diff options
Diffstat (limited to 'roms/u-boot/arch/powerpc/cpu/mpc8xx/speed.c')
-rw-r--r-- | roms/u-boot/arch/powerpc/cpu/mpc8xx/speed.c | 44 |
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; +} |