[PATCH/RFC] Add support for freescale watchdog to CPM serial driver.

[Jochen Friedrich]

If a freescale watchdog device node is present, reset the watchdog
while waiting for serial input.

Signed-off-by: Jochen Friedrich <[EMAIL PROTECTED]>
---
 arch/powerpc/boot/cpm-serial.c |   33 ++++++++++++++++++++++++++++++++-
 1 files changed, 32 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/boot/cpm-serial.c b/arch/powerpc/boot/cpm-serial.c
index 28296fa..d85f038 100644
--- a/arch/powerpc/boot/cpm-serial.c
+++ b/arch/powerpc/boot/cpm-serial.c
@@ -6,6 +6,9 @@
  *
  * It is assumed that the firmware (or the platform file) has already set
  * up the port.
+ *
+ * If a watchdog node exists, periodically reset the watchdog while waiting
+ * for console input.
  */
 
 #include "types.h"
@@ -50,7 +53,16 @@ struct cpm_bd {
        u8 *addr; /* Buffer address in host memory */
 };
 
+struct pq_wdt {
+       u32 res0;
+       u32 swcrr; /* System watchdog control register */
+       u32 swcnr; /* System watchdog count register */
+       u8  res1[2];
+       u16 swsrr; /* System watchdog service register */
+};
+
 static void *cpcr;
+static struct pq_wdt *wdt;
 static struct cpm_param *param;
 static struct cpm_smc *smc;
 static struct cpm_scc *scc;
@@ -154,6 +166,11 @@ static void cpm_serial_putc(unsigned char c)
 
 static unsigned char cpm_serial_tstc(void)
 {
+       if (wdt) {
+               out_be16(&wdt->swsrr, 0x556c);
+               out_be16(&wdt->swsrr, 0xaa39);
+       }
+
        barrier();
        return !(rbdf->sc & 0x8000);
 }
@@ -178,7 +195,7 @@ int cpm_console_init(void *devp, struct serial_console_data 
*scdp)
        void *reg_virt[2];
        int is_smc = 0, is_cpm2 = 0, n;
        unsigned long reg_phys;
-       void *parent, *muram;
+       void *parent, *muram, *watchdog;
 
        if (dt_is_compatible(devp, "fsl,cpm1-smc-uart")) {
                is_smc = 1;
@@ -260,6 +277,20 @@ int cpm_console_init(void *devp, struct 
serial_console_data *scdp)
        if (n < 4)
                return -1;
 
+       watchdog = finddevice("/soc/wdt");
+       if (watchdog && (dt_is_compatible(watchdog, "fsl,pq1-wdt") ||
+                        dt_is_compatible(watchdog, "fsl,pq2-wdt") ||
+                        dt_is_compatible(watchdog, "fsl,pq2pro-wdt"))) {
+               n = getprop(watchdog, "virtual-reg", reg_virt,
+                        sizeof(reg_virt));
+               if (n < (int)sizeof(reg_virt)) {
+                       if (!dt_xlate_reg(watchdog, 0, &reg_phys, NULL))
+                               return -1;
+                       reg_virt[0] = (void *)reg_phys;
+               }
+               wdt = reg_virt[0];
+       }
+
        scdp->open = cpm_serial_open;
        scdp->putc = cpm_serial_putc;
        scdp->getc = cpm_serial_getc;
-- 
1.5.3.7

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