1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/drivers/mfd/mcp-core.c
4 *
5 * Copyright (C) 2001 Russell King
6 *
7 * Generic MCP (Multimedia Communications Port) layer. All MCP locking
8 * is solely held within this file.
9 */
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/errno.h>
13#include <linux/smp.h>
14#include <linux/device.h>
15#include <linux/slab.h>
16#include <linux/string.h>
17#include <linux/mfd/mcp.h>
18
19
20#define to_mcp(d) container_of(d, struct mcp, attached_device)
21#define to_mcp_driver(d) container_of(d, struct mcp_driver, drv)
22
23static int mcp_bus_match(struct device *dev, struct device_driver *drv)
24{
25 return 1;
26}
27
28static int mcp_bus_probe(struct device *dev)
29{
30 struct mcp *mcp = to_mcp(dev);
31 struct mcp_driver *drv = to_mcp_driver(dev->driver);
32
33 return drv->probe(mcp);
34}
35
36static void mcp_bus_remove(struct device *dev)
37{
38 struct mcp *mcp = to_mcp(dev);
39 struct mcp_driver *drv = to_mcp_driver(dev->driver);
40
41 drv->remove(mcp);
42}
43
44static struct bus_type mcp_bus_type = {
45 .name = "mcp",
46 .match = mcp_bus_match,
47 .probe = mcp_bus_probe,
48 .remove = mcp_bus_remove,
49};
50
51/**
52 * mcp_set_telecom_divisor - set the telecom divisor
53 * @mcp: MCP interface structure
54 * @div: SIB clock divisor
55 *
56 * Set the telecom divisor on the MCP interface. The resulting
57 * sample rate is SIBCLOCK/div.
58 */
59void mcp_set_telecom_divisor(struct mcp *mcp, unsigned int div)
60{
61 unsigned long flags;
62
63 spin_lock_irqsave(&mcp->lock, flags);
64 mcp->ops->set_telecom_divisor(mcp, div);
65 spin_unlock_irqrestore(lock: &mcp->lock, flags);
66}
67EXPORT_SYMBOL(mcp_set_telecom_divisor);
68
69/**
70 * mcp_set_audio_divisor - set the audio divisor
71 * @mcp: MCP interface structure
72 * @div: SIB clock divisor
73 *
74 * Set the audio divisor on the MCP interface.
75 */
76void mcp_set_audio_divisor(struct mcp *mcp, unsigned int div)
77{
78 unsigned long flags;
79
80 spin_lock_irqsave(&mcp->lock, flags);
81 mcp->ops->set_audio_divisor(mcp, div);
82 spin_unlock_irqrestore(lock: &mcp->lock, flags);
83}
84EXPORT_SYMBOL(mcp_set_audio_divisor);
85
86/**
87 * mcp_reg_write - write a device register
88 * @mcp: MCP interface structure
89 * @reg: 4-bit register index
90 * @val: 16-bit data value
91 *
92 * Write a device register. The MCP interface must be enabled
93 * to prevent this function hanging.
94 */
95void mcp_reg_write(struct mcp *mcp, unsigned int reg, unsigned int val)
96{
97 unsigned long flags;
98
99 spin_lock_irqsave(&mcp->lock, flags);
100 mcp->ops->reg_write(mcp, reg, val);
101 spin_unlock_irqrestore(lock: &mcp->lock, flags);
102}
103EXPORT_SYMBOL(mcp_reg_write);
104
105/**
106 * mcp_reg_read - read a device register
107 * @mcp: MCP interface structure
108 * @reg: 4-bit register index
109 *
110 * Read a device register and return its value. The MCP interface
111 * must be enabled to prevent this function hanging.
112 */
113unsigned int mcp_reg_read(struct mcp *mcp, unsigned int reg)
114{
115 unsigned long flags;
116 unsigned int val;
117
118 spin_lock_irqsave(&mcp->lock, flags);
119 val = mcp->ops->reg_read(mcp, reg);
120 spin_unlock_irqrestore(lock: &mcp->lock, flags);
121
122 return val;
123}
124EXPORT_SYMBOL(mcp_reg_read);
125
126/**
127 * mcp_enable - enable the MCP interface
128 * @mcp: MCP interface to enable
129 *
130 * Enable the MCP interface. Each call to mcp_enable will need
131 * a corresponding call to mcp_disable to disable the interface.
132 */
133void mcp_enable(struct mcp *mcp)
134{
135 unsigned long flags;
136
137 spin_lock_irqsave(&mcp->lock, flags);
138 if (mcp->use_count++ == 0)
139 mcp->ops->enable(mcp);
140 spin_unlock_irqrestore(lock: &mcp->lock, flags);
141}
142EXPORT_SYMBOL(mcp_enable);
143
144/**
145 * mcp_disable - disable the MCP interface
146 * @mcp: MCP interface to disable
147 *
148 * Disable the MCP interface. The MCP interface will only be
149 * disabled once the number of calls to mcp_enable matches the
150 * number of calls to mcp_disable.
151 */
152void mcp_disable(struct mcp *mcp)
153{
154 unsigned long flags;
155
156 spin_lock_irqsave(&mcp->lock, flags);
157 if (--mcp->use_count == 0)
158 mcp->ops->disable(mcp);
159 spin_unlock_irqrestore(lock: &mcp->lock, flags);
160}
161EXPORT_SYMBOL(mcp_disable);
162
163static void mcp_release(struct device *dev)
164{
165 struct mcp *mcp = container_of(dev, struct mcp, attached_device);
166
167 kfree(objp: mcp);
168}
169
170struct mcp *mcp_host_alloc(struct device *parent, size_t size)
171{
172 struct mcp *mcp;
173
174 mcp = kzalloc(size: sizeof(struct mcp) + size, GFP_KERNEL);
175 if (mcp) {
176 spin_lock_init(&mcp->lock);
177 device_initialize(dev: &mcp->attached_device);
178 mcp->attached_device.parent = parent;
179 mcp->attached_device.bus = &mcp_bus_type;
180 mcp->attached_device.dma_mask = parent->dma_mask;
181 mcp->attached_device.release = mcp_release;
182 }
183 return mcp;
184}
185EXPORT_SYMBOL(mcp_host_alloc);
186
187int mcp_host_add(struct mcp *mcp, void *pdata)
188{
189 mcp->attached_device.platform_data = pdata;
190 dev_set_name(dev: &mcp->attached_device, name: "mcp0");
191 return device_add(dev: &mcp->attached_device);
192}
193EXPORT_SYMBOL(mcp_host_add);
194
195void mcp_host_del(struct mcp *mcp)
196{
197 device_del(dev: &mcp->attached_device);
198}
199EXPORT_SYMBOL(mcp_host_del);
200
201void mcp_host_free(struct mcp *mcp)
202{
203 put_device(dev: &mcp->attached_device);
204}
205EXPORT_SYMBOL(mcp_host_free);
206
207int mcp_driver_register(struct mcp_driver *mcpdrv)
208{
209 mcpdrv->drv.bus = &mcp_bus_type;
210 return driver_register(drv: &mcpdrv->drv);
211}
212EXPORT_SYMBOL(mcp_driver_register);
213
214void mcp_driver_unregister(struct mcp_driver *mcpdrv)
215{
216 driver_unregister(drv: &mcpdrv->drv);
217}
218EXPORT_SYMBOL(mcp_driver_unregister);
219
220static int __init mcp_init(void)
221{
222 return bus_register(bus: &mcp_bus_type);
223}
224
225static void __exit mcp_exit(void)
226{
227 bus_unregister(bus: &mcp_bus_type);
228}
229
230module_init(mcp_init);
231module_exit(mcp_exit);
232
233MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
234MODULE_DESCRIPTION("Core multimedia communications port driver");
235MODULE_LICENSE("GPL");
236

source code of linux/drivers/mfd/mcp-core.c