1 // SPDX-License-Identifier: GPL-2.0-only
2 /* drivers/video/backlight/ili9320.c
3  *
4  * ILI9320 LCD controller driver core.
5  *
6  * Copyright 2007 Simtec Electronics
7  *	http://armlinux.simtec.co.uk/
8  *	Ben Dooks <ben@simtec.co.uk>
9 */
10 
11 #include <linux/delay.h>
12 #include <linux/err.h>
13 #include <linux/fb.h>
14 #include <linux/init.h>
15 #include <linux/lcd.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 
19 #include <linux/spi/spi.h>
20 
21 #include <video/ili9320.h>
22 
23 #include "ili9320.h"
24 
25 
26 static inline int ili9320_write_spi(struct ili9320 *ili,
27 				    unsigned int reg,
28 				    unsigned int value)
29 {
30 	struct ili9320_spi *spi = &ili->access.spi;
31 	unsigned char *addr = spi->buffer_addr;
32 	unsigned char *data = spi->buffer_data;
33 
34 	/* spi message consits of:
35 	 * first byte: ID and operation
36 	 */
37 
38 	addr[0] = spi->id | ILI9320_SPI_INDEX | ILI9320_SPI_WRITE;
39 	addr[1] = reg >> 8;
40 	addr[2] = reg;
41 
42 	/* second message is the data to transfer */
43 
44 	data[0] = spi->id | ILI9320_SPI_DATA  | ILI9320_SPI_WRITE;
45 	data[1] = value >> 8;
46 	data[2] = value;
47 
48 	return spi_sync(spi->dev, &spi->message);
49 }
50 
51 int ili9320_write(struct ili9320 *ili, unsigned int reg, unsigned int value)
52 {
53 	dev_dbg(ili->dev, "write: reg=%02x, val=%04x\n", reg, value);
54 	return ili->write(ili, reg, value);
55 }
56 EXPORT_SYMBOL_GPL(ili9320_write);
57 
58 int ili9320_write_regs(struct ili9320 *ili,
59 		       const struct ili9320_reg *values,
60 		       int nr_values)
61 {
62 	int index;
63 	int ret;
64 
65 	for (index = 0; index < nr_values; index++, values++) {
66 		ret = ili9320_write(ili, values->address, values->value);
67 		if (ret != 0)
68 			return ret;
69 	}
70 
71 	return 0;
72 }
73 EXPORT_SYMBOL_GPL(ili9320_write_regs);
74 
75 static void ili9320_reset(struct ili9320 *lcd)
76 {
77 	struct ili9320_platdata *cfg = lcd->platdata;
78 
79 	cfg->reset(1);
80 	mdelay(50);
81 
82 	cfg->reset(0);
83 	mdelay(50);
84 
85 	cfg->reset(1);
86 	mdelay(100);
87 }
88 
89 static inline int ili9320_init_chip(struct ili9320 *lcd)
90 {
91 	int ret;
92 
93 	ili9320_reset(lcd);
94 
95 	ret = lcd->client->init(lcd, lcd->platdata);
96 	if (ret != 0) {
97 		dev_err(lcd->dev, "failed to initialise display\n");
98 		return ret;
99 	}
100 
101 	lcd->initialised = 1;
102 	return 0;
103 }
104 
105 static inline int ili9320_power_on(struct ili9320 *lcd)
106 {
107 	if (!lcd->initialised)
108 		ili9320_init_chip(lcd);
109 
110 	lcd->display1 |= (ILI9320_DISPLAY1_D(3) | ILI9320_DISPLAY1_BASEE);
111 	ili9320_write(lcd, ILI9320_DISPLAY1, lcd->display1);
112 
113 	return 0;
114 }
115 
116 static inline int ili9320_power_off(struct ili9320 *lcd)
117 {
118 	lcd->display1 &= ~(ILI9320_DISPLAY1_D(3) | ILI9320_DISPLAY1_BASEE);
119 	ili9320_write(lcd, ILI9320_DISPLAY1, lcd->display1);
120 
121 	return 0;
122 }
123 
124 #define POWER_IS_ON(pwr)	((pwr) <= FB_BLANK_NORMAL)
125 
126 static int ili9320_power(struct ili9320 *lcd, int power)
127 {
128 	int ret = 0;
129 
130 	dev_dbg(lcd->dev, "power %d => %d\n", lcd->power, power);
131 
132 	if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
133 		ret = ili9320_power_on(lcd);
134 	else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
135 		ret = ili9320_power_off(lcd);
136 
137 	if (ret == 0)
138 		lcd->power = power;
139 	else
140 		dev_warn(lcd->dev, "failed to set power mode %d\n", power);
141 
142 	return ret;
143 }
144 
145 static inline struct ili9320 *to_our_lcd(struct lcd_device *lcd)
146 {
147 	return lcd_get_data(lcd);
148 }
149 
150 static int ili9320_set_power(struct lcd_device *ld, int power)
151 {
152 	struct ili9320 *lcd = to_our_lcd(ld);
153 
154 	return ili9320_power(lcd, power);
155 }
156 
157 static int ili9320_get_power(struct lcd_device *ld)
158 {
159 	struct ili9320 *lcd = to_our_lcd(ld);
160 
161 	return lcd->power;
162 }
163 
164 static struct lcd_ops ili9320_ops = {
165 	.get_power	= ili9320_get_power,
166 	.set_power	= ili9320_set_power,
167 };
168 
169 static void ili9320_setup_spi(struct ili9320 *ili,
170 					struct spi_device *dev)
171 {
172 	struct ili9320_spi *spi = &ili->access.spi;
173 
174 	ili->write = ili9320_write_spi;
175 	spi->dev = dev;
176 
177 	/* fill the two messages we are going to use to send the data
178 	 * with, the first the address followed by the data. The datasheet
179 	 * says they should be done as two distinct cycles of the SPI CS line.
180 	 */
181 
182 	spi->xfer[0].tx_buf = spi->buffer_addr;
183 	spi->xfer[1].tx_buf = spi->buffer_data;
184 	spi->xfer[0].len = 3;
185 	spi->xfer[1].len = 3;
186 	spi->xfer[0].bits_per_word = 8;
187 	spi->xfer[1].bits_per_word = 8;
188 	spi->xfer[0].cs_change = 1;
189 
190 	spi_message_init(&spi->message);
191 	spi_message_add_tail(&spi->xfer[0], &spi->message);
192 	spi_message_add_tail(&spi->xfer[1], &spi->message);
193 }
194 
195 int ili9320_probe_spi(struct spi_device *spi,
196 				struct ili9320_client *client)
197 {
198 	struct ili9320_platdata *cfg = dev_get_platdata(&spi->dev);
199 	struct device *dev = &spi->dev;
200 	struct ili9320 *ili;
201 	struct lcd_device *lcd;
202 	int ret = 0;
203 
204 	/* verify we where given some information */
205 
206 	if (cfg == NULL) {
207 		dev_err(dev, "no platform data supplied\n");
208 		return -EINVAL;
209 	}
210 
211 	if (cfg->hsize <= 0 || cfg->vsize <= 0 || cfg->reset == NULL) {
212 		dev_err(dev, "invalid platform data supplied\n");
213 		return -EINVAL;
214 	}
215 
216 	/* allocate and initialse our state */
217 
218 	ili = devm_kzalloc(&spi->dev, sizeof(struct ili9320), GFP_KERNEL);
219 	if (ili == NULL)
220 		return -ENOMEM;
221 
222 	ili->access.spi.id = ILI9320_SPI_IDCODE | ILI9320_SPI_ID(1);
223 
224 	ili->dev = dev;
225 	ili->client = client;
226 	ili->power = FB_BLANK_POWERDOWN;
227 	ili->platdata = cfg;
228 
229 	spi_set_drvdata(spi, ili);
230 
231 	ili9320_setup_spi(ili, spi);
232 
233 	lcd = devm_lcd_device_register(&spi->dev, "ili9320", dev, ili,
234 					&ili9320_ops);
235 	if (IS_ERR(lcd)) {
236 		dev_err(dev, "failed to register lcd device\n");
237 		return PTR_ERR(lcd);
238 	}
239 
240 	ili->lcd = lcd;
241 
242 	dev_info(dev, "initialising %s\n", client->name);
243 
244 	ret = ili9320_power(ili, FB_BLANK_UNBLANK);
245 	if (ret != 0) {
246 		dev_err(dev, "failed to set lcd power state\n");
247 		return ret;
248 	}
249 
250 	return 0;
251 }
252 EXPORT_SYMBOL_GPL(ili9320_probe_spi);
253 
254 void ili9320_remove(struct ili9320 *ili)
255 {
256 	ili9320_power(ili, FB_BLANK_POWERDOWN);
257 }
258 EXPORT_SYMBOL_GPL(ili9320_remove);
259 
260 #ifdef CONFIG_PM_SLEEP
261 int ili9320_suspend(struct ili9320 *lcd)
262 {
263 	int ret;
264 
265 	ret = ili9320_power(lcd, FB_BLANK_POWERDOWN);
266 
267 	if (lcd->platdata->suspend == ILI9320_SUSPEND_DEEP) {
268 		ili9320_write(lcd, ILI9320_POWER1, lcd->power1 |
269 			      ILI9320_POWER1_SLP |
270 			      ILI9320_POWER1_DSTB);
271 		lcd->initialised = 0;
272 	}
273 
274 	return ret;
275 }
276 EXPORT_SYMBOL_GPL(ili9320_suspend);
277 
278 int ili9320_resume(struct ili9320 *lcd)
279 {
280 	dev_info(lcd->dev, "resuming from power state %d\n", lcd->power);
281 
282 	if (lcd->platdata->suspend == ILI9320_SUSPEND_DEEP)
283 		ili9320_write(lcd, ILI9320_POWER1, 0x00);
284 
285 	return ili9320_power(lcd, FB_BLANK_UNBLANK);
286 }
287 EXPORT_SYMBOL_GPL(ili9320_resume);
288 #endif
289 
290 /* Power down all displays on reboot, poweroff or halt */
291 void ili9320_shutdown(struct ili9320 *lcd)
292 {
293 	ili9320_power(lcd, FB_BLANK_POWERDOWN);
294 }
295 EXPORT_SYMBOL_GPL(ili9320_shutdown);
296 
297 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
298 MODULE_DESCRIPTION("ILI9320 LCD Driver");
299 MODULE_LICENSE("GPL v2");
300