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Stefano Babic4cfbfa92013-04-29 16:17:50 -07001/*
2 * (C) Copyright 2008
3 * Stefano Babic, DENX Software Engineering, sbabic@denx.de.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation; either version 2 of
8 * the License, or (at your option) any later version.
9 *
10 * This driver implements a lcd device for the ILITEK 922x display
11 * controller. The interface to the display is SPI and the display's
12 * memory is cyclically updated over the RGB interface.
13 */
14
15#include <linux/fb.h>
16#include <linux/delay.h>
17#include <linux/errno.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/lcd.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/slab.h>
24#include <linux/spi/spi.h>
25#include <linux/string.h>
26
27/* Register offset, see manual section 8.2 */
28#define REG_START_OSCILLATION 0x00
29#define REG_DRIVER_CODE_READ 0x00
30#define REG_DRIVER_OUTPUT_CONTROL 0x01
31#define REG_LCD_AC_DRIVEING_CONTROL 0x02
32#define REG_ENTRY_MODE 0x03
33#define REG_COMPARE_1 0x04
34#define REG_COMPARE_2 0x05
35#define REG_DISPLAY_CONTROL_1 0x07
36#define REG_DISPLAY_CONTROL_2 0x08
37#define REG_DISPLAY_CONTROL_3 0x09
38#define REG_FRAME_CYCLE_CONTROL 0x0B
39#define REG_EXT_INTF_CONTROL 0x0C
40#define REG_POWER_CONTROL_1 0x10
41#define REG_POWER_CONTROL_2 0x11
42#define REG_POWER_CONTROL_3 0x12
43#define REG_POWER_CONTROL_4 0x13
44#define REG_RAM_ADDRESS_SET 0x21
45#define REG_WRITE_DATA_TO_GRAM 0x22
46#define REG_RAM_WRITE_MASK1 0x23
47#define REG_RAM_WRITE_MASK2 0x24
48#define REG_GAMMA_CONTROL_1 0x30
49#define REG_GAMMA_CONTROL_2 0x31
50#define REG_GAMMA_CONTROL_3 0x32
51#define REG_GAMMA_CONTROL_4 0x33
52#define REG_GAMMA_CONTROL_5 0x34
53#define REG_GAMMA_CONTROL_6 0x35
54#define REG_GAMMA_CONTROL_7 0x36
55#define REG_GAMMA_CONTROL_8 0x37
56#define REG_GAMMA_CONTROL_9 0x38
57#define REG_GAMMA_CONTROL_10 0x39
58#define REG_GATE_SCAN_CONTROL 0x40
59#define REG_VERT_SCROLL_CONTROL 0x41
60#define REG_FIRST_SCREEN_DRIVE_POS 0x42
61#define REG_SECOND_SCREEN_DRIVE_POS 0x43
62#define REG_RAM_ADDR_POS_H 0x44
63#define REG_RAM_ADDR_POS_V 0x45
64#define REG_OSCILLATOR_CONTROL 0x4F
65#define REG_GPIO 0x60
66#define REG_OTP_VCM_PROGRAMMING 0x61
67#define REG_OTP_VCM_STATUS_ENABLE 0x62
68#define REG_OTP_PROGRAMMING_ID_KEY 0x65
69
70/*
71 * maximum frequency for register access
72 * (not for the GRAM access)
73 */
74#define ILITEK_MAX_FREQ_REG 4000000
75
76/*
77 * Device ID as found in the datasheet (supports 9221 and 9222)
78 */
79#define ILITEK_DEVICE_ID 0x9220
80#define ILITEK_DEVICE_ID_MASK 0xFFF0
81
82/* Last two bits in the START BYTE */
83#define START_RS_INDEX 0
84#define START_RS_REG 1
85#define START_RW_WRITE 0
86#define START_RW_READ 1
87
88/**
89 * START_BYTE(id, rs, rw)
90 *
91 * Set the start byte according to the required operation.
92 * The start byte is defined as:
93 * ----------------------------------
94 * | 0 | 1 | 1 | 1 | 0 | ID | RS | RW |
95 * ----------------------------------
96 * @id: display's id as set by the manufacturer
97 * @rs: operation type bit, one of:
98 * - START_RS_INDEX set the index register
99 * - START_RS_REG write/read registers/GRAM
100 * @rw: read/write operation
101 * - START_RW_WRITE write
102 * - START_RW_READ read
103 */
104#define START_BYTE(id, rs, rw) \
105 (0x70 | (((id) & 0x01) << 2) | (((rs) & 0x01) << 1) | ((rw) & 0x01))
106
107/**
108 * CHECK_FREQ_REG(spi_device s, spi_transfer x) - Check the frequency
109 * for the SPI transfer. According to the datasheet, the controller
110 * accept higher frequency for the GRAM transfer, but it requires
111 * lower frequency when the registers are read/written.
112 * The macro sets the frequency in the spi_transfer structure if
113 * the frequency exceeds the maximum value.
114 */
115#define CHECK_FREQ_REG(s, x) \
116 do { \
117 if (s->max_speed_hz > ILITEK_MAX_FREQ_REG) \
118 ((struct spi_transfer *)x)->speed_hz = \
119 ILITEK_MAX_FREQ_REG; \
120 } while (0)
121
122#define CMD_BUFSIZE 16
123
124#define POWER_IS_ON(pwr) ((pwr) <= FB_BLANK_NORMAL)
125
126#define set_tx_byte(b) (tx_invert ? ~(b) : b)
127
128/**
129 * ili922x_id - id as set by manufacturer
130 */
131static int ili922x_id = 1;
132module_param(ili922x_id, int, 0);
133
134static int tx_invert;
135module_param(tx_invert, int, 0);
136
137/**
138 * driver's private structure
139 */
140struct ili922x {
141 struct spi_device *spi;
142 struct lcd_device *ld;
143 int power;
144};
145
146/**
147 * ili922x_read_status - read status register from display
148 * @spi: spi device
149 * @rs: output value
150 */
151static int ili922x_read_status(struct spi_device *spi, u16 *rs)
152{
153 struct spi_message msg;
154 struct spi_transfer xfer;
155 unsigned char tbuf[CMD_BUFSIZE];
156 unsigned char rbuf[CMD_BUFSIZE];
157 int ret, i;
158
159 memset(&xfer, 0, sizeof(struct spi_transfer));
160 spi_message_init(&msg);
161 xfer.tx_buf = tbuf;
162 xfer.rx_buf = rbuf;
163 xfer.cs_change = 1;
164 CHECK_FREQ_REG(spi, &xfer);
165
166 tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_INDEX,
167 START_RW_READ));
168 /*
169 * we need 4-byte xfer here due to invalid dummy byte
170 * received after start byte
171 */
172 for (i = 1; i < 4; i++)
173 tbuf[i] = set_tx_byte(0); /* dummy */
174
175 xfer.bits_per_word = 8;
176 xfer.len = 4;
177 spi_message_add_tail(&xfer, &msg);
178 ret = spi_sync(spi, &msg);
179 if (ret < 0) {
180 dev_dbg(&spi->dev, "Error sending SPI message 0x%x", ret);
181 return ret;
182 }
183
184 *rs = (rbuf[2] << 8) + rbuf[3];
185 return 0;
186}
187
188/**
189 * ili922x_read - read register from display
190 * @spi: spi device
191 * @reg: offset of the register to be read
192 * @rx: output value
193 */
194static int ili922x_read(struct spi_device *spi, u8 reg, u16 *rx)
195{
196 struct spi_message msg;
197 struct spi_transfer xfer_regindex, xfer_regvalue;
198 unsigned char tbuf[CMD_BUFSIZE];
199 unsigned char rbuf[CMD_BUFSIZE];
200 int ret, len = 0, send_bytes;
201
202 memset(&xfer_regindex, 0, sizeof(struct spi_transfer));
203 memset(&xfer_regvalue, 0, sizeof(struct spi_transfer));
204 spi_message_init(&msg);
205 xfer_regindex.tx_buf = tbuf;
206 xfer_regindex.rx_buf = rbuf;
207 xfer_regindex.cs_change = 1;
208 CHECK_FREQ_REG(spi, &xfer_regindex);
209
210 tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_INDEX,
211 START_RW_WRITE));
212 tbuf[1] = set_tx_byte(0);
213 tbuf[2] = set_tx_byte(reg);
214 xfer_regindex.bits_per_word = 8;
215 len = xfer_regindex.len = 3;
216 spi_message_add_tail(&xfer_regindex, &msg);
217
218 send_bytes = len;
219
220 tbuf[len++] = set_tx_byte(START_BYTE(ili922x_id, START_RS_REG,
221 START_RW_READ));
222 tbuf[len++] = set_tx_byte(0);
223 tbuf[len] = set_tx_byte(0);
224
225 xfer_regvalue.cs_change = 1;
226 xfer_regvalue.len = 3;
227 xfer_regvalue.tx_buf = &tbuf[send_bytes];
228 xfer_regvalue.rx_buf = &rbuf[send_bytes];
229 CHECK_FREQ_REG(spi, &xfer_regvalue);
230
231 spi_message_add_tail(&xfer_regvalue, &msg);
232 ret = spi_sync(spi, &msg);
233 if (ret < 0) {
234 dev_dbg(&spi->dev, "Error sending SPI message 0x%x", ret);
235 return ret;
236 }
237
238 *rx = (rbuf[1 + send_bytes] << 8) + rbuf[2 + send_bytes];
239 return 0;
240}
241
242/**
243 * ili922x_write - write a controller register
244 * @spi: struct spi_device *
245 * @reg: offset of the register to be written
246 * @value: value to be written
247 */
248static int ili922x_write(struct spi_device *spi, u8 reg, u16 value)
249{
250 struct spi_message msg;
251 struct spi_transfer xfer_regindex, xfer_regvalue;
252 unsigned char tbuf[CMD_BUFSIZE];
253 unsigned char rbuf[CMD_BUFSIZE];
254 int ret, len = 0;
255
256 memset(&xfer_regindex, 0, sizeof(struct spi_transfer));
257 memset(&xfer_regvalue, 0, sizeof(struct spi_transfer));
258
259 spi_message_init(&msg);
260 xfer_regindex.tx_buf = tbuf;
261 xfer_regindex.rx_buf = rbuf;
262 xfer_regindex.cs_change = 1;
263 CHECK_FREQ_REG(spi, &xfer_regindex);
264
265 tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_INDEX,
266 START_RW_WRITE));
267 tbuf[1] = set_tx_byte(0);
268 tbuf[2] = set_tx_byte(reg);
269 xfer_regindex.bits_per_word = 8;
270 xfer_regindex.len = 3;
271 spi_message_add_tail(&xfer_regindex, &msg);
272
273 ret = spi_sync(spi, &msg);
274
275 spi_message_init(&msg);
276 len = 0;
277 tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_REG,
278 START_RW_WRITE));
279 tbuf[1] = set_tx_byte((value & 0xFF00) >> 8);
280 tbuf[2] = set_tx_byte(value & 0x00FF);
281
282 xfer_regvalue.cs_change = 1;
283 xfer_regvalue.len = 3;
284 xfer_regvalue.tx_buf = tbuf;
285 xfer_regvalue.rx_buf = rbuf;
286 CHECK_FREQ_REG(spi, &xfer_regvalue);
287
288 spi_message_add_tail(&xfer_regvalue, &msg);
289
290 ret = spi_sync(spi, &msg);
291 if (ret < 0) {
292 dev_err(&spi->dev, "Error sending SPI message 0x%x", ret);
293 return ret;
294 }
295 return 0;
296}
297
298#ifdef DEBUG
299/**
300 * ili922x_reg_dump - dump all registers
301 */
302static void ili922x_reg_dump(struct spi_device *spi)
303{
304 u8 reg;
305 u16 rx;
306
307 dev_dbg(&spi->dev, "ILI922x configuration registers:\n");
308 for (reg = REG_START_OSCILLATION;
309 reg <= REG_OTP_PROGRAMMING_ID_KEY; reg++) {
310 ili922x_read(spi, reg, &rx);
311 dev_dbg(&spi->dev, "reg @ 0x%02X: 0x%04X\n", reg, rx);
312 }
313}
314#else
315static inline void ili922x_reg_dump(struct spi_device *spi) {}
316#endif
317
318/**
319 * set_write_to_gram_reg - initialize the display to write the GRAM
320 * @spi: spi device
321 */
322static void set_write_to_gram_reg(struct spi_device *spi)
323{
324 struct spi_message msg;
325 struct spi_transfer xfer;
326 unsigned char tbuf[CMD_BUFSIZE];
327
328 memset(&xfer, 0, sizeof(struct spi_transfer));
329
330 spi_message_init(&msg);
331 xfer.tx_buf = tbuf;
332 xfer.rx_buf = NULL;
333 xfer.cs_change = 1;
334
335 tbuf[0] = START_BYTE(ili922x_id, START_RS_INDEX, START_RW_WRITE);
336 tbuf[1] = 0;
337 tbuf[2] = REG_WRITE_DATA_TO_GRAM;
338
339 xfer.bits_per_word = 8;
340 xfer.len = 3;
341 spi_message_add_tail(&xfer, &msg);
342 spi_sync(spi, &msg);
343}
344
345/**
346 * ili922x_poweron - turn the display on
347 * @spi: spi device
348 *
349 * The sequence to turn on the display is taken from
350 * the datasheet and/or the example code provided by the
351 * manufacturer.
352 */
353static int ili922x_poweron(struct spi_device *spi)
354{
355 int ret;
356
357 /* Power on */
358 ret = ili922x_write(spi, REG_POWER_CONTROL_1, 0x0000);
359 usleep_range(10000, 10500);
360 ret += ili922x_write(spi, REG_POWER_CONTROL_2, 0x0000);
361 ret += ili922x_write(spi, REG_POWER_CONTROL_3, 0x0000);
362 msleep(40);
363 ret += ili922x_write(spi, REG_POWER_CONTROL_4, 0x0000);
364 msleep(40);
365 /* register 0x56 is not documented in the datasheet */
366 ret += ili922x_write(spi, 0x56, 0x080F);
367 ret += ili922x_write(spi, REG_POWER_CONTROL_1, 0x4240);
368 usleep_range(10000, 10500);
369 ret += ili922x_write(spi, REG_POWER_CONTROL_2, 0x0000);
370 ret += ili922x_write(spi, REG_POWER_CONTROL_3, 0x0014);
371 msleep(40);
372 ret += ili922x_write(spi, REG_POWER_CONTROL_4, 0x1319);
373 msleep(40);
374
375 return ret;
376}
377
378/**
379 * ili922x_poweroff - turn the display off
380 * @spi: spi device
381 */
382static int ili922x_poweroff(struct spi_device *spi)
383{
384 int ret;
385
386 /* Power off */
387 ret = ili922x_write(spi, REG_POWER_CONTROL_1, 0x0000);
388 usleep_range(10000, 10500);
389 ret += ili922x_write(spi, REG_POWER_CONTROL_2, 0x0000);
390 ret += ili922x_write(spi, REG_POWER_CONTROL_3, 0x0000);
391 msleep(40);
392 ret += ili922x_write(spi, REG_POWER_CONTROL_4, 0x0000);
393 msleep(40);
394
395 return ret;
396}
397
398/**
399 * ili922x_display_init - initialize the display by setting
400 * the configuration registers
401 * @spi: spi device
402 */
403static void ili922x_display_init(struct spi_device *spi)
404{
405 ili922x_write(spi, REG_START_OSCILLATION, 1);
406 usleep_range(10000, 10500);
407 ili922x_write(spi, REG_DRIVER_OUTPUT_CONTROL, 0x691B);
408 ili922x_write(spi, REG_LCD_AC_DRIVEING_CONTROL, 0x0700);
409 ili922x_write(spi, REG_ENTRY_MODE, 0x1030);
410 ili922x_write(spi, REG_COMPARE_1, 0x0000);
411 ili922x_write(spi, REG_COMPARE_2, 0x0000);
412 ili922x_write(spi, REG_DISPLAY_CONTROL_1, 0x0037);
413 ili922x_write(spi, REG_DISPLAY_CONTROL_2, 0x0202);
414 ili922x_write(spi, REG_DISPLAY_CONTROL_3, 0x0000);
415 ili922x_write(spi, REG_FRAME_CYCLE_CONTROL, 0x0000);
416
417 /* Set RGB interface */
418 ili922x_write(spi, REG_EXT_INTF_CONTROL, 0x0110);
419
420 ili922x_poweron(spi);
421
422 ili922x_write(spi, REG_GAMMA_CONTROL_1, 0x0302);
423 ili922x_write(spi, REG_GAMMA_CONTROL_2, 0x0407);
424 ili922x_write(spi, REG_GAMMA_CONTROL_3, 0x0304);
425 ili922x_write(spi, REG_GAMMA_CONTROL_4, 0x0203);
426 ili922x_write(spi, REG_GAMMA_CONTROL_5, 0x0706);
427 ili922x_write(spi, REG_GAMMA_CONTROL_6, 0x0407);
428 ili922x_write(spi, REG_GAMMA_CONTROL_7, 0x0706);
429 ili922x_write(spi, REG_GAMMA_CONTROL_8, 0x0000);
430 ili922x_write(spi, REG_GAMMA_CONTROL_9, 0x0C06);
431 ili922x_write(spi, REG_GAMMA_CONTROL_10, 0x0F00);
432 ili922x_write(spi, REG_RAM_ADDRESS_SET, 0x0000);
433 ili922x_write(spi, REG_GATE_SCAN_CONTROL, 0x0000);
434 ili922x_write(spi, REG_VERT_SCROLL_CONTROL, 0x0000);
435 ili922x_write(spi, REG_FIRST_SCREEN_DRIVE_POS, 0xDB00);
436 ili922x_write(spi, REG_SECOND_SCREEN_DRIVE_POS, 0xDB00);
437 ili922x_write(spi, REG_RAM_ADDR_POS_H, 0xAF00);
438 ili922x_write(spi, REG_RAM_ADDR_POS_V, 0xDB00);
439 ili922x_reg_dump(spi);
440 set_write_to_gram_reg(spi);
441}
442
443static int ili922x_lcd_power(struct ili922x *lcd, int power)
444{
445 int ret = 0;
446
447 if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
448 ret = ili922x_poweron(lcd->spi);
449 else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
450 ret = ili922x_poweroff(lcd->spi);
451
452 if (!ret)
453 lcd->power = power;
454
455 return ret;
456}
457
458static int ili922x_set_power(struct lcd_device *ld, int power)
459{
460 struct ili922x *ili = lcd_get_data(ld);
461
462 return ili922x_lcd_power(ili, power);
463}
464
465static int ili922x_get_power(struct lcd_device *ld)
466{
467 struct ili922x *ili = lcd_get_data(ld);
468
469 return ili->power;
470}
471
472static struct lcd_ops ili922x_ops = {
473 .get_power = ili922x_get_power,
474 .set_power = ili922x_set_power,
475};
476
477static int ili922x_probe(struct spi_device *spi)
478{
479 struct ili922x *ili;
480 struct lcd_device *lcd;
481 int ret;
482 u16 reg = 0;
483
484 ili = devm_kzalloc(&spi->dev, sizeof(*ili), GFP_KERNEL);
Jingoo Han619e1b42014-04-03 14:49:01 -0700485 if (!ili)
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700486 return -ENOMEM;
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700487
488 ili->spi = spi;
Jingoo Han40d88fc2013-04-29 16:17:57 -0700489 spi_set_drvdata(spi, ili);
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700490
491 /* check if the device is connected */
492 ret = ili922x_read(spi, REG_DRIVER_CODE_READ, &reg);
493 if (ret || ((reg & ILITEK_DEVICE_ID_MASK) != ILITEK_DEVICE_ID)) {
494 dev_err(&spi->dev,
495 "no LCD found: Chip ID 0x%x, ret %d\n",
496 reg, ret);
497 return -ENODEV;
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700498 }
499
Jingoo Han547f60c2014-08-27 10:11:33 +0900500 dev_info(&spi->dev, "ILI%x found, SPI freq %d, mode %d\n",
501 reg, spi->max_speed_hz, spi->mode);
502
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700503 ret = ili922x_read_status(spi, &reg);
504 if (ret) {
505 dev_err(&spi->dev, "reading RS failed...\n");
506 return ret;
Jingoo Han547f60c2014-08-27 10:11:33 +0900507 }
508
509 dev_dbg(&spi->dev, "status: 0x%x\n", reg);
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700510
511 ili922x_display_init(spi);
512
513 ili->power = FB_BLANK_POWERDOWN;
514
Jingoo Hana7e9e3f2013-11-12 15:09:26 -0800515 lcd = devm_lcd_device_register(&spi->dev, "ili922xlcd", &spi->dev, ili,
516 &ili922x_ops);
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700517 if (IS_ERR(lcd)) {
518 dev_err(&spi->dev, "cannot register LCD\n");
519 return PTR_ERR(lcd);
520 }
521
522 ili->ld = lcd;
523 spi_set_drvdata(spi, ili);
524
525 ili922x_lcd_power(ili, FB_BLANK_UNBLANK);
526
527 return 0;
528}
529
530static int ili922x_remove(struct spi_device *spi)
531{
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700532 ili922x_poweroff(spi);
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700533 return 0;
534}
535
536static struct spi_driver ili922x_driver = {
537 .driver = {
538 .name = "ili922x",
Stefano Babic4cfbfa92013-04-29 16:17:50 -0700539 },
540 .probe = ili922x_probe,
541 .remove = ili922x_remove,
542};
543
544module_spi_driver(ili922x_driver);
545
546MODULE_AUTHOR("Stefano Babic <sbabic@denx.de>");
547MODULE_DESCRIPTION("ILI9221/9222 LCD driver");
548MODULE_LICENSE("GPL");
549MODULE_PARM_DESC(ili922x_id, "set controller identifier (default=1)");
550MODULE_PARM_DESC(tx_invert, "invert bytes before sending");