ARM: OMAP: Add method to register additional I2C busses on the command line, v2
[linux-2.6.git] / arch / arm / plat-omap / i2c.c
1 /*
2  * linux/arch/arm/plat-omap/i2c.c
3  *
4  * Helper module for board specific I2C bus registration
5  *
6  * Copyright (C) 2007 Nokia Corporation.
7  *
8  * Contact: Jarkko Nikula <jarkko.nikula@nokia.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * version 2 as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22  * 02110-1301 USA
23  *
24  */
25
26 #include <linux/kernel.h>
27 #include <linux/platform_device.h>
28 #include <linux/i2c.h>
29 #include <mach/irqs.h>
30 #include <mach/mux.h>
31
32 #define OMAP_I2C_SIZE           0x3f
33 #define OMAP1_I2C_BASE          0xfffb3800
34 #define OMAP2_I2C_BASE1         0x48070000
35 #define OMAP2_I2C_BASE2         0x48072000
36 #define OMAP2_I2C_BASE3         0x48060000
37
38 static const char name[] = "i2c_omap";
39
40 #define I2C_RESOURCE_BUILDER(base, irq)                 \
41         {                                               \
42                 .start  = (base),                       \
43                 .end    = (base) + OMAP_I2C_SIZE,       \
44                 .flags  = IORESOURCE_MEM,               \
45         },                                              \
46         {                                               \
47                 .start  = (irq),                        \
48                 .flags  = IORESOURCE_IRQ,               \
49         },
50
51 static struct resource i2c_resources[][2] = {
52         { I2C_RESOURCE_BUILDER(0, 0) },
53 #if     defined(CONFIG_ARCH_OMAP24XX) || defined(CONFIG_ARCH_OMAP34XX)
54         { I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE2, INT_24XX_I2C2_IRQ) },
55 #endif
56 #if     defined(CONFIG_ARCH_OMAP34XX)
57         { I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE3, INT_34XX_I2C3_IRQ) },
58 #endif
59 };
60
61 #define I2C_DEV_BUILDER(bus_id, res, data)              \
62         {                                               \
63                 .id     = (bus_id),                     \
64                 .name   = name,                         \
65                 .num_resources  = ARRAY_SIZE(res),      \
66                 .resource       = (res),                \
67                 .dev            = {                     \
68                         .platform_data  = (data),       \
69                 },                                      \
70         }
71
72 static u32 i2c_rate[ARRAY_SIZE(i2c_resources)];
73 static struct platform_device omap_i2c_devices[] = {
74         I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_rate[0]),
75 #if     defined(CONFIG_ARCH_OMAP24XX) || defined(CONFIG_ARCH_OMAP34XX)
76         I2C_DEV_BUILDER(2, i2c_resources[1], &i2c_rate[1]),
77 #endif
78 #if     defined(CONFIG_ARCH_OMAP34XX)
79         I2C_DEV_BUILDER(3, i2c_resources[2], &i2c_rate[2]),
80 #endif
81 };
82
83 #if defined(CONFIG_ARCH_OMAP24XX)
84 static const int omap24xx_pins[][2] = {
85         { M19_24XX_I2C1_SCL, L15_24XX_I2C1_SDA },
86         { J15_24XX_I2C2_SCL, H19_24XX_I2C2_SDA },
87 };
88 #else
89 static const int omap24xx_pins[][2] = {};
90 #endif
91 #if defined(CONFIG_ARCH_OMAP34XX)
92 static const int omap34xx_pins[][2] = {
93         { K21_34XX_I2C1_SCL, J21_34XX_I2C1_SDA},
94         { AF15_34XX_I2C2_SCL, AE15_34XX_I2C2_SDA},
95         { AF14_34XX_I2C3_SCL, AG14_34XX_I2C3_SDA},
96 };
97 #else
98 static const int omap34xx_pins[][2] = {};
99 #endif
100
101 #define OMAP_I2C_CMDLINE_SETUP  (BIT(31))
102
103 static void __init omap_i2c_mux_pins(int bus)
104 {
105         int scl, sda;
106
107         if (cpu_class_is_omap1()) {
108                 scl = I2C_SCL;
109                 sda = I2C_SDA;
110         } else if (cpu_is_omap24xx()) {
111                 scl = omap24xx_pins[bus][0];
112                 sda = omap24xx_pins[bus][1];
113         } else if (cpu_is_omap34xx()) {
114                 scl = omap34xx_pins[bus][0];
115                 sda = omap34xx_pins[bus][1];
116         } else {
117                 return;
118         }
119
120         omap_cfg_reg(sda);
121         omap_cfg_reg(scl);
122 }
123
124 static int __init omap_i2c_nr_ports(void)
125 {
126         int ports = 0;
127
128         if (cpu_class_is_omap1())
129                 ports = 1;
130         else if (cpu_is_omap24xx())
131                 ports = 2;
132         else if (cpu_is_omap34xx())
133                 ports = 3;
134
135         return ports;
136 }
137
138 static int __init omap_i2c_add_bus(int bus_id)
139 {
140         struct platform_device *pdev;
141         struct resource *res;
142         resource_size_t base, irq;
143
144         pdev = &omap_i2c_devices[bus_id - 1];
145         if (bus_id == 1) {
146                 res = pdev->resource;
147                 if (cpu_class_is_omap1()) {
148                         base = OMAP1_I2C_BASE;
149                         irq = INT_I2C;
150                 } else {
151                         base = OMAP2_I2C_BASE1;
152                         irq = INT_24XX_I2C1_IRQ;
153                 }
154                 res[0].start = base;
155                 res[0].end = base + OMAP_I2C_SIZE;
156                 res[1].start = irq;
157         }
158
159         omap_i2c_mux_pins(bus_id - 1);
160         return platform_device_register(pdev);
161 }
162
163 /**
164  * omap_i2c_bus_setup - Process command line options for the I2C bus speed
165  * @str: String of options
166  *
167  * This function allow to override the default I2C bus speed for given I2C
168  * bus with a command line option.
169  *
170  * Format: i2c_bus=bus_id,clkrate (in kHz)
171  *
172  * Returns 1 on success, 0 otherwise.
173  */
174 static int __init omap_i2c_bus_setup(char *str)
175 {
176         int ports;
177         int ints[3];
178
179         ports = omap_i2c_nr_ports();
180         get_options(str, 3, ints);
181         if (ints[0] < 2 || ints[1] < 1 || ints[1] > ports)
182                 return 0;
183         i2c_rate[ints[1] - 1] = ints[2];
184         i2c_rate[ints[1] - 1] |= OMAP_I2C_CMDLINE_SETUP;
185
186         return 1;
187 }
188 __setup("i2c_bus=", omap_i2c_bus_setup);
189
190 /*
191  * Register busses defined in command line but that are not registered with
192  * omap_register_i2c_bus from board initialization code.
193  */
194 static int __init omap_register_i2c_bus_cmdline(void)
195 {
196         int i, err = 0;
197
198         for (i = 0; i < ARRAY_SIZE(i2c_rate); i++)
199                 if (i2c_rate[i] & OMAP_I2C_CMDLINE_SETUP) {
200                         i2c_rate[i] &= ~OMAP_I2C_CMDLINE_SETUP;
201                         err = omap_i2c_add_bus(i + 1);
202                         if (err)
203                                 goto out;
204                 }
205
206 out:
207         return err;
208 }
209 subsys_initcall(omap_register_i2c_bus_cmdline);
210
211 /**
212  * omap_register_i2c_bus - register I2C bus with device descriptors
213  * @bus_id: bus id counting from number 1
214  * @clkrate: clock rate of the bus in kHz
215  * @info: pointer into I2C device descriptor table or NULL
216  * @len: number of descriptors in the table
217  *
218  * Returns 0 on success or an error code.
219  */
220 int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
221                           struct i2c_board_info const *info,
222                           unsigned len)
223 {
224         int err;
225
226         BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());
227
228         if (info) {
229                 err = i2c_register_board_info(bus_id, info, len);
230                 if (err)
231                         return err;
232         }
233
234         if (!i2c_rate[bus_id - 1])
235                 i2c_rate[bus_id - 1] = clkrate;
236         i2c_rate[bus_id - 1] &= ~OMAP_I2C_CMDLINE_SETUP;
237
238         return omap_i2c_add_bus(bus_id);
239 }