MIPS: BCM63XX: add and use a clock for PCIe

Add a PCIe clock and use that instead of directly touching the clock
control register. While at it, fail if there is no such clock.

Signed-off-by: Jonas Gorski <[e-mail]>
Acked-by: Florian Fainelli <[e-mail]>
Patchwork: http://patchwork.linux-mips.org/patch/4452
Signed-off-by: John Crispin <[e-mail]>

arch/mips/bcm63xx/clk.c

···
 };
 
 /*
+ * PCIe clock
+ */
+
+static void pcie_set(struct clk *clk, int enable)
+{
+	bcm_hwclock_set(CKCTL_6328_PCIE_EN, enable);
+}
+
+static struct clk clk_pcie = {
+	.set	= pcie_set,
+};
+
+/*
  * Internal peripheral clock
  */
 static struct clk clk_periph = {
···
 		return &clk_pcm;
 	if (BCMCPU_IS_6368() && !strcmp(id, "ipsec"))
 		return &clk_ipsec;
+	if (BCMCPU_IS_6328() && !strcmp(id, "pcie"))
+		return &clk_pcie;
 	return ERR_PTR(-ENOENT);
 }
 

arch/mips/pci/pci-bcm63xx.c

···
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/delay.h>
+#include <linux/clk.h>
 #include <asm/bootinfo.h>
 
 #include "pci-bcm63xx.h"
···
 {
 	u32 val;
 
-	/* enable clock */
-	val = bcm_perf_readl(PERF_CKCTL_REG);
-	val |= CKCTL_6328_PCIE_EN;
-	bcm_perf_writel(val, PERF_CKCTL_REG);
-
 	/* enable SERDES */
 	val = bcm_misc_readl(MISC_SERDES_CTRL_REG);
 	val |= SERDES_PCIE_EN | SERDES_PCIE_EXD_EN;
···
 	mdelay(200);
 }
 
+static struct clk *pcie_clk;
+
 static int __init bcm63xx_register_pcie(void)
 {
 	u32 val;
+
+	/* enable clock */
+	pcie_clk = clk_get(NULL, "pcie");
+	if (IS_ERR_OR_NULL(pcie_clk))
+		return -ENODEV;
+
+	clk_prepare_enable(pcie_clk);
 
 	bcm63xx_reset_pcie();