[PATCH] 1/5 powerpc: Rework PowerMac i2c part 1

This is the first part of a rework of the PowerMac i2c code. It
completely reworks the "low_i2c" layer. It is now more flexible,
supports KeyWest, SMU and PMU i2c busses, and provides functions to
match device nodes to i2c busses and adapters.

This patch also extends & fix some bugs in the SMU driver related to i2c
support and removes the clock spreading hacks from the pmac feature code
rather than adapting them to the new API since they'll be replaced by
the platform function code completely in patch 3/5

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 71 insertions, 14 deletions

diff --git a/include/asm-powerpc/pmac_low_i2c.h b/include/asm-powerpc/pmac_low_i2c.h
index 3fb8d51540dd..adf4fa956572 100644
--- a/include/asm-powerpc/pmac_low_i2c.h
+++ b/include/asm-powerpc/pmac_low_i2c.h
@@ -15,30 +15,87 @@
 
 /* i2c mode (based on the platform functions format) */
 enum {
-        pmac_low_i2c_mode_dumb          = 1,
-        pmac_low_i2c_mode_std           = 2,
-        pmac_low_i2c_mode_stdsub        = 3,
-        pmac_low_i2c_mode_combined      = 4,
+        pmac_i2c_mode_dumb      = 1,
+        pmac_i2c_mode_std       = 2,
+        pmac_i2c_mode_stdsub    = 3,
+        pmac_i2c_mode_combined  = 4,
 };
 
 /* RW bit in address */
 enum {
-        pmac_low_i2c_read               = 0x01,
-        pmac_low_i2c_write              = 0x00
+        pmac_i2c_read           = 0x01,
+        pmac_i2c_write          = 0x00
 };
 
+/* i2c bus type */
+enum {
+        pmac_i2c_bus_keywest    = 0,
+        pmac_i2c_bus_pmu        = 1,
+        pmac_i2c_bus_smu        = 2,
+};
+
+/* i2c bus features */
+enum {
+        /* can_largesub : supports >1 byte subaddresses (SMU only) */
+        pmac_i2c_can_largesub   = 0x00000001u,
+
+        /* multibus : device node holds multiple busses, bus number is
+         * encoded in bits 0xff00 of "reg" of a given device
+         */
+        pmac_i2c_multibus       = 0x00000002u,
+};
+
+/* i2c busses in the system */
+struct pmac_i2c_bus;
+struct i2c_adapter;
+
 /* Init, called early during boot */
-extern void pmac_init_low_i2c(void);
+extern int pmac_i2c_init(void);
+
+/* Lookup an i2c bus for a device-node. The node can be either the bus
+ * node itself or a device below it. In the case of a multibus, the bus
+ * node itself is the controller node, else, it's a child of the controller
+ * node
+ */
+extern struct pmac_i2c_bus *pmac_i2c_find_bus(struct device_node *node);
+
+/* Get the address for an i2c device. This strips the bus number if
+ * necessary. The 7 bits address is returned 1 bit right shifted so that the
+ * direction can be directly ored in
+ */
+extern u8 pmac_i2c_get_dev_addr(struct device_node *device);
+
+/* Get infos about a bus */
+extern struct device_node *pmac_i2c_get_controller(struct pmac_i2c_bus *bus);
+extern struct device_node *pmac_i2c_get_bus_node(struct pmac_i2c_bus *bus);
+extern int pmac_i2c_get_type(struct pmac_i2c_bus *bus);
+extern int pmac_i2c_get_flags(struct pmac_i2c_bus *bus);
+
+/* i2c layer adapter attach/detach */
+extern void pmac_i2c_attach_adapter(struct pmac_i2c_bus *bus,
+                                    struct i2c_adapter *adapter);
+extern void pmac_i2c_detach_adapter(struct pmac_i2c_bus *bus,
+                                    struct i2c_adapter *adapter);
+extern struct i2c_adapter *pmac_i2c_get_adapter(struct pmac_i2c_bus *bus);
+
+/* March a device or bus with an i2c adapter structure, to be used by drivers
+ * to match device-tree nodes with i2c adapters during adapter discovery
+ * callbacks
+ */
+extern int pmac_i2c_match_adapter(struct device_node *dev,
+                                  struct i2c_adapter *adapter);
+
 
-/* Locking functions exposed to i2c-keywest */
-int pmac_low_i2c_lock(struct device_node *np);
-int pmac_low_i2c_unlock(struct device_node *np);
+/* (legacy) Locking functions exposed to i2c-keywest */
+extern int pmac_low_i2c_lock(struct device_node *np);
+extern int pmac_low_i2c_unlock(struct device_node *np);
 
 /* Access functions for platform code */
-int pmac_low_i2c_open(struct device_node *np, int channel);
-int pmac_low_i2c_close(struct device_node *np);
-int pmac_low_i2c_setmode(struct device_node *np, int mode);
-int pmac_low_i2c_xfer(struct device_node *np, u8 addrdir, u8 subaddr, u8 *data, int len);
+extern int pmac_i2c_open(struct pmac_i2c_bus *bus, int polled);
+extern void pmac_i2c_close(struct pmac_i2c_bus *bus);
+extern int pmac_i2c_setmode(struct pmac_i2c_bus *bus, int mode);
+extern int pmac_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
+                         u32 subaddr, u8 *data,  int len);
 
 
 #endif /* __KERNEL__ */