1 files changed, 893 insertions, 139 deletions

diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index fb535737d17d..9b38674fbf75 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -8,21 +8,15 @@
  */
 
 /*
- * For now, this driver includes:
- * - RTC get & set
- * - reboot & shutdown commands
- * all synchronous with IRQ disabled (ugh)
- *
  * TODO:
- *   rework in a way the PMU driver works, that is asynchronous
- *   with a queue of commands. I'll do that as soon as I have an
- *   SMU based machine at hand. Some more cleanup is needed too,
- *   like maybe fitting it into a platform device, etc...
- *   Also check what's up with cache coherency, and if we really
- *   can't do better than flushing the cache, maybe build a table
- *   of command len/reply len like the PMU driver to only flush
- *   what is actually necessary.
- *   --BenH.
+ *  - maybe add timeout to commands ?
+ *  - blocking version of time functions
+ *  - polling version of i2c commands (including timer that works with
+ *    interrutps 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/config.h>
@@ -36,6 +30,11 @@
 #include <linux/jiffies.h>
 #include <linux/interrupt.h>
 #include <linux/rtc.h>
+#include <linux/completion.h>
+#include <linux/miscdevice.h>
+#include <linux/delay.h>
+#include <linux/sysdev.h>
+#include <linux/poll.h>
 
 #include <asm/byteorder.h>
 #include <asm/io.h>
@@ -45,8 +44,13 @@
 #include <asm/smu.h>
 #include <asm/sections.h>
 #include <asm/abs_addr.h>
+#include <asm/uaccess.h>
+#include <asm/of_device.h>
+
+#define VERSION "0.6"
+#define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
 
-#define DEBUG_SMU 1
+#undef DEBUG_SMU
 
 #ifdef DEBUG_SMU
 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
@@ -57,20 +61,30 @@
 /*
  * This is the command buffer passed to the SMU hardware
  */
+#define SMU_MAX_DATA	254
+
 struct smu_cmd_buf {
 	u8 cmd;
 	u8 length;
-	u8 data[0x0FFE];
+	u8 data[SMU_MAX_DATA];
 };
 
 struct smu_device {
 	spinlock_t		lock;
 	struct device_node	*of_node;
-	int			db_ack;		/* doorbell ack GPIO */
-	int			db_req;		/* doorbell req GPIO */
+	struct of_device	*of_dev;
+	int			doorbell;	/* doorbell gpio */
 	u32 __iomem		*db_buf;	/* doorbell buffer */
+	int			db_irq;
+	int			msg;
+	int			msg_irq;
 	struct smu_cmd_buf	*cmd_buf;	/* command buffer virtual */
 	u32			cmd_buf_abs;	/* command buffer absolute */
+	struct list_head	cmd_list;
+	struct smu_cmd		*cmd_cur;	/* pending command */
+	struct list_head	cmd_i2c_list;
+	struct smu_i2c_cmd	*cmd_i2c_cur;	/* pending i2c command */
+	struct timer_list	i2c_timer;
 };
 
 /*
@@ -79,113 +93,245 @@ struct smu_device {
  */
 static struct smu_device	*smu;
 
+
 /*
- * SMU low level communication stuff
+ * SMU driver low level stuff
  */
-static inline int smu_cmd_stat(struct smu_cmd_buf *cmd_buf, u8 cmd_ack)
-{
-	rmb();
-	return cmd_buf->cmd == cmd_ack && cmd_buf->length != 0;
-}
 
-static inline u8 smu_save_ack_cmd(struct smu_cmd_buf *cmd_buf)
+static void smu_start_cmd(void)
 {
-	return (~cmd_buf->cmd) & 0xff;
-}
+	unsigned long faddr, fend;
+	struct smu_cmd *cmd;
 
-static void smu_send_cmd(struct smu_device *dev)
-{
-	/* SMU command buf is currently cacheable, we need a physical
-	 * address. This isn't exactly a DMA mapping here, I suspect
+	if (list_empty(&smu->cmd_list))
+		return;
+
+	/* Fetch first command in queue */
+	cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
+	smu->cmd_cur = cmd;
+	list_del(&cmd->link);
+
+	DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
+		cmd->data_len);
+	DPRINTK("SMU: data buffer: %02x %02x %02x %02x ...\n",
+		((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
+		((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3]);
+
+	/* Fill the SMU command buffer */
+	smu->cmd_buf->cmd = cmd->cmd;
+	smu->cmd_buf->length = cmd->data_len;
+	memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
+
+	/* Flush command and data to RAM */
+	faddr = (unsigned long)smu->cmd_buf;
+	fend = faddr + smu->cmd_buf->length + 2;
+	flush_inval_dcache_range(faddr, fend);
+
+	/* 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.
 	 */
-	writel(dev->cmd_buf_abs, dev->db_buf);
+	writel(smu->cmd_buf_abs, smu->db_buf);
 
 	/* Ring the SMU doorbell */
-	pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, dev->db_req, 4);
-	pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, dev->db_req, 4);
+	pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
 }
 
-static int smu_cmd_done(struct smu_device *dev)
+
+static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs)
 {
-	unsigned long wait = 0;
-	int gpio;
+	unsigned long flags;
+	struct smu_cmd *cmd;
+	void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
+	void *misc = NULL;
+	u8 gpio;
+	int rc = 0;
 
-	/* Check the SMU doorbell */
-	do  {
-		gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO,
-					    NULL, dev->db_ack);
-		if ((gpio & 7) == 7)
-			return 0;
-		udelay(100);
-	} while(++wait < 10000);
+	/* SMU completed the command, well, we hope, let's make sure
+	 * of it
+	 */
+	spin_lock_irqsave(&smu->lock, flags);
 
-	printk(KERN_ERR "SMU timeout !\n");
-	return -ENXIO;
+	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
+	if ((gpio & 7) != 7) {
+		spin_unlock_irqrestore(&smu->lock, flags);
+		return IRQ_HANDLED;
+	}
+
+	cmd = smu->cmd_cur;
+	smu->cmd_cur = NULL;
+	if (cmd == NULL)
+		goto bail;
+
+	if (rc == 0) {
+		unsigned long faddr;
+		int reply_len;
+		u8 ack;
+
+		/* CPU might have brought back the cache line, so we need
+		 * to flush again before peeking at the SMU response. We
+		 * flush the entire buffer for now as we haven't read the
+		 * reply lenght (it's only 2 cache lines anyway)
+		 */
+		faddr = (unsigned long)smu->cmd_buf;
+		flush_inval_dcache_range(faddr, faddr + 256);
+
+		/* Now check ack */
+		ack = (~cmd->cmd) & 0xff;
+		if (ack != smu->cmd_buf->cmd) {
+			DPRINTK("SMU: incorrect ack, want %x got %x\n",
+				ack, smu->cmd_buf->cmd);
+			rc = -EIO;
+		}
+		reply_len = rc == 0 ? smu->cmd_buf->length : 0;
+		DPRINTK("SMU: reply len: %d\n", reply_len);
+		if (reply_len > cmd->reply_len) {
+			printk(KERN_WARNING "SMU: reply buffer too small,"
+			       "got %d bytes for a %d bytes buffer\n",
+			       reply_len, cmd->reply_len);
+			reply_len = cmd->reply_len;
+		}
+		cmd->reply_len = reply_len;
+		if (cmd->reply_buf && reply_len)
+			memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
+	}
+
+	/* Now complete the command. Write status last in order as we lost
+	 * ownership of the command structure as soon as it's no longer -1
+	 */
+	done = cmd->done;
+	misc = cmd->misc;
+	mb();
+	cmd->status = rc;
+ bail:
+	/* Start next command if any */
+	smu_start_cmd();
+	spin_unlock_irqrestore(&smu->lock, flags);
+
+	/* Call command completion handler if any */
+	if (done)
+		done(cmd, misc);
+
+	/* It's an edge interrupt, nothing to do */
+	return IRQ_HANDLED;
 }
 
-static int smu_do_cmd(struct smu_device *dev)
+
+static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
 {
-	int rc;
-	u8 cmd_ack;
+	/* I don't quite know what to do with this one, we seem to never
+	 * receive it, so I suspect we have to arm it someway in the SMU
+	 * to start getting events that way.
+	 */
 
-	DPRINTK("SMU do_cmd %02x len=%d %02x\n",
-		dev->cmd_buf->cmd, dev->cmd_buf->length,
-		dev->cmd_buf->data[0]);
+	printk(KERN_INFO "SMU: message interrupt !\n");
 
-	cmd_ack = smu_save_ack_cmd(dev->cmd_buf);
+	/* It's an edge interrupt, nothing to do */
+	return IRQ_HANDLED;
+}
 
-	/* Clear cmd_buf cache lines */
-	flush_inval_dcache_range((unsigned long)dev->cmd_buf,
-				 ((unsigned long)dev->cmd_buf) +
-				 sizeof(struct smu_cmd_buf));
-	smu_send_cmd(dev);
-	rc = smu_cmd_done(dev);
-	if (rc == 0)
-		rc = smu_cmd_stat(dev->cmd_buf, cmd_ack) ? 0 : -1;
 
-	DPRINTK("SMU do_cmd %02x len=%d %02x => %d (%02x)\n",
-		dev->cmd_buf->cmd, dev->cmd_buf->length,
-		dev->cmd_buf->data[0], rc, cmd_ack);
+/*
+ * Queued command management.
+ *
+ */
+
+int smu_queue_cmd(struct smu_cmd *cmd)
+{
+	unsigned long flags;
 
-	return rc;
+	if (smu == NULL)
+		return -ENODEV;
+	if (cmd->data_len > SMU_MAX_DATA ||
+	    cmd->reply_len > SMU_MAX_DATA)
+		return -EINVAL;
+
+	cmd->status = 1;
+	spin_lock_irqsave(&smu->lock, flags);
+	list_add_tail(&cmd->link, &smu->cmd_list);
+	if (smu->cmd_cur == NULL)
+		smu_start_cmd();
+	spin_unlock_irqrestore(&smu->lock, flags);
+
+	return 0;
 }
+EXPORT_SYMBOL(smu_queue_cmd);
 
-/* RTC low level commands */
-static inline int bcd2hex (int n)
+
+int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
+		     unsigned int data_len,
+		     void (*done)(struct smu_cmd *cmd, void *misc),
+		     void *misc, ...)
 {
-	return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
+	struct smu_cmd *cmd = &scmd->cmd;
+	va_list list;
+	int i;
+
+	if (data_len > sizeof(scmd->buffer))
+		return -EINVAL;
+
+	memset(scmd, 0, sizeof(*scmd));
+	cmd->cmd = command;
+	cmd->data_len = data_len;
+	cmd->data_buf = scmd->buffer;
+	cmd->reply_len = sizeof(scmd->buffer);
+	cmd->reply_buf = scmd->buffer;
+	cmd->done = done;
+	cmd->misc = misc;
+
+	va_start(list, misc);
+	for (i = 0; i < data_len; ++i)
+		scmd->buffer[i] = (u8)va_arg(list, int);
+	va_end(list);
+
+	return smu_queue_cmd(cmd);
 }
+EXPORT_SYMBOL(smu_queue_simple);
 
-static inline int hex2bcd (int n)
+
+void smu_poll(void)
 {
-	return ((n / 10) << 4) + (n % 10);
+	u8 gpio;
+
+	if (smu == NULL)
+		return;
+
+	gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
+	if ((gpio & 7) == 7)
+		smu_db_intr(smu->db_irq, smu, NULL);
 }
+EXPORT_SYMBOL(smu_poll);
 
-#if 0
-static inline void smu_fill_set_pwrup_timer_cmd(struct smu_cmd_buf *cmd_buf)
+
+void smu_done_complete(struct smu_cmd *cmd, void *misc)
 {
-	cmd_buf->cmd = 0x8e;
-	cmd_buf->length = 8;
-	cmd_buf->data[0] = 0x00;
-	memset(cmd_buf->data + 1, 0, 7);
+	struct completion *comp = misc;
+
+	complete(comp);
 }
+EXPORT_SYMBOL(smu_done_complete);
+
 
-static inline void smu_fill_get_pwrup_timer_cmd(struct smu_cmd_buf *cmd_buf)
+void smu_spinwait_cmd(struct smu_cmd *cmd)
 {
-	cmd_buf->cmd = 0x8e;
-	cmd_buf->length = 1;
-	cmd_buf->data[0] = 0x01;
+	while(cmd->status == 1)
+		smu_poll();
 }
+EXPORT_SYMBOL(smu_spinwait_cmd);
+
 
-static inline void smu_fill_dis_pwrup_timer_cmd(struct smu_cmd_buf *cmd_buf)
+/* RTC low level commands */
+static inline int bcd2hex (int n)
 {
-	cmd_buf->cmd = 0x8e;
-	cmd_buf->length = 1;
-	cmd_buf->data[0] = 0x02;
+	return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
 }
-#endif
+
+
+static inline int hex2bcd (int n)
+{
+	return ((n / 10) << 4) + (n % 10);
+}
+
 
 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 					struct rtc_time *time)
@@ -202,100 +348,96 @@ static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
 	cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
 }
 
-static inline void smu_fill_get_rtc_cmd(struct smu_cmd_buf *cmd_buf)
-{
-	cmd_buf->cmd = 0x8e;
-	cmd_buf->length = 1;
-	cmd_buf->data[0] = 0x81;
-}
 
-static void smu_parse_get_rtc_reply(struct smu_cmd_buf *cmd_buf,
-				    struct rtc_time *time)
+int smu_get_rtc_time(struct rtc_time *time, int spinwait)
 {
-	time->tm_sec = bcd2hex(cmd_buf->data[0]);
-	time->tm_min = bcd2hex(cmd_buf->data[1]);
-	time->tm_hour = bcd2hex(cmd_buf->data[2]);
-	time->tm_wday = bcd2hex(cmd_buf->data[3]);
-	time->tm_mday = bcd2hex(cmd_buf->data[4]);
-	time->tm_mon = bcd2hex(cmd_buf->data[5]) - 1;
-	time->tm_year = bcd2hex(cmd_buf->data[6]) + 100;
-}
-
-int smu_get_rtc_time(struct rtc_time *time)
-{
-	unsigned long flags;
+	struct smu_simple_cmd cmd;
 	int rc;
 
 	if (smu == NULL)
 		return -ENODEV;
 
 	memset(time, 0, sizeof(struct rtc_time));
-	spin_lock_irqsave(&smu->lock, flags);
-	smu_fill_get_rtc_cmd(smu->cmd_buf);
-	rc = smu_do_cmd(smu);
-	if (rc == 0)
-		smu_parse_get_rtc_reply(smu->cmd_buf, time);
-	spin_unlock_irqrestore(&smu->lock, flags);
+	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
+			      SMU_CMD_RTC_GET_DATETIME);
+	if (rc)
+		return rc;
+	smu_spinwait_simple(&cmd);
 
-	return rc;
+	time->tm_sec = bcd2hex(cmd.buffer[0]);
+	time->tm_min = bcd2hex(cmd.buffer[1]);
+	time->tm_hour = bcd2hex(cmd.buffer[2]);
+	time->tm_wday = bcd2hex(cmd.buffer[3]);
+	time->tm_mday = bcd2hex(cmd.buffer[4]);
+	time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
+	time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
+
+	return 0;
 }
 
-int smu_set_rtc_time(struct rtc_time *time)
+
+int smu_set_rtc_time(struct rtc_time *time, int spinwait)
 {
-	unsigned long flags;
+	struct smu_simple_cmd cmd;
 	int rc;
 
 	if (smu == NULL)
 		return -ENODEV;
 
-	spin_lock_irqsave(&smu->lock, flags);
-	smu_fill_set_rtc_cmd(smu->cmd_buf, time);
-	rc = smu_do_cmd(smu);
-	spin_unlock_irqrestore(&smu->lock, flags);
+	rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
+			      SMU_CMD_RTC_SET_DATETIME,
+			      hex2bcd(time->tm_sec),
+			      hex2bcd(time->tm_min),
+			      hex2bcd(time->tm_hour),
+			      time->tm_wday,
+			      hex2bcd(time->tm_mday),
+			      hex2bcd(time->tm_mon) + 1,
+			      hex2bcd(time->tm_year - 100));
+	if (rc)
+		return rc;
+	smu_spinwait_simple(&cmd);
 
-	return rc;
+	return 0;
 }
 
+
 void smu_shutdown(void)
 {
-	const unsigned char *command = "SHUTDOWN";
-	unsigned long flags;
+	struct smu_simple_cmd cmd;
 
 	if (smu == NULL)
 		return;
 
-	spin_lock_irqsave(&smu->lock, flags);
-	smu->cmd_buf->cmd = 0xaa;
-	smu->cmd_buf->length = strlen(command);
-	strcpy(smu->cmd_buf->data, command);
-	smu_do_cmd(smu);
+	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
+			     'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
+		return;
+	smu_spinwait_simple(&cmd);
 	for (;;)
 		;
-	spin_unlock_irqrestore(&smu->lock, flags);
 }
 
+
 void smu_restart(void)
 {
-	const unsigned char *command = "RESTART";
-	unsigned long flags;
+	struct smu_simple_cmd cmd;
 
 	if (smu == NULL)
 		return;
 
-	spin_lock_irqsave(&smu->lock, flags);
-	smu->cmd_buf->cmd = 0xaa;
-	smu->cmd_buf->length = strlen(command);
-	strcpy(smu->cmd_buf->data, command);
-	smu_do_cmd(smu);
+	if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
+			     'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
+		return;
+	smu_spinwait_simple(&cmd);
 	for (;;)
 		;
-	spin_unlock_irqrestore(&smu->lock, flags);
 }
 
+
 int smu_present(void)
 {
 	return smu != NULL;
 }
+EXPORT_SYMBOL(smu_present);
 
 
 int smu_init (void)
@@ -307,6 +449,8 @@ int smu_init (void)
         if (np == NULL)
 		return -ENODEV;
 
+	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;
@@ -318,7 +462,13 @@ int smu_init (void)
 	memset(smu, 0, sizeof(*smu));
 
 	spin_lock_init(&smu->lock);
+	INIT_LIST_HEAD(&smu->cmd_list);
+	INIT_LIST_HEAD(&smu->cmd_i2c_list);
 	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
 	 */
@@ -331,8 +481,8 @@ int smu_init (void)
 		goto fail;
 	}
 	data = (u32 *)get_property(np, "reg", NULL);
-	of_node_put(np);
 	if (data == NULL) {
+		of_node_put(np);
 		printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
 		goto fail;
 	}
@@ -341,8 +491,31 @@ int smu_init (void)
 	 * and ack. GPIOs are at 0x50, best would be to find that out
 	 * in the device-tree though.
 	 */
-	smu->db_req = 0x50 + *data;
-	smu->db_ack = 0x50 + *data;
+	smu->doorbell = *data;
+	if (smu->doorbell < 0x50)
+		smu->doorbell += 0x50;
+	if (np->n_intrs > 0)
+		smu->db_irq = np->intrs[0].line;
+
+	of_node_put(np);
+
+	/* Now look for the smu-interrupt GPIO */
+	do {
+		np = of_find_node_by_name(NULL, "smu-interrupt");
+		if (np == NULL)
+			break;
+		data = (u32 *)get_property(np, "reg", NULL);
+		if (data == NULL) {
+			of_node_put(np);
+			break;
+		}
+		smu->msg = *data;
+		if (smu->msg < 0x50)
+			smu->msg += 0x50;
+		if (np->n_intrs > 0)
+			smu->msg_irq = np->intrs[0].line;
+		of_node_put(np);
+	} while(0);
 
 	/* Doorbell buffer is currently hard-coded, I didn't find a proper
 	 * device-tree entry giving the address. Best would probably to use
@@ -362,3 +535,584 @@ int smu_init (void)
 	return -ENXIO;
 
 }
+
+
+static int smu_late_init(void)
+{
+	if (!smu)
+		return 0;
+
+	/*
+	 * Try to request the interrupts
+	 */
+
+	if (smu->db_irq != NO_IRQ) {
+		if (request_irq(smu->db_irq, smu_db_intr,
+				SA_SHIRQ, "SMU doorbell", smu) < 0) {
+			printk(KERN_WARNING "SMU: can't "
+			       "request interrupt %d\n",
+			       smu->db_irq);
+			smu->db_irq = NO_IRQ;
+		}
+	}
+
+	if (smu->msg_irq != NO_IRQ) {
+		if (request_irq(smu->msg_irq, smu_msg_intr,
+				SA_SHIRQ, "SMU message", smu) < 0) {
+			printk(KERN_WARNING "SMU: can't "
+			       "request interrupt %d\n",
+			       smu->msg_irq);
+			smu->msg_irq = NO_IRQ;
+		}
+	}
+
+	return 0;
+}
+arch_initcall(smu_late_init);
+
+/*
+ * sysfs visibility
+ */
+
+static void smu_expose_childs(void *unused)
+{
+	struct device_node *np;
+
+	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);
+		}
+	}
+
+}
+
+static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
+
+static int smu_platform_probe(struct of_device* dev,
+			      const struct of_device_id *match)
+{
+	if (!smu)
+		return -ENODEV;
+	smu->of_dev = dev;
+
+	/*
+	 * Ok, we are matched, now expose all i2c busses. We have to defer
+	 * that unfortunately or it would deadlock inside the device model
+	 */
+	schedule_work(&smu_expose_childs_work);
+
+	return 0;
+}
+
+static struct of_device_id smu_platform_match[] =
+{
+	{
+		.type		= "smu",
+	},
+	{},
+};
+
+static struct of_platform_driver smu_of_platform_driver =
+{
+	.name 		= "smu",
+	.match_table	= smu_platform_match,
+	.probe		= smu_platform_probe,
+};
+
+static int __init smu_init_sysfs(void)
+{
+	int rc;
+
+	/*
+	 * Due to sysfs bogosity, a sysdev is not a real device, so
+	 * we should in fact create both if we want sysdev semantics
+	 * for power management.
+	 * For now, we don't power manage machines with an SMU chip,
+	 * I'm a bit too far from figuring out how that works with those
+	 * new chipsets, but that will come back and bite us
+	 */
+	rc = of_register_driver(&smu_of_platform_driver);
+	return 0;
+}
+
+device_initcall(smu_init_sysfs);
+
+struct of_device *smu_get_ofdev(void)
+{
+	if (!smu)
+		return NULL;
+	return smu->of_dev;
+}
+
+EXPORT_SYMBOL_GPL(smu_get_ofdev);
+
+/*
+ * i2c interface
+ */
+
+static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
+{
+	void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
+	void *misc = cmd->misc;
+	unsigned long flags;
+
+	/* Check for read case */
+	if (!fail && cmd->read) {
+		if (cmd->pdata[0] < 1)
+			fail = 1;
+		else
+			memcpy(cmd->info.data, &cmd->pdata[1],
+			       cmd->info.datalen);
+	}
+
+	DPRINTK("SMU: completing, success: %d\n", !fail);
+
+	/* Update status and mark no pending i2c command with lock
+	 * held so nobody comes in while we dequeue an eventual
+	 * pending next i2c command
+	 */
+	spin_lock_irqsave(&smu->lock, flags);
+	smu->cmd_i2c_cur = NULL;
+	wmb();
+	cmd->status = fail ? -EIO : 0;
+
+	/* Is there another i2c command waiting ? */
+	if (!list_empty(&smu->cmd_i2c_list)) {
+		struct smu_i2c_cmd *newcmd;
+
+		/* Fetch it, new current, remove from list */
+		newcmd = list_entry(smu->cmd_i2c_list.next,
+				    struct smu_i2c_cmd, link);
+		smu->cmd_i2c_cur = newcmd;
+		list_del(&cmd->link);
+
+		/* Queue with low level smu */
+		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
+		if (smu->cmd_cur == NULL)
+			smu_start_cmd();
+	}
+	spin_unlock_irqrestore(&smu->lock, flags);
+
+	/* Call command completion handler if any */
+	if (done)
+		done(cmd, misc);
+
+}
+
+
+static void smu_i2c_retry(unsigned long data)
+{
+	struct smu_i2c_cmd	*cmd = (struct smu_i2c_cmd *)data;
+
+	DPRINTK("SMU: i2c failure, requeuing...\n");
+
+	/* requeue command simply by resetting reply_len */
+	cmd->pdata[0] = 0xff;
+	cmd->scmd.reply_len = 0x10;
+	smu_queue_cmd(&cmd->scmd);
+}
+
+
+static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
+{
+	struct smu_i2c_cmd	*cmd = misc;
+	int			fail = 0;
+
+	DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
+		cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
+
+	/* Check for possible status */
+	if (scmd->status < 0)
+		fail = 1;
+	else if (cmd->read) {
+		if (cmd->stage == 0)
+			fail = cmd->pdata[0] != 0;
+		else
+			fail = cmd->pdata[0] >= 0x80;
+	} else {
+		fail = cmd->pdata[0] != 0;
+	}
+
+	/* Handle failures by requeuing command, after 5ms interval
+	 */
+	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);
+		return;
+	}
+
+	/* If failure or stage 1, command is complete */
+	if (fail || cmd->stage != 0) {
+		smu_i2c_complete_command(cmd, fail);
+		return;
+	}
+
+	DPRINTK("SMU: going to stage 1\n");
+
+	/* Ok, initial command complete, now poll status */
+	scmd->reply_buf = cmd->pdata;
+	scmd->reply_len = 0x10;
+	scmd->data_buf = cmd->pdata;
+	scmd->data_len = 1;
+	cmd->pdata[0] = 0;
+	cmd->stage = 1;
+	cmd->retries = 20;
+	smu_queue_cmd(scmd);
+}
+
+
+int smu_queue_i2c(struct smu_i2c_cmd *cmd)
+{
+	unsigned long flags;
+
+	if (smu == NULL)
+		return -ENODEV;
+
+	/* Fill most fields of scmd */
+	cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
+	cmd->scmd.done = smu_i2c_low_completion;
+	cmd->scmd.misc = cmd;
+	cmd->scmd.reply_buf = cmd->pdata;
+	cmd->scmd.reply_len = 0x10;
+	cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
+	cmd->scmd.status = 1;
+	cmd->stage = 0;
+	cmd->pdata[0] = 0xff;
+	cmd->retries = 20;
+	cmd->status = 1;
+
+	/* Check transfer type, sanitize some "info" fields
+	 * based on transfer type and do more checking
+	 */
+	cmd->info.caddr = cmd->info.devaddr;
+	cmd->read = cmd->info.devaddr & 0x01;
+	switch(cmd->info.type) {
+	case SMU_I2C_TRANSFER_SIMPLE:
+		memset(&cmd->info.sublen, 0, 4);
+		break;
+	case SMU_I2C_TRANSFER_COMBINED:
+		cmd->info.devaddr &= 0xfe;
+	case SMU_I2C_TRANSFER_STDSUB:
+		if (cmd->info.sublen > 3)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Finish setting up command based on transfer direction
+	 */
+	if (cmd->read) {
+		if (cmd->info.datalen > SMU_I2C_READ_MAX)
+			return -EINVAL;
+		memset(cmd->info.data, 0xff, cmd->info.datalen);
+		cmd->scmd.data_len = 9;
+	} else {
+		if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
+			return -EINVAL;
+		cmd->scmd.data_len = 9 + cmd->info.datalen;
+	}
+
+	DPRINTK("SMU: i2c enqueuing command\n");
+	DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
+		cmd->read ? "read" : "write", cmd->info.datalen,
+		cmd->info.bus, cmd->info.caddr,
+		cmd->info.subaddr[0], cmd->info.type);
+
+
+	/* Enqueue command in i2c list, and if empty, enqueue also in
+	 * main command list
+	 */
+	spin_lock_irqsave(&smu->lock, flags);
+	if (smu->cmd_i2c_cur == NULL) {
+		smu->cmd_i2c_cur = cmd;
+		list_add_tail(&cmd->scmd.link, &smu->cmd_list);
+		if (smu->cmd_cur == NULL)
+			smu_start_cmd();
+	} else
+		list_add_tail(&cmd->link, &smu->cmd_i2c_list);
+	spin_unlock_irqrestore(&smu->lock, flags);
+
+	return 0;
+}
+
+
+
+/*
+ * Userland driver interface
+ */
+
+
+static LIST_HEAD(smu_clist);
+static DEFINE_SPINLOCK(smu_clist_lock);
+
+enum smu_file_mode {
+	smu_file_commands,
+	smu_file_events,
+	smu_file_closing
+};
+
+struct smu_private
+{
+	struct list_head	list;
+	enum smu_file_mode	mode;
+	int			busy;
+	struct smu_cmd		cmd;
+	spinlock_t		lock;
+	wait_queue_head_t	wait;
+	u8			buffer[SMU_MAX_DATA];
+};
+
+
+static int smu_open(struct inode *inode, struct file *file)
+{
+	struct smu_private *pp;
+	unsigned long flags;
+
+	pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
+	if (pp == 0)
+		return -ENOMEM;
+	memset(pp, 0, sizeof(struct smu_private));
+	spin_lock_init(&pp->lock);
+	pp->mode = smu_file_commands;
+	init_waitqueue_head(&pp->wait);
+
+	spin_lock_irqsave(&smu_clist_lock, flags);
+	list_add(&pp->list, &smu_clist);
+	spin_unlock_irqrestore(&smu_clist_lock, flags);
+	file->private_data = pp;
+
+	return 0;
+}
+
+
+static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
+{
+	struct smu_private *pp = misc;
+
+	wake_up_all(&pp->wait);
+}
+
+
+static ssize_t smu_write(struct file *file, const char __user *buf,
+			 size_t count, loff_t *ppos)
+{
+	struct smu_private *pp = file->private_data;
+	unsigned long flags;
+	struct smu_user_cmd_hdr hdr;
+	int rc = 0;
+
+	if (pp->busy)
+		return -EBUSY;
+	else if (copy_from_user(&hdr, buf, sizeof(hdr)))
+		return -EFAULT;
+	else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
+		pp->mode = smu_file_events;
+		return 0;
+	} else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
+		return -EINVAL;
+	else if (pp->mode != smu_file_commands)
+		return -EBADFD;
+	else if (hdr.data_len > SMU_MAX_DATA)
+		return -EINVAL;
+
+	spin_lock_irqsave(&pp->lock, flags);
+	if (pp->busy) {
+		spin_unlock_irqrestore(&pp->lock, flags);
+		return -EBUSY;
+	}
+	pp->busy = 1;
+	pp->cmd.status = 1;
+	spin_unlock_irqrestore(&pp->lock, flags);
+
+	if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
+		pp->busy = 0;
+		return -EFAULT;
+	}
+
+	pp->cmd.cmd = hdr.cmd;
+	pp->cmd.data_len = hdr.data_len;
+	pp->cmd.reply_len = SMU_MAX_DATA;
+	pp->cmd.data_buf = pp->buffer;
+	pp->cmd.reply_buf = pp->buffer;
+	pp->cmd.done = smu_user_cmd_done;
+	pp->cmd.misc = pp;
+	rc = smu_queue_cmd(&pp->cmd);
+	if (rc < 0)
+		return rc;
+	return count;
+}
+
+
+static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
+				char __user *buf, size_t count)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	struct smu_user_reply_hdr hdr;
+	unsigned long flags;
+	int size, rc = 0;
+
+	if (!pp->busy)
+		return 0;
+	if (count < sizeof(struct smu_user_reply_hdr))
+		return -EOVERFLOW;
+	spin_lock_irqsave(&pp->lock, flags);
+	if (pp->cmd.status == 1) {
+		if (file->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+		add_wait_queue(&pp->wait, &wait);
+		for (;;) {
+			set_current_state(TASK_INTERRUPTIBLE);
+			rc = 0;
+			if (pp->cmd.status != 1)
+				break;
+			rc = -ERESTARTSYS;
+			if (signal_pending(current))
+				break;
+			spin_unlock_irqrestore(&pp->lock, flags);
+			schedule();
+			spin_lock_irqsave(&pp->lock, flags);
+		}
+		set_current_state(TASK_RUNNING);
+		remove_wait_queue(&pp->wait, &wait);
+	}
+	spin_unlock_irqrestore(&pp->lock, flags);
+	if (rc)
+		return rc;
+	if (pp->cmd.status != 0)
+		pp->cmd.reply_len = 0;
+	size = sizeof(hdr) + pp->cmd.reply_len;
+	if (count < size)
+		size = count;
+	rc = size;
+	hdr.status = pp->cmd.status;
+	hdr.reply_len = pp->cmd.reply_len;
+	if (copy_to_user(buf, &hdr, sizeof(hdr)))
+		return -EFAULT;
+	size -= sizeof(hdr);
+	if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
+		return -EFAULT;
+	pp->busy = 0;
+
+	return rc;
+}
+
+
+static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
+			       char __user *buf, size_t count)
+{
+	/* Not implemented */
+	msleep_interruptible(1000);
+	return 0;
+}
+
+
+static ssize_t smu_read(struct file *file, char __user *buf,
+			size_t count, loff_t *ppos)
+{
+	struct smu_private *pp = file->private_data;
+
+	if (pp->mode == smu_file_commands)
+		return smu_read_command(file, pp, buf, count);
+	if (pp->mode == smu_file_events)
+		return smu_read_events(file, pp, buf, count);
+
+	return -EBADFD;
+}
+
+static unsigned int smu_fpoll(struct file *file, poll_table *wait)
+{
+	struct smu_private *pp = file->private_data;
+	unsigned int mask = 0;
+	unsigned long flags;
+
+	if (pp == 0)
+		return 0;
+
+	if (pp->mode == smu_file_commands) {
+		poll_wait(file, &pp->wait, wait);
+
+		spin_lock_irqsave(&pp->lock, flags);
+		if (pp->busy && pp->cmd.status != 1)
+			mask |= POLLIN;
+		spin_unlock_irqrestore(&pp->lock, flags);
+	} if (pp->mode == smu_file_events) {
+		/* Not yet implemented */
+	}
+	return mask;
+}
+
+static int smu_release(struct inode *inode, struct file *file)
+{
+	struct smu_private *pp = file->private_data;
+	unsigned long flags;
+	unsigned int busy;
+
+	if (pp == 0)
+		return 0;
+
+	file->private_data = NULL;
+
+	/* Mark file as closing to avoid races with new request */
+	spin_lock_irqsave(&pp->lock, flags);
+	pp->mode = smu_file_closing;
+	busy = pp->busy;
+
+	/* Wait for any pending request to complete */
+	if (busy && pp->cmd.status == 1) {
+		DECLARE_WAITQUEUE(wait, current);
+
+		add_wait_queue(&pp->wait, &wait);
+		for (;;) {
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			if (pp->cmd.status != 1)
+				break;
+			spin_lock_irqsave(&pp->lock, flags);
+			schedule();
+			spin_unlock_irqrestore(&pp->lock, flags);
+		}
+		set_current_state(TASK_RUNNING);
+		remove_wait_queue(&pp->wait, &wait);
+	}
+	spin_unlock_irqrestore(&pp->lock, flags);
+
+	spin_lock_irqsave(&smu_clist_lock, flags);
+	list_del(&pp->list);
+	spin_unlock_irqrestore(&smu_clist_lock, flags);
+	kfree(pp);
+
+	return 0;
+}
+
+
+static struct file_operations smu_device_fops __pmacdata = {
+	.llseek		= no_llseek,
+	.read		= smu_read,
+	.write		= smu_write,
+	.poll		= smu_fpoll,
+	.open		= smu_open,
+	.release	= smu_release,
+};
+
+static struct miscdevice pmu_device __pmacdata = {
+	MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
+};
+
+static int smu_device_init(void)
+{
+	if (!smu)
+		return -ENODEV;
+	if (misc_register(&pmu_device) < 0)
+		printk(KERN_ERR "via-pmu: cannot register misc device.\n");
+	return 0;
+}
+device_initcall(smu_device_init);