[PATCH 5/6] mach-mpc85xx: speed: add fsl_set_timebase_clock() override

[Ahmad Fatoum]

Some platforms (e.g. QEMU) don't implement the GUTS PORPLLSR register,
so the register-based timebase frequency calculation returns 0. Add
fsl_set_timebase_clock() that allows board code to provide the correct
timebase frequency before initcalls run, bypassing the register read.

Co-Authored-By: Claude Opus 4.6 <noreply at anthropic.com>
Signed-off-by: Ahmad Fatoum <a.fatoum at barebox.org>
---
 arch/powerpc/mach-mpc85xx/include/mach/clock.h |  1 +
 arch/powerpc/mach-mpc85xx/speed.c              | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/arch/powerpc/mach-mpc85xx/include/mach/clock.h b/arch/powerpc/mach-mpc85xx/include/mach/clock.h
index bfd9cf4d8ecd..2d0f079f5c68 100644
--- a/arch/powerpc/mach-mpc85xx/include/mach/clock.h
+++ b/arch/powerpc/mach-mpc85xx/include/mach/clock.h
@@ -14,6 +14,7 @@ struct sys_info {
 
 unsigned long fsl_get_bus_freq(ulong dummy);
 unsigned long fsl_get_ddr_freq(ulong dummy);
+void fsl_set_timebase_clock(unsigned long freq);
 unsigned long fsl_get_timebase_clock(void);
 unsigned long fsl_get_i2c_freq(void);
 void fsl_get_sys_info(struct sys_info *sysInfo);
diff --git a/arch/powerpc/mach-mpc85xx/speed.c b/arch/powerpc/mach-mpc85xx/speed.c
index 4a69de3dc81a..8018132874ba 100644
--- a/arch/powerpc/mach-mpc85xx/speed.c
+++ b/arch/powerpc/mach-mpc85xx/speed.c
@@ -104,10 +104,20 @@ unsigned long fsl_get_ddr_freq(ulong dummy)
 	return sys_info.freqDDRBus;
 }
 
+static unsigned long timebase_clock_override;
+
+void fsl_set_timebase_clock(unsigned long freq)
+{
+	timebase_clock_override = freq;
+}
+
 unsigned long fsl_get_timebase_clock(void)
 {
 	struct sys_info sysinfo;
 
+	if (timebase_clock_override)
+		return timebase_clock_override;
+
 	fsl_get_sys_info(&sysinfo);
 
 	return (sysinfo.freqSystemBus + 4UL)/8UL;
-- 
2.47.3