1/*
 2 * Copyright (C) 1999 ARM Limited
 3 * Copyright (C) 2000 Deep Blue Solutions Ltd
 4 * Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved.
 5 * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
 6 * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
 7 * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
 8 *
 9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 */
14
15#include <linux/io.h>
16#include <linux/errno.h>
17#include <linux/delay.h>
18#include <linux/module.h>
 
19#include <linux/stmp_device.h>
20
21#define STMP_MODULE_CLKGATE	(1 << 30)
22#define STMP_MODULE_SFTRST	(1 << 31)
23
24/*
25 * Clear the bit and poll it cleared.  This is usually called with
26 * a reset address and mask being either SFTRST(bit 31) or CLKGATE
27 * (bit 30).
28 */
29static int stmp_clear_poll_bit(void __iomem *addr, u32 mask)
30{
31	int timeout = 0x400;
32
33	writel(mask, addr + STMP_OFFSET_REG_CLR);
34	udelay(1);
35	while ((readl(addr) & mask) && --timeout)
36		/* nothing */;
37
38	return !timeout;
39}
40
41int stmp_reset_block(void __iomem *reset_addr)
42{
43	int ret;
44	int timeout = 0x400;
45
46	/* clear and poll SFTRST */
47	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
48	if (unlikely(ret))
49		goto error;
50
51	/* clear CLKGATE */
52	writel(STMP_MODULE_CLKGATE, reset_addr + STMP_OFFSET_REG_CLR);
53
54	/* set SFTRST to reset the block */
55	writel(STMP_MODULE_SFTRST, reset_addr + STMP_OFFSET_REG_SET);
56	udelay(1);
57
58	/* poll CLKGATE becoming set */
59	while ((!(readl(reset_addr) & STMP_MODULE_CLKGATE)) && --timeout)
60		/* nothing */;
61	if (unlikely(!timeout))
62		goto error;
63
64	/* clear and poll SFTRST */
65	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
66	if (unlikely(ret))
67		goto error;
68
69	/* clear and poll CLKGATE */
70	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_CLKGATE);
71	if (unlikely(ret))
72		goto error;
73
74	return 0;
75
76error:
77	pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);
78	return -ETIMEDOUT;
79}
80EXPORT_SYMBOL(stmp_reset_block);

 1// SPDX-License-Identifier: GPL-2.0-or-later
 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, kernel@pengutronix.de
 7 * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
 8 * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
 
 
 
 
 
 9 */
10
11#include <linux/io.h>
12#include <linux/errno.h>
13#include <linux/delay.h>
14#include <linux/compiler.h>
15#include <linux/export.h>
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 */
26static 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
38int 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
73error:
74	pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);
75	return -ETIMEDOUT;
76}
77EXPORT_SYMBOL(stmp_reset_block);