MLK-11338-2 ARM: imx: add busfreq support for imx7d sdb board

This patch adds busfreq support for i.MX7D SDB
board with DDR3 memory, 3 setpoints supported:

HIGH: DRAM CLK = 533MHz, AXI = 332MHz, AHB = 135MHz;
AUDIO: DRAM CLK = 100MHz; AXI = 24MHz, AHB = 24MHz;
LOW: DRAM CLK = 24MHz; AXI = 24MHz, AHB = 24MHz;

Signed-off-by: Anson Huang <b20788@freescale.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/include/linux/busfreq-imx.h b/include/linux/busfreq-imx.h
new file mode 100644
index 000000000000..d309f3db02ae
--- /dev/null
+++ b/include/linux/busfreq-imx.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2012-2015 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_ARCH_MXC_BUSFREQ_H__
+#define __ASM_ARCH_MXC_BUSFREQ_H__
+
+#include <linux/notifier.h>
+
+/*
+ * This enumerates busfreq low power mode entry and exit.
+ */
+enum busfreq_event {
+	LOW_BUSFREQ_ENTER,
+	LOW_BUSFREQ_EXIT,
+};
+
+/*
+  * This enumerates the system bus and ddr frequencies in various modes.
+  * BUS_FREQ_HIGH - DDR @ 528MHz, AHB @ 132MHz.
+  * BUS_FREQ_MED - DDR @ 400MHz, AHB @ 132MHz
+  * BUS_FREQ_AUDIO - DDR @ 50MHz/100MHz, AHB @ 24MHz.
+  * BUS_FREQ_LOW  - DDR @ 24MHz, AHB @ 24MHz.
+  * BUS_FREQ_ULTRA_LOW - DDR @ 1MHz, AHB - 3MHz.
+  *
+  * Drivers need to request/release the bus/ddr frequencies based on
+  * their performance requirements. Drivers cannot request/release
+  * BUS_FREQ_ULTRA_LOW mode as this mode is automatically entered from
+  * either BUS_FREQ_AUDIO or BUS_FREQ_LOW
+  * modes.
+  */
+enum bus_freq_mode {
+	BUS_FREQ_HIGH,
+	BUS_FREQ_MED,
+	BUS_FREQ_AUDIO,
+	BUS_FREQ_LOW,
+	BUS_FREQ_ULTRA_LOW,
+};
+
+#ifdef CONFIG_CPU_FREQ
+void request_bus_freq(enum bus_freq_mode mode);
+void release_bus_freq(enum bus_freq_mode mode);
+int register_busfreq_notifier(struct notifier_block *nb);
+int unregister_busfreq_notifier(struct notifier_block *nb);
+int get_bus_freq_mode(void);
+#else
+static inline void request_bus_freq(enum bus_freq_mode mode)
+{
+}
+static inline void release_bus_freq(enum bus_freq_mode mode)
+{
+}
+static inline int register_busfreq_notifier(struct notifier_block *nb)
+{
+	return 0;
+}
+static inline int unregister_busfreq_notifier(struct notifier_block *nb)
+{
+	return 0;
+}
+static inline int get_bus_freq_mode(void)
+{
+	return BUS_FREQ_HIGH;
+}
+#endif
+#endif