[PATCH v6 1/5] i3c: Add HDR API support

[Frank Li <Frank.Li@nxp.com>]

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>
---
Why not add hdr mode in struct i3c_priv_xfer because mode can't be mixed in
one i3c transfer. for example, can't send a HDR follow one SDR between
START and STOP.

i3c_priv_xfer should be treat as whole i3c transactions. If user want send
HDR follow SDR, should be call i3c_device_do_priv_xfers_mode() twice,
instead put into a big i3c_priv_xfer[n].

change in v4
- Rename enum i3c_hdr_mode to i3c_xfer_mode.

change in v3
- Add Depreciated comment for priv_xfers.

change in v2
- don't use 'priv_' since it is refer to sdr mode transfer in spec.
- add 'mode_mask' indicate controller's capibility.
- add helper function to check master's supported transfer mode.
---
 drivers/i3c/device.c       | 27 ++++++++++++++++++++-------
 drivers/i3c/internals.h    |  6 +++---
 drivers/i3c/master.c       | 19 +++++++++++++++----
 include/linux/i3c/device.h | 34 ++++++++++++++++++++++++++--------
 include/linux/i3c/master.h |  4 ++++
 5 files changed, 68 insertions(+), 22 deletions(-)

diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c
index 2396545763ff853097d9f0173787e087f7a6e688..e6add862645196ad41d0c91d3d7103c877a1ef5a 100644
--- a/drivers/i3c/device.c
+++ b/drivers/i3c/device.c
@@ -15,12 +15,12 @@
 #include "internals.h"
 
 /**
- * i3c_device_do_priv_xfers() - do I3C SDR private transfers directed to a
- *				specific device
+ * i3c_device_do_xfers() - do I3C transfers directed to a specific device
  *
  * @dev: device with which the transfers should be done
  * @xfers: array of transfers
  * @nxfers: number of transfers
+ * @mode: transfer mode
  *
  * Initiate one or several private SDR transfers with @dev.
  *
@@ -33,9 +33,8 @@
  *   'xfers' some time later. See I3C spec ver 1.1.1 09-Jun-2021. Section:
  *   5.1.2.2.3.
  */
-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_priv_xfer *xfers,
+			int nxfers, enum i3c_xfer_mode mode)
 {
 	int ret, i;
 
@@ -48,12 +47,12 @@ int i3c_device_do_priv_xfers(struct i3c_device *dev,
 	}
 
 	i3c_bus_normaluse_lock(dev->bus);
-	ret = i3c_dev_do_priv_xfers_locked(dev->desc, xfers, nxfers);
+	ret = i3c_dev_do_xfers_locked(dev->desc, xfers, nxfers, mode);
 	i3c_bus_normaluse_unlock(dev->bus);
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(i3c_device_do_priv_xfers);
+EXPORT_SYMBOL_GPL(i3c_device_do_xfers);
 
 /**
  * i3c_device_do_setdasa() - do I3C dynamic address assignement with
@@ -260,6 +259,20 @@ i3c_device_match_id(struct i3c_device *i3cdev,
 }
 EXPORT_SYMBOL_GPL(i3c_device_match_id);
 
+/**
+ * i3c_device_get_supported_xfer_mode - Returns the supported transfer mode by
+ *					connected master controller.
+ * @dev: I3C device
+ *
+ * Return: a bit mask, which supported transfer mode, bit position is defined at
+ *	   enum i3c_hdr_mode
+ */
+u32 i3c_device_get_supported_xfer_mode(struct i3c_device *dev)
+{
+	return i3c_dev_get_master(dev->desc)->this->info.hdr_cap | BIT(I3C_SDR);
+}
+EXPORT_SYMBOL_GPL(i3c_device_get_supported_xfer_mode);
+
 /**
  * i3c_driver_register_with_owner() - register an I3C device driver
  *
diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
index 0d857cc68cc5d473db733b12ffcec0c1c28d9def..f8d68b9d6474cbc56640a643db3c2c4cd95dd26b 100644
--- a/drivers/i3c/internals.h
+++ b/drivers/i3c/internals.h
@@ -15,9 +15,9 @@ void i3c_bus_normaluse_lock(struct i3c_bus *bus);
 void i3c_bus_normaluse_unlock(struct i3c_bus *bus);
 
 int i3c_dev_setdasa_locked(struct i3c_dev_desc *dev);
-int i3c_dev_do_priv_xfers_locked(struct i3c_dev_desc *dev,
-				 struct i3c_priv_xfer *xfers,
-				 int nxfers);
+int i3c_dev_do_xfers_locked(struct i3c_dev_desc *dev,
+			    struct i3c_xfer *xfers,
+			    int nxfers, enum i3c_xfer_mode mode);
 int i3c_dev_disable_ibi_locked(struct i3c_dev_desc *dev);
 int i3c_dev_enable_ibi_locked(struct i3c_dev_desc *dev);
 int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev,
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 8efec085d396cf0c7dd9ee35b636eea9664c634f..b36d4ffadeff20641a1eeb84b702178f05eb891c 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2749,10 +2749,13 @@ EXPORT_SYMBOL_GPL(i3c_generic_ibi_recycle_slot);
 
 static int i3c_master_check_ops(const struct i3c_master_controller_ops *ops)
 {
-	if (!ops || !ops->bus_init || !ops->priv_xfers ||
+	if (!ops || !ops->bus_init ||
 	    !ops->send_ccc_cmd || !ops->do_daa || !ops->i2c_xfers)
 		return -EINVAL;
 
+	if (!ops->priv_xfers && !ops->i3c_xfers)
+		return -EINVAL;
+
 	if (ops->request_ibi &&
 	    (!ops->enable_ibi || !ops->disable_ibi || !ops->free_ibi ||
 	     !ops->recycle_ibi_slot))
@@ -2942,9 +2945,8 @@ int i3c_dev_setdasa_locked(struct i3c_dev_desc *dev)
 						dev->boardinfo->init_dyn_addr);
 }
 
-int i3c_dev_do_priv_xfers_locked(struct i3c_dev_desc *dev,
-				 struct i3c_priv_xfer *xfers,
-				 int nxfers)
+int i3c_dev_do_xfers_locked(struct i3c_dev_desc *dev, struct i3c_xfer *xfers,
+			    int nxfers, enum i3c_xfer_mode mode)
 {
 	struct i3c_master_controller *master;
 
@@ -2955,9 +2957,18 @@ int i3c_dev_do_priv_xfers_locked(struct i3c_dev_desc *dev,
 	if (!master || !xfers)
 		return -EINVAL;
 
+	if (mode != I3C_SDR && !(master->this->info.hdr_cap & BIT(mode)))
+		return -EOPNOTSUPP;
+
+	if (master->ops->i3c_xfers)
+		return master->ops->i3c_xfers(dev, xfers, nxfers, mode);
+
 	if (!master->ops->priv_xfers)
 		return -EOPNOTSUPP;
 
+	if (mode != I3C_SDR)
+		return -EINVAL;
+
 	return master->ops->priv_xfers(dev, xfers, nxfers);
 }
 
diff --git a/include/linux/i3c/device.h b/include/linux/i3c/device.h
index 7f136de4b73ef839fb4a1837a87b1aebbddbfe93..563e63f6dd99a95d66bd80aff0b760c231b487a9 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 {
+enum i3c_xfer_mode {
+	/* The below 3 value (I3C_HDR*) must match GETCAP1 Byte bit position */
 	I3C_HDR_DDR,
 	I3C_HDR_TSP,
 	I3C_HDR_TSL,
+	/* 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 043f5c7ff398ff631f1eea6acfc54a2e871016d8..ef1363122066215983d37c8e3ce062f3eefe48ae 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);
+	/* Depreciated, 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_priv_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,

-- 
2.34.1