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riscv: Try to get cpu frequency from a "clocks" node if it exists 

Instead of always using the "clock-frequency" property to determine cpu
frequency, try using a clock in "clocks" if it exists. This patch also
fixes a bug where there could be spurious higher frequencies if sizeof(u32)
!= sizeof(ulong).

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Sean Anderson 2020-06-24 06:41:21 -04:00 committed by Andes
parent 958a3f464c
commit ab24017a19
1 changed files with 18 additions and 1 deletions
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19
drivers/cpu/riscv_cpu.c
View File

@ -3,6 +3,7 @@
* Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
*/
#include <clk.h>
#include <common.h>
#include <cpu.h>
#include <dm.h>
@ -11,6 +12,7 @@
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <linux/bitops.h>
#include <linux/err.h>
DECLARE_GLOBAL_DATA_PTR;
@ -29,9 +31,24 @@ static int riscv_cpu_get_desc(struct udevice *dev, char *buf, int size)
static int riscv_cpu_get_info(struct udevice *dev, struct cpu_info *info)
{
int ret;
struct clk clk;
const char *mmu;
dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq);
/* Zero out the frequency, in case sizeof(ulong) != sizeof(u32) */
info->cpu_freq = 0;
/* First try getting the frequency from the assigned clock */
ret = clk_get_by_index(dev, 0, &clk);
if (!ret) {
ret = clk_get_rate(&clk);
if (!IS_ERR_VALUE(ret))
info->cpu_freq = ret;
clk_free(&clk);
}
if (!info->cpu_freq)
dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq);
mmu = dev_read_string(dev, "mmu-type");
if (!mmu)