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| Rev | Author | Line No. | Line |
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| 420 | giacomo | 1 | /* linux/drivers/i2c/scx200_i2c.c |
| 2 | |||
| 3 | Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> |
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| 4 | |||
| 5 | National Semiconductor SCx200 I2C bus on GPIO pins |
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| 6 | |||
| 7 | Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl |
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| 8 | |||
| 9 | This program is free software; you can redistribute it and/or modify |
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| 10 | it under the terms of the GNU General Public License as published by |
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| 11 | the Free Software Foundation; either version 2 of the License, or |
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| 12 | (at your option) any later version. |
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| 13 | |||
| 14 | This program is distributed in the hope that it will be useful, |
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| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 17 | GNU General Public License for more details. |
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| 18 | |||
| 19 | You should have received a copy of the GNU General Public License |
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| 20 | along with this program; if not, write to the Free Software |
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| 21 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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| 22 | */ |
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| 23 | |||
| 24 | #include <linux/config.h> |
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| 25 | #include <linux/module.h> |
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| 26 | #include <linux/errno.h> |
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| 27 | #include <linux/kernel.h> |
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| 28 | #include <linux/init.h> |
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| 29 | #include <linux/i2c.h> |
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| 30 | #include <linux/i2c-algo-bit.h> |
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| 31 | #include <asm/io.h> |
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| 32 | |||
| 33 | #include <linux/scx200_gpio.h> |
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| 34 | |||
| 35 | #define NAME "scx200_i2c" |
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| 36 | |||
| 37 | MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); |
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| 38 | MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver"); |
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| 39 | MODULE_LICENSE("GPL"); |
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| 40 | |||
| 41 | MODULE_PARM(scl, "i"); |
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| 42 | MODULE_PARM_DESC(scl, "GPIO line for SCL"); |
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| 43 | MODULE_PARM(sda, "i"); |
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| 44 | MODULE_PARM_DESC(sda, "GPIO line for SDA"); |
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| 45 | |||
| 46 | static int scl = CONFIG_SCx200_I2C_SCL; |
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| 47 | static int sda = CONFIG_SCx200_I2C_SDA; |
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| 48 | |||
| 49 | static void scx200_i2c_setscl(void *data, int state) |
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| 50 | { |
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| 51 | scx200_gpio_set(scl, state); |
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| 52 | } |
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| 53 | |||
| 54 | static void scx200_i2c_setsda(void *data, int state) |
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| 55 | { |
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| 56 | scx200_gpio_set(sda, state); |
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| 57 | } |
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| 58 | |||
| 59 | static int scx200_i2c_getscl(void *data) |
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| 60 | { |
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| 61 | return scx200_gpio_get(scl); |
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| 62 | } |
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| 63 | |||
| 64 | static int scx200_i2c_getsda(void *data) |
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| 65 | { |
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| 66 | return scx200_gpio_get(sda); |
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| 67 | } |
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| 68 | |||
| 69 | /* ------------------------------------------------------------------------ |
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| 70 | * Encapsulate the above functions in the correct operations structure. |
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| 71 | * This is only done when more than one hardware adapter is supported. |
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| 72 | */ |
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| 73 | |||
| 74 | static struct i2c_algo_bit_data scx200_i2c_data = { |
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| 75 | NULL, |
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| 76 | scx200_i2c_setsda, |
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| 77 | scx200_i2c_setscl, |
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| 78 | scx200_i2c_getsda, |
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| 79 | scx200_i2c_getscl, |
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| 80 | 10, 10, 100, /* waits, timeout */ |
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| 81 | }; |
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| 82 | |||
| 83 | static struct i2c_adapter scx200_i2c_ops = { |
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| 84 | .owner = THIS_MODULE, |
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| 85 | .algo_data = &scx200_i2c_data, |
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| 86 | .name = "NatSemi SCx200 I2C", |
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| 87 | }; |
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| 88 | |||
| 89 | int scx200_i2c_init(void) |
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| 90 | { |
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| 91 | printk(KERN_DEBUG NAME ": NatSemi SCx200 I2C Driver\n"); |
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| 92 | |||
| 93 | if (!scx200_gpio_present()) { |
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| 94 | printk(KERN_ERR NAME ": no SCx200 gpio pins available\n"); |
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| 95 | return -ENODEV; |
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| 96 | } |
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| 97 | |||
| 98 | printk(KERN_DEBUG NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n", |
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| 99 | scl, sda); |
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| 100 | |||
| 101 | if (scl == -1 || sda == -1 || scl == sda) { |
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| 102 | printk(KERN_ERR NAME ": scl and sda must be specified\n"); |
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| 103 | return -EINVAL; |
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| 104 | } |
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| 105 | |||
| 106 | /* Configure GPIOs as open collector outputs */ |
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| 107 | scx200_gpio_configure(scl, ~2, 5); |
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| 108 | scx200_gpio_configure(sda, ~2, 5); |
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| 109 | |||
| 110 | if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) { |
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| 111 | printk(KERN_ERR NAME ": adapter %s registration failed\n", |
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| 112 | scx200_i2c_ops.name); |
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| 113 | return -ENODEV; |
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| 114 | } |
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| 115 | |||
| 116 | return 0; |
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| 117 | } |
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| 118 | |||
| 119 | void scx200_i2c_cleanup(void) |
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| 120 | { |
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| 121 | i2c_bit_del_bus(&scx200_i2c_ops); |
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| 122 | } |
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| 123 | |||
| 124 | module_init(scx200_i2c_init); |
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| 125 | module_exit(scx200_i2c_cleanup); |
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| 126 | |||
| 127 | /* |
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| 128 | Local variables: |
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| 129 | compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules" |
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| 130 | c-basic-offset: 8 |
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| 131 | End: |
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| 132 | */ |