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 #include <linux/slab.h>
40 
41 /* The LVDS- and panel power controls sits on the
42  * GPIO port of the ISA bridge.
43  */
44 
45 #define CRVML_DEVICE_LPC    0x27B8
46 #define CRVML_REG_GPIOBAR   0x48
47 #define CRVML_REG_GPIOEN    0x4C
48 #define CRVML_GPIOEN_BIT    (1 << 4)
49 #define CRVML_PANEL_PORT    0x38
50 #define CRVML_LVDS_ON       0x00000001
51 #define CRVML_PANEL_ON      0x00000002
52 #define CRVML_BACKLIGHT_OFF 0x00000004
53 
54 /* The PLL Clock register sits on Host bridge */
55 #define CRVML_DEVICE_MCH   0x5001
56 #define CRVML_REG_MCHBAR   0x44
57 #define CRVML_REG_MCHEN    0x54
58 #define CRVML_MCHEN_BIT    (1 << 28)
59 #define CRVML_MCHMAP_SIZE  4096
60 #define CRVML_REG_CLOCK    0xc3c
61 #define CRVML_CLOCK_SHIFT  8
62 #define CRVML_CLOCK_MASK   0x00000f00
63 
64 static struct pci_dev *lpc_dev;
65 static u32 gpio_bar;
66 
67 struct cr_panel {
68 	struct backlight_device *cr_backlight_device;
69 	struct lcd_device *cr_lcd_device;
70 };
71 
72 static int cr_backlight_set_intensity(struct backlight_device *bd)
73 {
74 	int intensity = bd->props.brightness;
75 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
76 	u32 cur = inl(addr);
77 
78 	if (bd->props.power == FB_BLANK_UNBLANK)
79 		intensity = FB_BLANK_UNBLANK;
80 	if (bd->props.fb_blank == FB_BLANK_UNBLANK)
81 		intensity = FB_BLANK_UNBLANK;
82 	if (bd->props.power == FB_BLANK_POWERDOWN)
83 		intensity = FB_BLANK_POWERDOWN;
84 	if (bd->props.fb_blank == FB_BLANK_POWERDOWN)
85 		intensity = FB_BLANK_POWERDOWN;
86 
87 	if (intensity == FB_BLANK_UNBLANK) { /* FULL ON */
88 		cur &= ~CRVML_BACKLIGHT_OFF;
89 		outl(cur, addr);
90 	} else if (intensity == FB_BLANK_POWERDOWN) { /* OFF */
91 		cur |= CRVML_BACKLIGHT_OFF;
92 		outl(cur, addr);
93 	} /* anything else, don't bother */
94 
95 	return 0;
96 }
97 
98 static int cr_backlight_get_intensity(struct backlight_device *bd)
99 {
100 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
101 	u32 cur = inl(addr);
102 	u8 intensity;
103 
104 	if (cur & CRVML_BACKLIGHT_OFF)
105 		intensity = FB_BLANK_POWERDOWN;
106 	else
107 		intensity = FB_BLANK_UNBLANK;
108 
109 	return intensity;
110 }
111 
112 static const struct backlight_ops cr_backlight_ops = {
113 	.get_brightness = cr_backlight_get_intensity,
114 	.update_status = cr_backlight_set_intensity,
115 };
116 
117 static void cr_panel_on(void)
118 {
119 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
120 	u32 cur = inl(addr);
121 
122 	if (!(cur & CRVML_PANEL_ON)) {
123 		/* Make sure LVDS controller is down. */
124 		if (cur & 0x00000001) {
125 			cur &= ~CRVML_LVDS_ON;
126 			outl(cur, addr);
127 		}
128 		/* Power up Panel */
129 		schedule_timeout(HZ / 10);
130 		cur |= CRVML_PANEL_ON;
131 		outl(cur, addr);
132 	}
133 
134 	/* Power up LVDS controller */
135 
136 	if (!(cur & CRVML_LVDS_ON)) {
137 		schedule_timeout(HZ / 10);
138 		outl(cur | CRVML_LVDS_ON, addr);
139 	}
140 }
141 
142 static void cr_panel_off(void)
143 {
144 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
145 	u32 cur = inl(addr);
146 
147 	/* Power down LVDS controller first to avoid high currents */
148 	if (cur & CRVML_LVDS_ON) {
149 		cur &= ~CRVML_LVDS_ON;
150 		outl(cur, addr);
151 	}
152 	if (cur & CRVML_PANEL_ON) {
153 		schedule_timeout(HZ / 10);
154 		outl(cur & ~CRVML_PANEL_ON, addr);
155 	}
156 }
157 
158 static int cr_lcd_set_power(struct lcd_device *ld, int power)
159 {
160 	if (power == FB_BLANK_UNBLANK)
161 		cr_panel_on();
162 	if (power == FB_BLANK_POWERDOWN)
163 		cr_panel_off();
164 
165 	return 0;
166 }
167 
168 static struct lcd_ops cr_lcd_ops = {
169 	.set_power = cr_lcd_set_power,
170 };
171 
172 static int cr_backlight_probe(struct platform_device *pdev)
173 {
174 	struct backlight_properties props;
175 	struct backlight_device *bdp;
176 	struct lcd_device *ldp;
177 	struct cr_panel *crp;
178 	u8 dev_en;
179 
180 	lpc_dev = pci_get_device(PCI_VENDOR_ID_INTEL,
181 					CRVML_DEVICE_LPC, NULL);
182 	if (!lpc_dev) {
183 		printk("INTEL CARILLO RANCH LPC not found.\n");
184 		return -ENODEV;
185 	}
186 
187 	pci_read_config_byte(lpc_dev, CRVML_REG_GPIOEN, &dev_en);
188 	if (!(dev_en & CRVML_GPIOEN_BIT)) {
189 		printk(KERN_ERR
190 		       "Carillo Ranch GPIO device was not enabled.\n");
191 		pci_dev_put(lpc_dev);
192 		return -ENODEV;
193 	}
194 
195 	memset(&props, 0, sizeof(struct backlight_properties));
196 	props.type = BACKLIGHT_RAW;
197 	bdp = backlight_device_register("cr-backlight", &pdev->dev, NULL,
198 					&cr_backlight_ops, &props);
199 	if (IS_ERR(bdp)) {
200 		pci_dev_put(lpc_dev);
201 		return PTR_ERR(bdp);
202 	}
203 
204 	ldp = lcd_device_register("cr-lcd", &pdev->dev, NULL, &cr_lcd_ops);
205 	if (IS_ERR(ldp)) {
206 		backlight_device_unregister(bdp);
207 		pci_dev_put(lpc_dev);
208 		return PTR_ERR(ldp);
209 	}
210 
211 	pci_read_config_dword(lpc_dev, CRVML_REG_GPIOBAR,
212 			      &gpio_bar);
213 	gpio_bar &= ~0x3F;
214 
215 	crp = kzalloc(sizeof(*crp), GFP_KERNEL);
216 	if (!crp) {
217 		lcd_device_unregister(ldp);
218 		backlight_device_unregister(bdp);
219 		pci_dev_put(lpc_dev);
220 		return -ENOMEM;
221 	}
222 
223 	crp->cr_backlight_device = bdp;
224 	crp->cr_lcd_device = ldp;
225 	crp->cr_backlight_device->props.power = FB_BLANK_UNBLANK;
226 	crp->cr_backlight_device->props.brightness = 0;
227 	cr_backlight_set_intensity(crp->cr_backlight_device);
228 	cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_UNBLANK);
229 
230 	platform_set_drvdata(pdev, crp);
231 
232 	return 0;
233 }
234 
235 static int cr_backlight_remove(struct platform_device *pdev)
236 {
237 	struct cr_panel *crp = platform_get_drvdata(pdev);
238 	crp->cr_backlight_device->props.power = FB_BLANK_POWERDOWN;
239 	crp->cr_backlight_device->props.brightness = 0;
240 	crp->cr_backlight_device->props.max_brightness = 0;
241 	cr_backlight_set_intensity(crp->cr_backlight_device);
242 	cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_POWERDOWN);
243 	backlight_device_unregister(crp->cr_backlight_device);
244 	lcd_device_unregister(crp->cr_lcd_device);
245 	pci_dev_put(lpc_dev);
246 	kfree(crp);
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 	printk("Carillo Ranch Backlight Driver Initialized.\n");
275 
276 	return 0;
277 }
278 
279 static void __exit cr_backlight_exit(void)
280 {
281 	platform_device_unregister(crp);
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");
291