Gabe Black has uploaded this change for review. (
https://gem5-review.googlesource.com/c/public/gem5/+/37935 )
Change subject: dev: Set frequency ranges in OSC device tree nodes.
......................................................................
dev: Set frequency ranges in OSC device tree nodes.
The existing device tree generation method would the default frequency
as both the min and max frequency when setting up the OSC device tree
nodes. This would sort of work, except it seems that if the kernel
needed to adjust a frequency, it would fail to do so since it would
assume the new frequency was out of range.
Since the existing property is used to set the initial frequency of
those clocks, and because the default, min and max frequencies are all
mostly independent variables (other than obvious ordering restrictions),
two new properties were added, min_freq and max_freq, which are only
there to fill in the frequency range property in the device tree. If
they aren't set, then the device tree generation method falls back to
the old way of using the default frequency as both min and max.
Change-Id: Ie907bd673f8bcb149e69e45c5b486863149b8a68
---
M src/dev/arm/RealView.py
1 file changed, 25 insertions(+), 10 deletions(-)
diff --git a/src/dev/arm/RealView.py b/src/dev/arm/RealView.py
index bf8e0e6..1d3b54c 100644
--- a/src/dev/arm/RealView.py
+++ b/src/dev/arm/RealView.py
@@ -244,6 +244,10 @@
freq = Param.Clock("Default frequency")
+ # These are currently only used for the device tree.
+ min_freq = Param.Clock("0t", "Minimum frequency")
+ max_freq = Param.Clock("0t", "Maximum frequency")
+
def generateDeviceTree(self, state):
phandle = state.phandle(self)
node = FdtNode("osc@" + format(long(phandle), 'x'))
@@ -251,8 +255,16 @@
node.append(FdtPropertyWords("arm,vexpress-sysreg,func",
[0x1, int(self.device)]))
node.append(FdtPropertyWords("#clock-cells", [0]))
- freq = int(1.0/self.freq.value) # Values are stored as a clock
period
- node.append(FdtPropertyWords("freq-range", [freq, freq]))
+
+ minf = self.min_freq if self.min_freq.value else self.freq
+ maxf = self.max_freq if self.max_freq.value else self.freq
+
+ # Values are stored as a clock period.
+ def to_freq(prop):
+ return int(1.0 / prop.value)
+
+ node.append(FdtPropertyWords("freq-range",
+ [to_freq(minf), to_freq(maxf)]))
node.append(FdtPropertyStrings("clock-output-names",
["oscclk" + str(phandle)]))
node.appendPhandle(self)
@@ -288,10 +300,12 @@
class Temperature(RealViewTemperatureSensor):
site, position, dcc = (0, 0, 0)
- osc_mcc = Osc(device=0, freq="50MHz")
- osc_clcd = Osc(device=1, freq="23.75MHz")
+ osc_mcc = Osc(device=0, min_freq="25MHz", max_freq="60MHz",
freq="50MHz")
+ osc_clcd = Osc(device=1, min_freq="23.76MHz", max_freq="63.5MHz",
+ freq="23.75MHz")
osc_peripheral = Osc(device=2, freq="24MHz")
- osc_system_bus = Osc(device=4, freq="24MHz")
+ osc_system_bus = Osc(device=4, min_freq="2MHz", max_freq="230MHz",
+ freq="24MHz")
# See Table 4.19 in ARM DUI 0447J (Motherboard Express uATX TRM).
temp_crtl = Temperature(device=0)
@@ -322,11 +336,12 @@
site, position, dcc = (1, 0, 0)
# See Table 2.8 in ARM DUI 0604E (CoreTile Express A15x2 TRM)
- osc_cpu = Osc(device=0, freq="60MHz")
- osc_hsbm = Osc(device=4, freq="40MHz")
- osc_pxl = Osc(device=5, freq="23.75MHz")
- osc_smb = Osc(device=6, freq="50MHz")
- osc_sys = Osc(device=7, freq="60MHz")
+ osc_cpu = Osc(device=0, min_freq="20MHz", max_freq="60MHz",
freq="60MHz")
+ osc_hsbm = Osc(device=4, min_freq="20MHz", max_freq="40MHz",
freq="40MHz")
+ osc_pxl = Osc(device=5, min_freq="23.76MHz", max_freq="165MHz",
+ freq="23.75MHz")
+ osc_smb = Osc(device=6, min_freq="20MHz", max_freq="50MHz",
freq="50MHz")
+ osc_sys = Osc(device=7, min_freq="20MHz", max_freq="20MHz",
freq="60MHz")
osc_ddr = Osc(device=8, freq="40MHz")
def generateDeviceTree(self, state):
--
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Gerrit-Project: public/gem5
Gerrit-Branch: develop
Gerrit-Change-Id: Ie907bd673f8bcb149e69e45c5b486863149b8a68
Gerrit-Change-Number: 37935
Gerrit-PatchSet: 1
Gerrit-Owner: Gabe Black <gabe.bl...@gmail.com>
Gerrit-MessageType: newchange
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