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
58const 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
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