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>
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 7d242c9..02b6016 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -1656,6 +1656,33 @@
}
/**
+ * 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 *
* @idlemode: SIDLEMODE field bits (shifted to bit 0)