MIPS: Alchemy: usb: use clk framework

Add use of the common clock framework to set and enable the 48MHz
clock source for the onchip OHCI and UDC blocks.

Tested on a DB1500.  (Au1200 and Au1300 use an external 48MHz crystal).

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/7467/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 40 insertions, 7 deletions

diff --git a/arch/mips/alchemy/common/usb.c b/arch/mips/alchemy/common/usb.c
index d193dbea84a1..297805ade849 100644
--- a/arch/mips/alchemy/common/usb.c
+++ b/arch/mips/alchemy/common/usb.c
@@ -9,6 +9,7 @@
  *
  */
 
+#include <linux/clk.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/module.h>
@@ -387,10 +388,25 @@ static inline void au1200_usb_init(void)
         udelay(1000);
 }
 
-static inline void au1000_usb_init(unsigned long rb, int reg)
+static inline int au1000_usb_init(unsigned long rb, int reg)
 {
         void __iomem *base = (void __iomem *)KSEG1ADDR(rb + reg);
         unsigned long r = __raw_readl(base);
+        struct clk *c;
+
+        /* 48MHz check. Don't init if no one can provide it */
+        c = clk_get(NULL, "usbh_clk");
+        if (IS_ERR(c))
+                return -ENODEV;
+        if (clk_round_rate(c, 48000000) != 48000000) {
+                clk_put(c);
+                return -ENODEV;
+        }
+        if (clk_set_rate(c, 48000000)) {
+                clk_put(c);
+                return -ENODEV;
+        }
+        clk_put(c);
 
 #if defined(__BIG_ENDIAN)
         r |= USBHEN_BE;
@@ -400,6 +416,8 @@ static inline void au1000_usb_init(unsigned long rb, int reg)
         __raw_writel(r, base);
         wmb();
         udelay(1000);
+
+        return 0;
 }
 
 
@@ -407,8 +425,15 @@ static inline void __au1xx0_ohci_control(int enable, unsigned long rb, int creg)
 {
         void __iomem *base = (void __iomem *)KSEG1ADDR(rb);
         unsigned long r = __raw_readl(base + creg);
+        struct clk *c = clk_get(NULL, "usbh_clk");
+
+        if (IS_ERR(c))
+                return;
 
         if (enable) {
+                if (clk_prepare_enable(c))
+                        goto out;
+
                 __raw_writel(r | USBHEN_CE, base + creg);
                 wmb();
                 udelay(1000);
@@ -423,7 +448,10 @@ static inline void __au1xx0_ohci_control(int enable, unsigned long rb, int creg)
         } else {
                 __raw_writel(r & ~(USBHEN_CE | USBHEN_E), base + creg);
                 wmb();
+                clk_disable_unprepare(c);
         }
+out:
+        clk_put(c);
 }
 
 static inline int au1000_usb_control(int block, int enable, unsigned long rb,
@@ -457,11 +485,11 @@ int alchemy_usb_control(int block, int enable)
         case ALCHEMY_CPU_AU1500:
         case ALCHEMY_CPU_AU1100:
                 ret = au1000_usb_control(block, enable,
-                                AU1000_USB_OHCI_PHYS_ADDR, AU1000_OHCICFG);
+                        AU1000_USB_OHCI_PHYS_ADDR, AU1000_OHCICFG);
                 break;
         case ALCHEMY_CPU_AU1550:
                 ret = au1000_usb_control(block, enable,
-                                AU1550_USB_OHCI_PHYS_ADDR, AU1550_OHCICFG);
+                        AU1550_USB_OHCI_PHYS_ADDR, AU1550_OHCICFG);
                 break;
         case ALCHEMY_CPU_AU1200:
                 ret = au1200_usb_control(block, enable);
@@ -569,14 +597,18 @@ static struct syscore_ops alchemy_usb_pm_ops = {
 
 static int __init alchemy_usb_init(void)
 {
+        int ret = 0;
+
         switch (alchemy_get_cputype()) {
         case ALCHEMY_CPU_AU1000:
         case ALCHEMY_CPU_AU1500:
         case ALCHEMY_CPU_AU1100:
-                au1000_usb_init(AU1000_USB_OHCI_PHYS_ADDR, AU1000_OHCICFG);
+                ret = au1000_usb_init(AU1000_USB_OHCI_PHYS_ADDR,
+                                      AU1000_OHCICFG);
                 break;
         case ALCHEMY_CPU_AU1550:
-                au1000_usb_init(AU1550_USB_OHCI_PHYS_ADDR, AU1550_OHCICFG);
+                ret = au1000_usb_init(AU1550_USB_OHCI_PHYS_ADDR,
+                                      AU1550_OHCICFG);
                 break;
         case ALCHEMY_CPU_AU1200:
                 au1200_usb_init();
@@ -586,8 +618,9 @@ static int __init alchemy_usb_init(void)
                 break;
         }
 
-        register_syscore_ops(&alchemy_usb_pm_ops);
+        if (!ret)
+                register_syscore_ops(&alchemy_usb_pm_ops);
 
-        return 0;
+        return ret;
 }
 arch_initcall(alchemy_usb_init);