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authorHaavard Skinnemoen <hskinnemoen@atmel.com>2007-09-02 18:15:49 -0400
committerRichard Purdie <rpurdie@rpsys.net>2007-10-11 17:24:12 -0400
commit18f65c793a5106b9f99822ef248e71582db03386 (patch)
tree48883c01d63487ac44753ea9cd5a782250bbbc88 /drivers/video/backlight/ltv350qv.c
parent0b75f2dfa2a67012ff6996b322117e1d7e45abe1 (diff)
backlight: Add Samsung LTV350QV LCD driver
This patch adds support for powering on and off the Samsung LTV350QV LCD panel via SPI. The driver responds to framebuffer power management, it powers off the panel on reboot/halt/poweroff. It can also be controlled through sysfs. The panel is powered up when the module is loaded, and off when the module is unloaded. Verified on AVR32 STK1000. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Diffstat (limited to 'drivers/video/backlight/ltv350qv.c')
-rw-r--r--drivers/video/backlight/ltv350qv.c330
1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/video/backlight/ltv350qv.c b/drivers/video/backlight/ltv350qv.c
new file mode 100644
index 000000000000..2eb206bf73e6
--- /dev/null
+++ b/drivers/video/backlight/ltv350qv.c
@@ -0,0 +1,330 @@
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/spi/spi.h>
17
18#include "ltv350qv.h"
19
20#define POWER_IS_ON(pwr) ((pwr) <= FB_BLANK_NORMAL)
21
22struct ltv350qv {
23 struct spi_device *spi;
24 u8 *buffer;
25 int power;
26 struct lcd_device *ld;
27};
28
29/*
30 * The power-on and power-off sequences are taken from the
31 * LTV350QV-F04 data sheet from Samsung. The register definitions are
32 * taken from the S6F2002 command list also from Samsung. Both
33 * documents are distributed with the AVR32 Linux BSP CD from Atmel.
34 *
35 * There's still some voodoo going on here, but it's a lot better than
36 * in the first incarnation of the driver where all we had was the raw
37 * numbers from the initialization sequence.
38 */
39static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)
40{
41 struct spi_message msg;
42 struct spi_transfer index_xfer = {
43 .len = 3,
44 .cs_change = 1,
45 };
46 struct spi_transfer value_xfer = {
47 .len = 3,
48 };
49
50 spi_message_init(&msg);
51
52 /* register index */
53 lcd->buffer[0] = LTV_OPC_INDEX;
54 lcd->buffer[1] = 0x00;
55 lcd->buffer[2] = reg & 0x7f;
56 index_xfer.tx_buf = lcd->buffer;
57 spi_message_add_tail(&index_xfer, &msg);
58
59 /* register value */
60 lcd->buffer[4] = LTV_OPC_DATA;
61 lcd->buffer[5] = val >> 8;
62 lcd->buffer[6] = val;
63 value_xfer.tx_buf = lcd->buffer + 4;
64 spi_message_add_tail(&value_xfer, &msg);
65
66 return spi_sync(lcd->spi, &msg);
67}
68
69/* The comments are taken straight from the data sheet */
70static int ltv350qv_power_on(struct ltv350qv *lcd)
71{
72 int ret;
73
74 /* Power On Reset Display off State */
75 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))
76 goto err;
77 msleep(15);
78
79 /* Power Setting Function 1 */
80 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))
81 goto err;
82 if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))
83 goto err_power1;
84
85 /* Power Setting Function 2 */
86 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,
87 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
88 | LTV_SUPPLY_CURRENT(5)))
89 goto err_power2;
90
91 msleep(55);
92
93 /* Instruction Setting */
94 ret = ltv350qv_write_reg(lcd, LTV_IFCTL,
95 LTV_NMD | LTV_REV | LTV_NL(0x1d));
96 ret |= ltv350qv_write_reg(lcd, LTV_DATACTL,
97 LTV_DS_SAME | LTV_CHS_480
98 | LTV_DF_RGB | LTV_RGB_BGR);
99 ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,
100 LTV_VSPL_ACTIVE_LOW
101 | LTV_HSPL_ACTIVE_LOW
102 | LTV_DPL_SAMPLE_RISING
103 | LTV_EPL_ACTIVE_LOW
104 | LTV_SS_RIGHT_TO_LEFT);
105 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));
106 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
107 LTV_NW_INV_1LINE | LTV_FWI(3));
108 ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);
109 ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);
110 ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0));
111 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);
112 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);
113 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);
114 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);
115 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);
116 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);
117 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);
118 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);
119 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);
120 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);
121 if (ret)
122 goto err_settings;
123
124 /* Wait more than 2 frames */
125 msleep(20);
126
127 /* Display On Sequence */
128 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
129 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE
130 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5)
131 | LTV_SUPPLY_CURRENT(5));
132 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
133 LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3));
134 if (ret)
135 goto err_disp_on;
136
137 /* Display should now be ON. Phew. */
138 return 0;
139
140err_disp_on:
141 /*
142 * Try to recover. Error handling probably isn't very useful
143 * at this point, just make a best effort to switch the panel
144 * off.
145 */
146 ltv350qv_write_reg(lcd, LTV_PWRCTL1,
147 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
148 | LTV_SUPPLY_CURRENT(5));
149 ltv350qv_write_reg(lcd, LTV_GATECTL2,
150 LTV_NW_INV_1LINE | LTV_FWI(3));
151err_settings:
152err_power2:
153err_power1:
154 ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
155 msleep(1);
156err:
157 ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
158 return -EIO;
159}
160
161static int ltv350qv_power_off(struct ltv350qv *lcd)
162{
163 int ret;
164
165 /* Display Off Sequence */
166 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
167 LTV_VCOM_DISABLE
168 | LTV_DRIVE_CURRENT(5)
169 | LTV_SUPPLY_CURRENT(5));
170 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
171 LTV_NW_INV_1LINE | LTV_FWI(3));
172
173 /* Power down setting 1 */
174 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
175
176 /* Wait at least 1 ms */
177 msleep(1);
178
179 /* Power down setting 2 */
180 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
181
182 /*
183 * No point in trying to recover here. If we can't switch the
184 * panel off, what are we supposed to do other than inform the
185 * user about the failure?
186 */
187 if (ret)
188 return -EIO;
189
190 /* Display power should now be OFF */
191 return 0;
192}
193
194static int ltv350qv_power(struct ltv350qv *lcd, int power)
195{
196 int ret = 0;
197
198 if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
199 ret = ltv350qv_power_on(lcd);
200 else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
201 ret = ltv350qv_power_off(lcd);
202
203 if (!ret)
204 lcd->power = power;
205
206 return ret;
207}
208
209static int ltv350qv_set_power(struct lcd_device *ld, int power)
210{
211 struct ltv350qv *lcd = lcd_get_data(ld);
212
213 return ltv350qv_power(lcd, power);
214}
215
216static int ltv350qv_get_power(struct lcd_device *ld)
217{
218 struct ltv350qv *lcd = lcd_get_data(ld);
219
220 return lcd->power;
221}
222
223static struct lcd_ops ltv_ops = {
224 .get_power = ltv350qv_get_power,
225 .set_power = ltv350qv_set_power,
226};
227
228static int __devinit ltv350qv_probe(struct spi_device *spi)
229{
230 struct ltv350qv *lcd;
231 struct lcd_device *ld;
232 int ret;
233
234 lcd = kzalloc(sizeof(struct ltv350qv), GFP_KERNEL);
235 if (!lcd)
236 return -ENOMEM;
237
238 lcd->spi = spi;
239 lcd->power = FB_BLANK_POWERDOWN;
240 lcd->buffer = kzalloc(8, GFP_KERNEL);
241
242 ld = lcd_device_register("ltv350qv", &spi->dev, lcd, &ltv_ops);
243 if (IS_ERR(ld)) {
244 ret = PTR_ERR(ld);
245 goto out_free_lcd;
246 }
247 lcd->ld = ld;
248
249 ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
250 if (ret)
251 goto out_unregister;
252
253 dev_set_drvdata(&spi->dev, lcd);
254
255 return 0;
256
257out_unregister:
258 lcd_device_unregister(ld);
259out_free_lcd:
260 kfree(lcd);
261 return ret;
262}
263
264static int __devexit 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 kfree(lcd);
271
272 return 0;
273}
274
275#ifdef CONFIG_PM
276static int ltv350qv_suspend(struct spi_device *spi, pm_message_t state)
277{
278 struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
279
280 return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
281}
282
283static int ltv350qv_resume(struct spi_device *spi)
284{
285 struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
286
287 return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
288}
289#else
290#define ltv350qv_suspend NULL
291#define ltv350qv_resume NULL
292#endif
293
294/* Power down all displays on reboot, poweroff or halt */
295static void ltv350qv_shutdown(struct spi_device *spi)
296{
297 struct ltv350qv *lcd = dev_get_drvdata(&spi->dev);
298
299 ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
300}
301
302static struct spi_driver ltv350qv_driver = {
303 .driver = {
304 .name = "ltv350qv",
305 .bus = &spi_bus_type,
306 .owner = THIS_MODULE,
307 },
308
309 .probe = ltv350qv_probe,
310 .remove = __devexit_p(ltv350qv_remove),
311 .shutdown = ltv350qv_shutdown,
312 .suspend = ltv350qv_suspend,
313 .resume = ltv350qv_resume,
314};
315
316static int __init ltv350qv_init(void)
317{
318 return spi_register_driver(&ltv350qv_driver);
319}
320
321static void __exit ltv350qv_exit(void)
322{
323 spi_unregister_driver(&ltv350qv_driver);
324}
325module_init(ltv350qv_init);
326module_exit(ltv350qv_exit);
327
328MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
329MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
330MODULE_LICENSE("GPL");