OpenWrt – Blame information for rev 3
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Rev | Author | Line No. | Line |
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1 | office | 1 | /* |
2 | * Custom GPIO-based I2C driver |
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3 | * |
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4 | * Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org> |
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5 | * |
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6 | * This program is free software; you can redistribute it and/or modify |
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7 | * it under the terms of the GNU General Public License version 2 as |
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8 | * published by the Free Software Foundation. |
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9 | * |
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10 | * --------------------------------------------------------------------------- |
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11 | * |
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12 | * The behaviour of this driver can be altered by setting some parameters |
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13 | * from the insmod command line. |
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14 | * |
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15 | * The following parameters are adjustable: |
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16 | * |
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17 | * bus0 These four arguments can be arrays of |
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18 | * bus1 1-8 unsigned integers as follows: |
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19 | * bus2 |
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20 | * bus3 <id>,<sda>,<scl>,<udelay>,<timeout>,<sda_od>,<scl_od>,<scl_oo> |
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21 | * |
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22 | * where: |
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23 | * |
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24 | * <id> ID to used as device_id for the corresponding bus (required) |
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25 | * <sda> GPIO pin ID to used for SDA (required) |
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26 | * <scl> GPIO pin ID to used for SCL (required) |
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27 | * <udelay> signal toggle delay. |
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28 | * <timeout> clock stretching timeout. |
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29 | * <sda_od> SDA is configured as open drain. |
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30 | * <scl_od> SCL is configured as open drain. |
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31 | * <scl_oo> SCL output drivers cannot be turned off. |
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32 | * |
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33 | * See include/i2c-gpio.h for more information about the parameters. |
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34 | * |
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35 | * If this driver is built into the kernel, you can use the following kernel |
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36 | * command line parameters, with the same values as the corresponding module |
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37 | * parameters listed above: |
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38 | * |
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39 | * i2c-gpio-custom.bus0 |
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40 | * i2c-gpio-custom.bus1 |
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41 | * i2c-gpio-custom.bus2 |
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42 | * i2c-gpio-custom.bus3 |
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43 | */ |
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44 | |||
45 | #include <linux/kernel.h> |
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46 | #include <linux/module.h> |
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47 | #include <linux/init.h> |
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48 | #include <linux/platform_device.h> |
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49 | |||
50 | #include <linux/i2c-gpio.h> |
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51 | |||
52 | #define DRV_NAME "i2c-gpio-custom" |
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53 | #define DRV_DESC "Custom GPIO-based I2C driver" |
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54 | #define DRV_VERSION "0.1.1" |
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55 | |||
56 | #define PFX DRV_NAME ": " |
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57 | |||
58 | #define BUS_PARAM_ID 0 |
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59 | #define BUS_PARAM_SDA 1 |
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60 | #define BUS_PARAM_SCL 2 |
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61 | #define BUS_PARAM_UDELAY 3 |
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62 | #define BUS_PARAM_TIMEOUT 4 |
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63 | #define BUS_PARAM_SDA_OD 5 |
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64 | #define BUS_PARAM_SCL_OD 6 |
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65 | #define BUS_PARAM_SCL_OO 7 |
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66 | |||
67 | #define BUS_PARAM_REQUIRED 3 |
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68 | #define BUS_PARAM_COUNT 8 |
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69 | #define BUS_COUNT_MAX 4 |
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70 | |||
71 | static unsigned int bus0[BUS_PARAM_COUNT] __initdata; |
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72 | static unsigned int bus1[BUS_PARAM_COUNT] __initdata; |
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73 | static unsigned int bus2[BUS_PARAM_COUNT] __initdata; |
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74 | static unsigned int bus3[BUS_PARAM_COUNT] __initdata; |
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75 | |||
76 | static unsigned int bus_nump[BUS_COUNT_MAX] __initdata; |
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77 | |||
78 | #define BUS_PARM_DESC \ |
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79 | " config -> id,sda,scl[,udelay,timeout,sda_od,scl_od,scl_oo]" |
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80 | |||
81 | module_param_array(bus0, uint, &bus_nump[0], 0); |
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82 | MODULE_PARM_DESC(bus0, "bus0" BUS_PARM_DESC); |
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83 | module_param_array(bus1, uint, &bus_nump[1], 0); |
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84 | MODULE_PARM_DESC(bus1, "bus1" BUS_PARM_DESC); |
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85 | module_param_array(bus2, uint, &bus_nump[2], 0); |
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86 | MODULE_PARM_DESC(bus2, "bus2" BUS_PARM_DESC); |
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87 | module_param_array(bus3, uint, &bus_nump[3], 0); |
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88 | MODULE_PARM_DESC(bus3, "bus3" BUS_PARM_DESC); |
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89 | |||
90 | static struct platform_device *devices[BUS_COUNT_MAX]; |
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91 | static unsigned int nr_devices; |
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92 | |||
93 | static void i2c_gpio_custom_cleanup(void) |
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94 | { |
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95 | int i; |
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96 | |||
97 | for (i = 0; i < nr_devices; i++) |
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98 | if (devices[i]) |
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99 | platform_device_put(devices[i]); |
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100 | } |
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101 | |||
102 | static int __init i2c_gpio_custom_add_one(unsigned int id, unsigned int *params) |
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103 | { |
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104 | struct platform_device *pdev; |
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105 | struct i2c_gpio_platform_data pdata; |
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106 | int err; |
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107 | |||
108 | if (!bus_nump[id]) |
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109 | return 0; |
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110 | |||
111 | if (bus_nump[id] < BUS_PARAM_REQUIRED) { |
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112 | printk(KERN_ERR PFX "not enough parameters for bus%d\n", id); |
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113 | err = -EINVAL; |
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114 | goto err; |
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115 | } |
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116 | |||
117 | pdev = platform_device_alloc("i2c-gpio", params[BUS_PARAM_ID]); |
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118 | if (!pdev) { |
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119 | err = -ENOMEM; |
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120 | goto err; |
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121 | } |
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122 | |||
123 | pdata.sda_pin = params[BUS_PARAM_SDA]; |
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124 | pdata.scl_pin = params[BUS_PARAM_SCL]; |
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125 | pdata.udelay = params[BUS_PARAM_UDELAY]; |
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126 | pdata.timeout = params[BUS_PARAM_TIMEOUT]; |
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127 | pdata.sda_is_open_drain = params[BUS_PARAM_SDA_OD] != 0; |
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128 | pdata.scl_is_open_drain = params[BUS_PARAM_SCL_OD] != 0; |
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129 | pdata.scl_is_output_only = params[BUS_PARAM_SCL_OO] != 0; |
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130 | |||
131 | err = platform_device_add_data(pdev, &pdata, sizeof(pdata)); |
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132 | if (err) |
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133 | goto err_put; |
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134 | |||
135 | err = platform_device_add(pdev); |
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136 | if (err) |
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137 | goto err_put; |
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138 | |||
139 | devices[nr_devices++] = pdev; |
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140 | return 0; |
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141 | |||
142 | err_put: |
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143 | platform_device_put(pdev); |
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144 | err: |
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145 | return err; |
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146 | } |
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147 | |||
148 | static int __init i2c_gpio_custom_probe(void) |
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149 | { |
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150 | int err; |
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151 | |||
152 | printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n"); |
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153 | |||
154 | err = i2c_gpio_custom_add_one(0, bus0); |
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155 | if (err) |
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156 | goto err; |
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157 | |||
158 | err = i2c_gpio_custom_add_one(1, bus1); |
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159 | if (err) |
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160 | goto err; |
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161 | |||
162 | err = i2c_gpio_custom_add_one(2, bus2); |
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163 | if (err) |
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164 | goto err; |
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165 | |||
166 | err = i2c_gpio_custom_add_one(3, bus3); |
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167 | if (err) |
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168 | goto err; |
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169 | |||
170 | if (!nr_devices) { |
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171 | printk(KERN_ERR PFX "no bus parameter(s) specified\n"); |
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172 | err = -ENODEV; |
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173 | goto err; |
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174 | } |
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175 | |||
176 | return 0; |
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177 | |||
178 | err: |
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179 | i2c_gpio_custom_cleanup(); |
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180 | return err; |
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181 | } |
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182 | |||
183 | #ifdef MODULE |
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184 | static int __init i2c_gpio_custom_init(void) |
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185 | { |
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186 | return i2c_gpio_custom_probe(); |
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187 | } |
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188 | module_init(i2c_gpio_custom_init); |
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189 | |||
190 | static void __exit i2c_gpio_custom_exit(void) |
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191 | { |
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192 | i2c_gpio_custom_cleanup(); |
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193 | } |
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194 | module_exit(i2c_gpio_custom_exit); |
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195 | #else |
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196 | subsys_initcall(i2c_gpio_custom_probe); |
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197 | #endif /* MODULE*/ |
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198 | |||
199 | MODULE_LICENSE("GPL v2"); |
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200 | MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org >"); |
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201 | MODULE_DESCRIPTION(DRV_DESC); |
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202 | MODULE_VERSION(DRV_VERSION); |