drivers/media/pci/bt8xx/bttv-gpio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3
   4     bttv-gpio.c  --  gpio sub drivers
   5
   6     sysfs-based sub driver interface for bttv
   7     mainly intended for gpio access
   8
   9
  10     Copyright (C) 1996,97,98 Ralph  Metzler (rjkm@thp.uni-koeln.de)
  11                            & Marcus Metzler (mocm@thp.uni-koeln.de)
  12     (c) 1999-2003 Gerd Knorr <kraxel@bytesex.org>
  13
  14
  15 */
  16
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/delay.h>
  22 #include <linux/device.h>
  23 #include <linux/slab.h>
  24 #include <asm/io.h>
  25
  26 #include "bttvp.h"
  27
  28 /* ----------------------------------------------------------------------- */
  29 /* internal: the bttv "bus"                                                */
  30
  31 static int bttv_sub_bus_match(struct device *dev, struct device_driver *drv)
  32 {
  33         struct bttv_sub_driver *sub = to_bttv_sub_drv(drv);
  34         int len = strlen(sub->wanted);
  35
  36         if (0 == strncmp(dev_name(dev), sub->wanted, len))
  37                 return 1;
  38         return 0;
  39 }
  40
  41 static int bttv_sub_probe(struct device *dev)
  42 {
  43         struct bttv_sub_device *sdev = to_bttv_sub_dev(dev);
  44         struct bttv_sub_driver *sub = to_bttv_sub_drv(dev->driver);
  45
  46         return sub->probe ? sub->probe(sdev) : -ENODEV;
  47 }
  48
  49 static int bttv_sub_remove(struct device *dev)
  50 {
  51         struct bttv_sub_device *sdev = to_bttv_sub_dev(dev);
  52         struct bttv_sub_driver *sub = to_bttv_sub_drv(dev->driver);
  53
  54         if (sub->remove)
  55                 sub->remove(sdev);
  56         return 0;
  57 }
  58
  59 struct bus_type bttv_sub_bus_type = {
  60         .name   = "bttv-sub",
  61         .match  = &bttv_sub_bus_match,
  62         .probe  = bttv_sub_probe,
  63         .remove = bttv_sub_remove,
  64 };
  65
  66 static void release_sub_device(struct device *dev)
  67 {
  68         struct bttv_sub_device *sub = to_bttv_sub_dev(dev);
  69         kfree(sub);
  70 }
  71
  72 int bttv_sub_add_device(struct bttv_core *core, char *name)
  73 {
  74         struct bttv_sub_device *sub;
  75         int err;
  76
  77         sub = kzalloc(sizeof(*sub),GFP_KERNEL);
  78         if (NULL == sub)
  79                 return -ENOMEM;
  80
  81         sub->core        = core;
  82         sub->dev.parent  = &core->pci->dev;
  83         sub->dev.bus     = &bttv_sub_bus_type;
  84         sub->dev.release = release_sub_device;
  85         dev_set_name(&sub->dev, "%s%d", name, core->nr);
  86
  87         err = device_register(&sub->dev);
  88         if (0 != err) {
  89                 put_device(&sub->dev);
  90                 return err;
  91         }
  92         pr_info("%d: add subdevice \"%s\"\n", core->nr, dev_name(&sub->dev));
  93         list_add_tail(&sub->list,&core->subs);
  94         return 0;
  95 }
  96
  97 int bttv_sub_del_devices(struct bttv_core *core)
  98 {
  99         struct bttv_sub_device *sub, *save;
 100
 101         list_for_each_entry_safe(sub, save, &core->subs, list) {
 102                 list_del(&sub->list);
 103                 device_unregister(&sub->dev);
 104         }
 105         return 0;
 106 }
 107
 108 /* ----------------------------------------------------------------------- */
 109 /* external: sub-driver register/unregister                                */
 110
 111 int bttv_sub_register(struct bttv_sub_driver *sub, char *wanted)
 112 {
 113         sub->drv.bus = &bttv_sub_bus_type;
 114         snprintf(sub->wanted,sizeof(sub->wanted),"%s",wanted);
 115         return driver_register(&sub->drv);
 116 }
 117 EXPORT_SYMBOL(bttv_sub_register);
 118
 119 int bttv_sub_unregister(struct bttv_sub_driver *sub)
 120 {
 121         driver_unregister(&sub->drv);
 122         return 0;
 123 }
 124 EXPORT_SYMBOL(bttv_sub_unregister);
 125
 126 /* ----------------------------------------------------------------------- */
 127 /* external: gpio access functions                                         */
 128
 129 void bttv_gpio_inout(struct bttv_core *core, u32 mask, u32 outbits)
 130 {
 131         struct bttv *btv = container_of(core, struct bttv, c);
 132         unsigned long flags;
 133         u32 data;
 134
 135         spin_lock_irqsave(&btv->gpio_lock,flags);
 136         data = btread(BT848_GPIO_OUT_EN);
 137         data = data & ~mask;
 138         data = data | (mask & outbits);
 139         btwrite(data,BT848_GPIO_OUT_EN);
 140         spin_unlock_irqrestore(&btv->gpio_lock,flags);
 141 }
 142
 143 u32 bttv_gpio_read(struct bttv_core *core)
 144 {
 145         struct bttv *btv = container_of(core, struct bttv, c);
 146         u32 value;
 147
 148         value = btread(BT848_GPIO_DATA);
 149         return value;
 150 }
 151
 152 void bttv_gpio_write(struct bttv_core *core, u32 value)
 153 {
 154         struct bttv *btv = container_of(core, struct bttv, c);
 155
 156         btwrite(value,BT848_GPIO_DATA);
 157 }
 158
 159 void bttv_gpio_bits(struct bttv_core *core, u32 mask, u32 bits)
 160 {
 161         struct bttv *btv = container_of(core, struct bttv, c);
 162         unsigned long flags;
 163         u32 data;
 164
 165         spin_lock_irqsave(&btv->gpio_lock,flags);
 166         data = btread(BT848_GPIO_DATA);
 167         data = data & ~mask;
 168         data = data | (mask & bits);
 169         btwrite(data,BT848_GPIO_DATA);
 170         spin_unlock_irqrestore(&btv->gpio_lock,flags);
 171 }