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
);