From mboxrd@z Thu Jan 1 00:00:00 1970 From: w.sang@pengutronix.de (Wolfram Sang) Date: Wed, 16 Nov 2011 11:47:37 +0100 Subject: [PATCH 1/3] drivers: base: add support for stmp-style devices In-Reply-To: <1321440459-4527-1-git-send-email-w.sang@pengutronix.de> References: <1321440459-4527-1-git-send-email-w.sang@pengutronix.de> Message-ID: <1321440459-4527-2-git-send-email-w.sang@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Signed-off-by: Wolfram Sang --- drivers/base/Kconfig | 3 ++ drivers/base/Makefile | 1 + drivers/base/stmp_device.c | 80 +++++++++++++++++++++++++++++++++++++++++++ include/linux/stmp_device.h | 19 ++++++++++ 4 files changed, 103 insertions(+), 0 deletions(-) create mode 100644 drivers/base/stmp_device.c create mode 100644 include/linux/stmp_device.h diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 21cf46f..331f78f 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -172,6 +172,9 @@ config SYS_HYPERVISOR bool default n +config STMP_DEVICE + bool + source "drivers/base/regmap/Kconfig" endmenu diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 99a375a..b865072 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -17,6 +17,7 @@ ifeq ($(CONFIG_SYSFS),y) obj-$(CONFIG_MODULES) += module.o endif obj-$(CONFIG_SYS_HYPERVISOR) += hypervisor.o +obj-$(CONFIG_STMP_DEVICE) += stmp_device.o obj-$(CONFIG_REGMAP) += regmap/ ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG diff --git a/drivers/base/stmp_device.c b/drivers/base/stmp_device.c new file mode 100644 index 0000000..3e261e6 --- /dev/null +++ b/drivers/base/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 at pengutronix.de + * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok at 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 +#include +#include +#include +#include + +#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_CLR_ADDR); + 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_CLR_ADDR); + + /* set SFTRST to reset the block */ + writel(STMP_MODULE_SFTRST, reset_addr + STMP_SET_ADDR); + 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); diff --git a/include/linux/stmp_device.h b/include/linux/stmp_device.h new file mode 100644 index 0000000..330f8d8 --- /dev/null +++ b/include/linux/stmp_device.h @@ -0,0 +1,19 @@ +/* + * 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; version 2 of the License. + */ + +#ifndef __STMP_DEVICE_H__ +#define __STMP_DEVICE_H__ + +#define STMP_SET_ADDR 0x4 +#define STMP_CLR_ADDR 0x8 +#define STMP_TOG_ADDR 0xc + +extern int stmp_reset_block(void __iomem *); +#endif /* __STMP_DEVICE_H__ */ -- 1.7.7.1