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[1/2] i3c: Add basic HDR support

Message ID 20250129-i3c_ddr-v1-1-028a7a5d4324@nxp.com (mailing list archive)
State New
Headers show
Series i3c: Add basic HDR mode support | expand

Commit Message

Frank Li Jan. 29, 2025, 8:05 p.m. UTC
I3C HDR requires enter/exit patterns during each I3C transfer. Add a new
API i3c_device_do_priv_xfers_mode(). The existing
i3c_device_do_priv_xfers() now calls i3c_device_do_priv_xfers_mode(I3C_SDR)
to maintain backward compatibility.

Introduce a 'cmd' field in 'struct i3c_priv_xfer', using an anonymous union
with 'rnw' since HDR mode relies on read/write commands instead of the
'rnw' bit in the address as in SDR mode.

Add a priv_xfers_mode callback for I3C master drivers. If priv_xfers_mode
is not implemented, fallback to SDR mode using the existing priv_xfers
callback.

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].
---
 drivers/i3c/device.c       | 19 +++++++++++++------
 drivers/i3c/internals.h    |  2 +-
 drivers/i3c/master.c       |  8 +++++++-
 include/linux/i3c/device.h | 12 +++++++++++-
 include/linux/i3c/master.h |  3 +++
 5 files changed, 35 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c
index e80e487569146..e3db3a6a9e4f6 100644
--- a/drivers/i3c/device.c
+++ b/drivers/i3c/device.c
@@ -15,12 +15,13 @@ 
 #include "internals.h"
 
 /**
- * i3c_device_do_priv_xfers() - do I3C SDR private transfers directed to a
- *				specific device
+ * i3c_device_do_priv_xfers_mode() - do I3C SDR private 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.
  *
@@ -32,9 +33,9 @@ 
  *		    driver needs to resend the '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_priv_xfers_mode(struct i3c_device *dev,
+				  struct i3c_priv_xfer *xfers,
+				  int nxfers, enum i3c_hdr_mode mode)
 {
 	int ret, i;
 
@@ -47,11 +48,17 @@  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_priv_xfers_locked(dev->desc, xfers, nxfers, mode);
 	i3c_bus_normaluse_unlock(dev->bus);
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(i3c_device_do_priv_xfers_mode);
+
+int i3c_device_do_priv_xfers(struct i3c_device *dev, struct i3c_priv_xfer *xfers, int nxfers)
+{
+	return i3c_device_do_priv_xfers_mode(dev, xfers, nxfers, I3C_SDR);
+}
 EXPORT_SYMBOL_GPL(i3c_device_do_priv_xfers);
 
 /**
diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
index 433f6088b7cec..553edc9846ac0 100644
--- a/drivers/i3c/internals.h
+++ b/drivers/i3c/internals.h
@@ -16,7 +16,7 @@  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 nxfers, enum i3c_hdr_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 d5dc4180afbcf..67aaba0a38db2 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2945,7 +2945,7 @@  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 nxfers, enum i3c_hdr_mode mode)
 {
 	struct i3c_master_controller *master;
 
@@ -2956,9 +2956,15 @@  int i3c_dev_do_priv_xfers_locked(struct i3c_dev_desc *dev,
 	if (!master || !xfers)
 		return -EINVAL;
 
+	if (master->ops->priv_xfers_mode)
+		return master->ops->priv_xfers_mode(dev, xfers, nxfers, mode);
+
 	if (!master->ops->priv_xfers)
 		return -ENOTSUPP;
 
+	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 b674f64d0822e..7ce70d0967e27 100644
--- a/include/linux/i3c/device.h
+++ b/include/linux/i3c/device.h
@@ -40,11 +40,13 @@  enum i3c_error_code {
 
 /**
  * enum i3c_hdr_mode - HDR mode ids
+ * @I3C_SDR: SDR mode (NOT HDR mode)
  * @I3C_HDR_DDR: DDR mode
  * @I3C_HDR_TSP: TSP mode
  * @I3C_HDR_TSL: TSL mode
  */
 enum i3c_hdr_mode {
+	I3C_SDR,
 	I3C_HDR_DDR,
 	I3C_HDR_TSP,
 	I3C_HDR_TSL,
@@ -53,6 +55,7 @@  enum i3c_hdr_mode {
 /**
  * struct i3c_priv_xfer - I3C SDR private 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
@@ -61,7 +64,10 @@  enum i3c_hdr_mode {
  * @err: I3C error code
  */
 struct i3c_priv_xfer {
-	u8 rnw;
+	union {
+		u8 rnw;
+		u8 cmd;
+	};
 	u16 len;
 	u16 actual_len;
 	union {
@@ -301,6 +307,10 @@  int i3c_device_do_priv_xfers(struct i3c_device *dev,
 			     struct i3c_priv_xfer *xfers,
 			     int nxfers);
 
+int i3c_device_do_priv_xfers_mode(struct i3c_device *dev,
+				  struct i3c_priv_xfer *xfers,
+				  int nxfers, enum i3c_hdr_mode mode);
+
 int i3c_device_do_setdasa(struct i3c_device *dev);
 
 void i3c_device_get_info(const struct i3c_device *dev, struct i3c_device_info *info);
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index 12d532b012c5a..352bd41139569 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -472,6 +472,9 @@  struct i3c_master_controller_ops {
 	int (*priv_xfers)(struct i3c_dev_desc *dev,
 			  struct i3c_priv_xfer *xfers,
 			  int nxfers);
+	int (*priv_xfers_mode)(struct i3c_dev_desc *dev,
+			       struct i3c_priv_xfer *xfers,
+			       int nxfers, enum i3c_hdr_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,