tegra2: Add PWFM support

This adds support for the PWFM which provides for generation of a
selectable-frequency output with configurable duty cycle.

BUG=chromium-os:13228
TEST=Build, boot on Seaboard

Change-Id: Ic9e29fa9d4576e3cf70f5d67e5012158647c3fb5
Reviewed-on: http://gerrit.chromium.org/gerrit/1364
Tested-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anton Staaf <robotboy@chromium.org>

2 files changed, 38 insertions, 1 deletions

diff --git a/arch/arm/cpu/armv7/tegra2/Makefile b/arch/arm/cpu/armv7/tegra2/Makefile
index 74919b11a17..e23b8e87bf2 100644
--- a/arch/arm/cpu/armv7/tegra2/Makefile
+++ b/arch/arm/cpu/armv7/tegra2/Makefile
@@ -33,7 +33,7 @@ include $(TOPDIR)/config.mk
 LIB	=  $(obj)lib$(SOC).o
 
 SOBJS	:= lowlevel_init.o
-COBJS	:= ap20.o board.o clock.o pinmux.o sys_info.o timer.o
+COBJS	:= ap20.o board.o clock.o pinmux.o pwfm.o sys_info.o timer.o
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS) $(SOBJS))
diff --git a/arch/arm/cpu/armv7/tegra2/pwfm.c b/arch/arm/cpu/armv7/tegra2/pwfm.c
new file mode 100644
index 00000000000..1a37243fa47
--- /dev/null
+++ b/arch/arm/cpu/armv7/tegra2/pwfm.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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
+ */
+
+/* Tegra2 pulse width frequency modulator definitions */
+
+#include <asm/io.h>
+#include <asm/arch/bitfield.h>
+#include <asm/arch/pwfm.h>
+
+void pwfm_setup(struct pwfm_ctlr *pwfm, int enable, int pulse_width,
+		int freq_divider)
+{
+	u32 reg;
+
+	reg = bf_pack(PWFM_ENABLE, enable) |
+		bf_pack(PWFM_WIDTH, pulse_width) |
+		bf_pack(PWFM_DIVIDER, freq_divider);
+	writel(reg, &pwfm->control);
+}