| /* |
| * Copyright (c) 2012 Code Aurora Forum. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 and |
| * only version 2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| */ |
| |
| #ifndef _LINUX_IOPOLL_H |
| #define _LINUX_IOPOLL_H |
| |
| #include <linux/kernel.h> |
| #include <linux/types.h> |
| #include <linux/jiffies.h> |
| #include <linux/delay.h> |
| #include <asm-generic/errno.h> |
| #include <asm/io.h> |
| |
| /** |
| * readl_poll_timeout - Periodically poll an address until a condition is met or a timeout occurs |
| * @addr: Address to poll |
| * @val: Variable to read the value into |
| * @cond: Break condition (usually involving @val) |
| * @sleep_us: Maximum time to sleep between reads in uS (0 tight-loops) |
| * @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. Must not |
| * be called from atomic context if sleep_us or timeout_us are used. |
| */ |
| #define readl_poll_timeout(addr, val, cond, sleep_us, timeout_us) \ |
| ({ \ |
| unsigned long timeout = jiffies + usecs_to_jiffies(timeout_us); \ |
| might_sleep_if(timeout_us); \ |
| for (;;) { \ |
| (val) = readl(addr); \ |
| if ((cond) || (timeout_us && time_after(jiffies, timeout))) \ |
| break; \ |
| if (sleep_us) \ |
| usleep_range(DIV_ROUND_UP(sleep_us, 4), sleep_us); \ |
| } \ |
| (cond) ? 0 : -ETIMEDOUT; \ |
| }) |
| |
| /** |
| * readl_poll - Periodically poll an address until a condition is met |
| * @addr: Address to poll |
| * @val: Variable to read the value into |
| * @cond: Break condition (usually involving @val) |
| * @sleep_us: Maximum time to sleep between reads in uS (0 tight-loops) |
| * |
| * Must not be called from atomic context if sleep_us is used. |
| */ |
| #define readl_poll(addr, val, cond, sleep_us) \ |
| readl_poll_timeout(addr, val, cond, sleep_us, 0) |
| |
| /** |
| * readl_tight_poll_timeout - Tight-loop on an address until a condition is met or a timeout occurs |
| * @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. Must not |
| * be called from atomic context if timeout_us is used. |
| */ |
| #define readl_tight_poll_timeout(addr, val, cond, timeout_us) \ |
| readl_poll_timeout(addr, val, cond, 0, timeout_us) |
| |
| /** |
| * readl_tight_poll - Tight-loop on an address until a condition is met |
| * @addr: Address to poll |
| * @val: Variable to read the value into |
| * @cond: Break condition (usually involving @val) |
| * |
| * May be called from atomic context. |
| */ |
| #define readl_tight_poll(addr, val, cond) \ |
| readl_poll_timeout(addr, val, cond, 0, 0) |
| |
| #endif /* _LINUX_IOPOLL_H */ |