3 files changed, 54 insertions, 0 deletions

diff --git a/arch/arm/mach-bcm283x/include/mach/mbox.h b/arch/arm/mach-bcm283x/include/mach/mbox.h
index 7dcac583cc4..490664f878f 100644
--- a/arch/arm/mach-bcm283x/include/mach/mbox.h
+++ b/arch/arm/mach-bcm283x/include/mach/mbox.h
@@ -252,6 +252,22 @@ struct bcm2835_mbox_tag_get_clock_rate {
 	} body;
 };
 
+#define BCM2835_MBOX_TAG_SET_SDHOST_CLOCK	0x00038042
+
+struct bcm2835_mbox_tag_set_sdhost_clock {
+	struct bcm2835_mbox_tag_hdr tag_hdr;
+	union {
+		struct {
+			u32 rate_hz;
+		} req;
+		struct {
+			u32 rate_hz;
+			u32 rate_1;
+			u32 rate_2;
+		} resp;
+	} body;
+};
+
 #define BCM2835_MBOX_TAG_ALLOCATE_BUFFER	0x00040001
 
 struct bcm2835_mbox_tag_allocate_buffer {
diff --git a/arch/arm/mach-bcm283x/include/mach/msg.h b/arch/arm/mach-bcm283x/include/mach/msg.h
index eb3da93cc2f..e54da86e353 100644
--- a/arch/arm/mach-bcm283x/include/mach/msg.h
+++ b/arch/arm/mach-bcm283x/include/mach/msg.h
@@ -23,6 +23,16 @@ int bcm2835_power_on_module(u32 module);
 int bcm2835_get_mmc_clock(u32 clock_id);
 
 /**
+ * bcm2835_set_sdhost_clock() - determine if firmware controls sdhost cdiv
+ *
+ * @rate_hz: Input clock frequency
+ * @rate_1: Returns a clock frequency
+ * @rate_2: Returns a clock frequency
+ * @return 0 of OK, -EIO on error
+ */
+int bcm2835_set_sdhost_clock(u32 rate_hz, u32 *rate_1, u32 *rate_2);
+
+/**
  * bcm2835_get_video_size() - get the current display size
  *
  * @widthp: Returns the width in pixels
diff --git a/arch/arm/mach-bcm283x/msg.c b/arch/arm/mach-bcm283x/msg.c
index 68b2773875e..2188b38d84b 100644
--- a/arch/arm/mach-bcm283x/msg.c
+++ b/arch/arm/mach-bcm283x/msg.c
@@ -21,6 +21,12 @@ struct msg_get_clock_rate {
 	u32 end_tag;
 };
 
+struct msg_set_sdhost_clock {
+	struct bcm2835_mbox_hdr hdr;
+	struct bcm2835_mbox_tag_set_sdhost_clock set_sdhost_clock;
+	u32 end_tag;
+};
+
 struct msg_query {
 	struct bcm2835_mbox_hdr hdr;
 	struct bcm2835_mbox_tag_physical_w_h physical_w_h;
@@ -110,6 +116,28 @@ int bcm2835_get_mmc_clock(u32 clock_id)
 	return clock_rate;
 }
 
+int bcm2835_set_sdhost_clock(u32 rate_hz, u32 *rate_1, u32 *rate_2)
+{
+	ALLOC_CACHE_ALIGN_BUFFER(struct msg_set_sdhost_clock, msg_sdhost_clk, 1);
+	int ret;
+
+	BCM2835_MBOX_INIT_HDR(msg_sdhost_clk);
+	BCM2835_MBOX_INIT_TAG(&msg_sdhost_clk->set_sdhost_clock, SET_SDHOST_CLOCK);
+
+	msg_sdhost_clk->set_sdhost_clock.body.req.rate_hz = rate_hz;
+
+	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &msg_sdhost_clk->hdr);
+	if (ret) {
+		printf("bcm2835: Could not query sdhost clock rate\n");
+		return -EIO;
+	}
+
+	*rate_1 = msg_sdhost_clk->set_sdhost_clock.body.resp.rate_1;
+	*rate_2 = msg_sdhost_clk->set_sdhost_clock.body.resp.rate_2;
+
+	return 0;
+}
+
 int bcm2835_get_video_size(int *widthp, int *heightp)
 {
 	ALLOC_CACHE_ALIGN_BUFFER(struct msg_query, msg_query, 1);