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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-26 12:50:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-26 12:50:04 -0700
commit39b6cc668c5ecc66f6f9c9293ffab681cb6f7065 (patch)
treef048b17a1b1a0a0f6d6a8d33459e8789c600c634 /lib
parent27953437059c64d14086196eb96f43c78caa9db3 (diff)
parent3f81b2c49d31e763a9c1da831ceb6cef087cf6c6 (diff)
Merge tag 'stmp-dev' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull arm-soc stmp-dev library code from Olof Johansson: "A number of devices are using a common register layout, this adds support code for it in lib/stmp_device.c so we do not need to duplicate it in each driver." Fix up trivial conflicts in drivers/i2c/busses/i2c-mxs.c and lib/Makefile * tag 'stmp-dev' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: i2c: mxs: use global reset function lib: add support for stmp-style devices
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/Makefile2
-rw-r--r--lib/stmp_device.c80
3 files changed, 85 insertions, 0 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index 98230ac3db2..3e63af08908 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -36,6 +36,9 @@ 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 b98df505f33..2a1d7f9d39a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -127,6 +127,8 @@ obj-$(CONFIG_DDR) += jedec_ddr_data.o
obj-$(CONFIG_GENERIC_STRNCPY_FROM_USER) += strncpy_from_user.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 00000000000..8ac9bcc4289
--- /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);