misc: Add simple driver for some Nuvoton NCT6102D devices

[oweals/u-boot.git] / drivers / misc / nuvoton_nct6102d.c

diff --git a/drivers/misc/nuvoton_nct6102d.c b/drivers/misc/nuvoton_nct6102d.c
new file mode 100644 (file)
index 0000000..ced70f1
--- /dev/null
+++ b/drivers/misc/nuvoton_nct6102d.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2016 Stefan Roese <sr@denx.de>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <nuvoton_nct6102d.h>
+#include <asm/io.h>
+#include <asm/pnp_def.h>
+
+static void superio_outb(int reg, int val)
+{
+       outb(reg, NCT_EFER);
+       outb(val, NCT_EFDR);
+}
+
+static inline int superio_inb(int reg)
+{
+       outb(reg, NCT_EFER);
+       return inb(NCT_EFDR);
+}
+
+static int superio_enter(void)
+{
+       outb(NCT_ENTRY_KEY, NCT_EFER); /* Enter extended function mode */
+       outb(NCT_ENTRY_KEY, NCT_EFER); /* Again according to manual */
+
+       return 0;
+}
+
+static void superio_select(int ld)
+{
+       superio_outb(NCT_LD_SELECT_REG, ld);
+}
+
+static void superio_exit(void)
+{
+       outb(NCT_EXIT_KEY, NCT_EFER); /* Leave extended function mode */
+}
+
+/*
+ * The Nuvoton NCT6102D starts per default after reset with both,
+ * the internal watchdog and the internal legacy UART enabled. This
+ * code provides a function to disable the watchdog.
+ */
+int nct6102d_wdt_disable(void)
+{
+       superio_enter();
+       /* Select logical device for WDT */
+       superio_select(NCT6102D_LD_WDT);
+       superio_outb(NCT6102D_WDT_TIMEOUT, 0x00);
+       superio_exit();
+
+       return 0;
+}