78 lines
2.3 KiB
C
78 lines
2.3 KiB
C
/*
|
|
* IP block integration code for the HDQ1W/1-wire IP block
|
|
*
|
|
* Copyright (C) 2012 Texas Instruments, Inc.
|
|
* Paul Walmsley
|
|
*
|
|
* Based on the I2C reset code in arch/arm/mach-omap2/i2c.c by
|
|
* Avinash.H.M <avinashhm@ti.com>
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/err.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
#include "soc.h"
|
|
#include "omap_hwmod.h"
|
|
#include "omap_device.h"
|
|
#include "hdq1w.h"
|
|
|
|
#include "prm.h"
|
|
#include "common.h"
|
|
|
|
/**
|
|
* omap_hdq1w_reset - reset the OMAP HDQ1W module
|
|
* @oh: struct omap_hwmod *
|
|
*
|
|
* OCP soft reset the HDQ1W IP block. Section 20.6.1.4 "HDQ1W/1-Wire
|
|
* Software Reset" of the OMAP34xx Technical Reference Manual Revision
|
|
* ZR (SWPU223R) does not include the rather important fact that, for
|
|
* the reset to succeed, the HDQ1W module's internal clock gate must be
|
|
* programmed to allow the clock to propagate to the rest of the
|
|
* module. In this sense, it's rather similar to the I2C custom reset
|
|
* function. Returns 0.
|
|
*/
|
|
int omap_hdq1w_reset(struct omap_hwmod *oh)
|
|
{
|
|
u32 v;
|
|
int c = 0;
|
|
|
|
/* Write to the SOFTRESET bit */
|
|
omap_hwmod_softreset(oh);
|
|
|
|
/* Enable the module's internal clocks */
|
|
v = omap_hwmod_read(oh, HDQ_CTRL_STATUS_OFFSET);
|
|
v |= 1 << HDQ_CTRL_STATUS_CLOCKENABLE_SHIFT;
|
|
omap_hwmod_write(v, oh, HDQ_CTRL_STATUS_OFFSET);
|
|
|
|
/* Poll on RESETDONE bit */
|
|
omap_test_timeout((omap_hwmod_read(oh,
|
|
oh->class->sysc->syss_offs)
|
|
& SYSS_RESETDONE_MASK),
|
|
MAX_MODULE_SOFTRESET_WAIT, c);
|
|
|
|
if (c == MAX_MODULE_SOFTRESET_WAIT)
|
|
pr_warn("%s: %s: softreset failed (waited %d usec)\n",
|
|
__func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
|
|
else
|
|
pr_debug("%s: %s: softreset in %d usec\n", __func__,
|
|
oh->name, c);
|
|
|
|
return 0;
|
|
}
|