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, const struct device_driver *drv)
  32 {
  33         const 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 void 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 }
  57
  58 const struct bus_type bttv_sub_bus_type = {
  59         .name   = "bttv-sub",
  60         .match  = &bttv_sub_bus_match,
  61         .probe  = bttv_sub_probe,
  62         .remove = bttv_sub_remove,
  63 };
  64
  65 static void release_sub_device(struct device *dev)
  66 {
  67         struct bttv_sub_device *sub = to_bttv_sub_dev(dev);
  68         kfree(sub);
  69 }
  70
  71 int bttv_sub_add_device(struct bttv_core *core, char *name)
  72 {
  73         struct bttv_sub_device *sub;
  74         int err;
  75
  76         sub = kzalloc(sizeof(*sub),GFP_KERNEL);
  77         if (NULL == sub)
  78                 return -ENOMEM;
  79
  80         sub->core        = core;
  81         sub->dev.parent  = &core->pci->dev;
  82         sub->dev.bus     = &bttv_sub_bus_type;
  83         sub->dev.release = release_sub_device;
  84         dev_set_name(&sub->dev, "%s%d", name, core->nr);
  85
  86         err = device_register(&sub->dev);
  87         if (0 != err) {
  88                 put_device(&sub->dev);
  89                 return err;
  90         }
  91         pr_info("%d: add subdevice \"%s\"\n", core->nr, dev_name(&sub->dev));
  92         list_add_tail(&sub->list,&core->subs);
  93         return 0;
  94 }
  95
  96 int bttv_sub_del_devices(struct bttv_core *core)
  97 {
  98         struct bttv_sub_device *sub, *save;
  99
 100         list_for_each_entry_safe(sub, save, &core->subs, list) {
 101                 list_del(&sub->list);
 102                 device_unregister(&sub->dev);
 103         }
 104         return 0;
 105 }
 106
 107 /* ----------------------------------------------------------------------- */
 108 /* external: sub-driver register/unregister                                */
 109
 110 int bttv_sub_register(struct bttv_sub_driver *sub, char *wanted)
 111 {
 112         sub->drv.bus = &bttv_sub_bus_type;
 113         snprintf(sub->wanted,sizeof(sub->wanted),"%s",wanted);
 114         return driver_register(&sub->drv);
 115 }
 116 EXPORT_SYMBOL(bttv_sub_register);
 117
 118 int bttv_sub_unregister(struct bttv_sub_driver *sub)
 119 {
 120         driver_unregister(&sub->drv);
 121         return 0;
 122 }
 123 EXPORT_SYMBOL(bttv_sub_unregister);
 124
 125 /* ----------------------------------------------------------------------- */
 126 /* external: gpio access functions                                         */
 127
 128 void bttv_gpio_inout(struct bttv_core *core, u32 mask, u32 outbits)
 129 {
 130         struct bttv *btv = container_of(core, struct bttv, c);
 131         unsigned long flags;
 132         u32 data;
 133
 134         spin_lock_irqsave(&btv->gpio_lock,flags);
 135         data = btread(BT848_GPIO_OUT_EN);
 136         data = data & ~mask;
 137         data = data | (mask & outbits);
 138         btwrite(data,BT848_GPIO_OUT_EN);
 139         spin_unlock_irqrestore(&btv->gpio_lock,flags);
 140 }
 141
 142 u32 bttv_gpio_read(struct bttv_core *core)
 143 {
 144         struct bttv *btv = container_of(core, struct bttv, c);
 145         u32 value;
 146
 147         value = btread(BT848_GPIO_DATA);
 148         return value;
 149 }
 150
 151 void bttv_gpio_write(struct bttv_core *core, u32 value)
 152 {
 153         struct bttv *btv = container_of(core, struct bttv, c);
 154
 155         btwrite(value,BT848_GPIO_DATA);
 156 }
 157
 158 void bttv_gpio_bits(struct bttv_core *core, u32 mask, u32 bits)
 159 {
 160         struct bttv *btv = container_of(core, struct bttv, c);
 161         unsigned long flags;
 162         u32 data;
 163
 164         spin_lock_irqsave(&btv->gpio_lock,flags);
 165         data = btread(BT848_GPIO_DATA);
 166         data = data & ~mask;
 167         data = data | (mask & bits);
 168         btwrite(data,BT848_GPIO_DATA);
 169         spin_unlock_irqrestore(&btv->gpio_lock,flags);
 170 }