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>
diff --git a/drivers/cpu/riscv_cpu.c b/drivers/cpu/riscv_cpu.c
index cb04f56..2d44d1c 100644
--- a/drivers/cpu/riscv_cpu.c
+++ b/drivers/cpu/riscv_cpu.c
@@ -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_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)