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authorJean Delvare <khali@linux-fr.org>2008-07-16 13:30:06 -0400
committerJean Delvare <khali@mahadeva.delvare>2008-07-16 13:30:06 -0400
commit97addff6def3f8e228a634fa017589f45c69de5c (patch)
treeabdbe65bb56dd88dbdaeb1878168ef4640ff829c /drivers/i2c/chips
parent833bedb813689807385ae73175389c73a3f855c1 (diff)
i2c: Convert the pcf8575 driver to a new-style i2c driver
The new-style pcf8575 driver implements the optional detect() callback to cover the use cases of the legacy driver. Warning: users will now have to use the force module parameter to get the driver to attach to their device. That's not a bad thing as these devices can't be detected anyway. Note that this doesn't change the fact that this driver is deprecated in favor of gpio/pcf857x. Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c/chips')
-rw-r--r--drivers/i2c/chips/pcf8575.c96
1 files changed, 40 insertions, 56 deletions
diff --git a/drivers/i2c/chips/pcf8575.c b/drivers/i2c/chips/pcf8575.c
index 3ea08ac0bfa3..07fd7cb3c57d 100644
--- a/drivers/i2c/chips/pcf8575.c
+++ b/drivers/i2c/chips/pcf8575.c
@@ -32,11 +32,8 @@
32#include <linux/slab.h> /* kzalloc() */ 32#include <linux/slab.h> /* kzalloc() */
33#include <linux/sysfs.h> /* sysfs_create_group() */ 33#include <linux/sysfs.h> /* sysfs_create_group() */
34 34
35/* Addresses to scan */ 35/* Addresses to scan: none, device can't be detected */
36static const unsigned short normal_i2c[] = { 36static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
37 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
38 I2C_CLIENT_END
39};
40 37
41/* Insmod parameters */ 38/* Insmod parameters */
42I2C_CLIENT_INSMOD; 39I2C_CLIENT_INSMOD;
@@ -44,24 +41,9 @@ I2C_CLIENT_INSMOD;
44 41
45/* Each client has this additional data */ 42/* Each client has this additional data */
46struct pcf8575_data { 43struct pcf8575_data {
47 struct i2c_client client;
48 int write; /* last written value, or error code */ 44 int write; /* last written value, or error code */
49}; 45};
50 46
51static int pcf8575_attach_adapter(struct i2c_adapter *adapter);
52static int pcf8575_detect(struct i2c_adapter *adapter, int address, int kind);
53static int pcf8575_detach_client(struct i2c_client *client);
54
55/* This is the driver that will be inserted */
56static struct i2c_driver pcf8575_driver = {
57 .driver = {
58 .owner = THIS_MODULE,
59 .name = "pcf8575",
60 },
61 .attach_adapter = pcf8575_attach_adapter,
62 .detach_client = pcf8575_detach_client,
63};
64
65/* following are the sysfs callback functions */ 47/* following are the sysfs callback functions */
66static ssize_t show_read(struct device *dev, struct device_attribute *attr, 48static ssize_t show_read(struct device *dev, struct device_attribute *attr,
67 char *buf) 49 char *buf)
@@ -126,75 +108,77 @@ static const struct attribute_group pcf8575_attr_group = {
126 * Real code 108 * Real code
127 */ 109 */
128 110
129static int pcf8575_attach_adapter(struct i2c_adapter *adapter) 111/* Return 0 if detection is successful, -ENODEV otherwise */
112static int pcf8575_detect(struct i2c_client *client, int kind,
113 struct i2c_board_info *info)
130{ 114{
131 return i2c_probe(adapter, &addr_data, pcf8575_detect); 115 struct i2c_adapter *adapter = client->adapter;
116
117 if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
118 return -ENODEV;
119
120 /* This is the place to detect whether the chip at the specified
121 address really is a PCF8575 chip. However, there is no method known
122 to detect whether an I2C chip is a PCF8575 or any other I2C chip. */
123
124 strlcpy(info->type, "pcf8575", I2C_NAME_SIZE);
125
126 return 0;
132} 127}
133 128
134/* This function is called by i2c_probe */ 129static int pcf8575_probe(struct i2c_client *client,
135static int pcf8575_detect(struct i2c_adapter *adapter, int address, int kind) 130 const struct i2c_device_id *id)
136{ 131{
137 struct i2c_client *client;
138 struct pcf8575_data *data; 132 struct pcf8575_data *data;
139 int err = 0; 133 int err;
140
141 if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
142 goto exit;
143 134
144 /* OK. For now, we presume we have a valid client. We now create the
145 client structure, even though we cannot fill it completely yet. */
146 data = kzalloc(sizeof(struct pcf8575_data), GFP_KERNEL); 135 data = kzalloc(sizeof(struct pcf8575_data), GFP_KERNEL);
147 if (!data) { 136 if (!data) {
148 err = -ENOMEM; 137 err = -ENOMEM;
149 goto exit; 138 goto exit;
150 } 139 }
151 140
152 client = &data->client;
153 i2c_set_clientdata(client, data); 141 i2c_set_clientdata(client, data);
154 client->addr = address;
155 client->adapter = adapter;
156 client->driver = &pcf8575_driver;
157 strlcpy(client->name, "pcf8575", I2C_NAME_SIZE);
158 data->write = -EAGAIN; 142 data->write = -EAGAIN;
159 143
160 /* This is the place to detect whether the chip at the specified
161 address really is a PCF8575 chip. However, there is no method known
162 to detect whether an I2C chip is a PCF8575 or any other I2C chip. */
163
164 /* Tell the I2C layer a new client has arrived */
165 err = i2c_attach_client(client);
166 if (err)
167 goto exit_free;
168
169 /* Register sysfs hooks */ 144 /* Register sysfs hooks */
170 err = sysfs_create_group(&client->dev.kobj, &pcf8575_attr_group); 145 err = sysfs_create_group(&client->dev.kobj, &pcf8575_attr_group);
171 if (err) 146 if (err)
172 goto exit_detach; 147 goto exit_free;
173 148
174 return 0; 149 return 0;
175 150
176exit_detach:
177 i2c_detach_client(client);
178exit_free: 151exit_free:
179 kfree(data); 152 kfree(data);
180exit: 153exit:
181 return err; 154 return err;
182} 155}
183 156
184static int pcf8575_detach_client(struct i2c_client *client) 157static int pcf8575_remove(struct i2c_client *client)
185{ 158{
186 int err;
187
188 sysfs_remove_group(&client->dev.kobj, &pcf8575_attr_group); 159 sysfs_remove_group(&client->dev.kobj, &pcf8575_attr_group);
189
190 err = i2c_detach_client(client);
191 if (err)
192 return err;
193
194 kfree(i2c_get_clientdata(client)); 160 kfree(i2c_get_clientdata(client));
195 return 0; 161 return 0;
196} 162}
197 163
164static const struct i2c_device_id pcf8575_id[] = {
165 { "pcf8575", 0 },
166 { }
167};
168
169static struct i2c_driver pcf8575_driver = {
170 .driver = {
171 .owner = THIS_MODULE,
172 .name = "pcf8575",
173 },
174 .probe = pcf8575_probe,
175 .remove = pcf8575_remove,
176 .id_table = pcf8575_id,
177
178 .detect = pcf8575_detect,
179 .address_data = &addr_data,
180};
181
198static int __init pcf8575_init(void) 182static int __init pcf8575_init(void)
199{ 183{
200 return i2c_add_driver(&pcf8575_driver); 184 return i2c_add_driver(&pcf8575_driver);