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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
commit833bedb813689807385ae73175389c73a3f855c1 (patch)
treef9b33add52ca947fd9f8ae89753eb8d534efc70e /drivers/i2c
parent8b77e6ac4911a79993e583ece719736a9e035b1d (diff)
i2c: Convert the pcf8574 driver to a new-style i2c driver
The new-style pcf8574 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')
-rw-r--r--drivers/i2c/chips/pcf8574.c108
1 files changed, 46 insertions, 62 deletions
diff --git a/drivers/i2c/chips/pcf8574.c b/drivers/i2c/chips/pcf8574.c
index 1b3db2b3ada9..6ec309894c88 100644
--- a/drivers/i2c/chips/pcf8574.c
+++ b/drivers/i2c/chips/pcf8574.c
@@ -38,37 +38,19 @@
38#include <linux/slab.h> 38#include <linux/slab.h>
39#include <linux/i2c.h> 39#include <linux/i2c.h>
40 40
41/* Addresses to scan */ 41/* Addresses to scan: none, device can't be detected */
42static const unsigned short normal_i2c[] = { 42static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
43 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
44 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
45 I2C_CLIENT_END
46};
47 43
48/* Insmod parameters */ 44/* Insmod parameters */
49I2C_CLIENT_INSMOD_2(pcf8574, pcf8574a); 45I2C_CLIENT_INSMOD_2(pcf8574, pcf8574a);
50 46
51/* Each client has this additional data */ 47/* Each client has this additional data */
52struct pcf8574_data { 48struct pcf8574_data {
53 struct i2c_client client;
54
55 int write; /* Remember last written value */ 49 int write; /* Remember last written value */
56}; 50};
57 51
58static int pcf8574_attach_adapter(struct i2c_adapter *adapter);
59static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind);
60static int pcf8574_detach_client(struct i2c_client *client);
61static void pcf8574_init_client(struct i2c_client *client); 52static void pcf8574_init_client(struct i2c_client *client);
62 53
63/* This is the driver that will be inserted */
64static struct i2c_driver pcf8574_driver = {
65 .driver = {
66 .name = "pcf8574",
67 },
68 .attach_adapter = pcf8574_attach_adapter,
69 .detach_client = pcf8574_detach_client,
70};
71
72/* following are the sysfs callback functions */ 54/* following are the sysfs callback functions */
73static ssize_t show_read(struct device *dev, struct device_attribute *attr, char *buf) 55static ssize_t show_read(struct device *dev, struct device_attribute *attr, char *buf)
74{ 56{
@@ -119,41 +101,22 @@ static const struct attribute_group pcf8574_attr_group = {
119 * Real code 101 * Real code
120 */ 102 */
121 103
122static int pcf8574_attach_adapter(struct i2c_adapter *adapter) 104/* Return 0 if detection is successful, -ENODEV otherwise */
123{ 105static int pcf8574_detect(struct i2c_client *client, int kind,
124 return i2c_probe(adapter, &addr_data, pcf8574_detect); 106 struct i2c_board_info *info)
125}
126
127/* This function is called by i2c_probe */
128static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind)
129{ 107{
130 struct i2c_client *client; 108 struct i2c_adapter *adapter = client->adapter;
131 struct pcf8574_data *data; 109 const char *client_name;
132 int err = 0;
133 const char *client_name = "";
134 110
135 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 111 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
136 goto exit; 112 return -ENODEV;
137
138 /* OK. For now, we presume we have a valid client. We now create the
139 client structure, even though we cannot fill it completely yet. */
140 if (!(data = kzalloc(sizeof(struct pcf8574_data), GFP_KERNEL))) {
141 err = -ENOMEM;
142 goto exit;
143 }
144
145 client = &data->client;
146 i2c_set_clientdata(client, data);
147 client->addr = address;
148 client->adapter = adapter;
149 client->driver = &pcf8574_driver;
150 113
151 /* Now, we would do the remaining detection. But the PCF8574 is plainly 114 /* Now, we would do the remaining detection. But the PCF8574 is plainly
152 impossible to detect! Stupid chip. */ 115 impossible to detect! Stupid chip. */
153 116
154 /* Determine the chip type */ 117 /* Determine the chip type */
155 if (kind <= 0) { 118 if (kind <= 0) {
156 if (address >= 0x38 && address <= 0x3f) 119 if (client->addr >= 0x38 && client->addr <= 0x3f)
157 kind = pcf8574a; 120 kind = pcf8574a;
158 else 121 else
159 kind = pcf8574; 122 kind = pcf8574;
@@ -163,40 +126,43 @@ static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind)
163 client_name = "pcf8574a"; 126 client_name = "pcf8574a";
164 else 127 else
165 client_name = "pcf8574"; 128 client_name = "pcf8574";
129 strlcpy(info->type, client_name, I2C_NAME_SIZE);
166 130
167 /* Fill in the remaining client fields and put it into the global list */ 131 return 0;
168 strlcpy(client->name, client_name, I2C_NAME_SIZE); 132}
133
134static int pcf8574_probe(struct i2c_client *client,
135 const struct i2c_device_id *id)
136{
137 struct pcf8574_data *data;
138 int err;
139
140 data = kzalloc(sizeof(struct pcf8574_data), GFP_KERNEL);
141 if (!data) {
142 err = -ENOMEM;
143 goto exit;
144 }
145
146 i2c_set_clientdata(client, data);
169 147
170 /* Tell the I2C layer a new client has arrived */
171 if ((err = i2c_attach_client(client)))
172 goto exit_free;
173
174 /* Initialize the PCF8574 chip */ 148 /* Initialize the PCF8574 chip */
175 pcf8574_init_client(client); 149 pcf8574_init_client(client);
176 150
177 /* Register sysfs hooks */ 151 /* Register sysfs hooks */
178 err = sysfs_create_group(&client->dev.kobj, &pcf8574_attr_group); 152 err = sysfs_create_group(&client->dev.kobj, &pcf8574_attr_group);
179 if (err) 153 if (err)
180 goto exit_detach; 154 goto exit_free;
181 return 0; 155 return 0;
182 156
183 exit_detach:
184 i2c_detach_client(client);
185 exit_free: 157 exit_free:
186 kfree(data); 158 kfree(data);
187 exit: 159 exit:
188 return err; 160 return err;
189} 161}
190 162
191static int pcf8574_detach_client(struct i2c_client *client) 163static int pcf8574_remove(struct i2c_client *client)
192{ 164{
193 int err;
194
195 sysfs_remove_group(&client->dev.kobj, &pcf8574_attr_group); 165 sysfs_remove_group(&client->dev.kobj, &pcf8574_attr_group);
196
197 if ((err = i2c_detach_client(client)))
198 return err;
199
200 kfree(i2c_get_clientdata(client)); 166 kfree(i2c_get_clientdata(client));
201 return 0; 167 return 0;
202} 168}
@@ -208,6 +174,24 @@ static void pcf8574_init_client(struct i2c_client *client)
208 data->write = -EAGAIN; 174 data->write = -EAGAIN;
209} 175}
210 176
177static const struct i2c_device_id pcf8574_id[] = {
178 { "pcf8574", 0 },
179 { "pcf8574a", 0 },
180 { }
181};
182
183static struct i2c_driver pcf8574_driver = {
184 .driver = {
185 .name = "pcf8574",
186 },
187 .probe = pcf8574_probe,
188 .remove = pcf8574_remove,
189 .id_table = pcf8574_id,
190
191 .detect = pcf8574_detect,
192 .address_data = &addr_data,
193};
194
211static int __init pcf8574_init(void) 195static int __init pcf8574_init(void)
212{ 196{
213 return i2c_add_driver(&pcf8574_driver); 197 return i2c_add_driver(&pcf8574_driver);