diff options
| -rw-r--r-- | include/linux/stmp_device.h | 20 | ||||
| -rw-r--r-- | lib/Kconfig | 3 | ||||
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/stmp_device.c | 80 |
4 files changed, 105 insertions, 0 deletions
diff --git a/include/linux/stmp_device.h b/include/linux/stmp_device.h new file mode 100644 index 000000000000..6cf7ec9547cf --- /dev/null +++ b/include/linux/stmp_device.h @@ -0,0 +1,20 @@ +/* + * basic functions for devices following the "stmp" style register layout + * + * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __STMP_DEVICE_H__ +#define __STMP_DEVICE_H__ + +#define STMP_OFFSET_REG_SET 0x4 +#define STMP_OFFSET_REG_CLR 0x8 +#define STMP_OFFSET_REG_TOG 0xc + +extern int stmp_reset_block(void __iomem *); +#endif /* __STMP_DEVICE_H__ */ diff --git a/lib/Kconfig b/lib/Kconfig index 4a8aba2e5cc0..c5da1548b964 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -33,6 +33,9 @@ config GENERIC_IO boolean default n +config STMP_DEVICE + bool + config CRC_CCITT tristate "CRC-CCITT functions" help diff --git a/lib/Makefile b/lib/Makefile index 18515f0267c4..f78dbcdc7e3d 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -123,6 +123,8 @@ obj-$(CONFIG_SIGNATURE) += digsig.o obj-$(CONFIG_CLZ_TAB) += clz_tab.o +obj-$(CONFIG_STMP_DEVICE) += stmp_device.o + hostprogs-y := gen_crc32table clean-files := crc32table.h diff --git a/lib/stmp_device.c b/lib/stmp_device.c new file mode 100644 index 000000000000..8ac9bcc4289a --- /dev/null +++ b/lib/stmp_device.c @@ -0,0 +1,80 @@ +/* + * Copyright (C) 1999 ARM Limited + * Copyright (C) 2000 Deep Blue Solutions Ltd + * Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved. + * Copyright 2008 Juergen Beisert, kernel@pengutronix.de + * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com + * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/io.h> +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/stmp_device.h> + +#define STMP_MODULE_CLKGATE (1 << 30) +#define STMP_MODULE_SFTRST (1 << 31) + +/* + * Clear the bit and poll it cleared. This is usually called with + * a reset address and mask being either SFTRST(bit 31) or CLKGATE + * (bit 30). + */ +static int stmp_clear_poll_bit(void __iomem *addr, u32 mask) +{ + int timeout = 0x400; + + writel(mask, addr + STMP_OFFSET_REG_CLR); + udelay(1); + while ((readl(addr) & mask) && --timeout) + /* nothing */; + + return !timeout; +} + +int stmp_reset_block(void __iomem *reset_addr) +{ + int ret; + int timeout = 0x400; + + /* clear and poll SFTRST */ + ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST); + if (unlikely(ret)) + goto error; + + /* clear CLKGATE */ + writel(STMP_MODULE_CLKGATE, reset_addr + STMP_OFFSET_REG_CLR); + + /* set SFTRST to reset the block */ + writel(STMP_MODULE_SFTRST, reset_addr + STMP_OFFSET_REG_SET); + udelay(1); + + /* poll CLKGATE becoming set */ + while ((!(readl(reset_addr) & STMP_MODULE_CLKGATE)) && --timeout) + /* nothing */; + if (unlikely(!timeout)) + goto error; + + /* clear and poll SFTRST */ + ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST); + if (unlikely(ret)) + goto error; + + /* clear and poll CLKGATE */ + ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_CLKGATE); + if (unlikely(ret)) + goto error; + + return 0; + +error: + pr_err("%s(%p): module reset timeout\n", __func__, reset_addr); + return -ETIMEDOUT; +} +EXPORT_SYMBOL(stmp_reset_block); |