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 {
70 	struct backlight_device *cr_backlight_device;
71 	struct lcd_device *cr_lcd_device;
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 
182 	lpc_dev = pci_get_device(PCI_VENDOR_ID_INTEL,
183 					CRVML_DEVICE_LPC, NULL);
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)) {
207 		backlight_device_unregister(bdp);
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) {
218 		lcd_device_unregister(ldp);
219 		backlight_device_unregister(bdp);
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);
244 	backlight_device_unregister(crp->cr_backlight_device);
245 	lcd_device_unregister(crp->cr_lcd_device);
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 {
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