ARM: Orion: PCIE: Add support for clk

Prepare and enable the clocks when the board indicates the pcie buses
will be used.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Jamie Lentin <jm@lentin.co.uk>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/arm/mach-kirkwood/pcie.c b/arch/arm/mach-kirkwood/pcie.c
index f56a0118c1bb..881933a0b5eb 100644
--- a/arch/arm/mach-kirkwood/pcie.c
+++ b/arch/arm/mach-kirkwood/pcie.c
@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/slab.h>
+#include <linux/clk.h>
 #include <video/vga.h>
 #include <asm/irq.h>
 #include <asm/mach/pci.h>
@@ -19,6 +20,23 @@
 #include <plat/addr-map.h>
 #include "common.h"
 
+static void kirkwood_enable_pcie_clk(const char *port)
+{
+        struct clk *clk;
+
+        clk = clk_get_sys("pcie", port);
+        if (IS_ERR(clk)) {
+                printk(KERN_ERR "PCIE clock %s missing\n", port);
+                return;
+        }
+        clk_prepare_enable(clk);
+        clk_put(clk);
+}
+
+/* This function is called very early in the boot when probing the
+   hardware to determine what we actually are, and what rate tclk is
+   ticking at. Hence calling kirkwood_enable_pcie_clk() is not
+   possible since the clk tree has not been created yet. */
 void kirkwood_enable_pcie(void)
 {
         u32 curr = readl(CLOCK_GATING_CTRL);
@@ -183,10 +201,12 @@ static int __init kirkwood_pcie_setup(int nr, struct pci_sys_data *sys)
         switch (index) {
         case 0:
                 kirkwood_clk_ctrl |= CGC_PEX0;
+                kirkwood_enable_pcie_clk("0");
                 pcie0_ioresources_init(pp);
                 break;
         case 1:
                 kirkwood_clk_ctrl |= CGC_PEX1;
+                kirkwood_enable_pcie_clk("1");
                 pcie1_ioresources_init(pp);
                 break;
         default: