226d813edf011dfa20d463cd8801a1c83a0fba3f
[~shefty/rdma-dev.git] / drivers / video / backlight / ltv350qv.c
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 = lcd_device_register("ltv350qv", &spi->dev, lcd, &ltv_ops);
246         if (IS_ERR(ld))
247                 return PTR_ERR(ld);
248
249         lcd->ld = ld;
250
251         ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
252         if (ret)
253                 goto out_unregister;
254
255         dev_set_drvdata(&spi->dev, lcd);
256
257         return 0;
258
259 out_unregister:
260         lcd_device_unregister(ld);
261         return ret;
262 }
263
264 static int ltv350qv_remove(struct spi_device *spi)
265 {
266         struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
267
268         ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
269         lcd_device_unregister(lcd->ld);
270
271         return 0;
272 }
273
274 #ifdef CONFIG_PM
275 static int ltv350qv_suspend(struct spi_device *spi, pm_message_t state)
276 {
277         struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
278
279         return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
280 }
281
282 static int ltv350qv_resume(struct spi_device *spi)
283 {
284         struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
285
286         return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
287 }
288 #else
289 #define ltv350qv_suspend        NULL
290 #define ltv350qv_resume         NULL
291 #endif
292
293 /* Power down all displays on reboot, poweroff or halt */
294 static void ltv350qv_shutdown(struct spi_device *spi)
295 {
296         struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
297
298         ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
299 }
300
301 static struct spi_driver ltv350qv_driver = {
302         .driver = {
303                 .name           = "ltv350qv",
304                 .owner          = THIS_MODULE,
305         },
306
307         .probe          = ltv350qv_probe,
308         .remove         = ltv350qv_remove,
309         .shutdown       = ltv350qv_shutdown,
310         .suspend        = ltv350qv_suspend,
311         .resume         = ltv350qv_resume,
312 };
313
314 module_spi_driver(ltv350qv_driver);
315
316 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
317 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
318 MODULE_LICENSE("GPL");
319 MODULE_ALIAS("spi:ltv350qv");