[ARM] 4343/1: iop13xx: automatically detect the internal bus frequency

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

4 files changed, 63 insertions, 2 deletions

diff --git a/arch/arm/mach-iop13xx/iq81340mc.c b/arch/arm/mach-iop13xx/iq81340mc.c
index a519d707571c..1ae08cc04b48 100644
--- a/arch/arm/mach-iop13xx/iq81340mc.c
+++ b/arch/arm/mach-iop13xx/iq81340mc.c
@@ -79,7 +79,9 @@ static void __init iq81340mc_init(void)
 
 static void __init iq81340mc_timer_init(void)
 {
-        iop_init_time(400000000);
+        unsigned long bus_freq = iop13xx_core_freq() / iop13xx_xsi_bus_ratio();
+        printk(KERN_DEBUG "%s: bus frequency: %lu\n", __FUNCTION__, bus_freq);
+        iop_init_time(bus_freq);
 }
 
 static struct sys_timer iq81340mc_timer = {
diff --git a/arch/arm/mach-iop13xx/iq81340sc.c b/arch/arm/mach-iop13xx/iq81340sc.c
index 0e71fbcabe00..0f8801406f23 100644
--- a/arch/arm/mach-iop13xx/iq81340sc.c
+++ b/arch/arm/mach-iop13xx/iq81340sc.c
@@ -81,7 +81,9 @@ static void __init iq81340sc_init(void)
 
 static void __init iq81340sc_timer_init(void)
 {
-        iop_init_time(400000000);
+        unsigned long bus_freq = iop13xx_core_freq() / iop13xx_xsi_bus_ratio();
+        printk(KERN_DEBUG "%s: bus frequency: %lu\n", __FUNCTION__, bus_freq);
+        iop_init_time(bus_freq);
 }
 
 static struct sys_timer iq81340sc_timer = {
diff --git a/include/asm-arm/arch-iop13xx/iop13xx.h b/include/asm-arm/arch-iop13xx/iop13xx.h
index 2d1e23ba67c6..c8762ae8f628 100644
--- a/include/asm-arm/arch-iop13xx/iop13xx.h
+++ b/include/asm-arm/arch-iop13xx/iop13xx.h
@@ -455,4 +455,5 @@ static inline int iop13xx_cpu_id(void)
 #define IOP13XX_PBI_BAR1                IOP13XX_PBI_OFFSET(0x10)
 #define IOP13XX_PBI_LR1                 IOP13XX_PBI_OFFSET(0x14)
 
+#define IOP13XX_PROCESSOR_FREQ          IOP13XX_REG_ADDR32(0x2180)
 #endif /* _IOP13XX_HW_H_ */
diff --git a/include/asm-arm/arch-iop13xx/time.h b/include/asm-arm/arch-iop13xx/time.h
index 77a837a02dec..49213d9d7cad 100644
--- a/include/asm-arm/arch-iop13xx/time.h
+++ b/include/asm-arm/arch-iop13xx/time.h
@@ -7,9 +7,65 @@
 #define IOP_TMR_PRIVILEGED 0x08
 #define IOP_TMR_RATIO_1_1  0x00
 
+#define IOP13XX_XSI_FREQ_RATIO_MASK     (3 << 19)
+#define IOP13XX_XSI_FREQ_RATIO_2        (0 << 19)
+#define IOP13XX_XSI_FREQ_RATIO_3        (1 << 19)
+#define IOP13XX_XSI_FREQ_RATIO_4        (2 << 19)
+#define IOP13XX_CORE_FREQ_MASK          (7 << 16)
+#define IOP13XX_CORE_FREQ_600           (0 << 16)
+#define IOP13XX_CORE_FREQ_667           (1 << 16)
+#define IOP13XX_CORE_FREQ_800           (2 << 16)
+#define IOP13XX_CORE_FREQ_933           (3 << 16)
+#define IOP13XX_CORE_FREQ_1000          (4 << 16)
+#define IOP13XX_CORE_FREQ_1200          (5 << 16)
+
 void iop_init_time(unsigned long tickrate);
 unsigned long iop_gettimeoffset(void);
 
+static inline unsigned long iop13xx_core_freq(void)
+{
+        unsigned long freq = __raw_readl(IOP13XX_PROCESSOR_FREQ);
+        freq &= IOP13XX_CORE_FREQ_MASK;
+        switch (freq) {
+        case IOP13XX_CORE_FREQ_600:
+                return 600000000;
+        case IOP13XX_CORE_FREQ_667:
+                return 667000000;
+        case IOP13XX_CORE_FREQ_800:
+                return 800000000;
+        case IOP13XX_CORE_FREQ_933:
+                return 933000000;
+        case IOP13XX_CORE_FREQ_1000:
+                return 1000000000;
+        case IOP13XX_CORE_FREQ_1200:
+                return 1200000000;
+        default:
+                printk("%s: warning unknown frequency, defaulting to 800Mhz\n",
+                        __FUNCTION__);
+        }
+
+        return 800000000;
+}
+
+static inline unsigned long iop13xx_xsi_bus_ratio(void)
+{
+        unsigned long  ratio = __raw_readl(IOP13XX_PROCESSOR_FREQ);
+        ratio &= IOP13XX_XSI_FREQ_RATIO_MASK;
+        switch (ratio) {
+        case IOP13XX_XSI_FREQ_RATIO_2:
+                return 2;
+        case IOP13XX_XSI_FREQ_RATIO_3:
+                return 3;
+        case IOP13XX_XSI_FREQ_RATIO_4:
+                return 4;
+        default:
+                printk("%s: warning unknown ratio, defaulting to 2\n",
+                        __FUNCTION__);
+        }
+
+        return 2;
+}
+
 static inline void write_tmr0(u32 val)
 {
         asm volatile("mcr p6, 0, %0, c0, c9, 0" : : "r" (val));