[PATCHv6 08/26] clk: add support for setting clk rate from cmdline

Tero Kristo
2021-06-11T08:47:26Z

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.

Acked-by: Lukasz Majewski <lukma@denx.de>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tero Kristo <kristo@kernel.org>
---
cmd/clk.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 51 insertions(+), 2 deletions(-)

diff --git a/cmd/clk.c b/cmd/clk.c
index 0245b97136..7ece2454e0 100644
--- a/cmd/clk.c
+++ b/cmd/clk.c
@@ -98,8 +98,56 @@ static int do_clk_dump(struct cmd_tbl *cmdtp, int flag, int argc,
return ret;
}

+#if CONFIG_IS_ENABLED(DM) && CONFIG_IS_ENABLED(CLK)
+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;
+}
+#endif
+
static struct cmd_tbl cmd_clk_sub[] = {
U_BOOT_CMD_MKENT(dump, 1, 1, do_clk_dump, "", ""),
+#if CONFIG_IS_ENABLED(DM) && CONFIG_IS_ENABLED(CLK)
+ U_BOOT_CMD_MKENT(setfreq, 3, 1, do_clk_setfreq, "", ""),
+#endif
};

static int do_clk(struct cmd_tbl *cmdtp, int flag, int argc,
@@ -124,7 +172,8 @@ 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);
--
2.17.1