[PATCH 08/26] clk: add support for setting clk rate from cmdline

[Tero Kristo]

On 15/11/2020 12:29, Lokesh Vutla wrote:
> +Lucasz

This is just a nice to have patch. Found it quite useful while debugging 
the new drivers so decided to share.

-Tero

> 
> On 10/11/20 2:35 pm, Tero Kristo wrote:
>> Add new clk subcommand "clk setfreq", for setting up a clock rate
>> directly from u-boot cmdline. This is handy for any debugging purposes
>> towards clocks.
>>
>> Signed-off-by: Tero Kristo <t-kristo at ti.com>
>> ---
>>   cmd/clk.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
>>   1 file changed, 47 insertions(+), 2 deletions(-)
>>
>> diff --git a/cmd/clk.c b/cmd/clk.c
>> index 0245b97136..fd7944c02e 100644
>> --- a/cmd/clk.c
>> +++ b/cmd/clk.c
>> @@ -98,8 +98,52 @@ static int do_clk_dump(struct cmd_tbl *cmdtp, int flag, int argc,
>>   	return ret;
>>   }
>>   
>> +struct udevice *clk_lookup(const char *name)
>> +{
>> +	int i = 0;
>> +	struct udevice *dev;
>> +
>> +	do {
>> +		uclass_get_device(UCLASS_CLK, i++, &dev);
>> +		if (!strcmp(name, dev->name))
>> +			return dev;
>> +	} while (dev);
>> +
>> +	return NULL;
>> +}
>> +
>> +static int do_clk_setfreq(struct cmd_tbl *cmdtp, int flag, int argc,
>> +			  char *const argv[])
>> +{
>> +	struct clk *clk = NULL;
>> +	s32 freq;
>> +	struct udevice *dev;
>> +
>> +	freq = simple_strtoul(argv[2], NULL, 10);
>> +
>> +	dev = clk_lookup(argv[1]);
>> +
>> +	if (dev)
>> +		clk = dev_get_clk_ptr(dev);
>> +
>> +	if (!clk) {
>> +		printf("clock '%s' not found.\n", argv[1]);
>> +		return -EINVAL;
>> +	}
>> +
>> +	freq = clk_set_rate(clk, freq);
>> +	if (freq < 0) {
>> +		printf("set_rate failed: %d\n", freq);
>> +		return CMD_RET_FAILURE;
>> +	}
>> +
>> +	printf("set_rate returns %u\n", freq);
>> +	return 0;
>> +}
>> +
>>   static struct cmd_tbl cmd_clk_sub[] = {
>>   	U_BOOT_CMD_MKENT(dump, 1, 1, do_clk_dump, "", ""),
>> +	U_BOOT_CMD_MKENT(setfreq, 3, 1, do_clk_setfreq, "", ""),
>>   };
>>   
>>   static int do_clk(struct cmd_tbl *cmdtp, int flag, int argc,
>> @@ -124,7 +168,8 @@ static int do_clk(struct cmd_tbl *cmdtp, int flag, int argc,
>>   
>>   #ifdef CONFIG_SYS_LONGHELP
>>   static char clk_help_text[] =
>> -	"dump - Print clock frequencies";
>> +	"dump - Print clock frequencies\n"
>> +	"setfreq [clk] [freq] - Set clock frequency";
>>   #endif
>>   
>> -U_BOOT_CMD(clk, 2, 1, do_clk, "CLK sub-system", clk_help_text);
>> +U_BOOT_CMD(clk, 4, 1, do_clk, "CLK sub-system", clk_help_text);
>>

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