1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Power control for Samsung LTV350QV Quarter VGA LCD Panel
4 *
5 * Copyright (C) 2006, 2007 Atmel Corporation
6 */
7 #include <linux/delay.h>
8 #include <linux/err.h>
9 #include <linux/fb.h>
10 #include <linux/init.h>
11 #include <linux/lcd.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/spi/spi.h>
15
16 #include "ltv350qv.h"
17
18 #define POWER_IS_ON(pwr) ((pwr) <= FB_BLANK_NORMAL)
19
20 struct ltv350qv {
21 struct spi_device *spi;
22 u8 *buffer;
23 int power;
24 struct lcd_device *ld;
25 };
26
27 /*
28 * The power-on and power-off sequences are taken from the
29 * LTV350QV-F04 data sheet from Samsung. The register definitions are
30 * taken from the S6F2002 command list also from Samsung.
31 *
32 * There's still some voodoo going on here, but it's a lot better than
33 * in the first incarnation of the driver where all we had was the raw
34 * numbers from the initialization sequence.
35 */
ltv350qv_write_reg(struct ltv350qv * lcd,u8 reg,u16 val)36 static int ltv350qv_write_reg(struct ltv350qv *lcd, u8 reg, u16 val)
37 {
38 struct spi_message msg;
39 struct spi_transfer index_xfer = {
40 .len = 3,
41 .cs_change = 1,
42 };
43 struct spi_transfer value_xfer = {
44 .len = 3,
45 };
46
47 spi_message_init(&msg);
48
49 /* register index */
50 lcd->buffer[0] = LTV_OPC_INDEX;
51 lcd->buffer[1] = 0x00;
52 lcd->buffer[2] = reg & 0x7f;
53 index_xfer.tx_buf = lcd->buffer;
54 spi_message_add_tail(&index_xfer, &msg);
55
56 /* register value */
57 lcd->buffer[4] = LTV_OPC_DATA;
58 lcd->buffer[5] = val >> 8;
59 lcd->buffer[6] = val;
60 value_xfer.tx_buf = lcd->buffer + 4;
61 spi_message_add_tail(&value_xfer, &msg);
62
63 return spi_sync(lcd->spi, &msg);
64 }
65
66 /* The comments are taken straight from the data sheet */
ltv350qv_power_on(struct ltv350qv * lcd)67 static int ltv350qv_power_on(struct ltv350qv *lcd)
68 {
69 int ret;
70
71 /* Power On Reset Display off State */
72 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, 0x0000))
73 goto err;
74 usleep_range(15000, 16000);
75
76 /* Power Setting Function 1 */
77 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE))
78 goto err;
79 if (ltv350qv_write_reg(lcd, LTV_PWRCTL2, LTV_VCOML_ENABLE))
80 goto err_power1;
81
82 /* Power Setting Function 2 */
83 if (ltv350qv_write_reg(lcd, LTV_PWRCTL1,
84 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
85 | LTV_SUPPLY_CURRENT(5)))
86 goto err_power2;
87
88 msleep(55);
89
90 /* Instruction Setting */
91 ret = ltv350qv_write_reg(lcd, LTV_IFCTL,
92 LTV_NMD | LTV_REV | LTV_NL(0x1d));
93 ret |= ltv350qv_write_reg(lcd, LTV_DATACTL,
94 LTV_DS_SAME | LTV_CHS_480
95 | LTV_DF_RGB | LTV_RGB_BGR);
96 ret |= ltv350qv_write_reg(lcd, LTV_ENTRY_MODE,
97 LTV_VSPL_ACTIVE_LOW
98 | LTV_HSPL_ACTIVE_LOW
99 | LTV_DPL_SAMPLE_RISING
100 | LTV_EPL_ACTIVE_LOW
101 | LTV_SS_RIGHT_TO_LEFT);
102 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL1, LTV_CLW(3));
103 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
104 LTV_NW_INV_1LINE | LTV_FWI(3));
105 ret |= ltv350qv_write_reg(lcd, LTV_VBP, 0x000a);
106 ret |= ltv350qv_write_reg(lcd, LTV_HBP, 0x0021);
107 ret |= ltv350qv_write_reg(lcd, LTV_SOTCTL, LTV_SDT(3) | LTV_EQ(0));
108 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(0), 0x0103);
109 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(1), 0x0301);
110 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(2), 0x1f0f);
111 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(3), 0x1f0f);
112 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(4), 0x0707);
113 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(5), 0x0307);
114 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(6), 0x0707);
115 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(7), 0x0000);
116 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(8), 0x0004);
117 ret |= ltv350qv_write_reg(lcd, LTV_GAMMA(9), 0x0000);
118 if (ret)
119 goto err_settings;
120
121 /* Wait more than 2 frames */
122 msleep(20);
123
124 /* Display On Sequence */
125 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
126 LTV_VCOM_DISABLE | LTV_VCOMOUT_ENABLE
127 | LTV_POWER_ON | LTV_DRIVE_CURRENT(5)
128 | LTV_SUPPLY_CURRENT(5));
129 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
130 LTV_NW_INV_1LINE | LTV_DSC | LTV_FWI(3));
131 if (ret)
132 goto err_disp_on;
133
134 /* Display should now be ON. Phew. */
135 return 0;
136
137 err_disp_on:
138 /*
139 * Try to recover. Error handling probably isn't very useful
140 * at this point, just make a best effort to switch the panel
141 * off.
142 */
143 ltv350qv_write_reg(lcd, LTV_PWRCTL1,
144 LTV_VCOM_DISABLE | LTV_DRIVE_CURRENT(5)
145 | LTV_SUPPLY_CURRENT(5));
146 ltv350qv_write_reg(lcd, LTV_GATECTL2,
147 LTV_NW_INV_1LINE | LTV_FWI(3));
148 err_settings:
149 err_power2:
150 err_power1:
151 ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
152 usleep_range(1000, 1100);
153 err:
154 ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
155 return -EIO;
156 }
157
ltv350qv_power_off(struct ltv350qv * lcd)158 static int ltv350qv_power_off(struct ltv350qv *lcd)
159 {
160 int ret;
161
162 /* Display Off Sequence */
163 ret = ltv350qv_write_reg(lcd, LTV_PWRCTL1,
164 LTV_VCOM_DISABLE
165 | LTV_DRIVE_CURRENT(5)
166 | LTV_SUPPLY_CURRENT(5));
167 ret |= ltv350qv_write_reg(lcd, LTV_GATECTL2,
168 LTV_NW_INV_1LINE | LTV_FWI(3));
169
170 /* Power down setting 1 */
171 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL2, 0x0000);
172
173 /* Wait at least 1 ms */
174 usleep_range(1000, 1100);
175
176 /* Power down setting 2 */
177 ret |= ltv350qv_write_reg(lcd, LTV_PWRCTL1, LTV_VCOM_DISABLE);
178
179 /*
180 * No point in trying to recover here. If we can't switch the
181 * panel off, what are we supposed to do other than inform the
182 * user about the failure?
183 */
184 if (ret)
185 return -EIO;
186
187 /* Display power should now be OFF */
188 return 0;
189 }
190
ltv350qv_power(struct ltv350qv * lcd,int power)191 static int ltv350qv_power(struct ltv350qv *lcd, int power)
192 {
193 int ret = 0;
194
195 if (POWER_IS_ON(power) && !POWER_IS_ON(lcd->power))
196 ret = ltv350qv_power_on(lcd);
197 else if (!POWER_IS_ON(power) && POWER_IS_ON(lcd->power))
198 ret = ltv350qv_power_off(lcd);
199
200 if (!ret)
201 lcd->power = power;
202
203 return ret;
204 }
205
ltv350qv_set_power(struct lcd_device * ld,int power)206 static int ltv350qv_set_power(struct lcd_device *ld, int power)
207 {
208 struct ltv350qv *lcd = lcd_get_data(ld);
209
210 return ltv350qv_power(lcd, power);
211 }
212
ltv350qv_get_power(struct lcd_device * ld)213 static int ltv350qv_get_power(struct lcd_device *ld)
214 {
215 struct ltv350qv *lcd = lcd_get_data(ld);
216
217 return lcd->power;
218 }
219
220 static struct lcd_ops ltv_ops = {
221 .get_power = ltv350qv_get_power,
222 .set_power = ltv350qv_set_power,
223 };
224
ltv350qv_probe(struct spi_device * spi)225 static int ltv350qv_probe(struct spi_device *spi)
226 {
227 struct ltv350qv *lcd;
228 struct lcd_device *ld;
229 int ret;
230
231 lcd = devm_kzalloc(&spi->dev, sizeof(struct ltv350qv), GFP_KERNEL);
232 if (!lcd)
233 return -ENOMEM;
234
235 lcd->spi = spi;
236 lcd->power = FB_BLANK_POWERDOWN;
237 lcd->buffer = devm_kzalloc(&spi->dev, 8, GFP_KERNEL);
238 if (!lcd->buffer)
239 return -ENOMEM;
240
241 ld = devm_lcd_device_register(&spi->dev, "ltv350qv", &spi->dev, lcd,
242 <v_ops);
243 if (IS_ERR(ld))
244 return PTR_ERR(ld);
245
246 lcd->ld = ld;
247
248 ret = ltv350qv_power(lcd, FB_BLANK_UNBLANK);
249 if (ret)
250 return ret;
251
252 spi_set_drvdata(spi, lcd);
253
254 return 0;
255 }
256
ltv350qv_remove(struct spi_device * spi)257 static void ltv350qv_remove(struct spi_device *spi)
258 {
259 struct ltv350qv *lcd = spi_get_drvdata(spi);
260
261 ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
262 }
263
264 #ifdef CONFIG_PM_SLEEP
ltv350qv_suspend(struct device * dev)265 static int ltv350qv_suspend(struct device *dev)
266 {
267 struct ltv350qv *lcd = dev_get_drvdata(dev);
268
269 return ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
270 }
271
ltv350qv_resume(struct device * dev)272 static int ltv350qv_resume(struct device *dev)
273 {
274 struct ltv350qv *lcd = dev_get_drvdata(dev);
275
276 return ltv350qv_power(lcd, FB_BLANK_UNBLANK);
277 }
278 #endif
279
280 static SIMPLE_DEV_PM_OPS(ltv350qv_pm_ops, ltv350qv_suspend, ltv350qv_resume);
281
282 /* Power down all displays on reboot, poweroff or halt */
ltv350qv_shutdown(struct spi_device * spi)283 static void ltv350qv_shutdown(struct spi_device *spi)
284 {
285 struct ltv350qv *lcd = spi_get_drvdata(spi);
286
287 ltv350qv_power(lcd, FB_BLANK_POWERDOWN);
288 }
289
290 static struct spi_driver ltv350qv_driver = {
291 .driver = {
292 .name = "ltv350qv",
293 .pm = <v350qv_pm_ops,
294 },
295
296 .probe = ltv350qv_probe,
297 .remove = ltv350qv_remove,
298 .shutdown = ltv350qv_shutdown,
299 };
300
301 module_spi_driver(ltv350qv_driver);
302
303 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
304 MODULE_DESCRIPTION("Samsung LTV350QV LCD Driver");
305 MODULE_LICENSE("GPL");
306 MODULE_ALIAS("spi:ltv350qv");
307