forked from Minki/linux
ltc4215/ltc4245: Discard obsolete detect methods
There is no point in implementing a detect callback for the LTC4215 and LTC4245, as these devices can't be detected. It was there solely to handle "force" module parameters to instantiate devices, but now we have a better sysfs interface that can do the same. So we can get rid of the ugly module parameters and the detect callbacks. This shrinks the binary module sizes by 36% and 46%, respectively. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Ira W. Snyder <iws@ovro.caltech.edu>
This commit is contained in:
Jean Delvare
parent
0314b020c4
commit
2d2a7cff1b
@ -22,12 +22,13 @@ Usage Notes
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-----------
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This driver does not probe for LTC4215 devices, due to the fact that some
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of the possible addresses are unfriendly to probing. You will need to use
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the "force" parameter to tell the driver where to find the device.
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of the possible addresses are unfriendly to probing. You will have to
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instantiate the devices explicitly.
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Example: the following will load the driver for an LTC4215 at address 0x44
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on I2C bus #0:
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$ modprobe ltc4215 force=0,0x44
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$ modprobe ltc4215
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$ echo ltc4215 0x44 > /sys/bus/i2c/devices/i2c-0/new_device
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Sysfs entries
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@ -23,12 +23,13 @@ Usage Notes
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-----------
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This driver does not probe for LTC4245 devices, due to the fact that some
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of the possible addresses are unfriendly to probing. You will need to use
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the "force" parameter to tell the driver where to find the device.
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of the possible addresses are unfriendly to probing. You will have to
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instantiate the devices explicitly.
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Example: the following will load the driver for an LTC4245 at address 0x23
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on I2C bus #1:
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$ modprobe ltc4245 force=1,0x23
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$ modprobe ltc4245
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$ echo ltc4245 0x23 > /sys/bus/i2c/devices/i2c-1/new_device
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Sysfs entries
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@ -20,11 +20,6 @@
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
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/* Insmod parameters */
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I2C_CLIENT_INSMOD_1(ltc4215);
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/* Here are names of the chip's registers (a.k.a. commands) */
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enum ltc4215_cmd {
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LTC4215_CONTROL = 0x00, /* rw */
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@ -246,9 +241,13 @@ static const struct attribute_group ltc4215_group = {
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static int ltc4215_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct i2c_adapter *adapter = client->adapter;
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struct ltc4215_data *data;
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int ret;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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return -ENODEV;
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data = kzalloc(sizeof(*data), GFP_KERNEL);
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if (!data) {
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ret = -ENOMEM;
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@ -294,56 +293,20 @@ static int ltc4215_remove(struct i2c_client *client)
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return 0;
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}
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static int ltc4215_detect(struct i2c_client *client,
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int kind,
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struct i2c_board_info *info)
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{
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struct i2c_adapter *adapter = client->adapter;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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return -ENODEV;
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if (kind < 0) { /* probed detection - check the chip type */
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s32 v; /* 8 bits from the chip, or -ERRNO */
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/*
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* Register 0x01 bit b7 is reserved, expect 0
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* Register 0x03 bit b6 and b7 are reserved, expect 0
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*/
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v = i2c_smbus_read_byte_data(client, LTC4215_ALERT);
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if (v < 0 || (v & (1 << 7)) != 0)
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return -ENODEV;
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v = i2c_smbus_read_byte_data(client, LTC4215_FAULT);
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if (v < 0 || (v & ((1 << 6) | (1 << 7))) != 0)
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return -ENODEV;
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}
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strlcpy(info->type, "ltc4215", I2C_NAME_SIZE);
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dev_info(&adapter->dev, "ltc4215 %s at address 0x%02x\n",
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kind < 0 ? "probed" : "forced",
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client->addr);
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return 0;
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}
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static const struct i2c_device_id ltc4215_id[] = {
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{ "ltc4215", ltc4215 },
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{ "ltc4215", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, ltc4215_id);
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/* This is the driver that will be inserted */
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static struct i2c_driver ltc4215_driver = {
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.class = I2C_CLASS_HWMON,
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.driver = {
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.name = "ltc4215",
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},
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.probe = ltc4215_probe,
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.remove = ltc4215_remove,
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.id_table = ltc4215_id,
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.detect = ltc4215_detect,
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.address_data = &addr_data,
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};
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static int __init ltc4215_init(void)
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@ -22,15 +22,6 @@
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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/* Valid addresses are 0x20 - 0x3f
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*
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* For now, we do not probe, since some of these addresses
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* are known to be unfriendly to probing */
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static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
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/* Insmod parameters */
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I2C_CLIENT_INSMOD_1(ltc4245);
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/* Here are names of the chip's registers (a.k.a. commands) */
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enum ltc4245_cmd {
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LTC4245_STATUS = 0x00, /* readonly */
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@ -369,9 +360,13 @@ static const struct attribute_group ltc4245_group = {
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static int ltc4245_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct i2c_adapter *adapter = client->adapter;
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struct ltc4245_data *data;
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int ret;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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return -ENODEV;
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data = kzalloc(sizeof(*data), GFP_KERNEL);
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if (!data) {
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ret = -ENOMEM;
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@ -418,136 +413,20 @@ static int ltc4245_remove(struct i2c_client *client)
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return 0;
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}
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/* Check that some bits in a control register appear at all possible
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* locations without changing value
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*
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* @client: the i2c client to use
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* @reg: the register to read
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* @bits: the bits to check (0xff checks all bits,
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* 0x03 checks only the last two bits)
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*
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* return -ERRNO if the register read failed
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* return -ENODEV if the register value doesn't stay constant at all
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* possible addresses
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*
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* return 0 for success
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*/
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static int ltc4245_check_control_reg(struct i2c_client *client, u8 reg, u8 bits)
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{
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int i;
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s32 v, voff1, voff2;
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/* Read register and check for error */
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v = i2c_smbus_read_byte_data(client, reg);
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if (v < 0)
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return v;
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v &= bits;
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for (i = 0x00; i < 0xff; i += 0x20) {
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voff1 = i2c_smbus_read_byte_data(client, reg + i);
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if (voff1 < 0)
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return voff1;
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voff2 = i2c_smbus_read_byte_data(client, reg + i + 0x08);
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if (voff2 < 0)
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return voff2;
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voff1 &= bits;
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voff2 &= bits;
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if (v != voff1 || v != voff2)
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return -ENODEV;
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}
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return 0;
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}
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static int ltc4245_detect(struct i2c_client *client,
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int kind,
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struct i2c_board_info *info)
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{
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struct i2c_adapter *adapter = client->adapter;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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return -ENODEV;
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if (kind < 0) { /* probed detection - check the chip type */
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s32 v; /* 8 bits from the chip, or -ERRNO */
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/* Chip registers 0x00-0x07 are control registers
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* Chip registers 0x10-0x1f are data registers
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*
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* Address bits b7-b5 are ignored. This makes the chip "repeat"
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* in steps of 0x20. Any control registers should appear with
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* the same values across all duplicated addresses.
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*
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* Register 0x02 bit b2 is reserved, expect 0
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* Register 0x07 bits b7 to b4 are reserved, expect 0
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*
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* Registers 0x01, 0x02 are control registers and should not
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* change on their own.
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*
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* Register 0x06 bits b6 and b7 are control bits, and should
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* not change on their own.
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*
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* Register 0x07 bits b3 to b0 are control bits, and should
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* not change on their own.
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*/
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/* read register 0x02 reserved bit, expect 0 */
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v = i2c_smbus_read_byte_data(client, LTC4245_CONTROL);
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if (v < 0 || (v & 0x04) != 0)
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return -ENODEV;
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/* read register 0x07 reserved bits, expect 0 */
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v = i2c_smbus_read_byte_data(client, LTC4245_ADCADR);
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if (v < 0 || (v & 0xf0) != 0)
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return -ENODEV;
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/* check that the alert register appears at all locations */
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if (ltc4245_check_control_reg(client, LTC4245_ALERT, 0xff))
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return -ENODEV;
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/* check that the control register appears at all locations */
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if (ltc4245_check_control_reg(client, LTC4245_CONTROL, 0xff))
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return -ENODEV;
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/* check that register 0x06 bits b6 and b7 stay constant */
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if (ltc4245_check_control_reg(client, LTC4245_GPIO, 0xc0))
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return -ENODEV;
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/* check that register 0x07 bits b3-b0 stay constant */
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if (ltc4245_check_control_reg(client, LTC4245_ADCADR, 0x0f))
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return -ENODEV;
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}
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strlcpy(info->type, "ltc4245", I2C_NAME_SIZE);
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dev_info(&adapter->dev, "ltc4245 %s at address 0x%02x\n",
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kind < 0 ? "probed" : "forced",
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client->addr);
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return 0;
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}
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static const struct i2c_device_id ltc4245_id[] = {
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{ "ltc4245", ltc4245 },
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{ "ltc4245", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, ltc4245_id);
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/* This is the driver that will be inserted */
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static struct i2c_driver ltc4245_driver = {
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.class = I2C_CLASS_HWMON,
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.driver = {
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.name = "ltc4245",
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},
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.probe = ltc4245_probe,
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.remove = ltc4245_remove,
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.id_table = ltc4245_id,
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.detect = ltc4245_detect,
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.address_data = &addr_data,
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};
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static int __init ltc4245_init(void)
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