cpu/allwinner/a10: Refactor API for gating clocks to peripherals

Rather than having to track which bit in which register should be
cleared or set to gate or ungate the clock to a certain peripheral,
provide a simplified enum which encodes the register and bit. This
change comes with a function which decodes the enum and gates/ungates
the clock.

This also removes the register-dependent bitmasks for APB0 and APB1
gating registers.

Change-Id: Ib3ca16e54eb37eadc3ceb88f4ccc497829ac34bc
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/4571
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/src/cpu/allwinner/a10/clock.c b/src/cpu/allwinner/a10/clock.c
new file mode 100644
index 0000000000..87a3574783
--- /dev/null
+++ b/src/cpu/allwinner/a10/clock.c
@@ -0,0 +1,42 @@
+/*
+ * Helpers for clock control and gating on Allwinner CPUs
+ *
+ * Copyright (C) 2013  Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Subject to the GNU GPL v2, or (at your option) any later version.
+ */
+
+#include "clock.h"
+
+#include <arch/io.h>
+
+/**
+ * \brief Enable the clock source for the peripheral
+ *
+ * @param[in] periph peripheral and clock type to enable @see a1x_clken
+ */
+void a1x_periph_clock_enable(enum a1x_clken periph)
+{
+	void *addr;
+	u32 reg32;
+
+	addr = (void *)A1X_CCM_BASE + (periph >> 5);
+	reg32 = read32(addr);
+	reg32 |= 1 << (periph & 0x1f);
+	write32(reg32, addr);
+}
+
+/**
+ * \brief Disable the clock source for the peripheral
+ *
+ * @param[in] periph peripheral and clock type to disable @see a1x_clken
+ */
+void a1x_periph_clock_disable(enum a1x_clken periph)
+{
+	void *addr;
+	u32 reg32;
+
+	addr = (void *)A1X_CCM_BASE + (periph >> 5);
+	reg32 = read32(addr);
+	reg32 &= ~(1 << (periph & 0x1f));
+	write32(reg32, addr);
+}