[PATCH v2 0/3] Add helper methods i3c_writel_fifo() and i3c_readl_fifo()

[PATCH v2 0/3] Add helper methods i3c_writel_fifo() and i3c_readl_fifo()

[Jorge Marques]

The i3c abstraction excepts u8 buffers, but some controllers have a bus
width of 32-bits and don't support flagging valid bytes, so it is
required to read/write long words and to use memcpy on the remainder of
the number of bytes by 32-bits to not write/read outside the buffer
bounds.

Add two auxiliary methods to include/linux/i3c/master.h and use in the dw
and cdns i3c controller drivers. The adi controller driver will also use
these methods.

Related thread: https://lore.kernel.org/linux-i3c/aFNziEj7j31xy%2FmY@lizhi-Precision-Tower-5810/

Signed-off-by: Jorge Marques <jorge.marques@analog.com>
---
Changes in v2:
- Rename to i3c_readl_fifo() and i3c_writel_fifo()
- Change type u8 *bytes to void *bytes
- Move methods to internals.h
- Reword commit messages to include new names and ().
- Fixup dw read fifo address (master -> master->reg)
- Link to v1: https://lore.kernel.org/r/20250620-i3c-writesl-readsl-v1-0-e0aa1c014dff@analog.com

---
Jorge Marques (3):
      i3c: master: Add inline i3c_readl_fifo() and i3c_writel_fifo()
      i3c: master: cdns: Use i3c_master_writesl() and i3c_master_readsl()
      i3c: master: dw: Use i3c_master_writesl() and i3c_master_readsl()

 drivers/i3c/internals.h              | 37 ++++++++++++++++++++++++++++++++++++
 drivers/i3c/master/dw-i3c-master.c   | 25 ++++--------------------
 drivers/i3c/master/i3c-master-cdns.c | 25 +++++-------------------
 3 files changed, 46 insertions(+), 41 deletions(-)
---
base-commit: 51963783b876a2f493a3eac0ea9eba271cb6809a
change-id: 20250620-i3c-writesl-readsl-e2836534b665

Best regards,
-- 
Jorge Marques <jorge.marques@analog.com>

[PATCH v2 1/3] i3c: master: Add inline i3c_readl_fifo() and i3c_writel_fifo()

[Jorge Marques]

The i3c abstraction excepts u8 buffers, but some controllers have a bus
width of 32-bits and don't support flagging valid bytes, so it is
required to read/write long words and to use memcpy on the remainder of
the number of bytes by 32-bits to not write/read outside the buffer
bounds.

Signed-off-by: Jorge Marques <jorge.marques@analog.com>
---
 drivers/i3c/internals.h | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
index 433f6088b7cec8c77288ee24dbee8b18338aa1eb..88887b12122efafac81bcfdd093d943259e13a08 100644
--- a/drivers/i3c/internals.h
+++ b/drivers/i3c/internals.h
@@ -22,4 +22,41 @@ int i3c_dev_enable_ibi_locked(struct i3c_dev_desc *dev);
 int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev,
 			       const struct i3c_ibi_setup *req);
 void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev);
+
+/**
+ * i3c_master_writesl- Write bytes to long memory region from byte array
+ * @addr: Register to write to
+ * @bytes: Pointer to the data bytes to write
+ * @nbytes: Number of bytes to write
+ */
+static inline void i3c_writel_fifo(void __iomem *addr, const void *bytes,
+				   int nbytes)
+{
+	writesl(addr, bytes, nbytes / 4);
+	if (nbytes & 3) {
+		u32 tmp = 0;
+
+		memcpy(&tmp, bytes + (nbytes & ~3), nbytes & 3);
+		writel(tmp, addr);
+	}
+}
+
+/**
+ * i3c_master_readsl - Read bytes from long memory region to byte array
+ * @addr: Register to read from
+ * @bytes: Pointer to the buffer to store read bytes
+ * @nbytes: Number of bytes to read
+ */
+static inline void i3c_readl_fifo(const void __iomem *addr, void *bytes,
+				  int nbytes)
+{
+	readsl(addr, bytes, nbytes / 4);
+	if (nbytes & 3) {
+		u32 tmp;
+
+		tmp = readl(addr);
+		memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
+	}
+}
+
 #endif /* I3C_INTERNAL_H */

-- 
2.49.0

[PATCH v2 2/3] i3c: master: cdns: Use i3c_master_writesl() and i3c_master_readsl()

[Jorge Marques]

Use common inline i3c_master_writesl()/i3c_master_readsl() methods to
simplify code since the FIFO of controller is a 32bit width.

Signed-off-by: Jorge Marques <jorge.marques@analog.com>
---
 drivers/i3c/master/i3c-master-cdns.c | 25 +++++--------------------
 1 file changed, 5 insertions(+), 20 deletions(-)

diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
index fd3752cea654954ed1e37337754e45fddbbbf68e..321c04d2109ec1951f2b07a9d1b88c6aaf055c95 100644
--- a/drivers/i3c/master/i3c-master-cdns.c
+++ b/drivers/i3c/master/i3c-master-cdns.c
@@ -23,6 +23,8 @@
 #include <linux/spinlock.h>
 #include <linux/workqueue.h>
 
+#include "../internals.h"
+
 #define DEV_ID				0x0
 #define DEV_ID_I3C_MASTER		0x5034
 
@@ -427,25 +429,13 @@ to_cdns_i3c_master(struct i3c_master_controller *master)
 static void cdns_i3c_master_wr_to_tx_fifo(struct cdns_i3c_master *master,
 					  const u8 *bytes, int nbytes)
 {
-	writesl(master->regs + TX_FIFO, bytes, nbytes / 4);
-	if (nbytes & 3) {
-		u32 tmp = 0;
-
-		memcpy(&tmp, bytes + (nbytes & ~3), nbytes & 3);
-		writesl(master->regs + TX_FIFO, &tmp, 1);
-	}
+	i3c_writel_fifo(master->regs + TX_FIFO, bytes, nbytes);
 }
 
 static void cdns_i3c_master_rd_from_rx_fifo(struct cdns_i3c_master *master,
 					    u8 *bytes, int nbytes)
 {
-	readsl(master->regs + RX_FIFO, bytes, nbytes / 4);
-	if (nbytes & 3) {
-		u32 tmp;
-
-		readsl(master->regs + RX_FIFO, &tmp, 1);
-		memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
-	}
+	i3c_readl_fifo(master->regs + RX_FIFO, bytes, nbytes);
 }
 
 static bool cdns_i3c_master_supports_ccc_cmd(struct i3c_master_controller *m,
@@ -1330,12 +1320,7 @@ static void cdns_i3c_master_handle_ibi(struct cdns_i3c_master *master,
 	buf = slot->data;
 
 	nbytes = IBIR_XFER_BYTES(ibir);
-	readsl(master->regs + IBI_DATA_FIFO, buf, nbytes / 4);
-	if (nbytes % 3) {
-		u32 tmp = __raw_readl(master->regs + IBI_DATA_FIFO);
-
-		memcpy(buf + (nbytes & ~3), &tmp, nbytes & 3);
-	}
+	i3c_readl_fifo(master->regs + IBI_DATA_FIFO, buf, nbytes);
 
 	slot->len = min_t(unsigned int, IBIR_XFER_BYTES(ibir),
 			  dev->ibi->max_payload_len);

-- 
2.49.0

[PATCH v2 3/3] i3c: master: dw: Use i3c_master_writesl() and i3c_master_readsl()

[Jorge Marques]

Use common inline i3c_master_writesl()/i3c_master_readsl() methods to
simplify code since the FIFO of controller is a 32bit width.

Signed-off-by: Jorge Marques <jorge.marques@analog.com>
---
 drivers/i3c/master/dw-i3c-master.c | 25 ++++---------------------
 1 file changed, 4 insertions(+), 21 deletions(-)

diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 611c22b72c1572ddf717c8ad473e44a3b8fcceaf..886f8b74defda31ae93248467d144f9c8c561581 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -23,6 +23,7 @@
 #include <linux/reset.h>
 #include <linux/slab.h>
 
+#include "../internals.h"
 #include "dw-i3c-master.h"
 
 #define DEVICE_CTRL			0x0
@@ -336,37 +337,19 @@ static int dw_i3c_master_get_free_pos(struct dw_i3c_master *master)
 static void dw_i3c_master_wr_tx_fifo(struct dw_i3c_master *master,
 				     const u8 *bytes, int nbytes)
 {
-	writesl(master->regs + RX_TX_DATA_PORT, bytes, nbytes / 4);
-	if (nbytes & 3) {
-		u32 tmp = 0;
-
-		memcpy(&tmp, bytes + (nbytes & ~3), nbytes & 3);
-		writesl(master->regs + RX_TX_DATA_PORT, &tmp, 1);
-	}
-}
-
-static void dw_i3c_master_read_fifo(struct dw_i3c_master *master,
-				    int reg,  u8 *bytes, int nbytes)
-{
-	readsl(master->regs + reg, bytes, nbytes / 4);
-	if (nbytes & 3) {
-		u32 tmp;
-
-		readsl(master->regs + reg, &tmp, 1);
-		memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
-	}
+	i3c_writel_fifo(master->regs + RX_TX_DATA_PORT, bytes, nbytes);
 }
 
 static void dw_i3c_master_read_rx_fifo(struct dw_i3c_master *master,
 				       u8 *bytes, int nbytes)
 {
-	return dw_i3c_master_read_fifo(master, RX_TX_DATA_PORT, bytes, nbytes);
+	i3c_readl_fifo(master->regs + RX_TX_DATA_PORT, bytes, nbytes);
 }
 
 static void dw_i3c_master_read_ibi_fifo(struct dw_i3c_master *master,
 					u8 *bytes, int nbytes)
 {
-	return dw_i3c_master_read_fifo(master, IBI_QUEUE_STATUS, bytes, nbytes);
+	i3c_readl_fifo(master->regs + IBI_QUEUE_STATUS, bytes, nbytes);
 }
 
 static struct dw_i3c_xfer *

-- 
2.49.0

Re: [PATCH v2 1/3] i3c: master: Add inline i3c_readl_fifo() and i3c_writel_fifo()

[Frank Li]

On Sun, Jun 22, 2025 at 11:18:58AM +0200, Jorge Marques wrote:
> The i3c abstraction excepts u8 buffers, but some controllers have a bus
                      ^ expects?

> width of 32-bits and don't support flagging valid bytes, so it is
> required to read/write long words and to use memcpy on the remainder of
> the number of bytes by 32-bits to not write/read outside the buffer
> bounds.

The I3C abstraction expects u8 buffers, but some controllers operate with
a 32-bit bus width FIFO and cannot flag valid bytes individually. To avoid
reading or writing outside the buffer bounds, use 32-bit accesses where
possible and apply memcpy for any remaining bytes.

Frank
>
> Signed-off-by: Jorge Marques <jorge.marques@analog.com>
> ---
>  drivers/i3c/internals.h | 37 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
>
> diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
> index 433f6088b7cec8c77288ee24dbee8b18338aa1eb..88887b12122efafac81bcfdd093d943259e13a08 100644
> --- a/drivers/i3c/internals.h
> +++ b/drivers/i3c/internals.h
> @@ -22,4 +22,41 @@ int i3c_dev_enable_ibi_locked(struct i3c_dev_desc *dev);
>  int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev,
>  			       const struct i3c_ibi_setup *req);
>  void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev);
> +
> +/**
> + * i3c_master_writesl- Write bytes to long memory region from byte array

i3c_writel_fifo - Write data buffer to 32bit FIFO

> + * @addr: Register to write to

FIFO address

> + * @bytes: Pointer to the data bytes to write

bytes and nbytes is too similar, can you rename bytes to buf?

Check read_fifo also.

Frank
> + * @nbytes: Number of bytes to write
> + */
> +static inline void i3c_writel_fifo(void __iomem *addr, const void *bytes,
> +				   int nbytes)
> +{
> +	writesl(addr, bytes, nbytes / 4);
> +	if (nbytes & 3) {
> +		u32 tmp = 0;
> +
> +		memcpy(&tmp, bytes + (nbytes & ~3), nbytes & 3);
> +		writel(tmp, addr);
> +	}
> +}
> +
> +/**
> + * i3c_master_readsl - Read bytes from long memory region to byte array
> + * @addr: Register to read from
> + * @bytes: Pointer to the buffer to store read bytes
> + * @nbytes: Number of bytes to read
> + */
> +static inline void i3c_readl_fifo(const void __iomem *addr, void *bytes,
> +				  int nbytes)
> +{
> +	readsl(addr, bytes, nbytes / 4);
> +	if (nbytes & 3) {
> +		u32 tmp;
> +
> +		tmp = readl(addr);
> +		memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
> +	}
> +}
> +
>  #endif /* I3C_INTERNAL_H */
>
> --
> 2.49.0
>
>

Re: [PATCH v2 2/3] i3c: master: cdns: Use i3c_master_writesl() and i3c_master_readsl()

[Frank Li]

On Sun, Jun 22, 2025 at 11:18:59AM +0200, Jorge Marques wrote:
> Use common inline i3c_master_writesl()/i3c_master_readsl() methods to

API name changed, you need update it also, include subject.

Frank

> simplify code since the FIFO of controller is a 32bit width.
>
> Signed-off-by: Jorge Marques <jorge.marques@analog.com>
> ---
>  drivers/i3c/master/i3c-master-cdns.c | 25 +++++--------------------
>  1 file changed, 5 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
> index fd3752cea654954ed1e37337754e45fddbbbf68e..321c04d2109ec1951f2b07a9d1b88c6aaf055c95 100644
> --- a/drivers/i3c/master/i3c-master-cdns.c
> +++ b/drivers/i3c/master/i3c-master-cdns.c
> @@ -23,6 +23,8 @@
>  #include <linux/spinlock.h>
>  #include <linux/workqueue.h>
>
> +#include "../internals.h"
> +
>  #define DEV_ID				0x0
>  #define DEV_ID_I3C_MASTER		0x5034
>
> @@ -427,25 +429,13 @@ to_cdns_i3c_master(struct i3c_master_controller *master)
>  static void cdns_i3c_master_wr_to_tx_fifo(struct cdns_i3c_master *master,
>  					  const u8 *bytes, int nbytes)
>  {
> -	writesl(master->regs + TX_FIFO, bytes, nbytes / 4);
> -	if (nbytes & 3) {
> -		u32 tmp = 0;
> -
> -		memcpy(&tmp, bytes + (nbytes & ~3), nbytes & 3);
> -		writesl(master->regs + TX_FIFO, &tmp, 1);
> -	}
> +	i3c_writel_fifo(master->regs + TX_FIFO, bytes, nbytes);
>  }
>
>  static void cdns_i3c_master_rd_from_rx_fifo(struct cdns_i3c_master *master,
>  					    u8 *bytes, int nbytes)
>  {
> -	readsl(master->regs + RX_FIFO, bytes, nbytes / 4);
> -	if (nbytes & 3) {
> -		u32 tmp;
> -
> -		readsl(master->regs + RX_FIFO, &tmp, 1);
> -		memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
> -	}
> +	i3c_readl_fifo(master->regs + RX_FIFO, bytes, nbytes);
>  }
>
>  static bool cdns_i3c_master_supports_ccc_cmd(struct i3c_master_controller *m,
> @@ -1330,12 +1320,7 @@ static void cdns_i3c_master_handle_ibi(struct cdns_i3c_master *master,
>  	buf = slot->data;
>
>  	nbytes = IBIR_XFER_BYTES(ibir);
> -	readsl(master->regs + IBI_DATA_FIFO, buf, nbytes / 4);
> -	if (nbytes % 3) {
> -		u32 tmp = __raw_readl(master->regs + IBI_DATA_FIFO);
> -
> -		memcpy(buf + (nbytes & ~3), &tmp, nbytes & 3);
> -	}
> +	i3c_readl_fifo(master->regs + IBI_DATA_FIFO, buf, nbytes);
>
>  	slot->len = min_t(unsigned int, IBIR_XFER_BYTES(ibir),
>  			  dev->ibi->max_payload_len);
>
> --
> 2.49.0
>
>

Re: [PATCH v2 1/3] i3c: master: Add inline i3c_readl_fifo() and i3c_writel_fifo()

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 601 bytes --]

On Sun, Jun 22, 2025 at 11:18:58AM +0200, Jorge Marques wrote:
> The i3c abstraction excepts u8 buffers, but some controllers have a bus
> width of 32-bits and don't support flagging valid bytes, so it is
> required to read/write long words and to use memcpy on the remainder of
> the number of bytes by 32-bits to not write/read outside the buffer
> bounds.
> 
> Signed-off-by: Jorge Marques <jorge.marques@analog.com>

Despite Frank's valid comments, I tested this code with the Renesas
driver and it worked so far. Thanks!

Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

Re: [PATCH v2 1/3] i3c: master: Add inline i3c_readl_fifo() and i3c_writel_fifo()

[Jorge Marques]

On Mon, Jun 23, 2025 at 11:43:19AM -0400, Frank Li wrote:
> On Sun, Jun 22, 2025 at 11:18:58AM +0200, Jorge Marques wrote:
> > The i3c abstraction excepts u8 buffers, but some controllers have a bus
>                       ^ expects?
> 
> > width of 32-bits and don't support flagging valid bytes, so it is
> > required to read/write long words and to use memcpy on the remainder of
> > the number of bytes by 32-bits to not write/read outside the buffer
> > bounds.
> 
> The I3C abstraction expects u8 buffers, but some controllers operate with
> a 32-bit bus width FIFO and cannot flag valid bytes individually. To avoid
> reading or writing outside the buffer bounds, use 32-bit accesses where
> possible and apply memcpy for any remaining bytes.
Hi Frank,

gotcha,
> 
> Frank
> >
> > Signed-off-by: Jorge Marques <jorge.marques@analog.com>
> > ---
> >  drivers/i3c/internals.h | 37 +++++++++++++++++++++++++++++++++++++
> >  1 file changed, 37 insertions(+)
> >
> > diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h
> > index 433f6088b7cec8c77288ee24dbee8b18338aa1eb..88887b12122efafac81bcfdd093d943259e13a08 100644
> > --- a/drivers/i3c/internals.h
> > +++ b/drivers/i3c/internals.h
> > @@ -22,4 +22,41 @@ int i3c_dev_enable_ibi_locked(struct i3c_dev_desc *dev);
> >  int i3c_dev_request_ibi_locked(struct i3c_dev_desc *dev,
> >  			       const struct i3c_ibi_setup *req);
> >  void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev);
> > +
> > +/**
> > + * i3c_master_writesl- Write bytes to long memory region from byte array
> 
> i3c_writel_fifo - Write data buffer to 32bit FIFO
> 
> > + * @addr: Register to write to
> 
> FIFO address
> 
> > + * @bytes: Pointer to the data bytes to write
> 
> bytes and nbytes is too similar, can you rename bytes to buf?
Yep
> 
> Check read_fifo also.
Ack
> 
> Frank

Regards,
Jorge
> > + * @nbytes: Number of bytes to write
> > + */
> > +static inline void i3c_writel_fifo(void __iomem *addr, const void *bytes,
> > +				   int nbytes)
> > +{
> > +	writesl(addr, bytes, nbytes / 4);
> > +	if (nbytes & 3) {
> > +		u32 tmp = 0;
> > +
> > +		memcpy(&tmp, bytes + (nbytes & ~3), nbytes & 3);
> > +		writel(tmp, addr);
> > +	}
> > +}
> > +
> > +/**
> > + * i3c_master_readsl - Read bytes from long memory region to byte array
> > + * @addr: Register to read from
> > + * @bytes: Pointer to the buffer to store read bytes
> > + * @nbytes: Number of bytes to read
> > + */
> > +static inline void i3c_readl_fifo(const void __iomem *addr, void *bytes,
> > +				  int nbytes)
> > +{
> > +	readsl(addr, bytes, nbytes / 4);
> > +	if (nbytes & 3) {
> > +		u32 tmp;
> > +
> > +		tmp = readl(addr);
> > +		memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
> > +	}
> > +}
> > +
> >  #endif /* I3C_INTERNAL_H */
> >
> > --
> > 2.49.0
> >
> >

Re: [PATCH v2 2/3] i3c: master: cdns: Use i3c_master_writesl() and i3c_master_readsl()

[Jorge Marques]

On Mon, Jun 23, 2025 at 11:45:19AM -0400, Frank Li wrote:
> On Sun, Jun 22, 2025 at 11:18:59AM +0200, Jorge Marques wrote:
> > Use common inline i3c_master_writesl()/i3c_master_readsl() methods to
> 
> API name changed, you need update it also, include subject.
> 
> Frank
> 
Ack

Regards,
Jorge
> > simplify code since the FIFO of controller is a 32bit width.
> >
> > Signed-off-by: Jorge Marques <jorge.marques@analog.com>
> > ---
> >  drivers/i3c/master/i3c-master-cdns.c | 25 +++++--------------------
> >  1 file changed, 5 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
> > index fd3752cea654954ed1e37337754e45fddbbbf68e..321c04d2109ec1951f2b07a9d1b88c6aaf055c95 100644
> > --- a/drivers/i3c/master/i3c-master-cdns.c
> > +++ b/drivers/i3c/master/i3c-master-cdns.c
> > @@ -23,6 +23,8 @@
> >  #include <linux/spinlock.h>
> >  #include <linux/workqueue.h>
> >
> > +#include "../internals.h"
> > +
> >  #define DEV_ID				0x0
> >  #define DEV_ID_I3C_MASTER		0x5034
> >
> > @@ -427,25 +429,13 @@ to_cdns_i3c_master(struct i3c_master_controller *master)
> >  static void cdns_i3c_master_wr_to_tx_fifo(struct cdns_i3c_master *master,
> >  					  const u8 *bytes, int nbytes)
> >  {
> > -	writesl(master->regs + TX_FIFO, bytes, nbytes / 4);
> > -	if (nbytes & 3) {
> > -		u32 tmp = 0;
> > -
> > -		memcpy(&tmp, bytes + (nbytes & ~3), nbytes & 3);
> > -		writesl(master->regs + TX_FIFO, &tmp, 1);
> > -	}
> > +	i3c_writel_fifo(master->regs + TX_FIFO, bytes, nbytes);
> >  }
> >
> >  static void cdns_i3c_master_rd_from_rx_fifo(struct cdns_i3c_master *master,
> >  					    u8 *bytes, int nbytes)
> >  {
> > -	readsl(master->regs + RX_FIFO, bytes, nbytes / 4);
> > -	if (nbytes & 3) {
> > -		u32 tmp;
> > -
> > -		readsl(master->regs + RX_FIFO, &tmp, 1);
> > -		memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
> > -	}
> > +	i3c_readl_fifo(master->regs + RX_FIFO, bytes, nbytes);
> >  }
> >
> >  static bool cdns_i3c_master_supports_ccc_cmd(struct i3c_master_controller *m,
> > @@ -1330,12 +1320,7 @@ static void cdns_i3c_master_handle_ibi(struct cdns_i3c_master *master,
> >  	buf = slot->data;
> >
> >  	nbytes = IBIR_XFER_BYTES(ibir);
> > -	readsl(master->regs + IBI_DATA_FIFO, buf, nbytes / 4);
> > -	if (nbytes % 3) {
> > -		u32 tmp = __raw_readl(master->regs + IBI_DATA_FIFO);
> > -
> > -		memcpy(buf + (nbytes & ~3), &tmp, nbytes & 3);
> > -	}
> > +	i3c_readl_fifo(master->regs + IBI_DATA_FIFO, buf, nbytes);
> >
> >  	slot->len = min_t(unsigned int, IBIR_XFER_BYTES(ibir),
> >  			  dev->ibi->max_payload_len);
> >
> > --
> > 2.49.0
> >
> >