1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Toppoly TD043MTEA1 Panel Driver
4 *
5 * Copyright (C) 2019 Texas Instruments Incorporated
6 *
7 * Based on the omapdrm-specific panel-tpo-td043mtea1 driver
8 *
9 * Author: Gražvydas Ignotas <notasas@gmail.com>
10 */
11
12 #include <linux/delay.h>
13 #include <linux/module.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/spi/spi.h>
16
17 #include <drm/drm_connector.h>
18 #include <drm/drm_modes.h>
19 #include <drm/drm_panel.h>
20
21 #define TPO_R02_MODE(x) ((x) & 7)
22 #define TPO_R02_MODE_800x480 7
23 #define TPO_R02_NCLK_RISING BIT(3)
24 #define TPO_R02_HSYNC_HIGH BIT(4)
25 #define TPO_R02_VSYNC_HIGH BIT(5)
26
27 #define TPO_R03_NSTANDBY BIT(0)
28 #define TPO_R03_EN_CP_CLK BIT(1)
29 #define TPO_R03_EN_VGL_PUMP BIT(2)
30 #define TPO_R03_EN_PWM BIT(3)
31 #define TPO_R03_DRIVING_CAP_100 BIT(4)
32 #define TPO_R03_EN_PRE_CHARGE BIT(6)
33 #define TPO_R03_SOFTWARE_CTL BIT(7)
34
35 #define TPO_R04_NFLIP_H BIT(0)
36 #define TPO_R04_NFLIP_V BIT(1)
37 #define TPO_R04_CP_CLK_FREQ_1H BIT(2)
38 #define TPO_R04_VGL_FREQ_1H BIT(4)
39
40 #define TPO_R03_VAL_NORMAL \
41 (TPO_R03_NSTANDBY | TPO_R03_EN_CP_CLK | TPO_R03_EN_VGL_PUMP | \
42 TPO_R03_EN_PWM | TPO_R03_DRIVING_CAP_100 | TPO_R03_EN_PRE_CHARGE | \
43 TPO_R03_SOFTWARE_CTL)
44
45 #define TPO_R03_VAL_STANDBY \
46 (TPO_R03_DRIVING_CAP_100 | TPO_R03_EN_PRE_CHARGE | \
47 TPO_R03_SOFTWARE_CTL)
48
49 static const u16 td043mtea1_def_gamma[12] = {
50 105, 315, 381, 431, 490, 537, 579, 686, 780, 837, 880, 1023
51 };
52
53 struct td043mtea1_panel {
54 struct drm_panel panel;
55
56 struct spi_device *spi;
57 struct regulator *vcc_reg;
58 struct gpio_desc *reset_gpio;
59
60 unsigned int mode;
61 u16 gamma[12];
62 bool vmirror;
63 bool powered_on;
64 bool spi_suspended;
65 bool power_on_resume;
66 };
67
68 #define to_td043mtea1_device(p) container_of(p, struct td043mtea1_panel, panel)
69
70 /* -----------------------------------------------------------------------------
71 * Hardware Access
72 */
73
td043mtea1_write(struct td043mtea1_panel * lcd,u8 addr,u8 value)74 static int td043mtea1_write(struct td043mtea1_panel *lcd, u8 addr, u8 value)
75 {
76 struct spi_message msg;
77 struct spi_transfer xfer;
78 u16 data;
79 int ret;
80
81 spi_message_init(&msg);
82
83 memset(&xfer, 0, sizeof(xfer));
84
85 data = ((u16)addr << 10) | (1 << 8) | value;
86 xfer.tx_buf = &data;
87 xfer.bits_per_word = 16;
88 xfer.len = 2;
89 spi_message_add_tail(&xfer, &msg);
90
91 ret = spi_sync(lcd->spi, &msg);
92 if (ret < 0)
93 dev_warn(&lcd->spi->dev, "failed to write to LCD reg (%d)\n",
94 ret);
95
96 return ret;
97 }
98
td043mtea1_write_gamma(struct td043mtea1_panel * lcd)99 static void td043mtea1_write_gamma(struct td043mtea1_panel *lcd)
100 {
101 const u16 *gamma = lcd->gamma;
102 unsigned int i;
103 u8 val;
104
105 /* gamma bits [9:8] */
106 for (val = i = 0; i < 4; i++)
107 val |= (gamma[i] & 0x300) >> ((i + 1) * 2);
108 td043mtea1_write(lcd, 0x11, val);
109
110 for (val = i = 0; i < 4; i++)
111 val |= (gamma[i + 4] & 0x300) >> ((i + 1) * 2);
112 td043mtea1_write(lcd, 0x12, val);
113
114 for (val = i = 0; i < 4; i++)
115 val |= (gamma[i + 8] & 0x300) >> ((i + 1) * 2);
116 td043mtea1_write(lcd, 0x13, val);
117
118 /* gamma bits [7:0] */
119 for (i = 0; i < 12; i++)
120 td043mtea1_write(lcd, 0x14 + i, gamma[i] & 0xff);
121 }
122
td043mtea1_write_mirror(struct td043mtea1_panel * lcd)123 static int td043mtea1_write_mirror(struct td043mtea1_panel *lcd)
124 {
125 u8 reg4 = TPO_R04_NFLIP_H | TPO_R04_NFLIP_V |
126 TPO_R04_CP_CLK_FREQ_1H | TPO_R04_VGL_FREQ_1H;
127 if (lcd->vmirror)
128 reg4 &= ~TPO_R04_NFLIP_V;
129
130 return td043mtea1_write(lcd, 4, reg4);
131 }
132
td043mtea1_power_on(struct td043mtea1_panel * lcd)133 static int td043mtea1_power_on(struct td043mtea1_panel *lcd)
134 {
135 int ret;
136
137 if (lcd->powered_on)
138 return 0;
139
140 ret = regulator_enable(lcd->vcc_reg);
141 if (ret < 0)
142 return ret;
143
144 /* Wait for the panel to stabilize. */
145 msleep(160);
146
147 gpiod_set_value(lcd->reset_gpio, 0);
148
149 td043mtea1_write(lcd, 2, TPO_R02_MODE(lcd->mode) | TPO_R02_NCLK_RISING);
150 td043mtea1_write(lcd, 3, TPO_R03_VAL_NORMAL);
151 td043mtea1_write(lcd, 0x20, 0xf0);
152 td043mtea1_write(lcd, 0x21, 0xf0);
153 td043mtea1_write_mirror(lcd);
154 td043mtea1_write_gamma(lcd);
155
156 lcd->powered_on = true;
157
158 return 0;
159 }
160
td043mtea1_power_off(struct td043mtea1_panel * lcd)161 static void td043mtea1_power_off(struct td043mtea1_panel *lcd)
162 {
163 if (!lcd->powered_on)
164 return;
165
166 td043mtea1_write(lcd, 3, TPO_R03_VAL_STANDBY | TPO_R03_EN_PWM);
167
168 gpiod_set_value(lcd->reset_gpio, 1);
169
170 /* wait for at least 2 vsyncs before cutting off power */
171 msleep(50);
172
173 td043mtea1_write(lcd, 3, TPO_R03_VAL_STANDBY);
174
175 regulator_disable(lcd->vcc_reg);
176
177 lcd->powered_on = false;
178 }
179
180 /* -----------------------------------------------------------------------------
181 * sysfs
182 */
183
vmirror_show(struct device * dev,struct device_attribute * attr,char * buf)184 static ssize_t vmirror_show(struct device *dev, struct device_attribute *attr,
185 char *buf)
186 {
187 struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
188
189 return sysfs_emit(buf, "%d\n", lcd->vmirror);
190 }
191
vmirror_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)192 static ssize_t vmirror_store(struct device *dev, struct device_attribute *attr,
193 const char *buf, size_t count)
194 {
195 struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
196 int val;
197 int ret;
198
199 ret = kstrtoint(buf, 0, &val);
200 if (ret < 0)
201 return ret;
202
203 lcd->vmirror = !!val;
204
205 ret = td043mtea1_write_mirror(lcd);
206 if (ret < 0)
207 return ret;
208
209 return count;
210 }
211
mode_show(struct device * dev,struct device_attribute * attr,char * buf)212 static ssize_t mode_show(struct device *dev, struct device_attribute *attr,
213 char *buf)
214 {
215 struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
216
217 return sysfs_emit(buf, "%d\n", lcd->mode);
218 }
219
mode_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)220 static ssize_t mode_store(struct device *dev, struct device_attribute *attr,
221 const char *buf, size_t count)
222 {
223 struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
224 long val;
225 int ret;
226
227 ret = kstrtol(buf, 0, &val);
228 if (ret != 0 || val & ~7)
229 return -EINVAL;
230
231 lcd->mode = val;
232
233 val |= TPO_R02_NCLK_RISING;
234 td043mtea1_write(lcd, 2, val);
235
236 return count;
237 }
238
gamma_show(struct device * dev,struct device_attribute * attr,char * buf)239 static ssize_t gamma_show(struct device *dev, struct device_attribute *attr,
240 char *buf)
241 {
242 struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
243 ssize_t len = 0;
244 unsigned int i;
245 int ret;
246
247 for (i = 0; i < ARRAY_SIZE(lcd->gamma); i++) {
248 ret = snprintf(buf + len, PAGE_SIZE - len, "%u ",
249 lcd->gamma[i]);
250 if (ret < 0)
251 return ret;
252 len += ret;
253 }
254 buf[len - 1] = '\n';
255
256 return len;
257 }
258
gamma_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)259 static ssize_t gamma_store(struct device *dev, struct device_attribute *attr,
260 const char *buf, size_t count)
261 {
262 struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
263 unsigned int g[12];
264 unsigned int i;
265 int ret;
266
267 ret = sscanf(buf, "%u %u %u %u %u %u %u %u %u %u %u %u",
268 &g[0], &g[1], &g[2], &g[3], &g[4], &g[5],
269 &g[6], &g[7], &g[8], &g[9], &g[10], &g[11]);
270 if (ret != 12)
271 return -EINVAL;
272
273 for (i = 0; i < 12; i++)
274 lcd->gamma[i] = g[i];
275
276 td043mtea1_write_gamma(lcd);
277
278 return count;
279 }
280
281 static DEVICE_ATTR_RW(vmirror);
282 static DEVICE_ATTR_RW(mode);
283 static DEVICE_ATTR_RW(gamma);
284
285 static struct attribute *td043mtea1_attrs[] = {
286 &dev_attr_vmirror.attr,
287 &dev_attr_mode.attr,
288 &dev_attr_gamma.attr,
289 NULL,
290 };
291
292 static const struct attribute_group td043mtea1_attr_group = {
293 .attrs = td043mtea1_attrs,
294 };
295
296 /* -----------------------------------------------------------------------------
297 * Panel Operations
298 */
299
td043mtea1_unprepare(struct drm_panel * panel)300 static int td043mtea1_unprepare(struct drm_panel *panel)
301 {
302 struct td043mtea1_panel *lcd = to_td043mtea1_device(panel);
303
304 if (!lcd->spi_suspended)
305 td043mtea1_power_off(lcd);
306
307 return 0;
308 }
309
td043mtea1_prepare(struct drm_panel * panel)310 static int td043mtea1_prepare(struct drm_panel *panel)
311 {
312 struct td043mtea1_panel *lcd = to_td043mtea1_device(panel);
313 int ret;
314
315 /*
316 * If we are resuming from system suspend, SPI might not be enabled
317 * yet, so we'll program the LCD from SPI PM resume callback.
318 */
319 if (lcd->spi_suspended)
320 return 0;
321
322 ret = td043mtea1_power_on(lcd);
323 if (ret) {
324 dev_err(&lcd->spi->dev, "%s: power on failed (%d)\n",
325 __func__, ret);
326 return ret;
327 }
328
329 return 0;
330 }
331
332 static const struct drm_display_mode td043mtea1_mode = {
333 .clock = 36000,
334 .hdisplay = 800,
335 .hsync_start = 800 + 68,
336 .hsync_end = 800 + 68 + 1,
337 .htotal = 800 + 68 + 1 + 214,
338 .vdisplay = 480,
339 .vsync_start = 480 + 39,
340 .vsync_end = 480 + 39 + 1,
341 .vtotal = 480 + 39 + 1 + 34,
342 .type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
343 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
344 .width_mm = 94,
345 .height_mm = 56,
346 };
347
td043mtea1_get_modes(struct drm_panel * panel,struct drm_connector * connector)348 static int td043mtea1_get_modes(struct drm_panel *panel,
349 struct drm_connector *connector)
350 {
351 struct drm_display_mode *mode;
352
353 mode = drm_mode_duplicate(connector->dev, &td043mtea1_mode);
354 if (!mode)
355 return -ENOMEM;
356
357 drm_mode_set_name(mode);
358 drm_mode_probed_add(connector, mode);
359
360 connector->display_info.width_mm = td043mtea1_mode.width_mm;
361 connector->display_info.height_mm = td043mtea1_mode.height_mm;
362 /*
363 * FIXME: According to the datasheet sync signals are sampled on the
364 * rising edge of the clock, but the code running on the OMAP3 Pandora
365 * indicates sampling on the falling edge. This should be tested on a
366 * real device.
367 */
368 connector->display_info.bus_flags = DRM_BUS_FLAG_DE_HIGH
369 | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
370 | DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE;
371
372 return 1;
373 }
374
375 static const struct drm_panel_funcs td043mtea1_funcs = {
376 .unprepare = td043mtea1_unprepare,
377 .prepare = td043mtea1_prepare,
378 .get_modes = td043mtea1_get_modes,
379 };
380
381 /* -----------------------------------------------------------------------------
382 * Power Management, Probe and Remove
383 */
384
td043mtea1_suspend(struct device * dev)385 static int __maybe_unused td043mtea1_suspend(struct device *dev)
386 {
387 struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
388
389 if (lcd->powered_on) {
390 td043mtea1_power_off(lcd);
391 lcd->powered_on = true;
392 }
393
394 lcd->spi_suspended = true;
395
396 return 0;
397 }
398
td043mtea1_resume(struct device * dev)399 static int __maybe_unused td043mtea1_resume(struct device *dev)
400 {
401 struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
402 int ret;
403
404 lcd->spi_suspended = false;
405
406 if (lcd->powered_on) {
407 lcd->powered_on = false;
408 ret = td043mtea1_power_on(lcd);
409 if (ret)
410 return ret;
411 }
412
413 return 0;
414 }
415
416 static SIMPLE_DEV_PM_OPS(td043mtea1_pm_ops, td043mtea1_suspend,
417 td043mtea1_resume);
418
td043mtea1_probe(struct spi_device * spi)419 static int td043mtea1_probe(struct spi_device *spi)
420 {
421 struct td043mtea1_panel *lcd;
422 int ret;
423
424 lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
425 if (lcd == NULL)
426 return -ENOMEM;
427
428 spi_set_drvdata(spi, lcd);
429 lcd->spi = spi;
430 lcd->mode = TPO_R02_MODE_800x480;
431 memcpy(lcd->gamma, td043mtea1_def_gamma, sizeof(lcd->gamma));
432
433 lcd->vcc_reg = devm_regulator_get(&spi->dev, "vcc");
434 if (IS_ERR(lcd->vcc_reg))
435 return dev_err_probe(&spi->dev, PTR_ERR(lcd->vcc_reg),
436 "failed to get VCC regulator\n");
437
438 lcd->reset_gpio = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
439 if (IS_ERR(lcd->reset_gpio))
440 return dev_err_probe(&spi->dev, PTR_ERR(lcd->reset_gpio),
441 "failed to get reset GPIO\n");
442
443 spi->bits_per_word = 16;
444 spi->mode = SPI_MODE_0;
445
446 ret = spi_setup(spi);
447 if (ret < 0) {
448 dev_err(&spi->dev, "failed to setup SPI: %d\n", ret);
449 return ret;
450 }
451
452 ret = sysfs_create_group(&spi->dev.kobj, &td043mtea1_attr_group);
453 if (ret < 0) {
454 dev_err(&spi->dev, "failed to create sysfs files\n");
455 return ret;
456 }
457
458 drm_panel_init(&lcd->panel, &lcd->spi->dev, &td043mtea1_funcs,
459 DRM_MODE_CONNECTOR_DPI);
460
461 drm_panel_add(&lcd->panel);
462
463 return 0;
464 }
465
td043mtea1_remove(struct spi_device * spi)466 static void td043mtea1_remove(struct spi_device *spi)
467 {
468 struct td043mtea1_panel *lcd = spi_get_drvdata(spi);
469
470 drm_panel_remove(&lcd->panel);
471 drm_panel_disable(&lcd->panel);
472 drm_panel_unprepare(&lcd->panel);
473
474 sysfs_remove_group(&spi->dev.kobj, &td043mtea1_attr_group);
475 }
476
477 static const struct of_device_id td043mtea1_of_match[] = {
478 { .compatible = "tpo,td043mtea1", },
479 { /* sentinel */ },
480 };
481
482 MODULE_DEVICE_TABLE(of, td043mtea1_of_match);
483
484 static const struct spi_device_id td043mtea1_ids[] = {
485 { "td043mtea1", 0 },
486 { /* sentinel */ }
487 };
488
489 MODULE_DEVICE_TABLE(spi, td043mtea1_ids);
490
491 static struct spi_driver td043mtea1_driver = {
492 .probe = td043mtea1_probe,
493 .remove = td043mtea1_remove,
494 .id_table = td043mtea1_ids,
495 .driver = {
496 .name = "panel-tpo-td043mtea1",
497 .pm = &td043mtea1_pm_ops,
498 .of_match_table = td043mtea1_of_match,
499 },
500 };
501
502 module_spi_driver(td043mtea1_driver);
503
504 MODULE_AUTHOR("Gražvydas Ignotas <notasas@gmail.com>");
505 MODULE_DESCRIPTION("TPO TD043MTEA1 Panel Driver");
506 MODULE_LICENSE("GPL");
507