[PATCH V4 2/2] clk: scmi: support state_ctrl_forbidden

Peng Fan (OSS)
2024-01-21T11:04:52Z

From: Peng Fan <peng.fan@nxp.com>

Some clocks may exported to linux, while those clocks are not allowed
to configure by Linux. For example:

SYS_CLK1-----
\
--MUX--->MMC1_CLK
/
SYS_CLK2-----

MMC1 needs set parent, so SYS_CLK1 and SYS_CLK2 are exported to Linux,
then the clk propagation will touch SYS_CLK1 or SYS_CLK2.
So we need bypass the failure for SYS_CLK1 or SYS_CLK2 when enable
the clock of MMC1, adding scmi_no_state_ctrl_clk_ops to use software
enable counter, while not calling scmi api.

Co-developed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
---

V4:
Add scmi_no_state_ctrl_clk_ops per Cristian
Add Cristian's tag

V3:
Add check in atomic enable

V2:
New. Take Cristian's suggestion

drivers/clk/clk-scmi.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
index 8cbe24789c24..5747b6d651f0 100644
--- a/drivers/clk/clk-scmi.c
+++ b/drivers/clk/clk-scmi.c
@@ -194,6 +194,15 @@ static const struct clk_ops scmi_atomic_clk_ops = {
.determine_rate = scmi_clk_determine_rate,
};

+static const struct clk_ops scmi_no_state_ctrl_clk_ops = {
+ .recalc_rate = scmi_clk_recalc_rate,
+ .round_rate = scmi_clk_round_rate,
+ .set_rate = scmi_clk_set_rate,
+ .set_parent = scmi_clk_set_parent,
+ .get_parent = scmi_clk_get_parent,
+ .determine_rate = scmi_clk_determine_rate,
+};
+
static int scmi_clk_ops_init(struct device *dev, struct scmi_clk *sclk,
const struct clk_ops *scmi_ops)
{
@@ -290,8 +299,10 @@ static int scmi_clocks_probe(struct scmi_device *sdev)
* specify (or support) an enable_latency associated with a
* clock, we default to use atomic operations mode.
*/
- if (is_atomic &&
- sclk->info->enable_latency <= atomic_threshold)
+ if (sclk->info->state_ctrl_forbidden)
+ scmi_ops = &scmi_no_state_ctrl_clk_ops;
+ else if (is_atomic &&
+ sclk->info->enable_latency <= atomic_threshold)
scmi_ops = &scmi_atomic_clk_ops;
else
scmi_ops = &scmi_clk_ops;
--
2.37.1