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cr_bllcd.c
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1 /*
2  * Copyright (c) Intel Corp. 2007.
3  * All Rights Reserved.
4  *
5  * Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
6  * develop this driver.
7  *
8  * This file is part of the Carillo Ranch video subsystem driver.
9  * The Carillo Ranch video subsystem driver is free software;
10  * you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * The Carillo Ranch video subsystem driver is distributed
16  * in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this driver; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24  *
25  * Authors:
26  * Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
27  * Alan Hourihane <alanh-at-tungstengraphics-dot-com>
28  */
29 
30 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31 
32 #include <linux/module.h>
33 #include <linux/kernel.h>
34 #include <linux/init.h>
35 #include <linux/platform_device.h>
36 #include <linux/mutex.h>
37 #include <linux/fb.h>
38 #include <linux/backlight.h>
39 #include <linux/lcd.h>
40 #include <linux/pci.h>
41 #include <linux/slab.h>
42 
43 /* The LVDS- and panel power controls sits on the
44  * GPIO port of the ISA bridge.
45  */
46 
47 #define CRVML_DEVICE_LPC 0x27B8
48 #define CRVML_REG_GPIOBAR 0x48
49 #define CRVML_REG_GPIOEN 0x4C
50 #define CRVML_GPIOEN_BIT (1 << 4)
51 #define CRVML_PANEL_PORT 0x38
52 #define CRVML_LVDS_ON 0x00000001
53 #define CRVML_PANEL_ON 0x00000002
54 #define CRVML_BACKLIGHT_OFF 0x00000004
55 
56 /* The PLL Clock register sits on Host bridge */
57 #define CRVML_DEVICE_MCH 0x5001
58 #define CRVML_REG_MCHBAR 0x44
59 #define CRVML_REG_MCHEN 0x54
60 #define CRVML_MCHEN_BIT (1 << 28)
61 #define CRVML_MCHMAP_SIZE 4096
62 #define CRVML_REG_CLOCK 0xc3c
63 #define CRVML_CLOCK_SHIFT 8
64 #define CRVML_CLOCK_MASK 0x00000f00
65 
66 static struct pci_dev *lpc_dev;
67 static u32 gpio_bar;
68 
69 struct cr_panel {
72 };
73 
74 static int cr_backlight_set_intensity(struct backlight_device *bd)
75 {
76  int intensity = bd->props.brightness;
77  u32 addr = gpio_bar + CRVML_PANEL_PORT;
78  u32 cur = inl(addr);
79 
80  if (bd->props.power == FB_BLANK_UNBLANK)
81  intensity = FB_BLANK_UNBLANK;
82  if (bd->props.fb_blank == FB_BLANK_UNBLANK)
83  intensity = FB_BLANK_UNBLANK;
84  if (bd->props.power == FB_BLANK_POWERDOWN)
85  intensity = FB_BLANK_POWERDOWN;
86  if (bd->props.fb_blank == FB_BLANK_POWERDOWN)
87  intensity = FB_BLANK_POWERDOWN;
88 
89  if (intensity == FB_BLANK_UNBLANK) { /* FULL ON */
90  cur &= ~CRVML_BACKLIGHT_OFF;
91  outl(cur, addr);
92  } else if (intensity == FB_BLANK_POWERDOWN) { /* OFF */
93  cur |= CRVML_BACKLIGHT_OFF;
94  outl(cur, addr);
95  } /* anything else, don't bother */
96 
97  return 0;
98 }
99 
100 static int cr_backlight_get_intensity(struct backlight_device *bd)
101 {
102  u32 addr = gpio_bar + CRVML_PANEL_PORT;
103  u32 cur = inl(addr);
104  u8 intensity;
105 
106  if (cur & CRVML_BACKLIGHT_OFF)
107  intensity = FB_BLANK_POWERDOWN;
108  else
109  intensity = FB_BLANK_UNBLANK;
110 
111  return intensity;
112 }
113 
114 static const struct backlight_ops cr_backlight_ops = {
115  .get_brightness = cr_backlight_get_intensity,
116  .update_status = cr_backlight_set_intensity,
117 };
118 
119 static void cr_panel_on(void)
120 {
121  u32 addr = gpio_bar + CRVML_PANEL_PORT;
122  u32 cur = inl(addr);
123 
124  if (!(cur & CRVML_PANEL_ON)) {
125  /* Make sure LVDS controller is down. */
126  if (cur & 0x00000001) {
127  cur &= ~CRVML_LVDS_ON;
128  outl(cur, addr);
129  }
130  /* Power up Panel */
131  schedule_timeout(HZ / 10);
132  cur |= CRVML_PANEL_ON;
133  outl(cur, addr);
134  }
135 
136  /* Power up LVDS controller */
137 
138  if (!(cur & CRVML_LVDS_ON)) {
139  schedule_timeout(HZ / 10);
140  outl(cur | CRVML_LVDS_ON, addr);
141  }
142 }
143 
144 static void cr_panel_off(void)
145 {
146  u32 addr = gpio_bar + CRVML_PANEL_PORT;
147  u32 cur = inl(addr);
148 
149  /* Power down LVDS controller first to avoid high currents */
150  if (cur & CRVML_LVDS_ON) {
151  cur &= ~CRVML_LVDS_ON;
152  outl(cur, addr);
153  }
154  if (cur & CRVML_PANEL_ON) {
155  schedule_timeout(HZ / 10);
156  outl(cur & ~CRVML_PANEL_ON, addr);
157  }
158 }
159 
160 static int cr_lcd_set_power(struct lcd_device *ld, int power)
161 {
162  if (power == FB_BLANK_UNBLANK)
163  cr_panel_on();
164  if (power == FB_BLANK_POWERDOWN)
165  cr_panel_off();
166 
167  return 0;
168 }
169 
170 static struct lcd_ops cr_lcd_ops = {
171  .set_power = cr_lcd_set_power,
172 };
173 
174 static int cr_backlight_probe(struct platform_device *pdev)
175 {
176  struct backlight_properties props;
177  struct backlight_device *bdp;
178  struct lcd_device *ldp;
179  struct cr_panel *crp;
180  u8 dev_en;
181 
184  if (!lpc_dev) {
185  pr_err("INTEL CARILLO RANCH LPC not found.\n");
186  return -ENODEV;
187  }
188 
189  pci_read_config_byte(lpc_dev, CRVML_REG_GPIOEN, &dev_en);
190  if (!(dev_en & CRVML_GPIOEN_BIT)) {
191  pr_err("Carillo Ranch GPIO device was not enabled.\n");
192  pci_dev_put(lpc_dev);
193  return -ENODEV;
194  }
195 
196  memset(&props, 0, sizeof(struct backlight_properties));
197  props.type = BACKLIGHT_RAW;
198  bdp = backlight_device_register("cr-backlight", &pdev->dev, NULL,
199  &cr_backlight_ops, &props);
200  if (IS_ERR(bdp)) {
201  pci_dev_put(lpc_dev);
202  return PTR_ERR(bdp);
203  }
204 
205  ldp = lcd_device_register("cr-lcd", &pdev->dev, NULL, &cr_lcd_ops);
206  if (IS_ERR(ldp)) {
208  pci_dev_put(lpc_dev);
209  return PTR_ERR(ldp);
210  }
211 
212  pci_read_config_dword(lpc_dev, CRVML_REG_GPIOBAR,
213  &gpio_bar);
214  gpio_bar &= ~0x3F;
215 
216  crp = devm_kzalloc(&pdev->dev, sizeof(*crp), GFP_KERNEL);
217  if (!crp) {
220  pci_dev_put(lpc_dev);
221  return -ENOMEM;
222  }
223 
224  crp->cr_backlight_device = bdp;
225  crp->cr_lcd_device = ldp;
226  crp->cr_backlight_device->props.power = FB_BLANK_UNBLANK;
227  crp->cr_backlight_device->props.brightness = 0;
228  cr_backlight_set_intensity(crp->cr_backlight_device);
229  cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_UNBLANK);
230 
231  platform_set_drvdata(pdev, crp);
232 
233  return 0;
234 }
235 
236 static int cr_backlight_remove(struct platform_device *pdev)
237 {
238  struct cr_panel *crp = platform_get_drvdata(pdev);
239  crp->cr_backlight_device->props.power = FB_BLANK_POWERDOWN;
240  crp->cr_backlight_device->props.brightness = 0;
241  crp->cr_backlight_device->props.max_brightness = 0;
242  cr_backlight_set_intensity(crp->cr_backlight_device);
243  cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_POWERDOWN);
246  pci_dev_put(lpc_dev);
247 
248  return 0;
249 }
250 
251 static struct platform_driver cr_backlight_driver = {
252  .probe = cr_backlight_probe,
253  .remove = cr_backlight_remove,
254  .driver = {
255  .name = "cr_backlight",
256  },
257 };
258 
259 static struct platform_device *crp;
260 
261 static int __init cr_backlight_init(void)
262 {
263  int ret = platform_driver_register(&cr_backlight_driver);
264 
265  if (ret)
266  return ret;
267 
268  crp = platform_device_register_simple("cr_backlight", -1, NULL, 0);
269  if (IS_ERR(crp)) {
270  platform_driver_unregister(&cr_backlight_driver);
271  return PTR_ERR(crp);
272  }
273 
274  pr_info("Carillo Ranch Backlight Driver Initialized.\n");
275 
276  return 0;
277 }
278 
279 static void __exit cr_backlight_exit(void)
280 {
282  platform_driver_unregister(&cr_backlight_driver);
283 }
284 
285 module_init(cr_backlight_init);
286 module_exit(cr_backlight_exit);
287 
288 MODULE_AUTHOR("Tungsten Graphics Inc.");
289 MODULE_DESCRIPTION("Carillo Ranch Backlight Driver");
290 MODULE_LICENSE("GPL");