[ARM] 4495/1: iop: combined watchdog timer driver for iop3xx and iop13xx

In order for this driver to be shared across the iop architectures the
iop3xx and iop13xx header files are modified to present a common interface
for the iop_wdt driver.

Details:
* iop13xx supports disabling the timer while iop3xx does not.  This requires
  a few 'compatibility' definitions in include/asm-arm/hardware/iop3xx.h to
  preclude adding #ifdef CONFIG_ARCH_IOP13XX blocks to the driver code.
* The heartbeat interval is derived from the internal bus clock rate, so this
  this patch also exports the tick rate to the iop_wdt driver.

Cc: Curt Bruns <curt.e.bruns@intel.com>
Cc: Peter Milne <peter.milne@d-tacq.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 78 insertions, 32 deletions

diff --git a/include/asm-arm/arch-iop13xx/iop13xx.h b/include/asm-arm/arch-iop13xx/iop13xx.h
index d4e4f828577c..52b7fab7ef60 100644
--- a/include/asm-arm/arch-iop13xx/iop13xx.h
+++ b/include/asm-arm/arch-iop13xx/iop13xx.h
@@ -19,6 +19,39 @@ static inline int iop13xx_cpu_id(void)
         return id;
 }
 
+/* WDTCR CP6 R7 Page 9 */
+static inline u32 read_wdtcr(void)
+{
+        u32 val;
+        asm volatile("mrc p6, 0, %0, c7, c9, 0":"=r" (val));
+        return val;
+}
+static inline void write_wdtcr(u32 val)
+{
+        asm volatile("mcr p6, 0, %0, c7, c9, 0"::"r" (val));
+}
+
+/* WDTSR CP6 R8 Page 9 */
+static inline u32 read_wdtsr(void)
+{
+        u32 val;
+        asm volatile("mrc p6, 0, %0, c8, c9, 0":"=r" (val));
+        return val;
+}
+static inline void write_wdtsr(u32 val)
+{
+        asm volatile("mcr p6, 0, %0, c8, c9, 0"::"r" (val));
+}
+
+/* RCSR - Reset Cause Status Register  */
+static inline u32 read_rcsr(void)
+{
+        u32 val;
+        asm volatile("mrc p6, 0, %0, c0, c1, 0":"=r" (val));
+        return val;
+}
+
+extern unsigned long get_iop_tick_rate(void);
 #endif
 
 /*
@@ -480,4 +513,14 @@ static inline int iop13xx_cpu_id(void)
 #define IOP13XX_PBI_LR1                 IOP13XX_PBI_OFFSET(0x14)
 
 #define IOP13XX_PROCESSOR_FREQ          IOP13XX_REG_ADDR32(0x2180)
+
+/* Watchdog timer definitions */
+#define IOP_WDTCR_EN_ARM        0x1e1e1e1e
+#define IOP_WDTCR_EN            0xe1e1e1e1
+#define IOP_WDTCR_DIS_ARM       0x1f1f1f1f
+#define IOP_WDTCR_DIS           0xf1f1f1f1
+#define IOP_RCSR_WDT            (1 << 5) /* reset caused by watchdog timer */
+#define IOP13XX_WDTSR_WRITE_EN  (1 << 31) /* used to speed up reset requests */
+#define IOP13XX_WDTCR_IB_RESET  (1 << 0)
+
 #endif /* _IOP13XX_HW_H_ */
diff --git a/include/asm-arm/arch-iop13xx/system.h b/include/asm-arm/arch-iop13xx/system.h
index 127827058e1f..8575af8db78c 100644
--- a/include/asm-arm/arch-iop13xx/system.h
+++ b/include/asm-arm/arch-iop13xx/system.h
@@ -13,43 +13,13 @@ static inline void arch_idle(void)
         cpu_do_idle();
 }
 
-/* WDTCR CP6 R7 Page 9 */
-static inline u32 read_wdtcr(void)
-{
-        u32 val;
-        asm volatile("mrc p6, 0, %0, c7, c9, 0":"=r" (val));
-        return val;
-}
-static inline void write_wdtcr(u32 val)
-{
-        asm volatile("mcr p6, 0, %0, c7, c9, 0"::"r" (val));
-}
-
-/* WDTSR CP6 R8 Page 9 */
-static inline u32 read_wdtsr(void)
-{
-        u32 val;
-        asm volatile("mrc p6, 0, %0, c8, c9, 0":"=r" (val));
-        return val;
-}
-static inline void write_wdtsr(u32 val)
-{
-        asm volatile("mcr p6, 0, %0, c8, c9, 0"::"r" (val));
-}
-
-#define IOP13XX_WDTCR_EN_ARM    0x1e1e1e1e
-#define IOP13XX_WDTCR_EN        0xe1e1e1e1
-#define IOP13XX_WDTCR_DIS_ARM   0x1f1f1f1f
-#define IOP13XX_WDTCR_DIS       0xf1f1f1f1
-#define IOP13XX_WDTSR_WRITE_EN  (1 << 31)
-#define IOP13XX_WDTCR_IB_RESET  (1 << 0)
 static inline void arch_reset(char mode)
 {
         /*
          * Reset the internal bus (warning both cores are reset)
          */
-        write_wdtcr(IOP13XX_WDTCR_EN_ARM);
-        write_wdtcr(IOP13XX_WDTCR_EN);
+        write_wdtcr(IOP_WDTCR_EN_ARM);
+        write_wdtcr(IOP_WDTCR_EN);
         write_wdtsr(IOP13XX_WDTSR_WRITE_EN | IOP13XX_WDTCR_IB_RESET);
         write_wdtcr(0x1000);
 
diff --git a/include/asm-arm/hardware/iop3xx.h b/include/asm-arm/hardware/iop3xx.h
index 81ca5d3e2bff..fb90b421f31c 100644
--- a/include/asm-arm/hardware/iop3xx.h
+++ b/include/asm-arm/hardware/iop3xx.h
@@ -194,6 +194,13 @@ extern int init_atu;
 #define IOP_TMR_PRIVILEGED 0x08
 #define IOP_TMR_RATIO_1_1  0x00
 
+/* Watchdog timer definitions */
+#define IOP_WDTCR_EN_ARM        0x1e1e1e1e
+#define IOP_WDTCR_EN            0xe1e1e1e1
+/* iop3xx does not support stopping the watchdog, so we just re-arm */
+#define IOP_WDTCR_DIS_ARM       (IOP_WDTCR_EN_ARM)
+#define IOP_WDTCR_DIS           (IOP_WDTCR_EN)
+
 /* Application accelerator unit  */
 #define IOP3XX_AAU_PHYS_BASE (IOP3XX_PERIPHERAL_PHYS_BASE + 0x800)
 #define IOP3XX_AAU_UPPER_PA (IOP3XX_AAU_PHYS_BASE + 0xa7)
@@ -274,6 +281,32 @@ static inline void write_tisr(u32 val)
         asm volatile("mcr p6, 0, %0, c6, c1, 0" : : "r" (val));
 }
 
+static inline u32 read_wdtcr(void)
+{
+        u32 val;
+        asm volatile("mrc p6, 0, %0, c7, c1, 0":"=r" (val));
+        return val;
+}
+static inline void write_wdtcr(u32 val)
+{
+        asm volatile("mcr p6, 0, %0, c7, c1, 0"::"r" (val));
+}
+
+extern unsigned long get_iop_tick_rate(void);
+
+/* only iop13xx has these registers, we define these to present a
+ * common register interface for the iop_wdt driver.
+ */
+#define IOP_RCSR_WDT    (0)
+static inline u32 read_rcsr(void)
+{
+        return 0;
+}
+static inline void write_wdtsr(u32 val)
+{
+        do { } while (0);
+}
+
 extern struct platform_device iop3xx_dma_0_channel;
 extern struct platform_device iop3xx_dma_1_channel;
 extern struct platform_device iop3xx_aau_channel;