[U-Boot] [PATCH 3/4] i2c: dm: Record maximum id of devices before probing devices

[Michal Simek]

There is a need to find out the first free i2c ID which can be used for
i2s buses (including i2c buses connected to i2c mux). Do it early in
init and share this variable with other i2c classes for uniq bus
identification.

Signed-off-by: Michal Simek <michal.simek at xilinx.com>
---

 drivers/i2c/i2c-uclass.c | 19 +++++++++++++++++++
 include/i2c.h            |  3 +++
 2 files changed, 22 insertions(+)

diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c
index 975318e5f254..aaece115f02f 100644
--- a/drivers/i2c/i2c-uclass.c
+++ b/drivers/i2c/i2c-uclass.c
@@ -23,6 +23,8 @@ enum {
 	PIN_COUNT,
 };
 
+int i2c_highest_id = -1;
+
 /* Useful debugging function */
 void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs)
 {
@@ -619,10 +621,27 @@ static int i2c_child_post_bind(struct udevice *dev)
 #endif
 }
 
+int i2c_uclass_init(struct uclass *class)
+{
+#ifdef CONFIG_OF_LIVE
+	int ret;
+
+	ret = of_alias_get_highest_id("i2c");
+	if (ret >= 0)
+		i2c_highest_id = ret;
+#else
+	i2c_highest_id = fdtdec_get_alias_highest_id(gd->fdt_blob, "i2c");
+#endif
+	debug("%s: i2c highest_id %d\n", __func__, i2c_highest_id);
+
+	return 0;
+}
+
 UCLASS_DRIVER(i2c) = {
 	.id		= UCLASS_I2C,
 	.name		= "i2c",
 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
+	.init		= i2c_uclass_init,
 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
 	.post_bind	= dm_scan_fdt_dev,
 #endif
diff --git a/include/i2c.h b/include/i2c.h
index ccffc1955275..c69e26deaeed 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -16,6 +16,9 @@
 #ifndef _I2C_H_
 #define _I2C_H_
 
+/* Stores maximum highest i2c alias number */
+extern int i2c_highest_id;
+
 /*
  * For now there are essentially two parts to this file - driver model
  * here at the top, and the older code below (with CONFIG_SYS_I2C being
-- 
1.9.1