linux/arch/arm/plat-omap/include/plat/i2c.h
Avinash.H.M 6d3c55fd4f OMAP: hwmod: fix the i2c-reset timeout during bootup
The sequence of _ocp_softreset doesn't work for i2c. The i2c module has a
special sequence to reset the module. The sequence is
 - Disable the I2C.
 - Write to SOFTRESET bit.
 - Enable the I2C.
 - Poll on the RESETDONE bit.
The sequence is implemented as a function and the i2c_class is updated with
the correct 'reset' pointer.  omap_hwmod_softreset function is implemented
which triggers the softreset by writing into sysconfig register. On following
this sequence, i2c module resets properly and timeouts are not seen.

Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Signed-off-by: Avinash.H.M <avinashhm@ti.com>
[paul@pwsan.com: combined this patch with a patch to remove
 HWMOD_INIT_NO_RESET from the 44xx hwmod flags; change register
 offset conditional code to use the IP block revision; minor code
 cleanup]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2011-07-10 05:27:16 -06:00

60 lines
1.7 KiB
C

/*
* Helper module for board specific I2C bus registration
*
* Copyright (C) 2009 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#ifndef __ASM__ARCH_OMAP_I2C_H
#define __ASM__ARCH_OMAP_I2C_H
#include <linux/i2c.h>
#include <linux/i2c-omap.h>
#if defined(CONFIG_I2C_OMAP) || defined(CONFIG_I2C_OMAP_MODULE)
extern int omap_register_i2c_bus(int bus_id, u32 clkrate,
struct i2c_board_info const *info,
unsigned len);
#else
static inline int omap_register_i2c_bus(int bus_id, u32 clkrate,
struct i2c_board_info const *info,
unsigned len)
{
return 0;
}
#endif
/**
* i2c_dev_attr - OMAP I2C controller device attributes for omap_hwmod
* @fifo_depth: total controller FIFO size (in bytes)
* @flags: differences in hardware support capability
*
* @fifo_depth represents what exists on the hardware, not what is
* actually configured at runtime by the device driver.
*/
struct omap_i2c_dev_attr {
u8 fifo_depth;
u32 flags;
};
void __init omap1_i2c_mux_pins(int bus_id);
void __init omap2_i2c_mux_pins(int bus_id);
struct omap_hwmod;
int omap_i2c_reset(struct omap_hwmod *oh);
#endif /* __ASM__ARCH_OMAP_I2C_H */