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| 2 | * Copyright (C) 1999 ARM Limited
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| 3 | * Copyright (C) 2000 Deep Blue Solutions Ltd
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| 4 | * Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved.
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| 5 | * Copyright 2008 Juergen Beisert, [email protected]
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| 6 | * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, [email protected]
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| 7 | * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
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| 8 | *
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| 9 | * This program is free software; you can redistribute it and/or modify
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| 10 | * it under the terms of the GNU General Public License as published by
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| 11 | * the Free Software Foundation; either version 2 of the License, or
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| 12 | * (at your option) any later version.
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| 13 |
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| 14 |
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| 15 | #include <linux/io.h>
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| 16 | #include <linux/errno.h>
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| 17 | #include <linux/delay.h>
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| 18 | #include <linux/module.h>
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| 19 | #include <linux/stmp_device.h>
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| 20 |
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| 21 | #define STMP_MODULE_CLKGATE (1 << 30)
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| 22 | #define STMP_MODULE_SFTRST (1 << 31)
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| 23 |
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| 24 | |
| 25 | * Clear the bit and poll it cleared. This is usually called with
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| 26 | * a reset address and mask being either SFTRST(bit 31) or CLKGATE
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| 27 | * (bit 30).
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| 28 |
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| 29 | static int stmp_clear_poll_bit(void __iomem *addr, u32 mask)
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| 30 | {
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| 31 | int timeout = 0x400;
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| 32 |
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| 33 | writel(mask, addr + STMP_OFFSET_REG_CLR);
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| 34 | udelay(1);
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| 35 | while ((readl(addr) & mask) && --timeout)
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| 36 | ;
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| 37 |
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| 38 | return !timeout;
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| 39 | }
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| 40 |
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| 41 | int stmp_reset_block(void __iomem *reset_addr)
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| 42 | {
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| 43 | int ret;
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| 44 | int timeout = 0x400;
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| 45 |
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| 46 |
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| 47 | ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
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| 48 | if (unlikely(ret))
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| 49 | goto error;
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| 50 |
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| 51 |
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| 52 | writel(STMP_MODULE_CLKGATE, reset_addr + STMP_OFFSET_REG_CLR);
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| 53 |
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| 54 |
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| 55 | writel(STMP_MODULE_SFTRST, reset_addr + STMP_OFFSET_REG_SET);
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| 56 | udelay(1);
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| 57 |
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| 58 |
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| 59 | while ((!(readl(reset_addr) & STMP_MODULE_CLKGATE)) && --timeout)
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| 60 | ;
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| 61 | if (unlikely(!timeout))
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| 62 | goto error;
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| 63 |
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| 64 |
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| 65 | ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
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| 66 | if (unlikely(ret))
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| 67 | goto error;
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| 68 |
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| 69 |
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| 70 | ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_CLKGATE);
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| 71 | if (unlikely(ret))
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| 72 | goto error;
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| 73 |
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| 74 | return 0;
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| 75 |
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| 76 | error:
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| 77 | pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);
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| 78 | return -ETIMEDOUT;
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| 79 | }
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| 80 | EXPORT_SYMBOL(stmp_reset_block);
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