1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Helper module for board specific I2C bus registration
 4 *
 5 * Copyright (C) 2009 Nokia Corporation.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 6 */
 7
 8#include "soc.h"
 9#include "omap_hwmod.h"
10#include "omap_device.h"
 
11
12#include "prm.h"
13#include "common.h"
14#include "i2c.h"
15
16/* In register I2C_CON, Bit 15 is the I2C enable bit */
17#define I2C_EN					BIT(15)
18#define OMAP2_I2C_CON_OFFSET			0x24
19#define OMAP4_I2C_CON_OFFSET			0xA4
20
21#define MAX_OMAP_I2C_HWMOD_NAME_LEN	16
22
23/**
24 * omap_i2c_reset - reset the omap i2c module.
25 * @oh: struct omap_hwmod *
26 *
27 * The i2c moudle in omap2, omap3 had a special sequence to reset. The
28 * sequence is:
29 * - Disable the I2C.
30 * - Write to SOFTRESET bit.
31 * - Enable the I2C.
32 * - Poll on the RESETDONE bit.
33 * The sequence is implemented in below function. This is called for 2420,
34 * 2430 and omap3.
35 */
36int omap_i2c_reset(struct omap_hwmod *oh)
37{
38	u32 v;
39	u16 i2c_con;
40	int c = 0;
41
42	if (soc_is_omap24xx() || soc_is_omap34xx() || soc_is_am35xx())
43		i2c_con = OMAP2_I2C_CON_OFFSET;
44	else
45		i2c_con = OMAP4_I2C_CON_OFFSET;
 
 
 
 
 
 
 
46
47	/* Disable I2C */
48	v = omap_hwmod_read(oh, i2c_con);
49	v &= ~I2C_EN;
50	omap_hwmod_write(v, oh, i2c_con);
51
52	/* Write to the SOFTRESET bit */
53	omap_hwmod_softreset(oh);
54
55	/* Enable I2C */
56	v = omap_hwmod_read(oh, i2c_con);
57	v |= I2C_EN;
58	omap_hwmod_write(v, oh, i2c_con);
59
60	/* Poll on RESETDONE bit */
61	omap_test_timeout((omap_hwmod_read(oh,
62				oh->class->sysc->syss_offs)
63				& SYSS_RESETDONE_MASK),
64				MAX_MODULE_SOFTRESET_WAIT, c);
65
66	if (c == MAX_MODULE_SOFTRESET_WAIT)
67		pr_warn("%s: %s: softreset failed (waited %d usec)\n",
68			__func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
69	else
70		pr_debug("%s: %s: softreset in %d usec\n", __func__,
71			oh->name, c);
72
73	return 0;
74}

 
 1/*
 2 * Helper module for board specific I2C bus registration
 3 *
 4 * Copyright (C) 2009 Nokia Corporation.
 5 *
 6 * This program is free software; you can redistribute it and/or
 7 * modify it under the terms of the GNU General Public License
 8 * version 2 as published by the Free Software Foundation.
 9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
18 * 02110-1301 USA
19 *
20 */
21
22#include "soc.h"
23#include "omap_hwmod.h"
24#include "omap_device.h"
25#include "omap-pm.h"
26
27#include "prm.h"
28#include "common.h"
29#include "i2c.h"
30
31/* In register I2C_CON, Bit 15 is the I2C enable bit */
32#define I2C_EN					BIT(15)
33#define OMAP2_I2C_CON_OFFSET			0x24
34#define OMAP4_I2C_CON_OFFSET			0xA4
35
36#define MAX_OMAP_I2C_HWMOD_NAME_LEN	16
37
38/**
39 * omap_i2c_reset - reset the omap i2c module.
40 * @oh: struct omap_hwmod *
41 *
42 * The i2c moudle in omap2, omap3 had a special sequence to reset. The
43 * sequence is:
44 * - Disable the I2C.
45 * - Write to SOFTRESET bit.
46 * - Enable the I2C.
47 * - Poll on the RESETDONE bit.
48 * The sequence is implemented in below function. This is called for 2420,
49 * 2430 and omap3.
50 */
51int omap_i2c_reset(struct omap_hwmod *oh)
52{
53	u32 v;
54	u16 i2c_con;
55	int c = 0;
56
57	if (oh->class->rev == OMAP_I2C_IP_VERSION_2) {
 
 
58		i2c_con = OMAP4_I2C_CON_OFFSET;
59	} else if (oh->class->rev == OMAP_I2C_IP_VERSION_1) {
60		i2c_con = OMAP2_I2C_CON_OFFSET;
61	} else {
62		WARN(1, "Cannot reset I2C block %s: unsupported revision\n",
63		     oh->name);
64		return -EINVAL;
65	}
66
67	/* Disable I2C */
68	v = omap_hwmod_read(oh, i2c_con);
69	v &= ~I2C_EN;
70	omap_hwmod_write(v, oh, i2c_con);
71
72	/* Write to the SOFTRESET bit */
73	omap_hwmod_softreset(oh);
74
75	/* Enable I2C */
76	v = omap_hwmod_read(oh, i2c_con);
77	v |= I2C_EN;
78	omap_hwmod_write(v, oh, i2c_con);
79
80	/* Poll on RESETDONE bit */
81	omap_test_timeout((omap_hwmod_read(oh,
82				oh->class->sysc->syss_offs)
83				& SYSS_RESETDONE_MASK),
84				MAX_MODULE_SOFTRESET_WAIT, c);
85
86	if (c == MAX_MODULE_SOFTRESET_WAIT)
87		pr_warn("%s: %s: softreset failed (waited %d usec)\n",
88			__func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
89	else
90		pr_debug("%s: %s: softreset in %d usec\n", __func__,
91			oh->name, c);
92
93	return 0;
94}