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 }
172