[PATCH V2 0/3] ufs: ufs-qcom: Add support firmware managed platforms

[PATCH V2 0/3] ufs: ufs-qcom: Add support firmware managed platforms

[Ram Kumar Dwivedi]

On Qualcomm automotive SoC SA8255P, platform resource like clocks,
interconnect, resets, regulators and PHY are configured remotely by
firmware.

Logical power domain is used to abstract these resources in firmware
and SCMI power protocol is used to request resource operations by using
runtime PM framework APIs such as pm_runtime_get/put_sync to invoke
power_on/_off calls from kernel respectively.

Changes from V1
1. Updated "dma-coherent" property type from boolean to just true.
2. Switched from QUIC mail ID to OSS mail ID.
3. Added Acknowledged by tag from Dmitry for patch 1/3 
4. Added Reviewed-by tag from Manivannan for patch 1/3

Ram Kumar Dwivedi (3):
  MAINTAINERS: broaden UFS Qualcomm binding file pattern
  dt-bindings: ufs: Document bindings for SA8255P UFS Host Controller
  ufs: ufs-qcom: Add support for firmware-managed resource abstraction

 .../bindings/ufs/qcom,sa8255p-ufshc.yaml      |  62 +++++++
 MAINTAINERS                                   |   2 +-
 drivers/ufs/host/ufs-qcom.c                   | 161 +++++++++++++++++-
 drivers/ufs/host/ufs-qcom.h                   |   1 +
 4 files changed, 224 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/ufs/qcom,sa8255p-ufshc.yaml

-- 
2.34.1

[PATCH V2 1/3] MAINTAINERS: broaden UFS Qualcomm binding file pattern

[Ram Kumar Dwivedi]

Update the file pattern for UFS Qualcomm devicetree bindings to match
all files under `Documentation/devicetree/bindings/ufs/qcom*` instead
of only `qcom,ufs.yaml`. This ensures maintainers are correctly
notified for any related binding changes.

Acked-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Ram Kumar Dwivedi <ram.dwivedi@oss.qualcomm.com>
---
 MAINTAINERS | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index c5a7cda26c60..f4d01ad6462c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -26812,7 +26812,7 @@ M:	Manivannan Sadhasivam <mani@kernel.org>
 L:	linux-arm-msm@vger.kernel.org
 L:	linux-scsi@vger.kernel.org
 S:	Maintained
-F:	Documentation/devicetree/bindings/ufs/qcom,ufs.yaml
+F:	Documentation/devicetree/bindings/ufs/qcom*
 F:	drivers/ufs/host/ufs-qcom*
 
 UNIVERSAL FLASH STORAGE HOST CONTROLLER DRIVER RENESAS HOOKS
-- 
2.34.1

[PATCH V2 2/3] dt-bindings: ufs: Document bindings for SA8255P UFS Host Controller

[Ram Kumar Dwivedi]

Document the device tree bindings for UFS host controller on
Qualcomm SA8255P platform which integrates firmware-managed
resources.

The platform firmware implements the SCMI server and manages
resources such as the PHY, clocks, regulators and resets via the
SCMI power protocol. As a result, the OS-visible DT only describes
the controller’s MMIO, interrupt, IOMMU and power-domain interfaces.

The generic "qcom,ufshc" and "jedec,ufs-2.0" compatible strings are
removed from the binding, since this firmware managed design won't
be compatible with the drivers doing full resource management.

Co-developed-by: Anjana Hari <anjana.hari@oss.qualcomm.com>
Signed-off-by: Anjana Hari <anjana.hari@oss.qualcomm.com>
Signed-off-by: Ram Kumar Dwivedi <ram.dwivedi@oss.qualcomm.com>
---
 .../bindings/ufs/qcom,sa8255p-ufshc.yaml      | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/ufs/qcom,sa8255p-ufshc.yaml

diff --git a/Documentation/devicetree/bindings/ufs/qcom,sa8255p-ufshc.yaml b/Documentation/devicetree/bindings/ufs/qcom,sa8255p-ufshc.yaml
new file mode 100644
index 000000000000..ec006f7de752
--- /dev/null
+++ b/Documentation/devicetree/bindings/ufs/qcom,sa8255p-ufshc.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ufs/qcom,sa8255p-ufshc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm SA8255P UFS Host Controller
+
+maintainers:
+  - Ram Kumar Dwivedi <ram.dwivedi@oss.qualcomm.com>
+  - Anjana Hari <anjana.hari@oss.qualcomm.com>
+
+properties:
+  compatible:
+    const: qcom,sa8255p-ufshc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  iommus:
+    maxItems: 1
+
+  dma-coherent: true
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - power-domains
+  - iommus
+  - dma-coherent
+
+allOf:
+  - $ref: ufs-common.yaml
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        ufshc@1d84000 {
+            compatible = "qcom,sa8255p-ufshc";
+            reg = <0x0 0x01d84000 0x0 0x3000>;
+            interrupts = <GIC_SPI 265 IRQ_TYPE_LEVEL_HIGH>;
+            lanes-per-direction = <2>;
+
+            iommus = <&apps_smmu 0x100 0x0>;
+            power-domains = <&scmi3_pd 0>;
+            dma-coherent;
+        };
+    };
-- 
2.34.1

[PATCH V2 3/3] ufs: ufs-qcom: Add support for firmware-managed resource abstraction

[Ram Kumar Dwivedi]

Add a compatible string for SA8255p platforms where resources such as
PHY, clocks, regulators, and resets are managed by firmware through an
SCMI server. Use the SCMI power protocol to abstract these resources and
invoke power operations via runtime PM APIs (pm_runtime_get/put_sync).

Introduce vendor operations (vops) for SA8255p targets to enable SCMI-
based resource control. In this model, capabilities like clock scaling
and gating are not yet supported; these will be added incrementally.

Co-developed-by: Anjana Hari <anjana.hari@oss.qualcomm.com>
Signed-off-by: Anjana Hari <anjana.hari@oss.qualcomm.com>
Co-developed-by: Shazad Hussain <shazad.hussain@oss.qualcomm.com>
Signed-off-by: Shazad Hussain <shazad.hussain@oss.qualcomm.com>
Signed-off-by: Ram Kumar Dwivedi <ram.dwivedi@oss.qualcomm.com>
---
 drivers/ufs/host/ufs-qcom.c | 161 +++++++++++++++++++++++++++++++++++-
 drivers/ufs/host/ufs-qcom.h |   1 +
 2 files changed, 161 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 8d119b3223cb..13ccf1fb2ebf 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -14,6 +14,7 @@
 #include <linux/of.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm_domain.h>
 #include <linux/reset-controller.h>
 #include <linux/time.h>
 #include <linux/unaligned.h>
@@ -619,6 +620,27 @@ static int ufs_qcom_hce_enable_notify(struct ufs_hba *hba,
 	return err;
 }
 
+static int ufs_qcom_fw_managed_hce_enable_notify(struct ufs_hba *hba,
+						 enum ufs_notify_change_status status)
+{
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+
+	switch (status) {
+	case PRE_CHANGE:
+		ufs_qcom_select_unipro_mode(host);
+		break;
+	case POST_CHANGE:
+		ufs_qcom_enable_hw_clk_gating(hba);
+		ufs_qcom_ice_enable(host);
+		break;
+	default:
+		dev_err(hba->dev, "Invalid status %d\n", status);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /**
  * ufs_qcom_cfg_timers - Configure ufs qcom cfg timers
  *
@@ -789,6 +811,38 @@ static int ufs_qcom_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	return ufs_qcom_ice_resume(host);
 }
 
+static int ufs_qcom_fw_managed_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op,
+				       enum ufs_notify_change_status status)
+{
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+
+	if (status == PRE_CHANGE)
+		return 0;
+
+	if (hba->spm_lvl != UFS_PM_LVL_5) {
+		dev_err(hba->dev, "Unsupported spm level %d\n", hba->spm_lvl);
+		return -EINVAL;
+	}
+
+	pm_runtime_put_sync(hba->dev);
+
+	return ufs_qcom_ice_suspend(host);
+}
+
+static int ufs_qcom_fw_managed_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+{
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+	int err;
+
+	err = pm_runtime_resume_and_get(hba->dev);
+	if (err) {
+		dev_err(hba->dev, "PM runtime resume failed: %d\n", err);
+		return err;
+	}
+
+	return ufs_qcom_ice_resume(host);
+}
+
 static void ufs_qcom_dev_ref_clk_ctrl(struct ufs_qcom_host *host, bool enable)
 {
 	if (host->dev_ref_clk_ctrl_mmio &&
@@ -1421,6 +1475,52 @@ static void ufs_qcom_exit(struct ufs_hba *hba)
 	phy_exit(host->generic_phy);
 }
 
+static int ufs_qcom_fw_managed_init(struct ufs_hba *hba)
+{
+	struct device *dev = hba->dev;
+	struct ufs_qcom_host *host;
+	int err;
+
+	host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
+	if (!host)
+		return -ENOMEM;
+
+	host->hba = hba;
+	ufshcd_set_variant(hba, host);
+
+	ufs_qcom_get_controller_revision(hba, &host->hw_ver.major,
+					 &host->hw_ver.minor, &host->hw_ver.step);
+
+	err = ufs_qcom_ice_init(host);
+	if (err)
+		goto out_variant_clear;
+
+	ufs_qcom_get_default_testbus_cfg(host);
+	err = ufs_qcom_testbus_config(host);
+	if (err)
+		/* Failure is non-fatal */
+		dev_warn(dev, "Failed to configure the testbus %d\n", err);
+
+	hba->caps |= UFSHCD_CAP_WB_EN;
+
+	ufs_qcom_advertise_quirks(hba);
+	host->hba->quirks &= ~UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH;
+
+	ufs_qcom_set_host_params(hba);
+	ufs_qcom_parse_gear_limits(hba);
+
+	return 0;
+
+out_variant_clear:
+	ufshcd_set_variant(hba, NULL);
+	return err;
+}
+
+static void ufs_qcom_fw_managed_exit(struct ufs_hba *hba)
+{
+	pm_runtime_put_sync(hba->dev);
+}
+
 /**
  * ufs_qcom_set_clk_40ns_cycles - Configure 40ns clk cycles
  *
@@ -1952,6 +2052,39 @@ static int ufs_qcom_device_reset(struct ufs_hba *hba)
 	return 0;
 }
 
+/**
+ * ufs_qcom_fw_managed_device_reset - Reset UFS device under FW-managed design
+ * @hba: pointer to UFS host bus adapter
+ *
+ * In the firmware-managed reset model, cold boot power-on is handled
+ * automatically by the PM domain framework during SCMI protocol init,
+ * before ufshcd_device_reset() is reached. For subsequent resets
+ * (such as suspend/resume or recovery), the UFS driver must explicitly
+ * invoke PM runtime operations to reset the subsystem.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+static int ufs_qcom_fw_managed_device_reset(struct ufs_hba *hba)
+{
+	static bool is_boot = true;
+	int err;
+
+	/* Skip reset on cold boot; perform it on subsequent calls */
+	if (is_boot) {
+		is_boot = false;
+		return 0;
+	}
+
+	pm_runtime_put_sync(hba->dev);
+	err = pm_runtime_resume_and_get(hba->dev);
+	if (err < 0) {
+		dev_err(hba->dev, "PM runtime resume failed: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
 static void ufs_qcom_config_scaling_param(struct ufs_hba *hba,
 					struct devfreq_dev_profile *p,
 					struct devfreq_simple_ondemand_data *d)
@@ -2231,6 +2364,20 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
 	.freq_to_gear_speed	= ufs_qcom_freq_to_gear_speed,
 };
 
+static const struct ufs_hba_variant_ops ufs_hba_qcom_sa8255p_vops = {
+	.name                   = "qcom-sa8255p",
+	.init                   = ufs_qcom_fw_managed_init,
+	.exit                   = ufs_qcom_fw_managed_exit,
+	.hce_enable_notify      = ufs_qcom_fw_managed_hce_enable_notify,
+	.pwr_change_notify      = ufs_qcom_pwr_change_notify,
+	.apply_dev_quirks       = ufs_qcom_apply_dev_quirks,
+	.fixup_dev_quirks       = ufs_qcom_fixup_dev_quirks,
+	.suspend                = ufs_qcom_fw_managed_suspend,
+	.resume                 = ufs_qcom_fw_managed_resume,
+	.dbg_register_dump      = ufs_qcom_dump_dbg_regs,
+	.device_reset           = ufs_qcom_fw_managed_device_reset,
+};
+
 /**
  * ufs_qcom_probe - probe routine of the driver
  * @pdev: pointer to Platform device handle
@@ -2241,9 +2388,16 @@ static int ufs_qcom_probe(struct platform_device *pdev)
 {
 	int err;
 	struct device *dev = &pdev->dev;
+	const struct ufs_hba_variant_ops *vops;
+	const struct ufs_qcom_drvdata *drvdata = device_get_match_data(dev);
+
+	if (drvdata && drvdata->vops)
+		vops = drvdata->vops;
+	else
+		vops = &ufs_hba_qcom_vops;
 
 	/* Perform generic probe */
-	err = ufshcd_pltfrm_init(pdev, &ufs_hba_qcom_vops);
+	err = ufshcd_pltfrm_init(pdev, vops);
 	if (err)
 		return dev_err_probe(dev, err, "ufshcd_pltfrm_init() failed\n");
 
@@ -2271,10 +2425,15 @@ static const struct ufs_qcom_drvdata ufs_qcom_sm8550_drvdata = {
 	.no_phy_retention = true,
 };
 
+static const struct ufs_qcom_drvdata ufs_qcom_sa8255p_drvdata = {
+	.vops = &ufs_hba_qcom_sa8255p_vops
+};
+
 static const struct of_device_id ufs_qcom_of_match[] __maybe_unused = {
 	{ .compatible = "qcom,ufshc" },
 	{ .compatible = "qcom,sm8550-ufshc", .data = &ufs_qcom_sm8550_drvdata },
 	{ .compatible = "qcom,sm8650-ufshc", .data = &ufs_qcom_sm8550_drvdata },
+	{ .compatible = "qcom,sa8255p-ufshc", .data = &ufs_qcom_sa8255p_drvdata },
 	{},
 };
 MODULE_DEVICE_TABLE(of, ufs_qcom_of_match);
diff --git a/drivers/ufs/host/ufs-qcom.h b/drivers/ufs/host/ufs-qcom.h
index 380d02333d38..1111ab34da01 100644
--- a/drivers/ufs/host/ufs-qcom.h
+++ b/drivers/ufs/host/ufs-qcom.h
@@ -313,6 +313,7 @@ struct ufs_qcom_host {
 struct ufs_qcom_drvdata {
 	enum ufshcd_quirks quirks;
 	bool no_phy_retention;
+	const struct ufs_hba_variant_ops *vops;
 };
 
 static inline u32
-- 
2.34.1

Re: [PATCH V2 2/3] dt-bindings: ufs: Document bindings for SA8255P UFS Host Controller

[Krzysztof Kozlowski]

On 10/12/2025 16:50, Ram Kumar Dwivedi wrote:
> +
> +allOf:
> +  - $ref: ufs-common.yaml
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> +    soc {
> +        #address-cells = <2>;
> +        #size-cells = <2>;

Not much improved... Same comments. And if you repeat "we plan" or
"something else is something else" than answer will be the same - that
something else does not matter and we do not care about plans.

By useless disagreements you just postpone the acceptance of this
patchset. Especially about such nits... patch could have been reviewed
already :/

> +
> +        ufshc@1d84000 {
> +            compatible = "qcom,sa8255p-ufshc";
> +            reg = <0x0 0x01d84000 0x0 0x3000>;


Best regards,
Krzysztof

Re: [PATCH V2 2/3] dt-bindings: ufs: Document bindings for SA8255P UFS Host Controller

[Ram Kumar Dwivedi]

On 11-Dec-25 12:04 PM, Krzysztof Kozlowski wrote:
> On 10/12/2025 16:50, Ram Kumar Dwivedi wrote:
>> +
>> +allOf:
>> +  - $ref: ufs-common.yaml
>> +
>> +unevaluatedProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +
>> +    soc {
>> +        #address-cells = <2>;
>> +        #size-cells = <2>;
> 
> Not much improved... Same comments. And if you repeat "we plan" or
> "something else is something else" than answer will be the same - that
> something else does not matter and we do not care about plans.
> 
> By useless disagreements you just postpone the acceptance of this
> patchset. Especially about such nits... patch could have been reviewed
> already :/

Hi Krzysztof,

I have changed it to single-cell addressing in latest patchset.

Thanks,
Ram.




> 
>> +
>> +        ufshc@1d84000 {
>> +            compatible = "qcom,sa8255p-ufshc";
>> +            reg = <0x0 0x01d84000 0x0 0x3000>;
> 
> 
> Best regards,
> Krzysztof