linux/drivers/video/backlight/cr_bllcd.c
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   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
  52static struct pci_dev *lpc_dev;
  53static u32 gpio_bar;
  54
  55struct cr_panel {
  56        struct backlight_device *cr_backlight_device;
  57        struct lcd_device *cr_lcd_device;
  58};
  59
  60static 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
  78static 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
  92static const struct backlight_ops cr_backlight_ops = {
  93        .get_brightness = cr_backlight_get_intensity,
  94        .update_status = cr_backlight_set_intensity,
  95};
  96
  97static 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
 122static 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
 138static 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
 148static struct lcd_ops cr_lcd_ops = {
 149        .set_power = cr_lcd_set_power,
 150};
 151
 152static 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
 213static 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
 227static 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
 235static struct platform_device *crp;
 236
 237static 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
 255static void __exit cr_backlight_exit(void)
 256{
 257        platform_device_unregister(crp);
 258        platform_driver_unregister(&cr_backlight_driver);
 259}
 260
 261module_init(cr_backlight_init);
 262module_exit(cr_backlight_exit);
 263
 264MODULE_AUTHOR("Tungsten Graphics Inc.");
 265MODULE_DESCRIPTION("Carillo Ranch Backlight Driver");
 266MODULE_LICENSE("GPL");
 267