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 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
  58struct 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
  65static void release_sub_device(struct device *dev)
  66{
  67        struct bttv_sub_device *sub = to_bttv_sub_dev(dev);
  68        kfree(sub);
  69}
  70
  71int 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
  96int 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
 110int 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}
 116EXPORT_SYMBOL(bttv_sub_register);
 117
 118int bttv_sub_unregister(struct bttv_sub_driver *sub)
 119{
 120        driver_unregister(&sub->drv);
 121        return 0;
 122}
 123EXPORT_SYMBOL(bttv_sub_unregister);
 124
 125/* ----------------------------------------------------------------------- */
 126/* external: gpio access functions                                         */
 127
 128void 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
 142u32 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
 151void 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
 158void 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}
 171