linux/drivers/media/pci/bt8xx/bttv-gpio.c
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   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
  31static 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
  41static 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
  49static 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
  59struct 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
  66static void release_sub_device(struct device *dev)
  67{
  68        struct bttv_sub_device *sub = to_bttv_sub_dev(dev);
  69        kfree(sub);
  70}
  71
  72int 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
  97int 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
 111int 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}
 117EXPORT_SYMBOL(bttv_sub_register);
 118
 119int bttv_sub_unregister(struct bttv_sub_driver *sub)
 120{
 121        driver_unregister(&sub->drv);
 122        return 0;
 123}
 124EXPORT_SYMBOL(bttv_sub_unregister);
 125
 126/* ----------------------------------------------------------------------- */
 127/* external: gpio access functions                                         */
 128
 129void 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
 143u32 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
 152void 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
 159void 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}
 172