1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) Intel Corp. 2007.
4  * All Rights Reserved.
5  *
6  * Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
7  * develop this driver.
8  *
9  * This file is part of the Carillo Ranch video subsystem driver.
10  *
11  * Authors:
12  *   Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
13  *   Alan Hourihane <alanh-at-tungstengraphics-dot-com>
14  */
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/init.h>
21 #include <linux/platform_device.h>
22 #include <linux/mutex.h>
23 #include <linux/fb.h>
24 #include <linux/backlight.h>
25 #include <linux/lcd.h>
26 #include <linux/pci.h>
27 #include <linux/slab.h>
28 
29 /* The LVDS- and panel power controls sits on the
30  * GPIO port of the ISA bridge.
31  */
32 
33 #define CRVML_DEVICE_LPC    0x27B8
34 #define CRVML_REG_GPIOBAR   0x48
35 #define CRVML_REG_GPIOEN    0x4C
36 #define CRVML_GPIOEN_BIT    (1 << 4)
37 #define CRVML_PANEL_PORT    0x38
38 #define CRVML_LVDS_ON       0x00000001
39 #define CRVML_PANEL_ON      0x00000002
40 #define CRVML_BACKLIGHT_OFF 0x00000004
41 
42 /* The PLL Clock register sits on Host bridge */
43 #define CRVML_DEVICE_MCH   0x5001
44 #define CRVML_REG_MCHBAR   0x44
45 #define CRVML_REG_MCHEN    0x54
46 #define CRVML_MCHEN_BIT    (1 << 28)
47 #define CRVML_MCHMAP_SIZE  4096
48 #define CRVML_REG_CLOCK    0xc3c
49 #define CRVML_CLOCK_SHIFT  8
50 #define CRVML_CLOCK_MASK   0x00000f00
51 
52 static struct pci_dev *lpc_dev;
53 static u32 gpio_bar;
54 
55 struct cr_panel {
56 	struct backlight_device *cr_backlight_device;
57 	struct lcd_device *cr_lcd_device;
58 };
59 
60 static int cr_backlight_set_intensity(struct backlight_device *bd)
61 {
62 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
63 	u32 cur = inl(addr);
64 
65 	if (backlight_get_brightness(bd) == 0) {
66 		/* OFF */
67 		cur |= CRVML_BACKLIGHT_OFF;
68 		outl(cur, addr);
69 	} else {
70 		/* FULL ON */
71 		cur &= ~CRVML_BACKLIGHT_OFF;
72 		outl(cur, addr);
73 	}
74 
75 	return 0;
76 }
77 
78 static int cr_backlight_get_intensity(struct backlight_device *bd)
79 {
80 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
81 	u32 cur = inl(addr);
82 	u8 intensity;
83 
84 	if (cur & CRVML_BACKLIGHT_OFF)
85 		intensity = 0;
86 	else
87 		intensity = 1;
88 
89 	return intensity;
90 }
91 
92 static const struct backlight_ops cr_backlight_ops = {
93 	.get_brightness = cr_backlight_get_intensity,
94 	.update_status = cr_backlight_set_intensity,
95 };
96 
97 static void cr_panel_on(void)
98 {
99 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
100 	u32 cur = inl(addr);
101 
102 	if (!(cur & CRVML_PANEL_ON)) {
103 		/* Make sure LVDS controller is down. */
104 		if (cur & 0x00000001) {
105 			cur &= ~CRVML_LVDS_ON;
106 			outl(cur, addr);
107 		}
108 		/* Power up Panel */
109 		schedule_timeout(HZ / 10);
110 		cur |= CRVML_PANEL_ON;
111 		outl(cur, addr);
112 	}
113 
114 	/* Power up LVDS controller */
115 
116 	if (!(cur & CRVML_LVDS_ON)) {
117 		schedule_timeout(HZ / 10);
118 		outl(cur | CRVML_LVDS_ON, addr);
119 	}
120 }
121 
122 static void cr_panel_off(void)
123 {
124 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
125 	u32 cur = inl(addr);
126 
127 	/* Power down LVDS controller first to avoid high currents */
128 	if (cur & CRVML_LVDS_ON) {
129 		cur &= ~CRVML_LVDS_ON;
130 		outl(cur, addr);
131 	}
132 	if (cur & CRVML_PANEL_ON) {
133 		schedule_timeout(HZ / 10);
134 		outl(cur & ~CRVML_PANEL_ON, addr);
135 	}
136 }
137 
138 static int cr_lcd_set_power(struct lcd_device *ld, int power)
139 {
140 	if (power == FB_BLANK_UNBLANK)
141 		cr_panel_on();
142 	if (power == FB_BLANK_POWERDOWN)
143 		cr_panel_off();
144 
145 	return 0;
146 }
147 
148 static struct lcd_ops cr_lcd_ops = {
149 	.set_power = cr_lcd_set_power,
150 };
151 
152 static int cr_backlight_probe(struct platform_device *pdev)
153 {
154 	struct backlight_properties props;
155 	struct backlight_device *bdp;
156 	struct lcd_device *ldp;
157 	struct cr_panel *crp;
158 	u8 dev_en;
159 
160 	lpc_dev = pci_get_device(PCI_VENDOR_ID_INTEL,
161 					CRVML_DEVICE_LPC, NULL);
162 	if (!lpc_dev) {
163 		pr_err("INTEL CARILLO RANCH LPC not found.\n");
164 		return -ENODEV;
165 	}
166 
167 	pci_read_config_byte(lpc_dev, CRVML_REG_GPIOEN, &dev_en);
168 	if (!(dev_en & CRVML_GPIOEN_BIT)) {
169 		pr_err("Carillo Ranch GPIO device was not enabled.\n");
170 		pci_dev_put(lpc_dev);
171 		return -ENODEV;
172 	}
173 
174 	memset(&props, 0, sizeof(struct backlight_properties));
175 	props.type = BACKLIGHT_RAW;
176 	bdp = devm_backlight_device_register(&pdev->dev, "cr-backlight",
177 					&pdev->dev, NULL, &cr_backlight_ops,
178 					&props);
179 	if (IS_ERR(bdp)) {
180 		pci_dev_put(lpc_dev);
181 		return PTR_ERR(bdp);
182 	}
183 
184 	ldp = devm_lcd_device_register(&pdev->dev, "cr-lcd", &pdev->dev, NULL,
185 					&cr_lcd_ops);
186 	if (IS_ERR(ldp)) {
187 		pci_dev_put(lpc_dev);
188 		return PTR_ERR(ldp);
189 	}
190 
191 	pci_read_config_dword(lpc_dev, CRVML_REG_GPIOBAR,
192 			      &gpio_bar);
193 	gpio_bar &= ~0x3F;
194 
195 	crp = devm_kzalloc(&pdev->dev, sizeof(*crp), GFP_KERNEL);
196 	if (!crp) {
197 		pci_dev_put(lpc_dev);
198 		return -ENOMEM;
199 	}
200 
201 	crp->cr_backlight_device = bdp;
202 	crp->cr_lcd_device = ldp;
203 	crp->cr_backlight_device->props.power = FB_BLANK_UNBLANK;
204 	crp->cr_backlight_device->props.brightness = 0;
205 	cr_backlight_set_intensity(crp->cr_backlight_device);
206 	cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_UNBLANK);
207 
208 	platform_set_drvdata(pdev, crp);
209 
210 	return 0;
211 }
212 
213 static int cr_backlight_remove(struct platform_device *pdev)
214 {
215 	struct cr_panel *crp = platform_get_drvdata(pdev);
216 
217 	crp->cr_backlight_device->props.power = FB_BLANK_POWERDOWN;
218 	crp->cr_backlight_device->props.brightness = 0;
219 	crp->cr_backlight_device->props.max_brightness = 0;
220 	cr_backlight_set_intensity(crp->cr_backlight_device);
221 	cr_lcd_set_power(crp->cr_lcd_device, FB_BLANK_POWERDOWN);
222 	pci_dev_put(lpc_dev);
223 
224 	return 0;
225 }
226 
227 static struct platform_driver cr_backlight_driver = {
228 	.probe = cr_backlight_probe,
229 	.remove = cr_backlight_remove,
230 	.driver = {
231 		   .name = "cr_backlight",
232 		   },
233 };
234 
235 static struct platform_device *crp;
236 
237 static int __init cr_backlight_init(void)
238 {
239 	int ret = platform_driver_register(&cr_backlight_driver);
240 
241 	if (ret)
242 		return ret;
243 
244 	crp = platform_device_register_simple("cr_backlight", -1, NULL, 0);
245 	if (IS_ERR(crp)) {
246 		platform_driver_unregister(&cr_backlight_driver);
247 		return PTR_ERR(crp);
248 	}
249 
250 	pr_info("Carillo Ranch Backlight Driver Initialized.\n");
251 
252 	return 0;
253 }
254 
255 static void __exit cr_backlight_exit(void)
256 {
257 	platform_device_unregister(crp);
258 	platform_driver_unregister(&cr_backlight_driver);
259 }
260 
261 module_init(cr_backlight_init);
262 module_exit(cr_backlight_exit);
263 
264 MODULE_AUTHOR("Tungsten Graphics Inc.");
265 MODULE_DESCRIPTION("Carillo Ranch Backlight Driver");
266 MODULE_LICENSE("GPL");
267