Merge commit '85082fd7cbe3173198aac0eb5e85ab1edcc6352c' into test-build

[safe/jmp/linux-2.6] / drivers / macintosh / smu.c

diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index 7855906..96faa79 100644 (file)
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -12,13 +12,14 @@
  *  - maybe add timeout to commands ?
  *  - blocking version of time functions
  *  - polling version of i2c commands (including timer that works with
- *    interrutps off)
+ *    interrupts off)
  *  - maybe avoid some data copies with i2c by directly using the smu cmd
  *    buffer and a lower level internal interface
  *  - understand SMU -> CPU events and implement reception of them via
  *    the userland interface
  */
 
+#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/device.h>
@@ -35,6 +36,8 @@
 #include <linux/sysdev.h>
 #include <linux/poll.h>
 #include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
 
 #include <asm/byteorder.h>
 #include <asm/io.h>
@@ -45,8 +48,6 @@
 #include <asm/sections.h>
 #include <asm/abs_addr.h>
 #include <asm/uaccess.h>
-#include <asm/of_device.h>
-#include <asm/of_platform.h>
 
 #define VERSION "0.7"
 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
@@ -85,6 +86,7 @@ struct smu_device {
        u32                     cmd_buf_abs;    /* command buffer absolute */
        struct list_head        cmd_list;
        struct smu_cmd          *cmd_cur;       /* pending command */
+       int                     broken_nap;
        struct list_head        cmd_i2c_list;
        struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
        struct timer_list       i2c_timer;
@@ -135,6 +137,19 @@ static void smu_start_cmd(void)
        fend = faddr + smu->cmd_buf->length + 2;
        flush_inval_dcache_range(faddr, fend);
 
+
+       /* We also disable NAP mode for the duration of the command
+        * on U3 based machines.
+        * This is slightly racy as it can be written back to 1 by a sysctl
+        * but that never happens in practice. There seem to be an issue with
+        * U3 based machines such as the iMac G5 where napping for the
+        * whole duration of the command prevents the SMU from fetching it
+        * from memory. This might be related to the strange i2c based
+        * mechanism the SMU uses to access memory.
+        */
+       if (smu->broken_nap)
+               powersave_nap = 0;
+
        /* This isn't exactly a DMA mapping here, I suspect
         * the SMU is actually communicating with us via i2c to the
         * northbridge or the CPU to access RAM.
@@ -211,6 +226,10 @@ static irqreturn_t smu_db_intr(int irq, void *arg)
        misc = cmd->misc;
        mb();
        cmd->status = rc;
+
+       /* Re-enable NAP mode */
+       if (smu->broken_nap)
+               powersave_nap = 1;
  bail:
        /* Start next command if any */
        smu_start_cmd();
@@ -456,22 +475,21 @@ int __init smu_init (void)
 {
        struct device_node *np;
        const u32 *data;
+       int ret = 0;
 
         np = of_find_node_by_type(NULL, "smu");
         if (np == NULL)
                return -ENODEV;
 
-       printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
+       printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
 
        if (smu_cmdbuf_abs == 0) {
                printk(KERN_ERR "SMU: Command buffer not allocated !\n");
-               return -EINVAL;
+               ret = -EINVAL;
+               goto fail_np;
        }
 
        smu = alloc_bootmem(sizeof(struct smu_device));
-       if (smu == NULL)
-               return -ENOMEM;
-       memset(smu, 0, sizeof(*smu));
 
        spin_lock_init(&smu->lock);
        INIT_LIST_HEAD(&smu->cmd_list);
@@ -489,14 +507,14 @@ int __init smu_init (void)
        smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
        if (smu->db_node == NULL) {
                printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
-               goto fail;
+               ret = -ENXIO;
+               goto fail_bootmem;
        }
        data = of_get_property(smu->db_node, "reg", NULL);
        if (data == NULL) {
-               of_node_put(smu->db_node);
-               smu->db_node = NULL;
                printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
-               goto fail;
+               ret = -ENXIO;
+               goto fail_db_node;
        }
 
        /* Current setup has one doorbell GPIO that does both doorbell
@@ -530,16 +548,29 @@ int __init smu_init (void)
        smu->db_buf = ioremap(0x8000860c, 0x1000);
        if (smu->db_buf == NULL) {
                printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
-               goto fail;
+               ret = -ENXIO;
+               goto fail_msg_node;
        }
 
+       /* U3 has an issue with NAP mode when issuing SMU commands */
+       smu->broken_nap = pmac_get_uninorth_variant() < 4;
+       if (smu->broken_nap)
+               printk(KERN_INFO "SMU: using NAP mode workaround\n");
+
        sys_ctrler = SYS_CTRLER_SMU;
        return 0;
 
- fail:
+fail_msg_node:
+       if (smu->msg_node)
+               of_node_put(smu->msg_node);
+fail_db_node:
+       of_node_put(smu->db_node);
+fail_bootmem:
+       free_bootmem((unsigned long)smu, sizeof(struct smu_device));
        smu = NULL;
-       return -ENXIO;
-
+fail_np:
+       of_node_put(np);
+       return ret;
 }
 
 
@@ -1060,10 +1091,12 @@ static int smu_open(struct inode *inode, struct file *file)
        pp->mode = smu_file_commands;
        init_waitqueue_head(&pp->wait);
 
+       lock_kernel();
        spin_lock_irqsave(&smu_clist_lock, flags);
        list_add(&pp->list, &smu_clist);
        spin_unlock_irqrestore(&smu_clist_lock, flags);
        file->private_data = pp;
+       unlock_kernel();
 
        return 0;
 }