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
24 #include "omap_hwmod.h"
25 #include "omap_device.h"
30 /* In register I2C_CON, Bit 15 is the I2C enable bit */
31 #define I2C_EN BIT(15)
32 #define OMAP2_I2C_CON_OFFSET 0x24
33 #define OMAP4_I2C_CON_OFFSET 0xA4
35 /* Maximum microseconds to wait for OMAP module to softreset */
36 #define MAX_MODULE_SOFTRESET_WAIT 10000
38 #define MAX_OMAP_I2C_HWMOD_NAME_LEN 16
40 static void __init omap2_i2c_mux_pins(int bus_id)
42 char mux_name[sizeof("i2c2_scl.i2c2_scl")];
44 /* First I2C bus is not muxable */
48 sprintf(mux_name, "i2c%i_scl.i2c%i_scl", bus_id, bus_id);
49 omap_mux_init_signal(mux_name, OMAP_PIN_INPUT);
50 sprintf(mux_name, "i2c%i_sda.i2c%i_sda", bus_id, bus_id);
51 omap_mux_init_signal(mux_name, OMAP_PIN_INPUT);
55 * omap_i2c_reset - reset the omap i2c module.
56 * @oh: struct omap_hwmod *
58 * The i2c moudle in omap2, omap3 had a special sequence to reset. The
61 * - Write to SOFTRESET bit.
63 * - Poll on the RESETDONE bit.
64 * The sequence is implemented in below function. This is called for 2420,
67 int omap_i2c_reset(struct omap_hwmod *oh)
73 if (oh->class->rev == OMAP_I2C_IP_VERSION_2) {
74 i2c_con = OMAP4_I2C_CON_OFFSET;
75 } else if (oh->class->rev == OMAP_I2C_IP_VERSION_1) {
76 i2c_con = OMAP2_I2C_CON_OFFSET;
78 WARN(1, "Cannot reset I2C block %s: unsupported revision\n",
84 v = omap_hwmod_read(oh, i2c_con);
86 omap_hwmod_write(v, oh, i2c_con);
88 /* Write to the SOFTRESET bit */
89 omap_hwmod_softreset(oh);
92 v = omap_hwmod_read(oh, i2c_con);
94 omap_hwmod_write(v, oh, i2c_con);
96 /* Poll on RESETDONE bit */
97 omap_test_timeout((omap_hwmod_read(oh,
98 oh->class->sysc->syss_offs)
99 & SYSS_RESETDONE_MASK),
100 MAX_MODULE_SOFTRESET_WAIT, c);
102 if (c == MAX_MODULE_SOFTRESET_WAIT)
103 pr_warning("%s: %s: softreset failed (waited %d usec)\n",
104 __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
106 pr_debug("%s: %s: softreset in %d usec\n", __func__,
112 static const char name[] = "omap_i2c";
114 int __init omap_i2c_add_bus(struct omap_i2c_bus_platform_data *i2c_pdata,
118 struct omap_hwmod *oh;
119 struct platform_device *pdev;
120 char oh_name[MAX_OMAP_I2C_HWMOD_NAME_LEN];
121 struct omap_i2c_bus_platform_data *pdata;
122 struct omap_i2c_dev_attr *dev_attr;
124 omap2_i2c_mux_pins(bus_id);
126 l = snprintf(oh_name, MAX_OMAP_I2C_HWMOD_NAME_LEN, "i2c%d", bus_id);
127 WARN(l >= MAX_OMAP_I2C_HWMOD_NAME_LEN,
128 "String buffer overflow in I2C%d device setup\n", bus_id);
129 oh = omap_hwmod_lookup(oh_name);
131 pr_err("Could not look up %s\n", oh_name);
137 * pass the hwmod class's CPU-specific knowledge of I2C IP revision in
138 * use, and functionality implementation flags, up to the OMAP I2C
139 * driver via platform data
141 pdata->rev = oh->class->rev;
143 dev_attr = (struct omap_i2c_dev_attr *)oh->dev_attr;
144 pdata->flags = dev_attr->flags;
146 pdev = omap_device_build(name, bus_id, oh, pdata,
147 sizeof(struct omap_i2c_bus_platform_data),
149 WARN(IS_ERR(pdev), "Could not build omap_device for %s\n", name);
151 return PTR_RET(pdev);