i3c: Add HDR API support

Rename struct i3c_priv_xfer to struct i3c_xfer, since private xfer in the
I3C spec refers only to SDR transfers. Ref: i3c spec ver1.2, section 3,
Technical Overview.

i3c_xfer will be used for both SDR and HDR.

Rename enum i3c_hdr_mode to i3c_xfer_mode. Previous definition need match
CCC GET_CAP1 bit position. Use 31 as SDR transfer mode.

Add i3c_device_do_xfers() with an xfer mode argument, while keeping
i3c_device_do_priv_xfers() as a wrapper that calls i3c_device_do_xfers()
with I3C_SDR for backward compatibility.

Introduce a 'cmd' field in struct i3c_xfer as an anonymous union with
'rnw', since HDR mode uses read/write commands instead of the SDR address
bit.

Add .i3c_xfers() callback for master controllers. If not implemented, fall
back to SDR with .priv_xfers(). The .priv_xfers() API can be removed once
all controllers switch to .i3c_xfers().

Add 'mode_mask' bitmask to advertise controller capability.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20251106-i3c_ddr-v11-1-33a6a66ed095@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

2 files changed, 33 insertions, 11 deletions

diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h
index 7f136de4b73e..7f7738041f38 100644
--- a/include/linux/i3c/device.h
+++ b/include/linux/i3c/device.h
@@ -39,20 +39,25 @@ enum i3c_error_code {
 };
 
 /**
- * enum i3c_hdr_mode - HDR mode ids
+ * enum i3c_xfer_mode - I3C xfer mode ids
  * @I3C_HDR_DDR: DDR mode
  * @I3C_HDR_TSP: TSP mode
  * @I3C_HDR_TSL: TSL mode
+ * @I3C_SDR: SDR mode (NOT HDR mode)
  */
-enum i3c_hdr_mode {
-	I3C_HDR_DDR,
-	I3C_HDR_TSP,
-	I3C_HDR_TSL,
+enum i3c_xfer_mode {
+	/* The below 3 value (I3C_HDR*) must match GETCAP1 Byte bit position */
+	I3C_HDR_DDR = 0,
+	I3C_HDR_TSP = 1,
+	I3C_HDR_TSL = 2,
+	/* Use for default SDR transfer mode */
+	I3C_SDR = 0x31,
 };
 
 /**
- * struct i3c_priv_xfer - I3C SDR private transfer
+ * struct i3c_xfer - I3C data transfer
  * @rnw: encodes the transfer direction. true for a read, false for a write
+ * @cmd: Read/Write command in HDR mode, read: 0x80 - 0xff, write: 0x00 - 0x7f
  * @len: transfer length in bytes of the transfer
  * @actual_len: actual length in bytes are transferred by the controller
  * @data: input/output buffer
@@ -60,8 +65,11 @@ enum i3c_hdr_mode {
  * @data.out: output buffer. Must point to a DMA-able buffer
  * @err: I3C error code
  */
-struct i3c_priv_xfer {
-	u8 rnw;
+struct i3c_xfer {
+	union {
+		u8 rnw;
+		u8 cmd;
+	};
 	u16 len;
 	u16 actual_len;
 	union {
@@ -71,6 +79,9 @@ struct i3c_priv_xfer {
 	enum i3c_error_code err;
 };
 
+/* keep back compatible */
+#define i3c_priv_xfer i3c_xfer
+
 /**
  * enum i3c_dcr - I3C DCR values
  * @I3C_DCR_GENERIC_DEVICE: generic I3C device
@@ -297,9 +308,15 @@ static __always_inline void i3c_i2c_driver_unregister(struct i3c_driver *i3cdrv,
 		      i3c_i2c_driver_unregister,	\
 		      __i2cdrv)
 
-int i3c_device_do_priv_xfers(struct i3c_device *dev,
-			     struct i3c_priv_xfer *xfers,
-			     int nxfers);
+int i3c_device_do_xfers(struct i3c_device *dev, struct i3c_xfer *xfers,
+			int nxfers, enum i3c_xfer_mode mode);
+
+static inline int i3c_device_do_priv_xfers(struct i3c_device *dev,
+					   struct i3c_priv_xfer *xfers,
+					   int nxfers)
+{
+	return i3c_device_do_xfers(dev, xfers, nxfers, I3C_SDR);
+}
 
 int i3c_device_do_setdasa(struct i3c_device *dev);
 
@@ -341,5 +358,6 @@ int i3c_device_request_ibi(struct i3c_device *dev,
 void i3c_device_free_ibi(struct i3c_device *dev);
 int i3c_device_enable_ibi(struct i3c_device *dev);
 int i3c_device_disable_ibi(struct i3c_device *dev);
+u32 i3c_device_get_supported_xfer_mode(struct i3c_device *dev);
 
 #endif /* I3C_DEV_H */
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index c52a82dd79a6..d0d5b3a9049f 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -474,9 +474,13 @@ struct i3c_master_controller_ops {
 				 const struct i3c_ccc_cmd *cmd);
 	int (*send_ccc_cmd)(struct i3c_master_controller *master,
 			    struct i3c_ccc_cmd *cmd);
+	/* Deprecated, please use i3c_xfers() */
 	int (*priv_xfers)(struct i3c_dev_desc *dev,
 			  struct i3c_priv_xfer *xfers,
 			  int nxfers);
+	int (*i3c_xfers)(struct i3c_dev_desc *dev,
+			 struct i3c_xfer *xfers,
+			 int nxfers, enum i3c_xfer_mode mode);
 	int (*attach_i2c_dev)(struct i2c_dev_desc *dev);
 	void (*detach_i2c_dev)(struct i2c_dev_desc *dev);
 	int (*i2c_xfers)(struct i2c_dev_desc *dev,