[PATCH] riscv: Try to get cpu frequency from device tree
Instead of always using the "clock-frequency" property to determine cpu frequency, try using a clock in "clocks" if it exists.
Signed-off-by Sean Anderson seanga2@gmail.com --- This patch depends on https://patchwork.ozlabs.org/patch/1223933/.
drivers/cpu/riscv_cpu.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/cpu/riscv_cpu.c b/drivers/cpu/riscv_cpu.c index 1e32bb5678..280c9de376 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> @@ -27,11 +28,24 @@ 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 err; + struct clk clk; const char *mmu;
/* Zero out the frequency, in case sizeof(ulong) != sizeof(u32) */ info->cpu_freq = 0; - dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq); + + /* First try getting the frequency from the assigned clock */ + err = clk_get_by_index(dev, 0, &clk); + if (!err) { + err = clk_get_rate(&clk); + if (!IS_ERR_VALUE(err)) + info->cpu_freq = err; + 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)
Hi Sean,
On Fri, 2020-01-17 at 14:51 -0500, Sean Anderson wrote:
Instead of always using the "clock-frequency" property to determine cpu frequency, try using a clock in "clocks" if it exists.
Signed-off-by Sean Anderson seanga2@gmail.com
This patch depends on https://patchwork.ozlabs.org/patch/1223933/;.
drivers/cpu/riscv_cpu.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/cpu/riscv_cpu.c b/drivers/cpu/riscv_cpu.c index 1e32bb5678..280c9de376 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> @@ -27,11 +28,24 @@ 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 err;
struct clk clk; const char *mmu;
/* Zero out the frequency, in case sizeof(ulong) != sizeof(u32) */ info->cpu_freq = 0;
- dev_read_u32(dev, "clock-frequency", (u32 *)&info->cpu_freq);
- /* First try getting the frequency from the assigned clock */
- err = clk_get_by_index(dev, 0, &clk);
Usually, ret is used as a variable name here. I think it would actually make the code a bit nicer to read here, because the clock rate is not read from variable err.
But that's just nit-picking. The patch looks good otherwise!
Reviewed-by: Lukas Auer lukas@auer.io
if (!err) {
err = clk_get_rate(&clk);if (!IS_ERR_VALUE(err))info->cpu_freq = err;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)
On 1/26/20 11:34 AM, Lukas Auer wrote:
Hi Sean, Usually, ret is used as a variable name here. I think it would actually make the code a bit nicer to read here, because the clock rate is not read from variable err.
Hm, I chose err instead of ret since that variable is never the return value of the function. I can change that for v2 if you'd like.
But that's just nit-picking. The patch looks good otherwise!
Reviewed-by: Lukas Auer lukas@auer.io
On Sun, 2020-01-26 at 13:20 -0500, Sean Anderson wrote:
On 1/26/20 11:34 AM, Lukas Auer wrote:
Hi Sean, Usually, ret is used as a variable name here. I think it would actually make the code a bit nicer to read here, because the clock rate is not read from variable err.
Hm, I chose err instead of ret since that variable is never the return value of the function. I can change that for v2 if you'd like.
Makes sense. I think it's fine to keep it as is.
But that's just nit-picking. The patch looks good otherwise!
Reviewed-by: Lukas Auer lukas@auer.io
participants (2)
-
Lukas Auer -
Sean Anderson