LinuxPPC-Dev Archive on lore.kernel.org

* [PATCH/RFCv3] [POWERPC] Add support for freescale watchdog to CPM serial driver.
From: Jochen Friedrich @ 2008-01-18 22:12 UTC (permalink / raw)
  To: linuxppc-dev list; +Cc: Scott Wood, linux-kernel

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

Signed-off-by: Jochen Friedrich <jochen@scram.de>
---
 arch/powerpc/boot/Makefile     |    2 +-
 arch/powerpc/boot/cpm-serial.c |    6 +++
 arch/powerpc/boot/cuboot-8xx.c |    1 +
 arch/powerpc/boot/ops.h        |    8 ++++
 arch/powerpc/boot/watchdog.c   |   81 ++++++++++++++++++++++++++++++++++++++++
 5 files changed, 97 insertions(+), 1 deletions(-)
 create mode 100644 arch/powerpc/boot/watchdog.c

diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index d1e625c..66edf77 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -56,7 +56,7 @@ src-wlib := string.S crt0.S stdio.c main.c \
 		gunzip_util.c elf_util.c $(zlib) devtree.c oflib.c ofconsole.c \
 		4xx.c ebony.c mv64x60.c mpsc.c mv64x60_i2c.c cuboot.c bamboo.c \
 		cpm-serial.c stdlib.c mpc52xx-psc.c planetcore.c uartlite.c \
-		fsl-soc.c mpc8xx.c pq2.c
+		fsl-soc.c mpc8xx.c pq2.c watchdog.c
 src-plat := of.c cuboot-52xx.c cuboot-83xx.c cuboot-85xx.c holly.c \
 		cuboot-ebony.c treeboot-ebony.c prpmc2800.c \
 		ps3-head.S ps3-hvcall.S ps3.c treeboot-bamboo.c cuboot-8xx.c \
diff --git a/arch/powerpc/boot/cpm-serial.c b/arch/powerpc/boot/cpm-serial.c
index 28296fa..56b5fda 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"
@@ -154,6 +157,9 @@ static void cpm_serial_putc(unsigned char c)
 
 static unsigned char cpm_serial_tstc(void)
 {
+
+	watchdog_poke();
+
 	barrier();
 	return !(rbdf->sc & 0x8000);
 }
diff --git a/arch/powerpc/boot/cuboot-8xx.c b/arch/powerpc/boot/cuboot-8xx.c
index c202c88..767670e 100644
--- a/arch/powerpc/boot/cuboot-8xx.c
+++ b/arch/powerpc/boot/cuboot-8xx.c
@@ -43,5 +43,6 @@ void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
 	CUBOOT_INIT();
 	fdt_init(_dtb_start);
 	serial_console_init();
+	watchdog_init();
 	platform_ops.fixups = platform_fixups;
 }
diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h
index 6036a98..cc97e2b 100644
--- a/arch/powerpc/boot/ops.h
+++ b/arch/powerpc/boot/ops.h
@@ -70,6 +70,12 @@ struct serial_console_data {
 	void		(*close)(void);
 };
 
+/* Watchdog operations */
+struct watchdog_ops {
+	void 		(*poke)(void);
+};
+extern struct watchdog_ops watchdog_ops;
+
 struct loader_info {
 	void *promptr;
 	unsigned long initrd_addr, initrd_size;
@@ -86,6 +92,8 @@ int mpsc_console_init(void *devp, struct serial_console_data *scdp);
 int cpm_console_init(void *devp, struct serial_console_data *scdp);
 int mpc5200_psc_console_init(void *devp, struct serial_console_data *scdp);
 int uartlite_console_init(void *devp, struct serial_console_data *scdp);
+void watchdog_poke(void);
+void watchdog_init(void);
 void *simple_alloc_init(char *base, unsigned long heap_size,
 			unsigned long granularity, unsigned long max_allocs);
 extern void flush_cache(void *, unsigned long);
diff --git a/arch/powerpc/boot/watchdog.c b/arch/powerpc/boot/watchdog.c
new file mode 100644
index 0000000..2bdee77
--- /dev/null
+++ b/arch/powerpc/boot/watchdog.c
@@ -0,0 +1,81 @@
+/*
+ * PQ Watchdog
+ *
+ * Copyright 2008 Jochen Friedrich <jochen@scram.de>
+ *
+ * Search for PowerQUICC type watchdog devices. Provide a callback to
+ * periodically reset the watchdog while waiting for console input.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "types.h"
+#include "io.h"
+#include "ops.h"
+
+struct watchdog_ops watchdog_ops;
+
+/* pq Watchdog */
+
+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 struct pq_wdt *pq_wdt;
+
+static void pq_poke(void)
+{
+	out_be16(&pq_wdt->swsrr, 0x556c);
+	out_be16(&pq_wdt->swsrr, 0xaa39);
+}
+
+static void pq_init(void *wdt_node)
+{
+	int n;
+	void *reg_virt[2];
+	unsigned long reg_phys;
+
+	n = getprop(wdt_node, "virtual-reg", reg_virt, sizeof(reg_virt));
+	if (n < (int)sizeof(reg_virt)) {
+		if (!dt_xlate_reg(wdt_node, 0, &reg_phys, NULL))
+			return;
+		reg_virt[0] = (void *)reg_phys;
+	}
+	pq_wdt = reg_virt[0];
+	if (pq_wdt)
+		watchdog_ops.poke = pq_poke;
+}
+
+/* generic watchdog */
+
+void watchdog_poke(void)
+{
+	if (watchdog_ops.poke)
+		watchdog_ops.poke();
+}
+
+void watchdog_init(void)
+{
+	void *watchdog;
+
+	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")))
+		pq_init(watchdog);
+}
-- 
1.5.3.8

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