Commit 733b4393 authored by Jorge Marques's avatar Jorge Marques Committed by Alexandre Belloni
Browse files

i3c: master: Add inline i3c_readl_fifo() and i3c_writel_fifo() 



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

Signed-off-by: default avatarJorge Marques <jorge.marques@analog.com>
Suggested-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: default avatarFrank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250624-i3c-writesl-readsl-v3-1-63ccf0870f01@analog.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 12aa3e0c

drivers/i3c/internals.h

+37 −0
Original line number Diff line number Diff line
@@ -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_writel_fifo - Write data buffer to 32bit FIFO

 * @addr: FIFO Address to write to

 * @buf: Pointer to the data bytes to write

 * @nbytes: Number of bytes to write

 */

static inline void i3c_writel_fifo(void __iomem *addr, const void *buf,

				   int nbytes)

{

	writesl(addr, buf, nbytes / 4);

	if (nbytes & 3) {

		u32 tmp = 0;



		memcpy(&tmp, buf + (nbytes & ~3), nbytes & 3);

		writel(tmp, addr);

	}

}



/**

 * i3c_readl_fifo - Read data buffer from 32bit FIFO

 * @addr: FIFO Address to read from

 * @buf: 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 *buf,

				  int nbytes)

{

	readsl(addr, buf, nbytes / 4);

	if (nbytes & 3) {

		u32 tmp;



		tmp = readl(addr);

		memcpy(buf + (nbytes & ~3), &tmp, nbytes & 3);

	}

}



#endif /* I3C_INTERNAL_H */