xref: /openbmc/linux/drivers/video/backlight/hx8357.c (revision 39b6f3aa)
1 /*
2  * Driver for the Himax HX-8357 LCD Controller
3  *
4  * Copyright 2012 Free Electrons
5  *
6  * Licensed under the GPLv2 or later.
7  */
8 
9 #include <linux/delay.h>
10 #include <linux/lcd.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_device.h>
14 #include <linux/of_gpio.h>
15 #include <linux/spi/spi.h>
16 
17 #define HX8357_NUM_IM_PINS	3
18 
19 #define HX8357_SWRESET			0x01
20 #define HX8357_GET_RED_CHANNEL		0x06
21 #define HX8357_GET_GREEN_CHANNEL	0x07
22 #define HX8357_GET_BLUE_CHANNEL		0x08
23 #define HX8357_GET_POWER_MODE		0x0a
24 #define HX8357_GET_MADCTL		0x0b
25 #define HX8357_GET_PIXEL_FORMAT		0x0c
26 #define HX8357_GET_DISPLAY_MODE		0x0d
27 #define HX8357_GET_SIGNAL_MODE		0x0e
28 #define HX8357_GET_DIAGNOSTIC_RESULT	0x0f
29 #define HX8357_ENTER_SLEEP_MODE		0x10
30 #define HX8357_EXIT_SLEEP_MODE		0x11
31 #define HX8357_ENTER_PARTIAL_MODE	0x12
32 #define HX8357_ENTER_NORMAL_MODE	0x13
33 #define HX8357_EXIT_INVERSION_MODE	0x20
34 #define HX8357_ENTER_INVERSION_MODE	0x21
35 #define HX8357_SET_DISPLAY_OFF		0x28
36 #define HX8357_SET_DISPLAY_ON		0x29
37 #define HX8357_SET_COLUMN_ADDRESS	0x2a
38 #define HX8357_SET_PAGE_ADDRESS		0x2b
39 #define HX8357_WRITE_MEMORY_START	0x2c
40 #define HX8357_READ_MEMORY_START	0x2e
41 #define HX8357_SET_PARTIAL_AREA		0x30
42 #define HX8357_SET_SCROLL_AREA		0x33
43 #define HX8357_SET_TEAR_OFF		0x34
44 #define HX8357_SET_TEAR_ON		0x35
45 #define HX8357_SET_ADDRESS_MODE		0x36
46 #define HX8357_SET_SCROLL_START		0x37
47 #define HX8357_EXIT_IDLE_MODE		0x38
48 #define HX8357_ENTER_IDLE_MODE		0x39
49 #define HX8357_SET_PIXEL_FORMAT		0x3a
50 #define HX8357_SET_PIXEL_FORMAT_DBI_3BIT	(0x1)
51 #define HX8357_SET_PIXEL_FORMAT_DBI_16BIT	(0x5)
52 #define HX8357_SET_PIXEL_FORMAT_DBI_18BIT	(0x6)
53 #define HX8357_SET_PIXEL_FORMAT_DPI_3BIT	(0x1 << 4)
54 #define HX8357_SET_PIXEL_FORMAT_DPI_16BIT	(0x5 << 4)
55 #define HX8357_SET_PIXEL_FORMAT_DPI_18BIT	(0x6 << 4)
56 #define HX8357_WRITE_MEMORY_CONTINUE	0x3c
57 #define HX8357_READ_MEMORY_CONTINUE	0x3e
58 #define HX8357_SET_TEAR_SCAN_LINES	0x44
59 #define HX8357_GET_SCAN_LINES		0x45
60 #define HX8357_READ_DDB_START		0xa1
61 #define HX8357_SET_DISPLAY_MODE		0xb4
62 #define HX8357_SET_DISPLAY_MODE_RGB_THROUGH	(0x3)
63 #define HX8357_SET_DISPLAY_MODE_RGB_INTERFACE	(1 << 4)
64 #define HX8357_SET_PANEL_DRIVING	0xc0
65 #define HX8357_SET_DISPLAY_FRAME	0xc5
66 #define HX8357_SET_RGB			0xc6
67 #define HX8357_SET_RGB_ENABLE_HIGH		(1 << 1)
68 #define HX8357_SET_GAMMA		0xc8
69 #define HX8357_SET_POWER		0xd0
70 #define HX8357_SET_VCOM			0xd1
71 #define HX8357_SET_POWER_NORMAL		0xd2
72 #define HX8357_SET_PANEL_RELATED	0xe9
73 
74 struct hx8357_data {
75 	unsigned		im_pins[HX8357_NUM_IM_PINS];
76 	unsigned		reset;
77 	struct spi_device	*spi;
78 	int			state;
79 };
80 
81 static u8 hx8357_seq_power[] = {
82 	HX8357_SET_POWER, 0x44, 0x41, 0x06,
83 };
84 
85 static u8 hx8357_seq_vcom[] = {
86 	HX8357_SET_VCOM, 0x40, 0x10,
87 };
88 
89 static u8 hx8357_seq_power_normal[] = {
90 	HX8357_SET_POWER_NORMAL, 0x05, 0x12,
91 };
92 
93 static u8 hx8357_seq_panel_driving[] = {
94 	HX8357_SET_PANEL_DRIVING, 0x14, 0x3b, 0x00, 0x02, 0x11,
95 };
96 
97 static u8 hx8357_seq_display_frame[] = {
98 	HX8357_SET_DISPLAY_FRAME, 0x0c,
99 };
100 
101 static u8 hx8357_seq_panel_related[] = {
102 	HX8357_SET_PANEL_RELATED, 0x01,
103 };
104 
105 static u8 hx8357_seq_undefined1[] = {
106 	0xea, 0x03, 0x00, 0x00,
107 };
108 
109 static u8 hx8357_seq_undefined2[] = {
110 	0xeb, 0x40, 0x54, 0x26, 0xdb,
111 };
112 
113 static u8 hx8357_seq_gamma[] = {
114 	HX8357_SET_GAMMA, 0x00, 0x15, 0x00, 0x22, 0x00,
115 	0x08, 0x77, 0x26, 0x77, 0x22, 0x04, 0x00,
116 };
117 
118 static u8 hx8357_seq_address_mode[] = {
119 	HX8357_SET_ADDRESS_MODE, 0xc0,
120 };
121 
122 static u8 hx8357_seq_pixel_format[] = {
123 	HX8357_SET_PIXEL_FORMAT,
124 	HX8357_SET_PIXEL_FORMAT_DPI_18BIT |
125 	HX8357_SET_PIXEL_FORMAT_DBI_18BIT,
126 };
127 
128 static u8 hx8357_seq_column_address[] = {
129 	HX8357_SET_COLUMN_ADDRESS, 0x00, 0x00, 0x01, 0x3f,
130 };
131 
132 static u8 hx8357_seq_page_address[] = {
133 	HX8357_SET_PAGE_ADDRESS, 0x00, 0x00, 0x01, 0xdf,
134 };
135 
136 static u8 hx8357_seq_rgb[] = {
137 	HX8357_SET_RGB, 0x02,
138 };
139 
140 static u8 hx8357_seq_display_mode[] = {
141 	HX8357_SET_DISPLAY_MODE,
142 	HX8357_SET_DISPLAY_MODE_RGB_THROUGH |
143 	HX8357_SET_DISPLAY_MODE_RGB_INTERFACE,
144 };
145 
146 static int hx8357_spi_write_then_read(struct lcd_device *lcdev,
147 				u8 *txbuf, u16 txlen,
148 				u8 *rxbuf, u16 rxlen)
149 {
150 	struct hx8357_data *lcd = lcd_get_data(lcdev);
151 	struct spi_message msg;
152 	struct spi_transfer xfer[2];
153 	u16 *local_txbuf = NULL;
154 	int ret = 0;
155 
156 	memset(xfer, 0, sizeof(xfer));
157 	spi_message_init(&msg);
158 
159 	if (txlen) {
160 		int i;
161 
162 		local_txbuf = kcalloc(txlen, sizeof(*local_txbuf), GFP_KERNEL);
163 
164 		if (!local_txbuf)
165 			return -ENOMEM;
166 
167 		for (i = 0; i < txlen; i++) {
168 			local_txbuf[i] = txbuf[i];
169 			if (i > 0)
170 				local_txbuf[i] |= 1 << 8;
171 		}
172 
173 		xfer[0].len = 2 * txlen;
174 		xfer[0].bits_per_word = 9;
175 		xfer[0].tx_buf = local_txbuf;
176 		spi_message_add_tail(&xfer[0], &msg);
177 	}
178 
179 	if (rxlen) {
180 		xfer[1].len = rxlen;
181 		xfer[1].bits_per_word = 8;
182 		xfer[1].rx_buf = rxbuf;
183 		spi_message_add_tail(&xfer[1], &msg);
184 	}
185 
186 	ret = spi_sync(lcd->spi, &msg);
187 	if (ret < 0)
188 		dev_err(&lcdev->dev, "Couldn't send SPI data\n");
189 
190 	if (txlen)
191 		kfree(local_txbuf);
192 
193 	return ret;
194 }
195 
196 static inline int hx8357_spi_write_array(struct lcd_device *lcdev,
197 					u8 *value, u8 len)
198 {
199 	return hx8357_spi_write_then_read(lcdev, value, len, NULL, 0);
200 }
201 
202 static inline int hx8357_spi_write_byte(struct lcd_device *lcdev,
203 					u8 value)
204 {
205 	return hx8357_spi_write_then_read(lcdev, &value, 1, NULL, 0);
206 }
207 
208 static int hx8357_enter_standby(struct lcd_device *lcdev)
209 {
210 	int ret;
211 
212 	ret = hx8357_spi_write_byte(lcdev, HX8357_SET_DISPLAY_OFF);
213 	if (ret < 0)
214 		return ret;
215 
216 	usleep_range(10000, 12000);
217 
218 	ret = hx8357_spi_write_byte(lcdev, HX8357_ENTER_SLEEP_MODE);
219 	if (ret < 0)
220 		return ret;
221 
222 	msleep(120);
223 
224 	return 0;
225 }
226 
227 static int hx8357_exit_standby(struct lcd_device *lcdev)
228 {
229 	int ret;
230 
231 	ret = hx8357_spi_write_byte(lcdev, HX8357_EXIT_SLEEP_MODE);
232 	if (ret < 0)
233 		return ret;
234 
235 	msleep(120);
236 
237 	ret = hx8357_spi_write_byte(lcdev, HX8357_SET_DISPLAY_ON);
238 	if (ret < 0)
239 		return ret;
240 
241 	return 0;
242 }
243 
244 static int hx8357_lcd_init(struct lcd_device *lcdev)
245 {
246 	struct hx8357_data *lcd = lcd_get_data(lcdev);
247 	int ret;
248 
249 	/*
250 	 * Set the interface selection pins to SPI mode, with three
251 	 * wires
252 	 */
253 	gpio_set_value_cansleep(lcd->im_pins[0], 1);
254 	gpio_set_value_cansleep(lcd->im_pins[1], 0);
255 	gpio_set_value_cansleep(lcd->im_pins[2], 1);
256 
257 	/* Reset the screen */
258 	gpio_set_value(lcd->reset, 1);
259 	usleep_range(10000, 12000);
260 	gpio_set_value(lcd->reset, 0);
261 	usleep_range(10000, 12000);
262 	gpio_set_value(lcd->reset, 1);
263 	msleep(120);
264 
265 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_power,
266 				ARRAY_SIZE(hx8357_seq_power));
267 	if (ret < 0)
268 		return ret;
269 
270 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_vcom,
271 				ARRAY_SIZE(hx8357_seq_vcom));
272 	if (ret < 0)
273 		return ret;
274 
275 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_power_normal,
276 				ARRAY_SIZE(hx8357_seq_power_normal));
277 	if (ret < 0)
278 		return ret;
279 
280 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_panel_driving,
281 				ARRAY_SIZE(hx8357_seq_panel_driving));
282 	if (ret < 0)
283 		return ret;
284 
285 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_display_frame,
286 				ARRAY_SIZE(hx8357_seq_display_frame));
287 	if (ret < 0)
288 		return ret;
289 
290 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_panel_related,
291 				ARRAY_SIZE(hx8357_seq_panel_related));
292 	if (ret < 0)
293 		return ret;
294 
295 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_undefined1,
296 				ARRAY_SIZE(hx8357_seq_undefined1));
297 	if (ret < 0)
298 		return ret;
299 
300 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_undefined2,
301 				ARRAY_SIZE(hx8357_seq_undefined2));
302 	if (ret < 0)
303 		return ret;
304 
305 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_gamma,
306 				ARRAY_SIZE(hx8357_seq_gamma));
307 	if (ret < 0)
308 		return ret;
309 
310 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_address_mode,
311 				ARRAY_SIZE(hx8357_seq_address_mode));
312 	if (ret < 0)
313 		return ret;
314 
315 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_pixel_format,
316 				ARRAY_SIZE(hx8357_seq_pixel_format));
317 	if (ret < 0)
318 		return ret;
319 
320 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_column_address,
321 				ARRAY_SIZE(hx8357_seq_column_address));
322 	if (ret < 0)
323 		return ret;
324 
325 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_page_address,
326 				ARRAY_SIZE(hx8357_seq_page_address));
327 	if (ret < 0)
328 		return ret;
329 
330 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_rgb,
331 				ARRAY_SIZE(hx8357_seq_rgb));
332 	if (ret < 0)
333 		return ret;
334 
335 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_display_mode,
336 				ARRAY_SIZE(hx8357_seq_display_mode));
337 	if (ret < 0)
338 		return ret;
339 
340 	ret = hx8357_spi_write_byte(lcdev, HX8357_EXIT_SLEEP_MODE);
341 	if (ret < 0)
342 		return ret;
343 
344 	msleep(120);
345 
346 	ret = hx8357_spi_write_byte(lcdev, HX8357_SET_DISPLAY_ON);
347 	if (ret < 0)
348 		return ret;
349 
350 	usleep_range(5000, 7000);
351 
352 	ret = hx8357_spi_write_byte(lcdev, HX8357_WRITE_MEMORY_START);
353 	if (ret < 0)
354 		return ret;
355 
356 	return 0;
357 }
358 
359 #define POWER_IS_ON(pwr)	((pwr) <= FB_BLANK_NORMAL)
360 
361 static int hx8357_set_power(struct lcd_device *lcdev, int power)
362 {
363 	struct hx8357_data *lcd = lcd_get_data(lcdev);
364 	int ret = 0;
365 
366 	if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->state))
367 		ret = hx8357_exit_standby(lcdev);
368 	else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->state))
369 		ret = hx8357_enter_standby(lcdev);
370 
371 	if (ret == 0)
372 		lcd->state = power;
373 	else
374 		dev_warn(&lcdev->dev, "failed to set power mode %d\n", power);
375 
376 	return ret;
377 }
378 
379 static int hx8357_get_power(struct lcd_device *lcdev)
380 {
381 	struct hx8357_data *lcd = lcd_get_data(lcdev);
382 
383 	return lcd->state;
384 }
385 
386 static struct lcd_ops hx8357_ops = {
387 	.set_power	= hx8357_set_power,
388 	.get_power	= hx8357_get_power,
389 };
390 
391 static int hx8357_probe(struct spi_device *spi)
392 {
393 	struct lcd_device *lcdev;
394 	struct hx8357_data *lcd;
395 	int i, ret;
396 
397 	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
398 	if (!lcd) {
399 		dev_err(&spi->dev, "Couldn't allocate lcd internal structure!\n");
400 		return -ENOMEM;
401 	}
402 
403 	ret = spi_setup(spi);
404 	if (ret < 0) {
405 		dev_err(&spi->dev, "SPI setup failed.\n");
406 		return ret;
407 	}
408 
409 	lcd->spi = spi;
410 
411 	lcd->reset = of_get_named_gpio(spi->dev.of_node, "gpios-reset", 0);
412 	if (!gpio_is_valid(lcd->reset)) {
413 		dev_err(&spi->dev, "Missing dt property: gpios-reset\n");
414 		return -EINVAL;
415 	}
416 
417 	ret = devm_gpio_request_one(&spi->dev, lcd->reset,
418 				    GPIOF_OUT_INIT_HIGH,
419 				    "hx8357-reset");
420 	if (ret) {
421 		dev_err(&spi->dev,
422 			"failed to request gpio %d: %d\n",
423 			lcd->reset, ret);
424 		return -EINVAL;
425 	}
426 
427 	for (i = 0; i < HX8357_NUM_IM_PINS; i++) {
428 		lcd->im_pins[i] = of_get_named_gpio(spi->dev.of_node,
429 						"im-gpios", i);
430 		if (lcd->im_pins[i] == -EPROBE_DEFER) {
431 			dev_info(&spi->dev, "GPIO requested is not here yet, deferring the probe\n");
432 			return -EPROBE_DEFER;
433 		}
434 		if (!gpio_is_valid(lcd->im_pins[i])) {
435 			dev_err(&spi->dev, "Missing dt property: im-gpios\n");
436 			return -EINVAL;
437 		}
438 
439 		ret = devm_gpio_request_one(&spi->dev, lcd->im_pins[i],
440 					GPIOF_OUT_INIT_LOW, "im_pins");
441 		if (ret) {
442 			dev_err(&spi->dev, "failed to request gpio %d: %d\n",
443 				lcd->im_pins[i], ret);
444 			return -EINVAL;
445 		}
446 	}
447 
448 	lcdev = lcd_device_register("mxsfb", &spi->dev, lcd, &hx8357_ops);
449 	if (IS_ERR(lcdev)) {
450 		ret = PTR_ERR(lcdev);
451 		return ret;
452 	}
453 	spi_set_drvdata(spi, lcdev);
454 
455 	ret = hx8357_lcd_init(lcdev);
456 	if (ret) {
457 		dev_err(&spi->dev, "Couldn't initialize panel\n");
458 		goto init_error;
459 	}
460 
461 	dev_info(&spi->dev, "Panel probed\n");
462 
463 	return 0;
464 
465 init_error:
466 	lcd_device_unregister(lcdev);
467 	return ret;
468 }
469 
470 static int hx8357_remove(struct spi_device *spi)
471 {
472 	struct lcd_device *lcdev = spi_get_drvdata(spi);
473 
474 	lcd_device_unregister(lcdev);
475 	return 0;
476 }
477 
478 static const struct of_device_id hx8357_dt_ids[] = {
479 	{ .compatible = "himax,hx8357" },
480 	{},
481 };
482 MODULE_DEVICE_TABLE(of, hx8357_dt_ids);
483 
484 static struct spi_driver hx8357_driver = {
485 	.probe  = hx8357_probe,
486 	.remove = hx8357_remove,
487 	.driver = {
488 		.name = "hx8357",
489 		.of_match_table = of_match_ptr(hx8357_dt_ids),
490 	},
491 };
492 
493 module_spi_driver(hx8357_driver);
494 
495 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
496 MODULE_DESCRIPTION("Himax HX-8357 LCD Driver");
497 MODULE_LICENSE("GPL");
498