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: Grant Likely <grant.likely@secretlab.ca>

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 23ffb7c0caf24148277ddd19c7430b5c90fb6fcb..ad8ac1a8af28689acc7198b22fe95a888d62e6a6 100644 (file)
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -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);
+

diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c
index 344e1b03dd8b708661fcb08982d27ebd79bd586b..6a98dc8aa30b1af9a1e8ce9a2a8264073a631eee 100644 (file)
--- a/drivers/of/of_i2c.c
+++ b/drivers/of/of_i2c.c
@@ -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);

diff --git a/include/linux/of.h b/include/linux/of.h
index 59a61bdc98b69b58da4f6f9797c131a275c690d1..79886ade070f2e791274c92814bc04bfbcff4947 100644 (file)
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -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 */