From a722de305eacb382a5d306f9f8e502f81bab682d Mon Sep 17 00:00:00 2001 From: Sven Peter Date: Sun, 14 Dec 2025 11:51:34 +0000 Subject: soc: apple: Add hardware tunable support Various hardware, like the Type-C PHY or the Thunderbolt/USB4 NHI, present on Apple SoCs need machine-specific tunables passed from our bootloader m1n1 to the device tree. Add generic helpers so that we don't have to duplicate this across multiple drivers. Reviewed-by: Alyssa Rosenzweig Reviewed-by: Neal Gompa Reviewed-by: Janne Grunau Signed-off-by: Sven Peter Link: https://patch.msgid.link/20251214-b4-atcphy-v3-1-ba82b20e9459@kernel.org Signed-off-by: Vinod Koul --- include/linux/soc/apple/tunable.h | 62 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 include/linux/soc/apple/tunable.h (limited to 'include/linux/soc') diff --git a/include/linux/soc/apple/tunable.h b/include/linux/soc/apple/tunable.h new file mode 100644 index 000000000000..531ca814cd02 --- /dev/null +++ b/include/linux/soc/apple/tunable.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0-only OR MIT */ +/* + * Apple Silicon hardware tunable support + * + * Each tunable is a list with each entry containing a offset into the MMIO + * region, a mask of bits to be cleared and a set of bits to be set. These + * tunables are passed along by the previous boot stages and vary from device + * to device such that they cannot be hardcoded in the individual drivers. + * + * Copyright (C) The Asahi Linux Contributors + */ + +#ifndef _LINUX_SOC_APPLE_TUNABLE_H_ +#define _LINUX_SOC_APPLE_TUNABLE_H_ + +#include +#include + +/** + * Struct to store an Apple Silicon hardware tunable. + * + * Each tunable is a list with each entry containing a offset into the MMIO + * region, a mask of bits to be cleared and a set of bits to be set. These + * tunables are passed along by the previous boot stages and vary from device + * to device such that they cannot be hardcoded in the individual drivers. + * + * @param sz Number of [offset, mask, value] tuples stored in values. + * @param values [offset, mask, value] array. + */ +struct apple_tunable { + size_t sz; + struct { + u32 offset; + u32 mask; + u32 value; + } values[] __counted_by(sz); +}; + +/** + * Parse an array of hardware tunables from the device tree. + * + * @dev: Device node used for devm_kzalloc internally. + * @np: Device node which contains the tunable array. + * @name: Name of the device tree property which contains the tunables. + * @res: Resource to which the tunables will be applied, used for bound checking + * + * @return: devres allocated struct on success or PTR_ERR on failure. + */ +struct apple_tunable *devm_apple_tunable_parse(struct device *dev, + struct device_node *np, + const char *name, + struct resource *res); + +/** + * Apply a previously loaded hardware tunable. + * + * @param regs: MMIO to which the tunable will be applied. + * @param tunable: Pointer to the tunable. + */ +void apple_tunable_apply(void __iomem *regs, struct apple_tunable *tunable); + +#endif -- cgit v1.2.3