1 /*
2  * Power control for Samsung LTV350QV Quarter VGA LCD Panel
3  *
4  * Copyright (C) 2006, 2007 Atmel Corporation
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/fb.h>
13 #include <linux/init.h>
14 #include <linux/lcd.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/spi/spi.h>
18 
19 #include "ltv350qv.h"
20 
21 #define POWER_IS_ON(pwr)	((pwr) <= FB_BLANK_NORMAL)
22 
23 struct ltv350qv {
24 	struct spi_device	*spi;
25 	u8			*buffer;
26 	int			power;
27 	struct lcd_device	*ld;
28 };
29 
30 /*
31  * The power-on and power-off sequences are taken from the
32  * LTV350QV-F04 data sheet from Samsung. The register definitions are
33  * taken from the S6F2002 command list also from Samsung. Both
34  * documents are distributed with the AVR32 Linux BSP CD from Atmel.
35  *
36  * There's still some voodoo going on here, but it's a lot better than
37  * in the first incarnation of the driver where all we had was the raw
38  * numbers from the initialization sequence.
39  */
40 static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)
41 {
42 	struct spi_message msg;
43 	struct spi_transfer index_xfer = {
44 		.len		= 3,
45 		.cs_change	= 1,
46 	};
47 	struct spi_transfer value_xfer = {
48 		.len		= 3,
49 	};
50 
51 	spi_message_init(&msg);
52 
53 	/* register index */
54 	lcd->buffer[0] = LTV_OPC_INDEX;
55 	lcd->buffer[1] = 0x00;
56 	lcd->buffer[2] = reg & 0x7f;
57 	index_xfer.tx_buf = lcd->buffer;
58 	spi_message_add_tail(&index_xfer, &msg);
59 
60 	/* register value */
61 	lcd->buffer[4] = LTV_OPC_DATA;
62 	lcd->buffer[5] = val >> 8;
63 	lcd->buffer[6] = val;
64 	value_xfer.tx_buf = lcd->buffer + 4;
65 	spi_message_add_tail(&value_xfer, &msg);
66 
67 	return spi_sync(lcd->spi, &msg);
68 }
69 
70 /* The comments are taken straight from the data sheet */
71 static int ltv350qv_power_on(struct ltv350qv *lcd)
72 {
73 	int ret;
74 
75 	/* Power On Reset Display off State */
76 	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))
77 		goto err;
78 	usleep_range(15000, 16000);
79 
80 	/* Power Setting Function 1 */
81 	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))
82 		goto err;
83 	if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))
84 		goto err_power1;
85 
86 	/* Power Setting Function 2 */
87 	if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,
88 			       LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
89 			       | LTV_SUPPLY_CURRENT(5)))
90 		goto err_power2;
91 
92 	msleep(55);
93 
94 	/* Instruction Setting */
95 	ret = ltv350qv_write_reg(lcd, LTV_IFCTL,
96 				 LTV_NMD | LTV_REV | LTV_NL(0x1d));
97 	ret |= ltv350qv_write_reg(lcd, LTV_DATACTL,
98 				  LTV_DS_SAME | LTV_CHS_480
99 				  | LTV_DF_RGB | LTV_RGB_BGR);
100 	ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,
101 				  LTV_VSPL_ACTIVE_LOW
102 				  | LTV_HSPL_ACTIVE_LOW
103 				  | LTV_DPL_SAMPLE_RISING
104 				  | LTV_EPL_ACTIVE_LOW
105 				  | LTV_SS_RIGHT_TO_LEFT);
106 	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));
107 	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
108 				  LTV_NW_INV_1LINE | LTV_FWI(3));
109 	ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);
110 	ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);
111 	ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0));
112 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);
113 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);
114 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);
115 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);
116 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);
117 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);
118 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);
119 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);
120 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);
121 	ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);
122 	if (ret)
123 		goto err_settings;
124 
125 	/* Wait more than 2 frames */
126 	msleep(20);
127 
128 	/* Display On Sequence */
129 	ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
130 				 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE
131 				 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5)
132 				 | LTV_SUPPLY_CURRENT(5));
133 	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
134 				  LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3));
135 	if (ret)
136 		goto err_disp_on;
137 
138 	/* Display should now be ON. Phew. */
139 	return 0;
140 
141 err_disp_on:
142 	/*
143 	 * Try to recover. Error handling probably isn't very useful
144 	 * at this point, just make a best effort to switch the panel
145 	 * off.
146 	 */
147 	ltv350qv_write_reg(lcd, LTV_PWRCTL1,
148 			   LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
149 			   | LTV_SUPPLY_CURRENT(5));
150 	ltv350qv_write_reg(lcd, LTV_GATECTL2,
151 			   LTV_NW_INV_1LINE | LTV_FWI(3));
152 err_settings:
153 err_power2:
154 err_power1:
155 	ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
156 	usleep_range(1000, 1100);
157 err:
158 	ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
159 	return -EIO;
160 }
161 
162 static int ltv350qv_power_off(struct ltv350qv *lcd)
163 {
164 	int ret;
165 
166 	/* Display Off Sequence */
167 	ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
168 				 LTV_VCOM_DISABLE
169 				 | LTV_DRIVE_CURRENT(5)
170 				 | LTV_SUPPLY_CURRENT(5));
171 	ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
172 				  LTV_NW_INV_1LINE | LTV_FWI(3));
173 
174 	/* Power down setting 1 */
175 	ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
176 
177 	/* Wait at least 1 ms */
178 	usleep_range(1000, 1100);
179 
180 	/* Power down setting 2 */
181 	ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
182 
183 	/*
184 	 * No point in trying to recover here. If we can't switch the
185 	 * panel off, what are we supposed to do other than inform the
186 	 * user about the failure?
187 	 */
188 	if (ret)
189 		return -EIO;
190 
191 	/* Display power should now be OFF */
192 	return 0;
193 }
194 
195 static int ltv350qv_power(struct ltv350qv *lcd, int power)
196 {
197 	int ret = 0;
198 
199 	if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
200 		ret = ltv350qv_power_on(lcd);
201 	else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
202 		ret = ltv350qv_power_off(lcd);
203 
204 	if (!ret)
205 		lcd->power = power;
206 
207 	return ret;
208 }
209 
210 static int ltv350qv_set_power(struct lcd_device *ld, int power)
211 {
212 	struct ltv350qv *lcd = lcd_get_data(ld);
213 
214 	return ltv350qv_power(lcd, power);
215 }
216 
217 static int ltv350qv_get_power(struct lcd_device *ld)
218 {
219 	struct ltv350qv *lcd = lcd_get_data(ld);
220 
221 	return lcd->power;
222 }
223 
224 static struct lcd_ops ltv_ops = {
225 	.get_power	= ltv350qv_get_power,
226 	.set_power	= ltv350qv_set_power,
227 };
228 
229 static int ltv350qv_probe(struct spi_device *spi)
230 {
231 	struct ltv350qv *lcd;
232 	struct lcd_device *ld;
233 	int ret;
234 
235 	lcd = devm_kzalloc(&spi->dev, sizeof(struct ltv350qv), GFP_KERNEL);
236 	if (!lcd)
237 		return -ENOMEM;
238 
239 	lcd->spi = spi;
240 	lcd->power = FB_BLANK_POWERDOWN;
241 	lcd->buffer = devm_kzalloc(&spi->dev, 8, GFP_KERNEL);
242 	if (!lcd->buffer)
243 		return -ENOMEM;
244 
245 	ld = devm_lcd_device_register(&spi->dev, "ltv350qv", &spi->dev, lcd,
246 					&ltv_ops);
247 	if (IS_ERR(ld))
248 		return PTR_ERR(ld);
249 
250 	lcd->ld = ld;
251 
252 	ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
253 	if (ret)
254 		return ret;
255 
256 	spi_set_drvdata(spi, lcd);
257 
258 	return 0;
259 }
260 
261 static int ltv350qv_remove(struct spi_device *spi)
262 {
263 	struct ltv350qv *lcd = spi_get_drvdata(spi);
264 
265 	ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
266 	return 0;
267 }
268 
269 #ifdef CONFIG_PM_SLEEP
270 static int ltv350qv_suspend(struct device *dev)
271 {
272 	struct ltv350qv *lcd = dev_get_drvdata(dev);
273 
274 	return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
275 }
276 
277 static int ltv350qv_resume(struct device *dev)
278 {
279 	struct ltv350qv *lcd = dev_get_drvdata(dev);
280 
281 	return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
282 }
283 #endif
284 
285 static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume);
286 
287 /* Power down all displays on reboot, poweroff or halt */
288 static void ltv350qv_shutdown(struct spi_device *spi)
289 {
290 	struct ltv350qv *lcd = spi_get_drvdata(spi);
291 
292 	ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
293 }
294 
295 static struct spi_driver ltv350qv_driver = {
296 	.driver = {
297 		.name		= "ltv350qv",
298 		.pm		= &ltv350qv_pm_ops,
299 	},
300 
301 	.probe		= ltv350qv_probe,
302 	.remove		= ltv350qv_remove,
303 	.shutdown	= ltv350qv_shutdown,
304 };
305 
306 module_spi_driver(ltv350qv_driver);
307 
308 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
309 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
310 MODULE_LICENSE("GPL");
311 MODULE_ALIAS("spi:ltv350qv");
312