From 733b439375b494e8a6950ab47d18a4b615b73cb3 Mon Sep 17 00:00:00 2001 From: Jorge Marques Date: Tue, 24 Jun 2025 11:06:04 +0200 Subject: [PATCH] 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: Jorge Marques Suggested-by: Wolfram Sang Reviewed-by: Wolfram Sang Tested-by: Wolfram Sang Reviewed-by: Frank Li Link: https://lore.kernel.org/r/20250624-i3c-writesl-readsl-v3-1-63ccf0870f01@analog.com Signed-off-by: Alexandre Belloni --- drivers/i3c/internals.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/i3c/internals.h b/drivers/i3c/internals.h index 433f6088b7cec..6a11437fee47b 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_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 */ -- 2.47.2