From aade6ceb29765f1d53e659560fb9123636c0f2d2 Mon Sep 17 00:00:00 2001 From: Andrey Smirnov Date: Thu, 14 Jun 2018 20:44:01 -0700 Subject: Port from U-Boot Signed-off-by: Andrey Smirnov Signed-off-by: Sascha Hauer --- include/linux/iopoll.h | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 include/linux/iopoll.h diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h new file mode 100644 index 0000000000..66c8f652ca --- /dev/null +++ b/include/linux/iopoll.h @@ -0,0 +1,75 @@ +/* + * Copyright (c) 2012-2014 The Linux Foundation. All rights reserved. + * + * SPDX-License-Identifier: GPL-2.0 + */ + +#ifndef _LINUX_IOPOLL_H +#define _LINUX_IOPOLL_H + +#include +#include +#include +#include + +/** + * readx_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs + * @op: accessor function (takes @addr as its only argument) + * @addr: Address to poll + * @val: Variable to read the value into + * @cond: Break condition (usually involving @val) + * @timeout_us: Timeout in us, 0 means never timeout + * + * Returns 0 on success and -ETIMEDOUT upon a timeout. In either + * case, the last read value at @addr is stored in @val. + * + * When available, you'll probably want to use one of the specialized + * macros defined below rather than this macro directly. + * + * We do not have timing functions in the PBL, so ignore the timeout value and + * loop infinitely here. + */ +#define readx_poll_timeout(op, addr, val, cond, timeout_us) \ +({ \ + uint64_t start; \ + if (!IN_PBL && timeout_us) \ + start = get_time_ns(); \ + for (;;) { \ + (val) = op(addr); \ + if (cond) \ + break; \ + if (!IN_PBL && timeout_us && \ + is_timeout(start, ((timeout_us) * USECOND))) { \ + (val) = op(addr); \ + break; \ + } \ + } \ + (cond) ? 0 : -ETIMEDOUT; \ +}) + + +#define readb_poll_timeout(addr, val, cond, timeout_us) \ + readx_poll_timeout(readb, addr, val, cond, timeout_us) + +#define readw_poll_timeout(addr, val, cond, timeout_us) \ + readx_poll_timeout(readw, addr, val, cond, timeout_us) + +#define readl_poll_timeout(addr, val, cond, timeout_us) \ + readx_poll_timeout(readl, addr, val, cond, timeout_us) + +#define readq_poll_timeout(addr, val, cond, timeout_us) \ + readx_poll_timeout(readq, addr, val, cond, timeout_us) + +#define readb_relaxed_poll_timeout(addr, val, cond, timeout_us) \ + readx_poll_timeout(readb_relaxed, addr, val, cond, timeout_us) + +#define readw_relaxed_poll_timeout(addr, val, cond, timeout_us) \ + readx_poll_timeout(readw_relaxed, addr, val, cond, timeout_us) + +#define readl_relaxed_poll_timeout(addr, val, cond, timeout_us) \ + readx_poll_timeout(readl_relaxed, addr, val, cond, timeout_us) + +#define readq_relaxed_poll_timeout(addr, val, cond, timeout_us) \ + readx_poll_timeout(readq_relaxed, addr, val, cond, timeout_us) + +#endif /* _LINUX_IOPOLL_H */ -- cgit v1.2.3