[PATCH v6 4/4] firmware: ti_sci: add support for restoring clock context during resume

Thomas Richard (TI)
2026-04-27T12:22:26Z

Some DM-Firmware are not able to restore the clock rates and the clock
parents after a suspend-resume. The CLK_CONTEXT_LOST firmware capability
has been introduced to identify this characteristic. In this case the
responsibility is therefore delegated to the ti_sci driver, which uses
clk_restore_context() to trigger the context_restore() operation for all
registered clocks, including those managed by the sci-clk. The sci-clk
driver implements the context_restore() operation to ensure rates and clock
parents are correctly restored.

Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Kendall Willis <k-willis@ti.com>
Signed-off-by: Thomas Richard (TI) <thomas.richard@bootlin.com>
---
drivers/firmware/ti_sci.c | 9 +++++++--
drivers/firmware/ti_sci.h | 2 ++
2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index b5c4324287b0..0148bafd71a0 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -9,6 +9,7 @@
#define pr_fmt(fmt) "%s: " fmt, __func__

#include <linux/bitmap.h>
+#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/debugfs.h>
#include <linux/export.h>
@@ -3981,6 +3982,9 @@ static int ti_sci_resume_noirq(struct device *dev)
return ret;
}
}
+
+ if (info->fw_caps & MSG_FLAG_CAPS_LPM_CLK_CONTEXT_LOST)
+ clk_restore_context();
break;
default:
break;
@@ -4141,14 +4145,15 @@ static int ti_sci_probe(struct platform_device *pdev)
}

ti_sci_msg_cmd_query_fw_caps(&info->handle, &info->fw_caps);
- dev_dbg(dev, "Detected firmware capabilities: %s%s%s%s%s%s%s\n",
+ dev_dbg(dev, "Detected firmware capabilities: %s%s%s%s%s%s%s%s\n",
info->fw_caps & MSG_FLAG_CAPS_GENERIC ? "Generic" : "",
info->fw_caps & MSG_FLAG_CAPS_LPM_PARTIAL_IO ? " Partial-IO" : "",
info->fw_caps & MSG_FLAG_CAPS_LPM_DM_MANAGED ? " DM-Managed" : "",
info->fw_caps & MSG_FLAG_CAPS_LPM_ABORT ? " LPM-Abort" : "",
info->fw_caps & MSG_FLAG_CAPS_IO_ISOLATION ? " IO-Isolation" : "",
info->fw_caps & MSG_FLAG_CAPS_LPM_BOARDCFG_MANAGED ? " BoardConfig-Managed" : "",
- info->fw_caps & MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST ? " IRQ-Context-Lost" : ""
+ info->fw_caps & MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST ? " IRQ-Context-Lost" : "",
+ info->fw_caps & MSG_FLAG_CAPS_LPM_CLK_CONTEXT_LOST ? " Clk-Context-Lost" : ""
);

ti_sci_setup_ops(info);
diff --git a/drivers/firmware/ti_sci.h b/drivers/firmware/ti_sci.h
index 67f16e8c69a1..2d75667a6723 100644
--- a/drivers/firmware/ti_sci.h
+++ b/drivers/firmware/ti_sci.h
@@ -152,6 +152,7 @@ struct ti_sci_msg_req_reboot {
* MSG_FLAG_CAPS_IO_ISOLATION: IO Isolation support
* MSG_FLAG_CAPS_LPM_BOARDCFG_MANAGED: LPM config done statically for the DM via boardcfg
* MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST: DM is not able to restore IRQ context
+ * MSG_FLAG_CAPS_LPM_CLK_CONTEXT_LOST: DM is not able to restore Clock context
*
* Response to a generic message with message type TI_SCI_MSG_QUERY_FW_CAPS
* providing currently available SOC/firmware capabilities. SoC that don't
@@ -166,6 +167,7 @@ struct ti_sci_msg_resp_query_fw_caps {
#define MSG_FLAG_CAPS_IO_ISOLATION TI_SCI_MSG_FLAG(7)
#define MSG_FLAG_CAPS_LPM_BOARDCFG_MANAGED TI_SCI_MSG_FLAG(12)
#define MSG_FLAG_CAPS_LPM_IRQ_CONTEXT_LOST TI_SCI_MSG_FLAG(14)
+#define MSG_FLAG_CAPS_LPM_CLK_CONTEXT_LOST TI_SCI_MSG_FLAG(15)
#define MSG_MASK_CAPS_LPM GENMASK_ULL(4, 1)
u64 fw_caps;
} __packed;

--
2.53.0