1 files changed, 53 insertions, 1 deletions

diff --git a/arch/sh/boards/mach-sdk7786/setup.c b/arch/sh/boards/mach-sdk7786/setup.c
index 2ec1ea5cf8ef..7e0c4e3878e0 100644
--- a/arch/sh/boards/mach-sdk7786/setup.c
+++ b/arch/sh/boards/mach-sdk7786/setup.c
@@ -20,6 +20,8 @@
 #include <asm/machvec.h>
 #include <asm/heartbeat.h>
 #include <asm/sizes.h>
+#include <asm/clock.h>
+#include <asm/clkdev.h>
 #include <asm/reboot.h>
 #include <asm/smp-ops.h>
 
@@ -140,6 +142,45 @@ static int sdk7786_mode_pins(void)
 	return fpga_read_reg(MODSWR);
 }
 
+/*
+ * FPGA-driven PCIe clocks
+ *
+ * Historically these include the oscillator, clock B (slots 2/3/4) and
+ * clock A (slot 1 and the CPU clock). Newer revs of the PCB shove
+ * everything under a single PCIe clocks enable bit that happens to map
+ * to the same bit position as the oscillator bit for earlier FPGA
+ * versions.
+ *
+ * Given that the legacy clocks have the side-effect of shutting the CPU
+ * off through the FPGA along with the PCI slots, we simply leave them in
+ * their initial state and don't bother registering them with the clock
+ * framework.
+ */
+static int sdk7786_pcie_clk_enable(struct clk *clk)
+{
+	fpga_write_reg(fpga_read_reg(PCIECR) | PCIECR_CLKEN, PCIECR);
+	return 0;
+}
+
+static void sdk7786_pcie_clk_disable(struct clk *clk)
+{
+	fpga_write_reg(fpga_read_reg(PCIECR) & ~PCIECR_CLKEN, PCIECR);
+}
+
+static struct clk_ops sdk7786_pcie_clk_ops = {
+	.enable		= sdk7786_pcie_clk_enable,
+	.disable	= sdk7786_pcie_clk_disable,
+};
+
+static struct clk sdk7786_pcie_clk = {
+	.ops		= &sdk7786_pcie_clk_ops,
+};
+
+static struct clk_lookup sdk7786_pcie_cl = {
+	.con_id		= "pcie_plat_clk",
+	.clk		= &sdk7786_pcie_clk,
+};
+
 static int sdk7786_clk_init(void)
 {
 	struct clk *clk;
@@ -158,7 +199,18 @@ static int sdk7786_clk_init(void)
 	ret = clk_set_rate(clk, 33333333);
 	clk_put(clk);
 
-	return ret;
+	/*
+	 * Setup the FPGA clocks.
+	 */
+	ret = clk_register(&sdk7786_pcie_clk);
+	if (unlikely(ret)) {
+		pr_err("FPGA clock registration failed\n");
+		return ret;
+	}
+
+	clkdev_add(&sdk7786_pcie_cl);
+
+	return 0;
 }
 
 static void sdk7786_restart(char *cmd)