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
mcp_bus_match(struct device * dev,struct device_driver * drv)23 static int mcp_bus_match(struct device *dev, struct device_driver *drv)
24 {
25 return 1;
26 }
27
mcp_bus_probe(struct device * dev)28 static 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
mcp_bus_remove(struct device * dev)36 static 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
44 static 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 */
mcp_set_telecom_divisor(struct mcp * mcp,unsigned int div)59 void 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(&mcp->lock, flags);
66 }
67 EXPORT_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 */
mcp_set_audio_divisor(struct mcp * mcp,unsigned int div)76 void 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(&mcp->lock, flags);
83 }
84 EXPORT_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 */
mcp_reg_write(struct mcp * mcp,unsigned int reg,unsigned int val)95 void 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(&mcp->lock, flags);
102 }
103 EXPORT_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 */
mcp_reg_read(struct mcp * mcp,unsigned int reg)113 unsigned 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(&mcp->lock, flags);
121
122 return val;
123 }
124 EXPORT_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 */
mcp_enable(struct mcp * mcp)133 void 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(&mcp->lock, flags);
141 }
142 EXPORT_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 */
mcp_disable(struct mcp * mcp)152 void 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(&mcp->lock, flags);
160 }
161 EXPORT_SYMBOL(mcp_disable);
162
mcp_release(struct device * dev)163 static void mcp_release(struct device *dev)
164 {
165 struct mcp *mcp = container_of(dev, struct mcp, attached_device);
166
167 kfree(mcp);
168 }
169
mcp_host_alloc(struct device * parent,size_t size)170 struct mcp *mcp_host_alloc(struct device *parent, size_t size)
171 {
172 struct mcp *mcp;
173
174 mcp = kzalloc(sizeof(struct mcp) + size, GFP_KERNEL);
175 if (mcp) {
176 spin_lock_init(&mcp->lock);
177 device_initialize(&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 }
185 EXPORT_SYMBOL(mcp_host_alloc);
186
mcp_host_add(struct mcp * mcp,void * pdata)187 int mcp_host_add(struct mcp *mcp, void *pdata)
188 {
189 mcp->attached_device.platform_data = pdata;
190 dev_set_name(&mcp->attached_device, "mcp0");
191 return device_add(&mcp->attached_device);
192 }
193 EXPORT_SYMBOL(mcp_host_add);
194
mcp_host_del(struct mcp * mcp)195 void mcp_host_del(struct mcp *mcp)
196 {
197 device_del(&mcp->attached_device);
198 }
199 EXPORT_SYMBOL(mcp_host_del);
200
mcp_host_free(struct mcp * mcp)201 void mcp_host_free(struct mcp *mcp)
202 {
203 put_device(&mcp->attached_device);
204 }
205 EXPORT_SYMBOL(mcp_host_free);
206
mcp_driver_register(struct mcp_driver * mcpdrv)207 int mcp_driver_register(struct mcp_driver *mcpdrv)
208 {
209 mcpdrv->drv.bus = &mcp_bus_type;
210 return driver_register(&mcpdrv->drv);
211 }
212 EXPORT_SYMBOL(mcp_driver_register);
213
mcp_driver_unregister(struct mcp_driver * mcpdrv)214 void mcp_driver_unregister(struct mcp_driver *mcpdrv)
215 {
216 driver_unregister(&mcpdrv->drv);
217 }
218 EXPORT_SYMBOL(mcp_driver_unregister);
219
mcp_init(void)220 static int __init mcp_init(void)
221 {
222 return bus_register(&mcp_bus_type);
223 }
224
mcp_exit(void)225 static void __exit mcp_exit(void)
226 {
227 bus_unregister(&mcp_bus_type);
228 }
229
230 module_init(mcp_init);
231 module_exit(mcp_exit);
232
233 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
234 MODULE_DESCRIPTION("Core multimedia communications port driver");
235 MODULE_LICENSE("GPL");
236