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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-24 08:46:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-24 08:46:03 -0700 |
| commit | cf9610f9116d55c5a66ef9f1faecacabd93a9322 (patch) | |
| tree | 757a3d280760c654767631cab5ad8af2d86d1848 /include/asm-generic/delay.h | |
| download | linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.tar.gz linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.zip | |
Merge tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlgrafted
Pull pin control updates from Linus Walleij:
"Core changes:
- Use the non-blocking mux_state_try_select() in the generic MUX pin
control back-end
- Free pin maps on pinctrl_generic_to_map() failure in the core
helpers
New hardware pin control:
- Qualcomm Maili TLMM SoC, PMG1110 PMIC, and Eliza LPASS LPI TLMM SoC
(this is for the low power audio, LPASS = Low Power Audio SubSystem
portions)
- Upboard support on top of the Intel pin controller
- Apple T6030 and T6031 support (just compatible strings)
- Samsung Exynos 8855 SoC
- Mediatek MT6858 SoC
- Rockchip RK3308B and RV1106 SoCs
- Airoha EN7523 and AN7563 SoCs
Improvements:
- Qualcomm TLMM GPIOs are unconditionally marked as wakeup capable
- Qualcomm improvements on top of the Qualcomm PDC (power domain
controller) irqchip improvements from tglx:s tree
- Qualcomm IPQ806x and IPQ9650 non-urgent pin grop fixups
- The NPCM8xx driver has been put into shape fixing many pin and
group definitions
- Some non-urgent Tegra 264 pin assignments are fixed up
- Some non-urgent fixups to Airoha AN7581 and AN7583 registers and
pin assignments, missing features etc"
* tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (130 commits)
dt-bindings: pinctrl: Convert TI DA850 pupd to DT schema
pinctrl: meson: sync some modify from A4
pinctrl: meson: a4: Add input enable pin configuration
pinctrl: realtek: rtd1625: remove unused group name spdif_sel
pinctrl: realtek: rtd1625: fix base_bit for VE4 GPIO 13
dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema
Revert "Merge branch 'ib-rsk7204' into devel"
pinctrl: rockchip: Add RV1106 pinctrl support
dt-bindings: pinctrl: rockchip: Add RV1106 compatible
pinctrl: rockchip: Decode drive strength in the get function
pinctrl: fix PINCTRL_GENERIC_MUX not always being selectable
pinctrl: airoha: add support of an7563 SoC
dt-bindings: pinctrl: airoha: add support of an7563 pin controller
pinctrl: airoha: try to find chip scu node by phandle first
pinctrl: airoha: add support of en7523 SoC
dt-bindings: pinctrl: airoha: add support of en7523 pin controller
pinctrl: airoha: an7583: add support for olt pinmux
pinctrl: airoha: an7583: add support for pon_alt pinmux
pinctrl: airoha: an7583: add support for npu_uart pinmux
dt-bindings: pinctrl: airoha: an7583: add missed features
...
Diffstat (limited to 'include/asm-generic/delay.h')
| -rw-r--r-- | include/asm-generic/delay.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/include/asm-generic/delay.h b/include/asm-generic/delay.h new file mode 100644 index 000000000..03b0ec7af --- /dev/null +++ b/include/asm-generic/delay.h @@ -0,0 +1,87 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_GENERIC_DELAY_H +#define __ASM_GENERIC_DELAY_H + +#include <linux/math.h> +#include <vdso/time64.h> + +/* Undefined functions to get compile-time errors */ +extern void __bad_udelay(void); +extern void __bad_ndelay(void); + +extern void __udelay(unsigned long usecs); +extern void __ndelay(unsigned long nsecs); +extern void __const_udelay(unsigned long xloops); +extern void __delay(unsigned long loops); + +/* + * The microseconds/nanosecond delay multiplicators are used to convert a + * constant microseconds/nanoseconds value to a value which can be used by the + * architectures specific implementation to transform it into loops. + */ +#define UDELAY_CONST_MULT ((unsigned long)DIV_ROUND_UP(1ULL << 32, USEC_PER_SEC)) +#define NDELAY_CONST_MULT ((unsigned long)DIV_ROUND_UP(1ULL << 32, NSEC_PER_SEC)) + +/* + * The maximum constant udelay/ndelay value picked out of thin air to prevent + * too long constant udelays/ndelays. + */ +#define DELAY_CONST_MAX 20000 + +/** + * udelay - Inserting a delay based on microseconds with busy waiting + * @usec: requested delay in microseconds + * + * When delaying in an atomic context ndelay(), udelay() and mdelay() are the + * only valid variants of delaying/sleeping to go with. + * + * When inserting delays in non atomic context which are shorter than the time + * which is required to queue e.g. an hrtimer and to enter then the scheduler, + * it is also valuable to use udelay(). But it is not simple to specify a + * generic threshold for this which will fit for all systems. An approximation + * is a threshold for all delays up to 10 microseconds. + * + * When having a delay which is larger than the architecture specific + * %MAX_UDELAY_MS value, please make sure mdelay() is used. Otherwise a overflow + * risk is given. + * + * Please note that ndelay(), udelay() and mdelay() may return early for several + * reasons (https://lists.openwall.net/linux-kernel/2011/01/09/56): + * + * #. computed loops_per_jiffy too low (due to the time taken to execute the + * timer interrupt.) + * #. cache behaviour affecting the time it takes to execute the loop function. + * #. CPU clock rate changes. + */ +static __always_inline void udelay(unsigned long usec) +{ + if (__builtin_constant_p(usec)) { + if (usec >= DELAY_CONST_MAX) + __bad_udelay(); + else + __const_udelay(usec * UDELAY_CONST_MULT); + } else { + __udelay(usec); + } +} + +/** + * ndelay - Inserting a delay based on nanoseconds with busy waiting + * @nsec: requested delay in nanoseconds + * + * See udelay() for basic information about ndelay() and it's variants. + */ +static __always_inline void ndelay(unsigned long nsec) +{ + if (__builtin_constant_p(nsec)) { + if (nsec >= DELAY_CONST_MAX) + __bad_ndelay(); + else + __const_udelay(nsec * NDELAY_CONST_MULT); + } else { + __ndelay(nsec); + } +} +#define ndelay(x) ndelay(x) + +#endif /* __ASM_GENERIC_DELAY_H */ |
