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>

arch/arm/mach-kirkwood/common.c

@@ -87,7 +87,7 @@ static struct clk __init *kirkwood_register_gate(const char *name, u8 bit_idx)
 void __init kirkwood_clk_init(void)
 {
 	struct clk *runit, *ge0, *ge1, *sata0, *sata1, *usb0, *sdio;
-	struct clk *crypto, *xor0, *xor1;
+	struct clk *crypto, *xor0, *xor1, *pex0, *pex1;
 
 	tclk = clk_register_fixed_rate(NULL, "tclk", NULL,
 				       CLK_IS_ROOT, kirkwood_tclk);
@@ -102,8 +102,8 @@ void __init kirkwood_clk_init(void)
 	crypto = kirkwood_register_gate("crypto", CGC_BIT_CRYPTO);
 	xor0 = kirkwood_register_gate("xor0",   CGC_BIT_XOR0);
 	xor1 = kirkwood_register_gate("xor1",   CGC_BIT_XOR1);
-	kirkwood_register_gate("pex0",   CGC_BIT_PEX0);
-	kirkwood_register_gate("pex1",   CGC_BIT_PEX1);
+	pex0 = kirkwood_register_gate("pex0",   CGC_BIT_PEX0);
+	pex1 = kirkwood_register_gate("pex1",   CGC_BIT_PEX1);
 	kirkwood_register_gate("audio",  CGC_BIT_AUDIO);
 	kirkwood_register_gate("tdm",    CGC_BIT_TDM);
 	kirkwood_register_gate("tsu",    CGC_BIT_TSU);
@@ -122,6 +122,8 @@ void __init kirkwood_clk_init(void)
 	orion_clkdev_add(NULL, "mv_crypto", crypto);
 	orion_clkdev_add(NULL, MV_XOR_SHARED_NAME ".0", xor0);
 	orion_clkdev_add(NULL, MV_XOR_SHARED_NAME ".1", xor1);
+	orion_clkdev_add("0", "pcie", pex0);
+	orion_clkdev_add("1", "pcie", pex1);
 }
 
 /*****************************************************************************

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: