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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
parent27953437059c64d14086196eb96f43c78caa9db3 (diff)
parent3f81b2c49d31e763a9c1da831ceb6cef087cf6c6 (diff)
downloadlinux-39b6cc668c5ecc66f6f9c9293ffab681cb6f7065.tar.bz2
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
-rw-r--r--drivers/i2c/busses/Kconfig1
-rw-r--r--drivers/i2c/busses/i2c-mxs.c9
-rw-r--r--include/linux/stmp_device.h20
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/Makefile2
-rw-r--r--lib/stmp_device.c80
6 files changed, 108 insertions, 7 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 94468a64ce3a..eec2cf57539a 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -483,6 +483,7 @@ config I2C_MV64XXX
config I2C_MXS
tristate "Freescale i.MX28 I2C interface"
depends on SOC_IMX28
+ select STMP_DEVICE
help
Say Y here if you want to use the I2C bus controller on
the Freescale i.MX28 processors.
diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c
index 7fa73eed84a7..58a338846f06 100644
--- a/drivers/i2c/busses/i2c-mxs.c
+++ b/drivers/i2c/busses/i2c-mxs.c
@@ -27,8 +27,7 @@
#include <linux/jiffies.h>
#include <linux/io.h>
#include <linux/pinctrl/consumer.h>
-
-#include <mach/common.h>
+#include <linux/stmp_device.h>
#define DRIVER_NAME "mxs-i2c"
@@ -112,13 +111,9 @@ struct mxs_i2c_dev {
struct i2c_adapter adapter;
};
-/*
- * TODO: check if calls to here are really needed. If not, we could get rid of
- * mxs_reset_block and the mach-dependency. Needs an I2C analyzer, probably.
- */
static void mxs_i2c_reset(struct mxs_i2c_dev *i2c)
{
- mxs_reset_block(i2c->regs);
+ stmp_reset_block(i2c->regs);
writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET);
writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE,
i2c->regs + MXS_I2C_QUEUECTRL_SET);
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 98230ac3db29..3e63af089082 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 b98df505f335..2a1d7f9d39a2 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 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);