PM / devfreq: Add Exynos5-bus devfreq driver for Exynos5250

Exynos5-bus device devfreq driver monitors PPMU counters and
adjusts operating frequencies and voltages with OPP. ASV should
be used to provide appropriate voltages as per the speed group
of the SoC rather than using a constant 1.025V.
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
[myungjoo.ham@samsung.com: minor style update]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Jonghwan Choi <jhbird.choi@samsung.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>

drivers/devfreq/Kconfig

@@ -78,4 +78,14 @@ config ARM_EXYNOS4_BUS_DEVFREQ
 	  To operate with optimal voltages, ASV support is required
 	  (CONFIG_EXYNOS_ASV).
 
+config ARM_EXYNOS5_BUS_DEVFREQ
+	bool "ARM Exynos5250 Bus DEVFREQ Driver"
+	depends on SOC_EXYNOS5250
+	select ARCH_HAS_OPP
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	help
+	  This adds the DEVFREQ driver for Exynos5250 bus interface (vdd_int).
+	  It reads PPMU counters of memory controllers and adjusts the
+	  operating frequencies and voltages with OPP support.
+
 endif # PM_DEVFREQ

drivers/devfreq/Makefile

@@ -6,3 +6,4 @@ obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
 
 # DEVFREQ Drivers
 obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos/
+obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos/

drivers/devfreq/exynos/Makefile

 # Exynos DEVFREQ Drivers
 obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos4_bus.o
+obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos_ppmu.o exynos5_bus.o

drivers/devfreq/exynos/exynos_ppmu.c

+/*
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * EXYNOS - PPMU support
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/io.h>
+
+#include "exynos_ppmu.h"
+
+void exynos_ppmu_reset(void __iomem *ppmu_base)
+{
+	__raw_writel(PPMU_CYCLE_RESET | PPMU_COUNTER_RESET, ppmu_base);
+	__raw_writel(PPMU_ENABLE_CYCLE  |
+		     PPMU_ENABLE_COUNT0 |
+		     PPMU_ENABLE_COUNT1 |
+		     PPMU_ENABLE_COUNT2 |
+		     PPMU_ENABLE_COUNT3,
+		     ppmu_base + PPMU_CNTENS);
+}
+
+void exynos_ppmu_setevent(void __iomem *ppmu_base, unsigned int ch,
+			unsigned int evt)
+{
+	__raw_writel(evt, ppmu_base + PPMU_BEVTSEL(ch));
+}
+
+void exynos_ppmu_start(void __iomem *ppmu_base)
+{
+	__raw_writel(PPMU_ENABLE, ppmu_base);
+}
+
+void exynos_ppmu_stop(void __iomem *ppmu_base)
+{
+	__raw_writel(PPMU_DISABLE, ppmu_base);
+}
+
+unsigned int exynos_ppmu_read(void __iomem *ppmu_base, unsigned int ch)
+{
+	unsigned int total;
+
+	if (ch == PPMU_PMNCNT3)
+		total = ((__raw_readl(ppmu_base + PMCNT_OFFSET(ch)) << 8) |
+			  __raw_readl(ppmu_base + PMCNT_OFFSET(ch + 1)));
+	else
+		total = __raw_readl(ppmu_base + PMCNT_OFFSET(ch));
+
+	return total;
+}

drivers/devfreq/exynos/exynos_ppmu.h

+/*
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * EXYNOS PPMU header
+ *
+ * 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 __DEVFREQ_EXYNOS_PPMU_H
+#define __DEVFREQ_EXYNOS_PPMU_H __FILE__
+
+#include <linux/ktime.h>
+
+/* For PPMU Control */
+#define PPMU_ENABLE             BIT(0)
+#define PPMU_DISABLE            0x0
+#define PPMU_CYCLE_RESET        BIT(1)
+#define PPMU_COUNTER_RESET      BIT(2)
+
+#define PPMU_ENABLE_COUNT0      BIT(0)
+#define PPMU_ENABLE_COUNT1      BIT(1)
+#define PPMU_ENABLE_COUNT2      BIT(2)
+#define PPMU_ENABLE_COUNT3      BIT(3)
+#define PPMU_ENABLE_CYCLE       BIT(31)
+
+#define PPMU_CNTENS		0x10
+#define PPMU_FLAG		0x50
+#define PPMU_CCNT_OVERFLOW	BIT(31)
+#define PPMU_CCNT		0x100
+
+#define PPMU_PMCNT0		0x110
+#define PPMU_PMCNT_OFFSET	0x10
+#define PMCNT_OFFSET(x)		(PPMU_PMCNT0 + (PPMU_PMCNT_OFFSET * x))
+
+#define PPMU_BEVT0SEL		0x1000
+#define PPMU_BEVTSEL_OFFSET	0x100
+#define PPMU_BEVTSEL(x)		(PPMU_BEVT0SEL + (ch * PPMU_BEVTSEL_OFFSET))
+
+/* For Event Selection */
+#define RD_DATA_COUNT		0x5
+#define WR_DATA_COUNT		0x6
+#define RDWR_DATA_COUNT		0x7
+
+enum ppmu_counter {
+	PPMU_PMNCNT0,
+	PPMU_PMCCNT1,
+	PPMU_PMNCNT2,
+	PPMU_PMNCNT3,
+	PPMU_PMNCNT_MAX,
+};
+
+struct bus_opp_table {
+	unsigned int idx;
+	unsigned long clk;
+	unsigned long volt;
+};
+
+struct exynos_ppmu {
+	void __iomem *hw_base;
+	unsigned int ccnt;
+	unsigned int event[PPMU_PMNCNT_MAX];
+	unsigned int count[PPMU_PMNCNT_MAX];
+	unsigned long long ns;
+	ktime_t reset_time;
+	bool ccnt_overflow;
+	bool count_overflow[PPMU_PMNCNT_MAX];
+};
+
+void exynos_ppmu_reset(void __iomem *ppmu_base);
+void exynos_ppmu_setevent(void __iomem *ppmu_base, unsigned int ch,
+			unsigned int evt);
+void exynos_ppmu_start(void __iomem *ppmu_base);
+void exynos_ppmu_stop(void __iomem *ppmu_base);
+unsigned int exynos_ppmu_read(void __iomem *ppmu_base, unsigned int ch);
+#endif /* __DEVFREQ_EXYNOS_PPMU_H */