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Diffstat (limited to 'roms/u-boot/arch/powerpc/cpu/mpc8xx/speed.c')
-rw-r--r--roms/u-boot/arch/powerpc/cpu/mpc8xx/speed.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/roms/u-boot/arch/powerpc/cpu/mpc8xx/speed.c b/roms/u-boot/arch/powerpc/cpu/mpc8xx/speed.c
new file mode 100644
index 000000000..ad3d3f910
--- /dev/null
+++ b/roms/u-boot/arch/powerpc/cpu/mpc8xx/speed.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2000-2004
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ */
+
+#include <common.h>
+#include <clock_legacy.h>
+#include <mpc8xx.h>
+#include <asm/global_data.h>
+#include <asm/processor.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * get_clocks() fills in gd->cpu_clock depending on CONFIG_8xx_GCLK_FREQ
+ */
+int get_clocks(void)
+{
+ immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR;
+ uint sccr = in_be32(&immap->im_clkrst.car_sccr);
+ uint divider = 1 << (((sccr & SCCR_DFBRG11) >> 11) * 2);
+
+ /*
+ * If for some reason measuring the gclk frequency won't
+ * work, we return the hardwired value.
+ * (For example, the cogent CMA286-60 CPU module has no
+ * separate oscillator for PITRTCLK)
+ */
+ gd->cpu_clk = CONFIG_8xx_GCLK_FREQ;
+
+ if ((sccr & SCCR_EBDF11) == 0) {
+ /* No Bus Divider active */
+ gd->bus_clk = gd->cpu_clk;
+ } else {
+ /* The MPC8xx has only one BDF: half clock speed */
+ gd->bus_clk = gd->cpu_clk / 2;
+ }
+
+ gd->arch.brg_clk = gd->cpu_clk / divider;
+
+ return 0;
+}