[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, 37 insertions, 21 deletions

diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index 96226116a646..9ecd76849e35 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -94,6 +94,8 @@ struct smu_device {
 static struct smu_device        *smu;
 static DECLARE_MUTEX(smu_part_access);
 
+static void smu_i2c_retry(unsigned long data);
+
 /*
  * SMU driver low level stuff
  */
@@ -469,7 +471,6 @@ int __init smu_init (void)
         smu->of_node = np;
         smu->db_irq = NO_IRQ;
         smu->msg_irq = NO_IRQ;
-        init_timer(&smu->i2c_timer);
 
         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
          * 32 bits value safely
@@ -544,6 +545,10 @@ static int smu_late_init(void)
         if (!smu)
                 return 0;
 
+        init_timer(&smu->i2c_timer);
+        smu->i2c_timer.function = smu_i2c_retry;
+        smu->i2c_timer.data = (unsigned long)smu;
+
         /*
          * Try to request the interrupts
          */
@@ -570,28 +575,41 @@ static int smu_late_init(void)
 
         return 0;
 }
-arch_initcall(smu_late_init);
+/* This has to be before arch_initcall as the low i2c stuff relies on the
+ * above having been done before we reach arch_initcalls
+ */
+core_initcall(smu_late_init);
 
 /*
  * sysfs visibility
  */
 
+static void smu_create_i2c(struct device_node *np)
+{
+        char name[32];
+        u32 *reg = (u32 *)get_property(np, "reg", NULL);
+
+        if (reg != NULL) {
+                sprintf(name, "smu-i2c-%02x", *reg);
+                of_platform_device_create(np, name, &smu->of_dev->dev);
+        }
+}
+
 static void smu_expose_childs(void *unused)
 {
-        struct device_node *np;
+        struct device_node *np, *gp;
 
         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;) {
-                if (device_is_compatible(np, "smu-i2c")) {
-                        char name[32];
-                        u32 *reg = (u32 *)get_property(np, "reg", NULL);
-
-                        if (reg == NULL)
-                                continue;
-                        sprintf(name, "smu-i2c-%02x", *reg);
-                        of_platform_device_create(np, name, &smu->of_dev->dev);
-                }
+                if (device_is_compatible(np, "smu-i2c-control")) {
+                        gp = NULL;
+                        while ((gp = of_get_next_child(np, gp)) != NULL)
+                                if (device_is_compatible(gp, "i2c-bus"))
+                                        smu_create_i2c(gp);
+                } else if (device_is_compatible(np, "smu-i2c"))
+                        smu_create_i2c(np);
                 if (device_is_compatible(np, "smu-sensors"))
-                        of_platform_device_create(np, "smu-sensors", &smu->of_dev->dev);
+                        of_platform_device_create(np, "smu-sensors",
+                                                  &smu->of_dev->dev);
         }
 
 }
@@ -712,13 +730,13 @@ static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
 
 static void smu_i2c_retry(unsigned long data)
 {
-        struct smu_i2c_cmd      *cmd = (struct smu_i2c_cmd *)data;
+        struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
 
         DPRINTK("SMU: i2c failure, requeuing...\n");
 
         /* requeue command simply by resetting reply_len */
         cmd->pdata[0] = 0xff;
-        cmd->scmd.reply_len = 0x10;
+        cmd->scmd.reply_len = sizeof(cmd->pdata);
         smu_queue_cmd(&cmd->scmd);
 }
 
@@ -747,10 +765,8 @@ static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
          */
         if (fail && --cmd->retries > 0) {
                 DPRINTK("SMU: i2c failure, starting timer...\n");
-                smu->i2c_timer.function = smu_i2c_retry;
-                smu->i2c_timer.data = (unsigned long)cmd;
-                smu->i2c_timer.expires = jiffies + msecs_to_jiffies(5);
-                add_timer(&smu->i2c_timer);
+                BUG_ON(cmd != smu->cmd_i2c_cur);
+                mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
                 return;
         }
 
@@ -764,7 +780,7 @@ static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
 
         /* Ok, initial command complete, now poll status */
         scmd->reply_buf = cmd->pdata;
-        scmd->reply_len = 0x10;
+        scmd->reply_len = sizeof(cmd->pdata);
         scmd->data_buf = cmd->pdata;
         scmd->data_len = 1;
         cmd->pdata[0] = 0;
@@ -786,7 +802,7 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd)
         cmd->scmd.done = smu_i2c_low_completion;
         cmd->scmd.misc = cmd;
         cmd->scmd.reply_buf = cmd->pdata;
-        cmd->scmd.reply_len = 0x10;
+        cmd->scmd.reply_len = sizeof(cmd->pdata);
         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
         cmd->scmd.status = 1;
         cmd->stage = 0;