User:CesarB/cpufreq - Revision history

CesarB: link to ML post

2008-02-13T01:27:32Z

link to ML post

CesarB: /* Hints */ testing hints

2008-02-07T23:57:56Z

‎Hints: testing hints

CesarB: update

2008-02-07T23:40:52Z

update

CesarB: update

2008-02-06T21:37:45Z

update

CesarB: /* Frequency restrictions */ change heading level

2008-02-04T23:25:55Z

‎Frequency restrictions: change heading level

CesarB: /* What's missing */ update

2008-02-04T23:25:32Z

‎What's missing: update

CesarB: /* Hints */ modules

2008-02-04T20:09:55Z

‎Hints: modules

CesarB: /* To build */ wip branch

2008-02-03T02:53:37Z

‎To build: wip branch

CesarB: /* What's already done */ framebuffer -> working

2008-02-03T02:53:07Z

‎What's already done: framebuffer -> working

CesarB: update

2008-02-02T01:25:56Z

update

← Older revision		Revision as of 01:27, 13 February 2008
Line 100:		Line 100:

	* [[Neo1973 GTA01 Power Management]]		* [[Neo1973 GTA01 Power Management]]
		+
		+	== External links ==
		+
		+	* [http://lists.openmoko.org/pipermail/openmoko-kernel/2008-February/001021.html Experimental S3C2410A cpufreq driver] (2008-02-12)

@@ Line 25: / Line 25: @@
 * Do not compile the cpufreq driver as a module, since several of the notifiers depend on functions defined in it and would thus end up being compiled as modules too.
 * To test on 2.6.22.5, use <code>git format-patch -o ''dir'' master-om..s3c2410-cpufreq-om</code> to generate a set of patches, and apply them all on top of the OpenMoko patches 2.6.22.5 kernel, ''except'' the framebuffer patch(es) (the 2.6.24.x code for the framebuffer is different from the 2.6.22.5 one).
 == What's already done ==

@@ Line 38: / Line 38: @@
 | nand || Working || '''Untested'''
 |-
-| serial || Working || '''Missing'''
+| serial || Working || '''Untested'''
 |-
 | framebuffer || Working || '''Untested'''
@@ Line 77: / Line 77: @@
 * IIS
 * SPI
 == Frequency restrictions ==

@@ Line 30: / Line 30: @@
 {| border="1"
 |-
-! Driver !! Status
+! Driver !! Status (GTA01) !! Status (GTA02)
 |-
-| core || Working
+| core || Working || '''Untested'''
 |-
-| timer || Working
+| timer || Working || '''Untested'''
 |-
-| nand || Working
+| nand || Working || '''Untested'''
 |-
-| serial || Working
+| serial || Working || '''Missing'''
 |-
-| framebuffer || Working
+| framebuffer || Working || '''Untested'''
 |}

@@ Line 82: / Line 82: @@
 The GTA02 uses a different (but similar) SoC. Parts of the code have to be changed to be able to work on both. Also, part of the serial notifier code is specific to each kind of SoC.
-=== Frequency restrictions ===
+== Frequency restrictions ==
 Some drivers need specific frequencies. Currently there's no way to tell the cpufreq core of that, but at minimum a cpufreq notifier should be used to turn them off if they won't be able to work with that frequency.

← Older revision		Revision as of 23:25, 4 February 2008
Line 68:		Line 68:

	== What's missing ==		== What's missing ==
−
−	~~=== S3C2410A cpufreq driver ===~~
−
−	~~The frequency table should be checked for better divisor values (1:1:1 might be appropriate in more situations), and the code should be able to deal with HDIVN1 and different bus modes.~~

	=== Missing drivers ===		=== Missing drivers ===

← Older revision		Revision as of 20:09, 4 February 2008
Line 23:		Line 23:

	* Enable <code>CONFIG_CPU_FREQ_DEBUG</code> and add <code>cpufreq.debug=7</code> to the kernel command line to enable the relevant debug output. You can also enable it after boot by going to the correct place at /sys/modules and changing the values there.		* Enable <code>CONFIG_CPU_FREQ_DEBUG</code> and add <code>cpufreq.debug=7</code> to the kernel command line to enable the relevant debug output. You can also enable it after boot by going to the correct place at /sys/modules and changing the values there.
		+	* Do not compile the cpufreq driver as a module, since several of the notifiers depend on functions defined in it and would thus end up being compiled as modules too.
	* To test on 2.6.22.5, use <code>git format-patch -o ''dir'' master-om..s3c2410-cpufreq-om</code> to generate a set of patches, and apply them all on top of the OpenMoko patches 2.6.22.5 kernel, ''except'' the framebuffer patch(es) (the 2.6.24.x code for the framebuffer is different from the 2.6.22.5 one).		* To test on 2.6.22.5, use <code>git format-patch -o ''dir'' master-om..s3c2410-cpufreq-om</code> to generate a set of patches, and apply them all on top of the OpenMoko patches 2.6.22.5 kernel, ''except'' the framebuffer patch(es) (the 2.6.24.x code for the framebuffer is different from the 2.6.22.5 one).

@@ Line 13: / Line 13: @@
 You need a fully built OpenMoko tree for the cross-compiler and uboot tools.
-# Checkout the s3c2410-cpufreq-om branch
+# Checkout the s3c2410-cpufreq-om branch (or the wip branch for work in progress)
 # Copy the defconfig file from branches/src/target/kernel/2.6.24.x/config on the OpenMoko svn as the <code>.config</code> file
 # Set the PATH to the correct value (check the run.* temporary files bitbake generates to find out the correct value)

@@ Line 39: / Line 39: @@
 | serial || Working
 |-
-| framebuffer || Broken
+| framebuffer || Working
 |}
@@ Line 60: / Line 60: @@
 === Framebuffer driver ===
-The cpufreq notifier on <code>drivers/video/s3c2410fb.c</code> is responsible for turning off the video before the frequency change and reloading its configuration after the frequency change.
+The cpufreq notifier on <code>drivers/video/s3c2410fb.c</code> is responsible for dynamically changing the frequency divider used to derive the video clocks.
 === NAND driver ===

@@ Line 5: / Line 5: @@
 This project aims to implement the cpufreq driver (which manages the CPU frequency transitions) and a cpufreq notifier for all the affected drivers (to do two things: quiesce the device before the change, and adjust the frequency after the change). Deciding which frequency to use is the responsability of code from somewhere else (either cpufreq governors or userspace).
-The most recent version of the code can be found at http://repo.or.cz/w/linux-2.6/s3c2410-cpufreq.git on the branches s3c2410-cpufreq (for code which applies on top of the upstream "git HEAD" kernel) and s3c2410-cpufreq-gta01 (for code which applies on top of the OpenMoko patched kernel).
+The most recent version of the code can be found at http://repo.or.cz/w/linux-2.6/s3c2410-cpufreq.git on the s3c2410-cpufreq-om branch.
 == To build ==
-{{note|Do not run on real hardware, unless you '''''really''''' know what you are doing. This code is completely untested. It might even not compile.}}
+{{note|Do not run on real hardware, unless you '''''really''''' know what you are doing. This code is mostly untested, and changes frequently. It might even not compile.}}
 You need a fully built OpenMoko tree for the cross-compiler and uboot tools.
-# Checkout the s3c2410-cpufreq-gta01 branch
+# Checkout the s3c2410-cpufreq-om branch
 # Copy the defconfig file from branches/src/target/kernel/2.6.24.x/config on the OpenMoko svn as the <code>.config</code> file
 # Set the PATH to the correct value (check the run.* temporary files bitbake generates to find out the correct value)
@@ Line 23: / Line 23: @@
 * Enable <code>CONFIG_CPU_FREQ_DEBUG</code> and add <code>cpufreq.debug=7</code> to the kernel command line to enable the relevant debug output. You can also enable it after boot by going to the correct place at /sys/modules and changing the values there.
-* To test on 2.6.22.5, use <code>git format-patch -o ''dir'' master..s3c2410-cpufreq</code> to generate a set of patches, and apply them all on top of the OpenMoko patches 2.6.22.5 kernel, ''except'' the framebuffer patch(es) (the 2.6.24.x code for the framebuffer is different from the 2.6.22.5 one).
+* To test on 2.6.22.5, use <code>git format-patch -o ''dir'' master-om..s3c2410-cpufreq-om</code> to generate a set of patches, and apply them all on top of the OpenMoko patches 2.6.22.5 kernel, ''except'' the framebuffer patch(es) (the 2.6.24.x code for the framebuffer is different from the 2.6.22.5 one).
 == What's already done ==
 === S3C2410A cpufreq driver ===
@@ Line 56: / Line 71: @@
 The frequency table should be checked for better divisor values (1:1:1 might be appropriate in more situations), and the code should be able to deal with HDIVN1 and different bus modes.
 === Missing drivers ===
@@ Line 73: / Line 80: @@
 * IIS
 * SPI
 === Frequency restrictions ===
@@ Line 82: / Line 93: @@
 * The LCD device might also need a minimum frequency.
 * The serial baudrate generator might not have a good enough divider value for some baud rates and some clock frequencies (for instance, 115200 at 12000 kHz)
 == See also ==
 * [[Neo1973 GTA01 Power Management]]