From db7f6fb75282a305c2b0f5540d2f7be939f20dde Mon Sep 17 00:00:00 2001 From: Julius Werner Date: Mon, 12 Aug 2019 16:45:21 -0700 Subject: Add buffer_to/from_fifo32(_prefix) helpers Many peripheral drivers across different SoCs regularly face the same task of piping a transfer buffer into (or reading it out of) a 32-bit FIFO register. Sometimes it's just one register, sometimes a whole array of registers. Sometimes you actually transfer 4 bytes per register read/write, sometimes only 2 (or even 1). Sometimes writes need to be prefixed with one or two command bytes which makes the actual payload buffer "misaligned" in relation to the FIFO and requires a bunch of tricky bit packing logic to get right. Most of the times transfer lengths are not guaranteed to be divisible by 4, which also requires a bunch of logic to treat the potential unaligned end of the transfer correctly. We have a dozen different implementations of this same pattern across coreboot. This patch introduces a new family of helper functions that aims to solve all these use cases once and for all (*fingers crossed*). Change-Id: Ia71f66c1cee530afa4c77c46a838b4de646ffcfb Signed-off-by: Julius Werner Reviewed-on: https://review.coreboot.org/c/coreboot/+/34850 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi --- payloads/libpayload/include/libpayload.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'payloads/libpayload/include/libpayload.h') diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h index 57a3afc6b1..80bfaae6bf 100644 --- a/payloads/libpayload/include/libpayload.h +++ b/payloads/libpayload/include/libpayload.h @@ -445,6 +445,25 @@ static inline int __ffs(u32 x) { return log2(x & (u32)(-(s32)x)); } /** @} */ +/** + * @defgroup mmio MMIO helper functions + * @{ + */ +#if !CONFIG(LP_ARCH_MIPS) +void buffer_from_fifo32(void *buffer, size_t size, void *fifo, + int fifo_stride, int fifo_width); +void buffer_to_fifo32_prefix(void *buffer, u32 prefix, int prefsz, size_t size, + void *fifo, int fifo_stride, int fifo_width); +static inline void buffer_to_fifo32(void *buffer, size_t size, void *fifo, + int fifo_stride, int fifo_width) +{ + buffer_to_fifo32_prefix(buffer, size, 0, 0, fifo, + fifo_stride, fifo_width); +} +#endif +/** @} */ + + /** * @defgroup hash Hashing functions * @{ -- cgit v1.2.3