diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/i2c/busses/i2c-ixp4xx.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/i2c/busses/i2c-ixp4xx.c')
-rw-r--r-- | drivers/i2c/busses/i2c-ixp4xx.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-ixp4xx.c b/drivers/i2c/busses/i2c-ixp4xx.c new file mode 100644 index 000000000000..8c55eafc3a09 --- /dev/null +++ b/drivers/i2c/busses/i2c-ixp4xx.c | |||
@@ -0,0 +1,181 @@ | |||
1 | /* | ||
2 | * drivers/i2c/i2c-adap-ixp4xx.c | ||
3 | * | ||
4 | * Intel's IXP4xx XScale NPU chipsets (IXP420, 421, 422, 425) do not have | ||
5 | * an on board I2C controller but provide 16 GPIO pins that are often | ||
6 | * used to create an I2C bus. This driver provides an i2c_adapter | ||
7 | * interface that plugs in under algo_bit and drives the GPIO pins | ||
8 | * as instructed by the alogorithm driver. | ||
9 | * | ||
10 | * Author: Deepak Saxena <dsaxena@plexity.net> | ||
11 | * | ||
12 | * Copyright (c) 2003-2004 MontaVista Software Inc. | ||
13 | * | ||
14 | * This file is licensed under the terms of the GNU General Public | ||
15 | * License version 2. This program is licensed "as is" without any | ||
16 | * warranty of any kind, whether express or implied. | ||
17 | * | ||
18 | * NOTE: Since different platforms will use different GPIO pins for | ||
19 | * I2C, this driver uses an IXP4xx-specific platform_data | ||
20 | * pointer to pass the GPIO numbers to the driver. This | ||
21 | * allows us to support all the different IXP4xx platforms | ||
22 | * w/o having to put #ifdefs in this driver. | ||
23 | * | ||
24 | * See arch/arm/mach-ixp4xx/ixdp425.c for an example of building a | ||
25 | * device list and filling in the ixp4xx_i2c_pins data structure | ||
26 | * that is passed as the platform_data to this driver. | ||
27 | */ | ||
28 | |||
29 | #include <linux/config.h> | ||
30 | #ifdef CONFIG_I2C_DEBUG_BUS | ||
31 | #define DEBUG 1 | ||
32 | #endif | ||
33 | |||
34 | #include <linux/kernel.h> | ||
35 | #include <linux/init.h> | ||
36 | #include <linux/device.h> | ||
37 | #include <linux/module.h> | ||
38 | #include <linux/i2c.h> | ||
39 | #include <linux/i2c-algo-bit.h> | ||
40 | |||
41 | #include <asm/hardware.h> /* Pick up IXP4xx-specific bits */ | ||
42 | |||
43 | static inline int ixp4xx_scl_pin(void *data) | ||
44 | { | ||
45 | return ((struct ixp4xx_i2c_pins*)data)->scl_pin; | ||
46 | } | ||
47 | |||
48 | static inline int ixp4xx_sda_pin(void *data) | ||
49 | { | ||
50 | return ((struct ixp4xx_i2c_pins*)data)->sda_pin; | ||
51 | } | ||
52 | |||
53 | static void ixp4xx_bit_setscl(void *data, int val) | ||
54 | { | ||
55 | gpio_line_set(ixp4xx_scl_pin(data), 0); | ||
56 | gpio_line_config(ixp4xx_scl_pin(data), | ||
57 | val ? IXP4XX_GPIO_IN : IXP4XX_GPIO_OUT ); | ||
58 | } | ||
59 | |||
60 | static void ixp4xx_bit_setsda(void *data, int val) | ||
61 | { | ||
62 | gpio_line_set(ixp4xx_sda_pin(data), 0); | ||
63 | gpio_line_config(ixp4xx_sda_pin(data), | ||
64 | val ? IXP4XX_GPIO_IN : IXP4XX_GPIO_OUT ); | ||
65 | } | ||
66 | |||
67 | static int ixp4xx_bit_getscl(void *data) | ||
68 | { | ||
69 | int scl; | ||
70 | |||
71 | gpio_line_config(ixp4xx_scl_pin(data), IXP4XX_GPIO_IN ); | ||
72 | gpio_line_get(ixp4xx_scl_pin(data), &scl); | ||
73 | |||
74 | return scl; | ||
75 | } | ||
76 | |||
77 | static int ixp4xx_bit_getsda(void *data) | ||
78 | { | ||
79 | int sda; | ||
80 | |||
81 | gpio_line_config(ixp4xx_sda_pin(data), IXP4XX_GPIO_IN ); | ||
82 | gpio_line_get(ixp4xx_sda_pin(data), &sda); | ||
83 | |||
84 | return sda; | ||
85 | } | ||
86 | |||
87 | struct ixp4xx_i2c_data { | ||
88 | struct ixp4xx_i2c_pins *gpio_pins; | ||
89 | struct i2c_adapter adapter; | ||
90 | struct i2c_algo_bit_data algo_data; | ||
91 | }; | ||
92 | |||
93 | static int ixp4xx_i2c_remove(struct device *dev) | ||
94 | { | ||
95 | struct platform_device *plat_dev = to_platform_device(dev); | ||
96 | struct ixp4xx_i2c_data *drv_data = dev_get_drvdata(&plat_dev->dev); | ||
97 | |||
98 | dev_set_drvdata(&plat_dev->dev, NULL); | ||
99 | |||
100 | i2c_bit_del_bus(&drv_data->adapter); | ||
101 | |||
102 | kfree(drv_data); | ||
103 | |||
104 | return 0; | ||
105 | } | ||
106 | |||
107 | static int ixp4xx_i2c_probe(struct device *dev) | ||
108 | { | ||
109 | int err; | ||
110 | struct platform_device *plat_dev = to_platform_device(dev); | ||
111 | struct ixp4xx_i2c_pins *gpio = plat_dev->dev.platform_data; | ||
112 | struct ixp4xx_i2c_data *drv_data = | ||
113 | kmalloc(sizeof(struct ixp4xx_i2c_data), GFP_KERNEL); | ||
114 | |||
115 | if(!drv_data) | ||
116 | return -ENOMEM; | ||
117 | |||
118 | memzero(drv_data, sizeof(struct ixp4xx_i2c_data)); | ||
119 | drv_data->gpio_pins = gpio; | ||
120 | |||
121 | /* | ||
122 | * We could make a lot of these structures static, but | ||
123 | * certain platforms may have multiple GPIO-based I2C | ||
124 | * buses for various device domains, so we need per-device | ||
125 | * algo_data->data. | ||
126 | */ | ||
127 | drv_data->algo_data.data = gpio; | ||
128 | drv_data->algo_data.setsda = ixp4xx_bit_setsda; | ||
129 | drv_data->algo_data.setscl = ixp4xx_bit_setscl; | ||
130 | drv_data->algo_data.getsda = ixp4xx_bit_getsda; | ||
131 | drv_data->algo_data.getscl = ixp4xx_bit_getscl; | ||
132 | drv_data->algo_data.udelay = 10; | ||
133 | drv_data->algo_data.mdelay = 10; | ||
134 | drv_data->algo_data.timeout = 100; | ||
135 | |||
136 | drv_data->adapter.id = I2C_HW_B_IXP4XX; | ||
137 | drv_data->adapter.algo_data = &drv_data->algo_data; | ||
138 | |||
139 | drv_data->adapter.dev.parent = &plat_dev->dev; | ||
140 | |||
141 | gpio_line_config(gpio->scl_pin, IXP4XX_GPIO_IN); | ||
142 | gpio_line_config(gpio->sda_pin, IXP4XX_GPIO_IN); | ||
143 | gpio_line_set(gpio->scl_pin, 0); | ||
144 | gpio_line_set(gpio->sda_pin, 0); | ||
145 | |||
146 | if ((err = i2c_bit_add_bus(&drv_data->adapter) != 0)) { | ||
147 | printk(KERN_ERR "ERROR: Could not install %s\n", dev->bus_id); | ||
148 | |||
149 | kfree(drv_data); | ||
150 | return err; | ||
151 | } | ||
152 | |||
153 | dev_set_drvdata(&plat_dev->dev, drv_data); | ||
154 | |||
155 | return 0; | ||
156 | } | ||
157 | |||
158 | static struct device_driver ixp4xx_i2c_driver = { | ||
159 | .name = "IXP4XX-I2C", | ||
160 | .bus = &platform_bus_type, | ||
161 | .probe = ixp4xx_i2c_probe, | ||
162 | .remove = ixp4xx_i2c_remove, | ||
163 | }; | ||
164 | |||
165 | static int __init ixp4xx_i2c_init(void) | ||
166 | { | ||
167 | return driver_register(&ixp4xx_i2c_driver); | ||
168 | } | ||
169 | |||
170 | static void __exit ixp4xx_i2c_exit(void) | ||
171 | { | ||
172 | driver_unregister(&ixp4xx_i2c_driver); | ||
173 | } | ||
174 | |||
175 | module_init(ixp4xx_i2c_init); | ||
176 | module_exit(ixp4xx_i2c_exit); | ||
177 | |||
178 | MODULE_DESCRIPTION("GPIO-based I2C adapter for IXP4xx systems"); | ||
179 | MODULE_LICENSE("GPL"); | ||
180 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); | ||
181 | |||