projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 4ccf4bea WS |
2 | /* |
| 3 | * Copyright (C) 1999 ARM Limited | |
| 4 | * Copyright (C) 2000 Deep Blue Solutions Ltd | |
| 5 | * Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved. | |
| 6 | * Copyright 2008 Juergen Beisert, [email protected] | |
| 7 | * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, [email protected] | |
| 8 | * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K. | |
| 4ccf4bea WS |
9 | */ |
| 10 | ||
| 11 | #include <linux/io.h> | |
| 12 | #include <linux/errno.h> | |
| 13 | #include <linux/delay.h> | |
| b6d4f322 RV |
14 | #include <linux/compiler.h> |
| 15 | #include <linux/export.h> | |
| 4ccf4bea WS |
16 | #include <linux/stmp_device.h> |
| 17 | ||
| 18 | #define STMP_MODULE_CLKGATE (1 << 30) | |
| 19 | #define STMP_MODULE_SFTRST (1 << 31) | |
| 20 | ||
| 21 | /* | |
| 22 | * Clear the bit and poll it cleared. This is usually called with | |
| 23 | * a reset address and mask being either SFTRST(bit 31) or CLKGATE | |
| 24 | * (bit 30). | |
| 25 | */ | |
| 26 | static int stmp_clear_poll_bit(void __iomem *addr, u32 mask) | |
| 27 | { | |
| 28 | int timeout = 0x400; | |
| 29 | ||
| 30 | writel(mask, addr + STMP_OFFSET_REG_CLR); | |
| 31 | udelay(1); | |
| 32 | while ((readl(addr) & mask) && --timeout) | |
| 33 | /* nothing */; | |
| 34 | ||
| 35 | return !timeout; | |
| 36 | } | |
| 37 | ||
| 38 | int stmp_reset_block(void __iomem *reset_addr) | |
| 39 | { | |
| 40 | int ret; | |
| 41 | int timeout = 0x400; | |
| 42 | ||
| 43 | /* clear and poll SFTRST */ | |
| 44 | ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST); | |
| 45 | if (unlikely(ret)) | |
| 46 | goto error; | |
| 47 | ||
| 48 | /* clear CLKGATE */ | |
| 49 | writel(STMP_MODULE_CLKGATE, reset_addr + STMP_OFFSET_REG_CLR); | |
| 50 | ||
| 51 | /* set SFTRST to reset the block */ | |
| 52 | writel(STMP_MODULE_SFTRST, reset_addr + STMP_OFFSET_REG_SET); | |
| 53 | udelay(1); | |
| 54 | ||
| 55 | /* poll CLKGATE becoming set */ | |
| 56 | while ((!(readl(reset_addr) & STMP_MODULE_CLKGATE)) && --timeout) | |
| 57 | /* nothing */; | |
| 58 | if (unlikely(!timeout)) | |
| 59 | goto error; | |
| 60 | ||
| 61 | /* clear and poll SFTRST */ | |
| 62 | ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST); | |
| 63 | if (unlikely(ret)) | |
| 64 | goto error; | |
| 65 | ||
| 66 | /* clear and poll CLKGATE */ | |
| 67 | ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_CLKGATE); | |
| 68 | if (unlikely(ret)) | |
| 69 | goto error; | |
| 70 | ||
| 71 | return 0; | |
| 72 | ||
| 73 | error: | |
| 74 | pr_err("%s(%p): module reset timeout\n", __func__, reset_addr); | |
| 75 | return -ETIMEDOUT; | |
| 76 | } | |
| 77 | EXPORT_SYMBOL(stmp_reset_block); |