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OMAP: hwmod: fix the i2c-reset timeout during bootup

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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>
This commit is contained in:
Avinash.H.M
2011-07-10 05:27:16 -06:00
committed by Paul Walmsley
parent 4d4441a622
commit 6d3c55fd4f
8 changed files with 111 additions and 7 deletions
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27
arch/arm/mach-omap2/omap_hwmod.c
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@ -1655,6 +1655,33 @@ void omap_hwmod_write(u32 v, struct omap_hwmod *oh, u16 reg_offs)
__raw_writel(v, oh->_mpu_rt_va + reg_offs);
}
/**
* omap_hwmod_softreset - reset a module via SYSCONFIG.SOFTRESET bit
* @oh: struct omap_hwmod *
*
* This is a public function exposed to drivers. Some drivers may need to do
* some settings before and after resetting the device. Those drivers after
* doing the necessary settings could use this function to start a reset by
* setting the SYSCONFIG.SOFTRESET bit.
*/
int omap_hwmod_softreset(struct omap_hwmod *oh)
{
u32 v;
int ret;
if (!oh || !(oh->_sysc_cache))
return -EINVAL;
v = oh->_sysc_cache;
ret = _set_softreset(oh, &v);
if (ret)
goto error;
_write_sysconfig(v, oh);
error:
return ret;
}
/**
* omap_hwmod_set_slave_idlemode - set the hwmod's OCP slave idlemode
* @oh: struct omap_hwmod *