From: Corey Minyard <cminyard@xxxxxxxxxx>
Some devices might need parameters to control their operation,
add the ability to pass these parameters to the client.
This also makes the parsing of sysfs-added I2C devices a little
more flexible, allowing tabs and arbitrary numbers of spaces.
Signed-off-by: Corey Minyard <cminyard@xxxxxxxxxx>
---
drivers/i2c/i2c-core.c | 46 ++++++++++++++++++++++++++++++++++------------
include/linux/i2c.h | 3 +++
2 files changed, 37 insertions(+), 12 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index ffe715d..e2e42fc 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -785,7 +785,10 @@ static void i2c_device_shutdown(struct device *dev)
static void i2c_client_dev_release(struct device *dev)
{
- kfree(to_i2c_client(dev));
+ struct i2c_client *client = to_i2c_client(dev);
+
+ kfree(client->parms);
+ kfree(client);
}
static ssize_t
@@ -1052,6 +1055,13 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
client->flags = info->flags;
client->addr = info->addr;
client->irq = info->irq;
+ if (info->parms) {
+ client->parms = kstrdup(info->parms, GFP_KERNEL);
+ if (!client->parms) {
+ dev_err(&adap->dev, "Out of memory allocating parms\n");
+ goto out_err_silent;
+ }
+ }
strlcpy(client->name, info->type, sizeof(client->name));
@@ -1201,31 +1211,43 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
struct i2c_adapter *adap = to_i2c_adapter(dev);
struct i2c_board_info info;
struct i2c_client *client;
- char *blank, end;
+ char *pos, end;
int res;
memset(&info, 0, sizeof(struct i2c_board_info));
- blank = strchr(buf, ' ');
- if (!blank) {
+ pos = strpbrk(buf, " \t");
+ if (!pos) {
dev_err(dev, "%s: Missing parameters\n", "new_device");
return -EINVAL;
}
- if (blank - buf > I2C_NAME_SIZE - 1) {
+ if (pos - buf > I2C_NAME_SIZE - 1) {
dev_err(dev, "%s: Invalid device name\n", "new_device");
return -EINVAL;
}
- memcpy(info.type, buf, blank - buf);
+ memcpy(info.type, buf, pos - buf);
- /* Parse remaining parameters, reject extra parameters */
- res = sscanf(++blank, "%hi%c", &info.addr, &end);
- if (res < 1) {
+ while (isspace(*pos))
+ pos++;
+
+ /* Parse address, saving remaining parameters. */
+ res = sscanf(pos, "%hi%c", &info.addr, &end);
+ if (res < 1 || !isspace(end)) {
dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
return -EINVAL;
}
- if (res > 1 && end != '\n') {
- dev_err(dev, "%s: Extra parameters\n", "new_device");
- return -EINVAL;
+ if (res > 1 && end != '\n') {
+ if (isspace(end)) {
+ /* Extra parms, skip the address and space. */
+ while (!isspace(*pos))
+ pos++;
+ while (isspace(*pos))
+ pos++;
+ info.parms = pos;
+ } else {
+ dev_err(dev, "%s: Extra parameters\n", "new_device");
+ return -EINVAL;
+ }
}
if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 200cf13b..35db0dd 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -225,6 +225,7 @@ struct i2c_client {
char name[I2C_NAME_SIZE];
struct i2c_adapter *adapter; /* the adapter we sit on */
struct device dev; /* the device structure */
+ char *parms; /* sysfs extra parms */
int irq; /* irq issued by device */
struct list_head detected;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
@@ -282,6 +283,7 @@ static inline int i2c_slave_event(struct i2c_client *client,
* @archdata: copied into i2c_client.dev.archdata
* @of_node: pointer to OpenFirmware device node
* @fwnode: device node supplied by the platform firmware
+ * @parms: Parameters supplied on the sysfs command line
* @irq: stored in i2c_client.irq
*
* I2C doesn't actually support hardware probing, although controllers and
@@ -303,6 +305,7 @@ struct i2c_board_info {
struct dev_archdata *archdata;
struct device_node *of_node;
struct fwnode_handle *fwnode;
+ char *parms;
int irq;
};
--
2.5.0
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