Commit 3f07af49 authored by Grant Likely's avatar Grant Likely

of: adapt of_find_i2c_driver() to be usable by SPI also

SPI has a similar problem as I2C in that it needs to determine an
appropriate modalias value for each device node.  This patch adapts
the of_i2c of_find_i2c_driver() function to be usable by of_spi also.
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent 5047887c
......@@ -385,3 +385,91 @@ struct device_node *of_find_matching_node(struct device_node *from,
return np;
}
EXPORT_SYMBOL(of_find_matching_node);
/**
* of_modalias_table: Table of explicit compatible ==> modalias mappings
*
* This table allows particulare compatible property values to be mapped
* to modalias strings. This is useful for busses which do not directly
* understand the OF device tree but are populated based on data contained
* within the device tree. SPI and I2C are the two current users of this
* table.
*
* In most cases, devices do not need to be listed in this table because
* the modalias value can be derived directly from the compatible table.
* However, if for any reason a value cannot be derived, then this table
* provides a method to override the implicit derivation.
*
* At the moment, a single table is used for all bus types because it is
* assumed that the data size is small and that the compatible values
* should already be distinct enough to differentiate between SPI, I2C
* and other devices.
*/
struct of_modalias_table {
char *of_device;
char *modalias;
};
static struct of_modalias_table of_modalias_table[] = {
/* Empty for now; add entries as needed */
};
/**
* of_modalias_node - Lookup appropriate modalias for a device node
* @node: pointer to a device tree node
* @modalias: Pointer to buffer that modalias value will be copied into
* @len: Length of modalias value
*
* Based on the value of the compatible property, this routine will determine
* an appropriate modalias value for a particular device tree node. Three
* separate methods are used to derive a modalias value.
*
* First method is to lookup the compatible value in of_modalias_table.
* Second is to look for a "linux,<modalias>" entry in the compatible list
* and used that for modalias. Third is to strip off the manufacturer
* prefix from the first compatible entry and use the remainder as modalias
*
* This routine returns 0 on success
*/
int of_modalias_node(struct device_node *node, char *modalias, int len)
{
int i, cplen;
const char *compatible;
const char *p;
/* 1. search for exception list entry */
for (i = 0; i < ARRAY_SIZE(of_modalias_table); i++) {
compatible = of_modalias_table[i].of_device;
if (!of_device_is_compatible(node, compatible))
continue;
strlcpy(modalias, of_modalias_table[i].modalias, len);
return 0;
}
compatible = of_get_property(node, "compatible", &cplen);
if (!compatible)
return -ENODEV;
/* 2. search for linux,<modalias> entry */
p = compatible;
while (cplen > 0) {
if (!strncmp(p, "linux,", 6)) {
p += 6;
strlcpy(modalias, p, len);
return 0;
}
i = strlen(p) + 1;
p += i;
cplen -= i;
}
/* 3. take first compatible entry and strip manufacturer */
p = strchr(compatible, ',');
if (!p)
return -ENODEV;
p++;
strlcpy(modalias, p, len);
return 0;
}
EXPORT_SYMBOL_GPL(of_modalias_node);
......@@ -16,62 +16,6 @@
#include <linux/of_i2c.h>
#include <linux/module.h>
struct i2c_driver_device {
char *of_device;
char *i2c_type;
};
static struct i2c_driver_device i2c_devices[] = {
};
static int of_find_i2c_driver(struct device_node *node,
struct i2c_board_info *info)
{
int i, cplen;
const char *compatible;
const char *p;
/* 1. search for exception list entry */
for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) {
if (!of_device_is_compatible(node, i2c_devices[i].of_device))
continue;
if (strlcpy(info->type, i2c_devices[i].i2c_type,
I2C_NAME_SIZE) >= I2C_NAME_SIZE)
return -ENOMEM;
return 0;
}
compatible = of_get_property(node, "compatible", &cplen);
if (!compatible)
return -ENODEV;
/* 2. search for linux,<i2c-type> entry */
p = compatible;
while (cplen > 0) {
if (!strncmp(p, "linux,", 6)) {
p += 6;
if (strlcpy(info->type, p,
I2C_NAME_SIZE) >= I2C_NAME_SIZE)
return -ENOMEM;
return 0;
}
i = strlen(p) + 1;
p += i;
cplen -= i;
}
/* 3. take fist compatible entry and strip manufacturer */
p = strchr(compatible, ',');
if (!p)
return -ENODEV;
p++;
if (strlcpy(info->type, p, I2C_NAME_SIZE) >= I2C_NAME_SIZE)
return -ENOMEM;
return 0;
}
void of_register_i2c_devices(struct i2c_adapter *adap,
struct device_node *adap_node)
{
......@@ -83,6 +27,9 @@ void of_register_i2c_devices(struct i2c_adapter *adap,
const u32 *addr;
int len;
if (of_modalias_node(node, info.type, sizeof(info.type)) < 0)
continue;
addr = of_get_property(node, "reg", &len);
if (!addr || len < sizeof(int) || *addr > (1 << 10) - 1) {
printk(KERN_ERR
......@@ -92,11 +39,6 @@ void of_register_i2c_devices(struct i2c_adapter *adap,
info.irq = irq_of_parse_and_map(node, 0);
if (of_find_i2c_driver(node, &info) < 0) {
irq_dispose_mapping(info.irq);
continue;
}
info.addr = *addr;
request_module(info.type);
......
......@@ -70,5 +70,6 @@ extern int of_n_addr_cells(struct device_node *np);
extern int of_n_size_cells(struct device_node *np);
extern const struct of_device_id *of_match_node(
const struct of_device_id *matches, const struct device_node *node);
extern int of_modalias_node(struct device_node *node, char *modalias, int len);
#endif /* _LINUX_OF_H */
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