71, |
335 | .height_mm = 53, |
336 | .bus_format = MEDIA_BUS_FMT_RGB888_1X24, |
337 | .bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE, |
338 | }; |
339 | |
340 | static const struct of_device_id nt39016_of_match[] = { |
341 | { .compatible = "kingdisplay,kd035g6-54nt" , .data = &kd035g6_info }, |
342 | { /* sentinel */ } |
343 | }; |
344 | MODULE_DEVICE_TABLE(of, nt39016_of_match); |
345 | |
346 | static struct spi_driver nt39016_driver = { |
347 | .driver = { |
348 | .name = "nt39016" , |
349 | .of_match_table = nt39016_of_match, |
350 | }, |
351 | .probe = nt39016_probe, |
352 | .remove = nt39016_remove, |
353 | }; |
354 | |
355 | module_spi_driver(nt39016_driver); |
356 | |
357 | MODULE_AUTHOR("Maarten ter Huurne <maarten@treewalker.org>" ); |
358 | MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>" ); |
359 | MODULE_LICENSE("GPL v2" ); |
360 | |