tegra: Add PMU to manage power supplies

Power supplies must be adjusted in line with clock frequency. This code
provides a simple routine to set the voltage to allow operation at maximum
frequency.

- Split PMU code into separate TPS6586X driver

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

3 files changed, 101 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/tegra2/Makefile b/arch/arm/cpu/armv7/tegra2/Makefile
index dcd6329..dba684d 100644
--- a/arch/arm/cpu/armv7/tegra2/Makefile
+++ b/arch/arm/cpu/armv7/tegra2/Makefile
@@ -35,6 +35,7 @@ LIB	=  $(obj)lib$(SOC).o
 SOBJS	:= lowlevel_init.o
 COBJS-y	:= ap20.o board.o clock.o funcmux.o pinmux.o sys_info.o timer.o
 COBJS-$(CONFIG_TEGRA_CLOCK_SCALING) += emc.o
+COBJS-$(CONFIG_TEGRA_PMU) += pmu.o
 COBJS-$(CONFIG_USB_EHCI_TEGRA) += usb.o
 
 COBJS	:= $(COBJS-y)
diff --git a/arch/arm/cpu/armv7/tegra2/pmu.c b/arch/arm/cpu/armv7/tegra2/pmu.c
new file mode 100644
index 0000000..4673802
--- /dev/null
+++ b/arch/arm/cpu/armv7/tegra2/pmu.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * (C) Copyright 2010,2011 NVIDIA Corporation <www.nvidia.com>
+ *
+ * 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
+ */
+
+#include <common.h>
+#include <tps6586x.h>
+#include <asm/io.h>
+#include <asm/arch/ap20.h>
+#include <asm/arch/tegra2.h>
+#include <asm/arch/tegra_i2c.h>
+#include <asm/arch/sys_proto.h>
+
+#define VDD_CORE_NOMINAL_T25	0x17	/* 1.3v */
+#define VDD_CPU_NOMINAL_T25	0x10	/* 1.125v */
+
+#define VDD_CORE_NOMINAL_T20	0x16	/* 1.275v */
+#define VDD_CPU_NOMINAL_T20	0x0f	/* 1.1v */
+
+#define VDD_RELATION		0x02	/*  50mv */
+#define VDD_TRANSITION_STEP	0x06	/* 150mv */
+#define VDD_TRANSITION_RATE	0x06	/* 3.52mv/us */
+
+int pmu_set_nominal(void)
+{
+	int core, cpu, bus;
+
+	/* by default, the table has been filled with T25 settings */
+	switch (tegra_get_chip_type()) {
+	case TEGRA_SOC_T20:
+		core = VDD_CORE_NOMINAL_T20;
+		cpu = VDD_CPU_NOMINAL_T20;
+		break;
+	case TEGRA_SOC_T25:
+		core = VDD_CORE_NOMINAL_T25;
+		cpu = VDD_CPU_NOMINAL_T25;
+		break;
+	default:
+		debug("%s: Unknown chip type\n", __func__);
+		return -1;
+	}
+
+	bus = tegra_i2c_get_dvc_bus_num();
+	if (bus == -1) {
+		debug("%s: Cannot find DVC I2C bus\n", __func__);
+		return -1;
+	}
+	tps6586x_init(bus);
+	tps6586x_set_pwm_mode(TPS6586X_PWM_SM1);
+	return tps6586x_adjust_sm0_sm1(core, cpu, VDD_TRANSITION_STEP,
+				VDD_TRANSITION_RATE, VDD_RELATION);
+}
diff --git a/arch/arm/include/asm/arch-tegra2/pmu.h b/arch/arm/include/asm/arch-tegra2/pmu.h
new file mode 100644
index 0000000..390815f
--- /dev/null
+++ b/arch/arm/include/asm/arch-tegra2/pmu.h
@@ -0,0 +1,30 @@
+/*
+ *  (C) Copyright 2010,2011
+ *  NVIDIA Corporation <www.nvidia.com>
+ *
+ * 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
+ */
+
+#ifndef _ARCH_PMU_H_
+#define _ARCH_PMU_H_
+
+/* Set core and CPU voltages to nominal levels */
+int pmu_set_nominal(void);
+
+#endif	/* _ARCH_PMU_H_ */