Merge branch 'next-s3c24xx-cpufreq' into next-s3c

Documentation/arm/Samsung-S3C24XX/CPUfreq.txt

@@ -0,0 +1,75 @@
+		S3C24XX CPUfreq support
+		=======================
+
+Introduction
+------------
+
+ The S3C24XX series support a number of power saving systems, such as
+ the ability to change the core, memory and peripheral operating
+ frequencies. The core control is exported via the CPUFreq driver
+ which has a number of different manual or automatic controls over the
+ rate the core is running at.
+
+ There are two forms of the driver depending on the specific CPU and
+ how the clocks are arranged. The first implementation used as single
+ PLL to feed the ARM, memory and peripherals via a series of dividers
+ and muxes and this is the implementation that is documented here. A
+ newer version where there is a seperate PLL and clock divider for the
+ ARM core is available as a seperate driver.
+
+
+Layout
+------
+
+ The code core manages the CPU specific drivers, any data that they
+ need to register and the interface to the generic drivers/cpufreq
+ system. Each CPU registers a driver to control the PLL, clock dividers
+ and anything else associated with it. Any board that wants to use this
+ framework needs to supply at least basic details of what is required.
+
+ The core registers with drivers/cpufreq at init time if all the data
+ necessary has been supplied.
+
+
+CPU support
+-----------
+
+ The support for each CPU depends on the facilities provided by the
+ SoC and the driver as each device has different PLL and clock chains
+ associated with it.
+
+
+Slow Mode
+---------
+
+ The SLOW mode where the PLL is turned off altogether and the
+ system is fed by the external crystal input is currently not
+ supported.
+
+
+sysfs
+-----
+
+ The core code exports extra information via sysfs in the directory
+ devices/system/cpu/cpu0/arch-freq.
+
+
+Board Support
+-------------
+
+ Each board that wants to use the cpufreq code must register some basic
+ information with the core driver to provide information about what the
+ board requires and any restrictions being placed on it.
+
+ The board needs to supply information about whether it needs the IO bank
+ timings changing, any maximum frequency limits and information about the
+ SDRAM refresh rate.
+
+
+
+
+Document Author
+---------------
+
+Ben Dooks, Copyright 2009 Simtec Electronics
+Licensed under GPLv2

arch/arm/Kconfig

@@ -126,6 +126,13 @@ config ARCH_HAS_ILOG2_U32
 config ARCH_HAS_ILOG2_U64
 	bool
 
+config ARCH_HAS_CPUFREQ
+	bool
+	help
+	  Internal node to signify that the ARCH has CPUFREQ support
+	  and that the relevant menu configurations are displayed for
+	  it.
+
 config GENERIC_HWEIGHT
 	bool
 	default y
@@ -203,6 +210,7 @@ config ARCH_AAEC2000
 config ARCH_INTEGRATOR
 	bool "ARM Ltd. Integrator family"
 	select ARM_AMBA
+	select ARCH_HAS_CPUFREQ
 	select HAVE_CLK
 	select COMMON_CLKDEV
 	select ICST525
@@ -509,6 +517,7 @@ config ARCH_PXA
 	bool "PXA2xx/PXA3xx-based"
 	depends on MMU
 	select ARCH_MTD_XIP
+	select ARCH_HAS_CPUFREQ
 	select GENERIC_GPIO
 	select HAVE_CLK
 	select COMMON_CLKDEV
@@ -551,6 +560,7 @@ config ARCH_SA1100
 	select ISA
 	select ARCH_SPARSEMEM_ENABLE
 	select ARCH_MTD_XIP
+	select ARCH_HAS_CPUFREQ
 	select GENERIC_GPIO
 	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
@@ -563,6 +573,7 @@ config ARCH_SA1100
 config ARCH_S3C2410
 	bool "Samsung S3C2410, S3C2412, S3C2413, S3C2440, S3C2442, S3C2443"
 	select GENERIC_GPIO
+	select ARCH_HAS_CPUFREQ
 	select HAVE_CLK
 	help
 	  Samsung S3C2410X CPU based systems, such as the Simtec Electronics
@@ -573,6 +584,7 @@ config ARCH_S3C64XX
 	bool "Samsung S3C64XX"
 	select GENERIC_GPIO
 	select HAVE_CLK
+	select ARCH_HAS_CPUFREQ
 	help
 	  Samsung S3C64XX series based systems
 
@@ -632,6 +644,7 @@ config ARCH_OMAP
 	select GENERIC_GPIO
 	select HAVE_CLK
 	select ARCH_REQUIRE_GPIOLIB
+	select ARCH_HAS_CPUFREQ
 	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	help
@@ -1241,7 +1254,7 @@ endmenu
 
 menu "CPU Power Management"
 
-if (ARCH_SA1100 || ARCH_INTEGRATOR || ARCH_OMAP || ARCH_PXA || ARCH_S3C64XX)
+if ARCH_HAS_CPUFREQ
 
 source "drivers/cpufreq/Kconfig"
 
@@ -1276,6 +1289,52 @@ config CPU_FREQ_S3C64XX
 	bool "CPUfreq support for Samsung S3C64XX CPUs"
 	depends on CPU_FREQ && CPU_S3C6410
 
+config CPU_FREQ_S3C
+	bool
+	help
+	  Internal configuration node for common cpufreq on Samsung SoC
+
+config CPU_FREQ_S3C24XX
+	bool "CPUfreq driver for Samsung S3C24XX series CPUs"
+	depends on ARCH_S3C2410 && CPU_FREQ && EXPERIMENTAL
+	select CPU_FREQ_S3C
+	help
+	  This enables the CPUfreq driver for the Samsung S3C24XX family
+	  of CPUs.
+
+	  For details, take a look at <file:Documentation/cpu-freq>.
+
+	  If in doubt, say N.
+
+config CPU_FREQ_S3C24XX_PLL
+	bool "Support CPUfreq changing of PLL frequency"
+	depends on CPU_FREQ_S3C24XX && EXPERIMENTAL
+	help
+	  Compile in support for changing the PLL frequency from the
+	  S3C24XX series CPUfreq driver. The PLL takes time to settle
+	  after a frequency change, so by default it is not enabled.
+
+	  This also means that the PLL tables for the selected CPU(s) will
+	  be built which may increase the size of the kernel image.
+
+config CPU_FREQ_S3C24XX_DEBUG
+	bool "Debug CPUfreq Samsung driver core"
+	depends on CPU_FREQ_S3C24XX
+	help
+	  Enable s3c_freq_dbg for the Samsung S3C CPUfreq core
+
+config CPU_FREQ_S3C24XX_IODEBUG
+	bool "Debug CPUfreq Samsung driver IO timing"
+	depends on CPU_FREQ_S3C24XX
+	help
+	  Enable s3c_freq_iodbg for the Samsung S3C CPUfreq core
+
+config CPU_FREQ_S3C24XX_DEBUGFS
+	bool "Export debugfs for CPUFreq"
+	depends on CPU_FREQ_S3C24XX && DEBUG_FS
+	help
+	  Export status information via debugfs.
+
 endif
 
 source "drivers/cpuidle/Kconfig"

arch/arm/mach-s3c2410/Kconfig

@@ -12,6 +12,7 @@ config CPU_S3C2410
 	select S3C2410_GPIO
 	select CPU_LLSERIAL_S3C2410
 	select S3C2410_PM if PM
+	select S3C2410_CPUFREQ if CPU_FREQ_S3C24XX
 	help
 	  Support for S3C2410 and S3C2410A family from the S3C24XX line
 	  of Samsung Mobile CPUs.
@@ -45,6 +46,22 @@ config MACH_BAST_IDE
 	  Internal node for machines with an BAST style IDE
 	  interface
 
+# cpu frequency scaling support
+
+config S3C2410_CPUFREQ
+	bool
+	depends on CPU_FREQ_S3C24XX && CPU_S3C2410
+	select S3C2410_CPUFREQ_UTILS
+	help
+	  CPU Frequency scaling support for S3C2410
+
+config S3C2410_PLLTABLE
+	bool
+	depends on S3C2410_CPUFREQ && CPU_FREQ_S3C24XX_PLL
+	default y
+	help
+	  Select the PLL table for the S3C2410
+
 menu "S3C2410 Machines"
 
 config ARCH_SMDK2410
@@ -79,6 +96,7 @@ config MACH_N30
 config ARCH_BAST
 	bool "Simtec Electronics BAST (EB2410ITX)"
 	select CPU_S3C2410
+	select S3C2410_IOTIMING if S3C2410_CPUFREQ
 	select PM_SIMTEC if PM
 	select SIMTEC_NOR
 	select MACH_BAST_IDE

arch/arm/mach-s3c2410/Makefile

@@ -15,6 +15,8 @@ obj-$(CONFIG_CPU_S3C2410_DMA)	+= dma.o
 obj-$(CONFIG_CPU_S3C2410_DMA)	+= dma.o
 obj-$(CONFIG_S3C2410_PM)	+= pm.o sleep.o
 obj-$(CONFIG_S3C2410_GPIO)	+= gpio.o
+obj-$(CONFIG_S3C2410_CPUFREQ)	+= cpu-freq.o
+obj-$(CONFIG_S3C2410_PLLTABLE)	+= pll.o
 
 # Machine support