diff options
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-mxs.c | 9 | ||||
| -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 |
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); |