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 #include <linux/module.h>
31 #include <linux/kernel.h>
32 #include <linux/init.h>
33 #include <linux/platform_device.h>
34 #include <linux/mutex.h>
35 #include <linux/fb.h>
36 #include <linux/backlight.h>
37 #include <linux/lcd.h>
38 #include <linux/pci.h>
39 
40 /* The LVDS- and panel power controls sits on the
41  * GPIO port of the ISA bridge.
42  */
43 
44 #define CRVML_DEVICE_LPC    0x27B8
45 #define CRVML_REG_GPIOBAR   0x48
46 #define CRVML_REG_GPIOEN    0x4C
47 #define CRVML_GPIOEN_BIT    (1 << 4)
48 #define CRVML_PANEL_PORT    0x38
49 #define CRVML_LVDS_ON       0x00000001
50 #define CRVML_PANEL_ON      0x00000002
51 #define CRVML_BACKLIGHT_OFF 0x00000004
52 
53 /* The PLL Clock register sits on Host bridge */
54 #define CRVML_DEVICE_MCH   0x5001
55 #define CRVML_REG_MCHBAR   0x44
56 #define CRVML_REG_MCHEN    0x54
57 #define CRVML_MCHEN_BIT    (1 << 28)
58 #define CRVML_MCHMAP_SIZE  4096
59 #define CRVML_REG_CLOCK    0xc3c
60 #define CRVML_CLOCK_SHIFT  8
61 #define CRVML_CLOCK_MASK   0x00000f00
62 
63 static struct pci_dev *lpc_dev;
64 static u32 gpio_bar;
65 
66 struct cr_panel {
67 	struct backlight_device *cr_backlight_device;
68 	struct lcd_device *cr_lcd_device;
69 };
70 
71 static int cr_backlight_set_intensity(struct backlight_device *bd)
72 {
73 	int intensity = bd->props.brightness;
74 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
75 	u32 cur = inl(addr);
76 
77 	if (bd->props.power == FB_BLANK_UNBLANK)
78 		intensity = FB_BLANK_UNBLANK;
79 	if (bd->props.fb_blank == FB_BLANK_UNBLANK)
80 		intensity = FB_BLANK_UNBLANK;
81 	if (bd->props.power == FB_BLANK_POWERDOWN)
82 		intensity = FB_BLANK_POWERDOWN;
83 	if (bd->props.fb_blank == FB_BLANK_POWERDOWN)
84 		intensity = FB_BLANK_POWERDOWN;
85 
86 	if (intensity == FB_BLANK_UNBLANK) { /* FULL ON */
87 		cur &= ~CRVML_BACKLIGHT_OFF;
88 		outl(cur, addr);
89 	} else if (intensity == FB_BLANK_POWERDOWN) { /* OFF */
90 		cur |= CRVML_BACKLIGHT_OFF;
91 		outl(cur, addr);
92 	} /* anything else, don't bother */
93 
94 	return 0;
95 }
96 
97 static int cr_backlight_get_intensity(struct backlight_device *bd)
98 {
99 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
100 	u32 cur = inl(addr);
101 	u8 intensity;
102 
103 	if (cur & CRVML_BACKLIGHT_OFF)
104 		intensity = FB_BLANK_POWERDOWN;
105 	else
106 		intensity = FB_BLANK_UNBLANK;
107 
108 	return intensity;
109 }
110 
111 static const struct backlight_ops cr_backlight_ops = {
112 	.get_brightness = cr_backlight_get_intensity,
113 	.update_status = cr_backlight_set_intensity,
114 };
115 
116 static void cr_panel_on(void)
117 {
118 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
119 	u32 cur = inl(addr);
120 
121 	if (!(cur & CRVML_PANEL_ON)) {
122 		/* Make sure LVDS controller is down. */
123 		if (cur & 0x00000001) {
124 			cur &= ~CRVML_LVDS_ON;
125 			outl(cur, addr);
126 		}
127 		/* Power up Panel */
128 		schedule_timeout(HZ / 10);
129 		cur |= CRVML_PANEL_ON;
130 		outl(cur, addr);
131 	}
132 
133 	/* Power up LVDS controller */
134 
135 	if (!(cur & CRVML_LVDS_ON)) {
136 		schedule_timeout(HZ / 10);
137 		outl(cur | CRVML_LVDS_ON, addr);
138 	}
139 }
140 
141 static void cr_panel_off(void)
142 {
143 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
144 	u32 cur = inl(addr);
145 
146 	/* Power down LVDS controller first to avoid high currents */
147 	if (cur & CRVML_LVDS_ON) {
148 		cur &= ~CRVML_LVDS_ON;
149 		outl(cur, addr);
150 	}
151 	if (cur & CRVML_PANEL_ON) {
152 		schedule_timeout(HZ / 10);
153 		outl(cur & ~CRVML_PANEL_ON, addr);
154 	}
155 }
156 
157 static int cr_lcd_set_power(struct lcd_device *ld, int power)
158 {
159 	if (power == FB_BLANK_UNBLANK)
160 		cr_panel_on();
161 	if (power == FB_BLANK_POWERDOWN)
162 		cr_panel_off();
163 
164 	return 0;
165 }
166 
167 static struct lcd_ops cr_lcd_ops = {
168 	.set_power = cr_lcd_set_power,
169 };
170 
171 static int cr_backlight_probe(struct platform_device *pdev)
172 {
173 	struct backlight_device *bdp;
174 	struct lcd_device *ldp;
175 	struct cr_panel *crp;
176 	u8 dev_en;
177 
178 	lpc_dev = pci_get_device(PCI_VENDOR_ID_INTEL,
179 					CRVML_DEVICE_LPC, NULL);
180 	if (!lpc_dev) {
181 		printk("INTEL CARILLO RANCH LPC not found.\n");
182 		return -ENODEV;
183 	}
184 
185 	pci_read_config_byte(lpc_dev, CRVML_REG_GPIOEN, &dev_en);
186 	if (!(dev_en & CRVML_GPIOEN_BIT)) {
187 		printk(KERN_ERR
188 		       "Carillo Ranch GPIO device was not enabled.\n");
189 		pci_dev_put(lpc_dev);
190 		return -ENODEV;
191 	}
192 
193 	bdp = backlight_device_register("cr-backlight",
194 					&pdev->dev, NULL, &cr_backlight_ops);
195 	if (IS_ERR(bdp)) {
196 		pci_dev_put(lpc_dev);
197 		return PTR_ERR(bdp);
198 	}
199 
200 	ldp = lcd_device_register("cr-lcd", &pdev->dev, NULL, &cr_lcd_ops);
201 	if (IS_ERR(ldp)) {
202 		backlight_device_unregister(bdp);
203 		pci_dev_put(lpc_dev);
204 		return PTR_ERR(ldp);
205 	}
206 
207 	pci_read_config_dword(lpc_dev, CRVML_REG_GPIOBAR,
208 			      &gpio_bar);
209 	gpio_bar &= ~0x3F;
210 
211 	crp = kzalloc(sizeof(*crp), GFP_KERNEL);
212 	if (!crp) {
213 		lcd_device_unregister(ldp);
214 		backlight_device_unregister(bdp);
215 		pci_dev_put(lpc_dev);
216 		return -ENOMEM;
217 	}
218 
219 	crp->cr_backlight_device = bdp;
220 	crp->cr_lcd_device = ldp;
221 	crp->cr_backlight_device->props.power = FB_BLANK_UNBLANK;
222 	crp->cr_backlight_device->props.brightness = 0;
223 	crp->cr_backlight_device->props.max_brightness = 0;
224 	cr_backlight_set_intensity(crp->cr_backlight_device);
225 
226 	cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_UNBLANK);
227 
228 	platform_set_drvdata(pdev, crp);
229 
230 	return 0;
231 }
232 
233 static int cr_backlight_remove(struct platform_device *pdev)
234 {
235 	struct cr_panel *crp = platform_get_drvdata(pdev);
236 	crp->cr_backlight_device->props.power = FB_BLANK_POWERDOWN;
237 	crp->cr_backlight_device->props.brightness = 0;
238 	crp->cr_backlight_device->props.max_brightness = 0;
239 	cr_backlight_set_intensity(crp->cr_backlight_device);
240 	cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_POWERDOWN);
241 	backlight_device_unregister(crp->cr_backlight_device);
242 	lcd_device_unregister(crp->cr_lcd_device);
243 	pci_dev_put(lpc_dev);
244 
245 	return 0;
246 }
247 
248 static struct platform_driver cr_backlight_driver = {
249 	.probe = cr_backlight_probe,
250 	.remove = cr_backlight_remove,
251 	.driver = {
252 		   .name = "cr_backlight",
253 		   },
254 };
255 
256 static struct platform_device *crp;
257 
258 static int __init cr_backlight_init(void)
259 {
260 	int ret = platform_driver_register(&cr_backlight_driver);
261 
262 	if (ret)
263 		return ret;
264 
265 	crp = platform_device_register_simple("cr_backlight", -1, NULL, 0);
266 	if (IS_ERR(crp)) {
267 		platform_driver_unregister(&cr_backlight_driver);
268 		return PTR_ERR(crp);
269 	}
270 
271 	printk("Carillo Ranch Backlight Driver Initialized.\n");
272 
273 	return 0;
274 }
275 
276 static void __exit cr_backlight_exit(void)
277 {
278 	platform_device_unregister(crp);
279 	platform_driver_unregister(&cr_backlight_driver);
280 }
281 
282 module_init(cr_backlight_init);
283 module_exit(cr_backlight_exit);
284 
285 MODULE_AUTHOR("Tungsten Graphics Inc.");
286 MODULE_DESCRIPTION("Carillo Ranch Backlight Driver");
287 MODULE_LICENSE("GPL");
288