[PATCH v3] clk: keystone: sci-clk: Adding support for non contiguous clocks

[Udit Kumar]

Most of clocks and their parents are defined in contiguous range,
But in few cases, there is gap in clock numbers[0].
Driver assumes clocks to be in contiguous range, and add their clock
ids incrementally.

New firmware started returning error while calling get_freq and is_on
API for non-available clock ids.

In this fix, driver checks and adds only valid clock ids.

Fixes: 3c13933c6033 ("clk: keystone: sci-clk: add support for dynamically probing clocks")

[0] https://software-dl.ti.com/tisci/esd/latest/5_soc_doc/j7200/clocks.html
Section Clocks for NAVSS0_CPTS_0 Device,
clock id 12-15 not present.

Signed-off-by: Udit Kumar <u-kumar1 at ti.com>
---
Changelog
Changes in v3
- instead of get_freq, is_auto API is used to check validilty of clock
- Address comments of v2, to have preindex increment
Link to v2 https://lore.kernel.org/all/20240206104357.3803517-1-u-kumar1@ti.com/

Changes in v2
- Updated commit message
- Simplified logic for valid clock id
link to v1 https://lore.kernel.org/all/20240205044557.3340848-1-u-kumar1@ti.com/


P.S
Firmawre returns total num_parents count including non available ids.
For above device id NAVSS0_CPTS_0, number of parents clocks are 16
i.e from id 2 to 17. But out of these ids few are not valid.
So driver adds only valid clock ids out ot total.

Original logs
https://gist.github.com/uditkumarti/de4b36b21247fb36725ad909ce4812f6#file-original-logs
Line 2630 for error

Logs with fix v3
https://gist.github.com/uditkumarti/94e3e28d62282fd708dbfe37435ce1d9#file-v3
Line 2586


 drivers/clk/keystone/sci-clk.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
index 35fe197dd303..31b7df05d7bb 100644
--- a/drivers/clk/keystone/sci-clk.c
+++ b/drivers/clk/keystone/sci-clk.c
@@ -516,6 +516,7 @@ static int ti_sci_scan_clocks_from_dt(struct sci_clk_provider *provider)
 	struct sci_clk *sci_clk, *prev;
 	int num_clks = 0;
 	int num_parents;
+	bool state;
 	int clk_id;
 	const char * const clk_names[] = {
 		"clocks", "assigned-clocks", "assigned-clock-parents", NULL
@@ -583,16 +584,23 @@ static int ti_sci_scan_clocks_from_dt(struct sci_clk_provider *provider)
 					num_parents = 255;
 				}
 
-				clk_id = args.args[1] + 1;
+				clk_id = args.args[1];
 
 				while (num_parents--) {
+					/* Check if this clock id is valid */
+					ret = provider->ops->is_auto(provider->sci,
+						sci_clk->dev_id, ++clk_id, &state);
+
+					if (ret)
+						continue;
+
 					sci_clk = devm_kzalloc(dev,
 							       sizeof(*sci_clk),
 							       GFP_KERNEL);
 					if (!sci_clk)
 						return -ENOMEM;
 					sci_clk->dev_id = args.args[0];
-					sci_clk->clk_id = clk_id++;
+					sci_clk->clk_id = clk_id;
 					sci_clk->provider = provider;
 					list_add_tail(&sci_clk->node, &clks);
 
-- 
2.34.1