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
 49static const u16 td043mtea1_def_gamma[12] = {
 50	105, 315, 381, 431, 490, 537, 579, 686, 780, 837, 880, 1023
 51};
 52
 53struct 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
 74static 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
 99static 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
123static 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
133static 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
161static 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
184static 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 snprintf(buf, PAGE_SIZE, "%d\n", lcd->vmirror);
190}
191
192static 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
212static 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 snprintf(buf, PAGE_SIZE, "%d\n", lcd->mode);
218}
219
220static 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
239static 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
259static 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
281static DEVICE_ATTR_RW(vmirror);
282static DEVICE_ATTR_RW(mode);
283static DEVICE_ATTR_RW(gamma);
284
285static struct attribute *td043mtea1_attrs[] = {
286	&dev_attr_vmirror.attr,
287	&dev_attr_mode.attr,
288	&dev_attr_gamma.attr,
289	NULL,
290};
291
292static const struct attribute_group td043mtea1_attr_group = {
293	.attrs = td043mtea1_attrs,
294};
295
296/* -----------------------------------------------------------------------------
297 * Panel Operations
298 */
299
300static 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
310static 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
332static 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	.vrefresh = 60,
343	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
344	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
345	.width_mm = 94,
346	.height_mm = 56,
347};
348
349static int td043mtea1_get_modes(struct drm_panel *panel)
350{
351	struct drm_connector *connector = panel->connector;
352	struct drm_display_mode *mode;
353
354	mode = drm_mode_duplicate(panel->drm, &td043mtea1_mode);
355	if (!mode)
356		return -ENOMEM;
357
358	drm_mode_set_name(mode);
359	drm_mode_probed_add(connector, mode);
360
361	connector->display_info.width_mm = td043mtea1_mode.width_mm;
362	connector->display_info.height_mm = td043mtea1_mode.height_mm;
363	/*
364	 * FIXME: According to the datasheet sync signals are sampled on the
365	 * rising edge of the clock, but the code running on the OMAP3 Pandora
366	 * indicates sampling on the falling edge. This should be tested on a
367	 * real device.
368	 */
369	connector->display_info.bus_flags = DRM_BUS_FLAG_DE_HIGH
370					  | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
371					  | DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE;
372
373	return 1;
374}
375
376static const struct drm_panel_funcs td043mtea1_funcs = {
377	.unprepare = td043mtea1_unprepare,
378	.prepare = td043mtea1_prepare,
379	.get_modes = td043mtea1_get_modes,
380};
381
382/* -----------------------------------------------------------------------------
383 * Power Management, Probe and Remove
384 */
385
386static int __maybe_unused td043mtea1_suspend(struct device *dev)
387{
388	struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
389
390	if (lcd->powered_on) {
391		td043mtea1_power_off(lcd);
392		lcd->powered_on = true;
393	}
394
395	lcd->spi_suspended = true;
396
397	return 0;
398}
399
400static int __maybe_unused td043mtea1_resume(struct device *dev)
401{
402	struct td043mtea1_panel *lcd = dev_get_drvdata(dev);
403	int ret;
404
405	lcd->spi_suspended = false;
406
407	if (lcd->powered_on) {
408		lcd->powered_on = false;
409		ret = td043mtea1_power_on(lcd);
410		if (ret)
411			return ret;
412	}
413
414	return 0;
415}
416
417static SIMPLE_DEV_PM_OPS(td043mtea1_pm_ops, td043mtea1_suspend,
418			 td043mtea1_resume);
419
420static int td043mtea1_probe(struct spi_device *spi)
421{
422	struct td043mtea1_panel *lcd;
423	int ret;
424
425	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
426	if (lcd == NULL)
427		return -ENOMEM;
428
429	spi_set_drvdata(spi, lcd);
430	lcd->spi = spi;
431	lcd->mode = TPO_R02_MODE_800x480;
432	memcpy(lcd->gamma, td043mtea1_def_gamma, sizeof(lcd->gamma));
433
434	lcd->vcc_reg = devm_regulator_get(&spi->dev, "vcc");
435	if (IS_ERR(lcd->vcc_reg)) {
436		dev_err(&spi->dev, "failed to get VCC regulator\n");
437		return PTR_ERR(lcd->vcc_reg);
438	}
439
440	lcd->reset_gpio = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
441	if (IS_ERR(lcd->reset_gpio)) {
442		dev_err(&spi->dev, "failed to get reset GPIO\n");
443		return PTR_ERR(lcd->reset_gpio);
444	}
445
446	spi->bits_per_word = 16;
447	spi->mode = SPI_MODE_0;
448
449	ret = spi_setup(spi);
450	if (ret < 0) {
451		dev_err(&spi->dev, "failed to setup SPI: %d\n", ret);
452		return ret;
453	}
454
455	ret = sysfs_create_group(&spi->dev.kobj, &td043mtea1_attr_group);
456	if (ret < 0) {
457		dev_err(&spi->dev, "failed to create sysfs files\n");
458		return ret;
459	}
460
461	drm_panel_init(&lcd->panel);
462	lcd->panel.dev = &lcd->spi->dev;
463	lcd->panel.funcs = &td043mtea1_funcs;
464
465	ret = drm_panel_add(&lcd->panel);
466	if (ret < 0) {
467		sysfs_remove_group(&spi->dev.kobj, &td043mtea1_attr_group);
468		return ret;
469	}
470
471	return 0;
472}
473
474static int td043mtea1_remove(struct spi_device *spi)
475{
476	struct td043mtea1_panel *lcd = spi_get_drvdata(spi);
477
478	drm_panel_remove(&lcd->panel);
479	drm_panel_disable(&lcd->panel);
480	drm_panel_unprepare(&lcd->panel);
481
482	sysfs_remove_group(&spi->dev.kobj, &td043mtea1_attr_group);
483
484	return 0;
485}
486
487static const struct of_device_id td043mtea1_of_match[] = {
488	{ .compatible = "tpo,td043mtea1", },
489	{ /* sentinel */ },
490};
491
492MODULE_DEVICE_TABLE(of, td043mtea1_of_match);
493
494static const struct spi_device_id td043mtea1_ids[] = {
495	{ "td043mtea1", 0 },
496	{ /* sentinel */ }
497};
498
499MODULE_DEVICE_TABLE(spi, td043mtea1_ids);
500
501static struct spi_driver td043mtea1_driver = {
502	.probe		= td043mtea1_probe,
503	.remove		= td043mtea1_remove,
504	.id_table	= td043mtea1_ids,
505	.driver		= {
506		.name	= "panel-tpo-td043mtea1",
507		.pm	= &td043mtea1_pm_ops,
508		.of_match_table = td043mtea1_of_match,
509	},
510};
511
512module_spi_driver(td043mtea1_driver);
513
514MODULE_AUTHOR("Gražvydas Ignotas <notasas@gmail.com>");
515MODULE_DESCRIPTION("TPO TD043MTEA1 Panel Driver");
516MODULE_LICENSE("GPL");