ARM: sun6i: Add support for the power reset control module found on the A31

The A31 has a new module called PRCM, or Power, Reset Control Module.
This module controls clocks and resets for RTC block modules, and also
PLL biasing in the main clock module.

This patch adds the register definitions, and also enables the clocks
and resets for the RTC block PIO (pin controller) and P2WI (push-pull
2 wire interface) which is used to talk to the PMIC.

Signed-off-by: Oliver Schinagl <oliver@schinagl.nl>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[wens@csie.org: spacing fixes reported by checkpatch.pl]
[wens@csie.org: Use setbits helper in PRCM init function]
[wens@csie.org: rephrase commit message to explain what the hardware
		supports and what we actually enable]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

2 files changed, 34 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/sunxi/Makefile b/arch/arm/cpu/armv7/sunxi/Makefile
index e9721b27b6..f0473d2ab8 100644
--- a/arch/arm/cpu/armv7/sunxi/Makefile
+++ b/arch/arm/cpu/armv7/sunxi/Makefile
@@ -11,6 +11,7 @@ obj-y	+= timer.o
 obj-y	+= board.o
 obj-y	+= clock.o
 obj-y	+= pinmux.o
+obj-$(CONFIG_SUN6I)	+= prcm.o
 obj-$(CONFIG_SUN4I)	+= clock_sun4i.o
 obj-$(CONFIG_SUN5I)	+= clock_sun4i.o
 obj-$(CONFIG_SUN7I)	+= clock_sun4i.o
diff --git a/arch/arm/cpu/armv7/sunxi/prcm.c b/arch/arm/cpu/armv7/sunxi/prcm.c
new file mode 100644
index 0000000000..7b3ee89302
--- /dev/null
+++ b/arch/arm/cpu/armv7/sunxi/prcm.c
@@ -0,0 +1,33 @@
+/*
+ * Sunxi A31 Power Management Unit
+ *
+ * (C) Copyright 2013 Oliver Schinagl <oliver@schinagl.nl>
+ * http://linux-sunxi.org
+ *
+ * Based on sun6i sources and earlier U-Boot Allwinner A10 SPL work
+ *
+ * (C) Copyright 2006-2013
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ * Berg Xing <bergxing@allwinnertech.com>
+ * Tom Cubie <tangliang@allwinnertech.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/prcm.h>
+#include <asm/arch/sys_proto.h>
+
+void prcm_init_apb0(void)
+{
+	struct sunxi_prcm_reg *prcm =
+		(struct sunxi_prcm_reg *)SUNXI_PRCM_BASE;
+
+	setbits_le32(&prcm->apb0_gate, PRCM_APB0_GATE_P2WI |
+				       PRCM_APB0_GATE_PIO);
+	setbits_le32(&prcm->apb0_reset, PRCM_APB0_RESET_P2WI |
+					PRCM_APB0_RESET_PIO);
+}