linux/drivers/video/backlight/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#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
  63static struct pci_dev *lpc_dev;
  64static u32 gpio_bar;
  65
  66struct cr_panel {
  67        struct backlight_device *cr_backlight_device;
  68        struct lcd_device *cr_lcd_device;
  69};
  70
  71static 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
  97static 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
 111static struct backlight_ops cr_backlight_ops = {
 112        .get_brightness = cr_backlight_get_intensity,
 113        .update_status = cr_backlight_set_intensity,
 114};
 115
 116static 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
 141static 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
 157static 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
 167static struct lcd_ops cr_lcd_ops = {
 168        .set_power = cr_lcd_set_power,
 169};
 170
 171static 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(bdp);
 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
 233static 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
 248static 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
 256static struct platform_device *crp;
 257
 258static 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
 276static void __exit cr_backlight_exit(void)
 277{
 278        platform_device_unregister(crp);
 279        platform_driver_unregister(&cr_backlight_driver);
 280}
 281
 282module_init(cr_backlight_init);
 283module_exit(cr_backlight_exit);
 284
 285MODULE_AUTHOR("Tungsten Graphics Inc.");
 286MODULE_DESCRIPTION("Carillo Ranch Backlight Driver");
 287MODULE_LICENSE("GPL");
 288