2 * Helper module for board specific I2C bus registration
4 * Copyright (C) 2009 Nokia Corporation.
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.
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.
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
23 #include "omap_hwmod.h"
24 #include "omap_device.h"
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
36 #define MAX_OMAP_I2C_HWMOD_NAME_LEN 16
39 * omap_i2c_reset - reset the omap i2c module.
40 * @oh: struct omap_hwmod *
42 * The i2c moudle in omap2, omap3 had a special sequence to reset. The
45 * - Write to SOFTRESET bit.
47 * - Poll on the RESETDONE bit.
48 * The sequence is implemented in below function. This is called for 2420,
51 int omap_i2c_reset(struct omap_hwmod *oh)
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;
62 WARN(1, "Cannot reset I2C block %s: unsupported revision\n",
68 v = omap_hwmod_read(oh, i2c_con);
70 omap_hwmod_write(v, oh, i2c_con);
72 /* Write to the SOFTRESET bit */
73 omap_hwmod_softreset(oh);
76 v = omap_hwmod_read(oh, i2c_con);
78 omap_hwmod_write(v, oh, i2c_con);
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);
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);
90 pr_debug("%s: %s: softreset in %d usec\n", __func__,