Introduce `ufshcd_dme_rmw` API to read, modify, and write DME
attributes in UFS host controllers using a mask and value.

Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
---
 drivers/ufs/core/ufshcd.c | 24 ++++++++++++++++++++++++
 include/ufs/ufshcd.h      |  1 +
 2 files changed, 25 insertions(+)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 13f7e0469141..42b9b7b0ee7c 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -4251,6 +4251,30 @@ int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
 }
 EXPORT_SYMBOL_GPL(ufshcd_dme_get_attr);

+/**
+ * ufshcd_dme_rmw - get modify set a DME attribute
+ * @hba: per adapter instance
+ * @mask: mask to apply on read value
+ * @val: actual value to write
+ * @attr: dme attribute
+ */
+int ufshcd_dme_rmw(struct ufs_hba *hba, u32 mask,
+		   u32 val, u32 attr)
+{
+	u32 cfg = 0;
+	int err;
+
+	err = ufshcd_dme_get(hba, UIC_ARG_MIB(attr), &cfg);
+	if (err)
+		return err;
+
+	cfg &= ~mask;
+	cfg |= (val & mask);
+
+	return ufshcd_dme_set(hba, UIC_ARG_MIB(attr), cfg);
+}
+EXPORT_SYMBOL_GPL(ufshcd_dme_rmw);
+
 /**
  * ufshcd_uic_pwr_ctrl - executes UIC commands (which affects the link power
  * state) and waits for it to take effect.
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 9b3515cee711..1d3943777584 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1480,6 +1480,7 @@ void ufshcd_resume_complete(struct device *dev);
 bool ufshcd_is_hba_active(struct ufs_hba *hba);
 void ufshcd_pm_qos_init(struct ufs_hba *hba);
 void ufshcd_pm_qos_exit(struct ufs_hba *hba);
+int ufshcd_dme_rmw(struct ufs_hba *hba, u32 mask, u32 val, u32 attr);

 /* Wrapper functions for safely calling variant operations */
 static inline int ufshcd_vops_init(struct ufs_hba *hba)
--
2.48.1

On 7/14/25 12:53 AM, Nitin Rawat wrote:
> + * @mask: mask to apply on read value

The description of 'mask' could have been more clear, e.g. "indicates
which bits to clear from the value that has been read". Anyway:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>