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 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 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 }
171