Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* ------------------------------------------------------------------------ * |
| 2 | * i2c-parport.c I2C bus over parallel port * |
| 3 | * ------------------------------------------------------------------------ * |
Jean Delvare | 7c81c60f | 2014-01-29 20:40:08 +0100 | [diff] [blame] | 4 | Copyright (C) 2003-2011 Jean Delvare <jdelvare@suse.de> |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 5 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | Based on older i2c-philips-par.c driver |
| 7 | Copyright (C) 1995-2000 Simon G. Vogl |
| 8 | With some changes from: |
| 9 | Frodo Looijaard <frodol@dds.nl> |
Jan Engelhardt | 96de0e2 | 2007-10-19 23:21:04 +0200 | [diff] [blame] | 10 | Kyösti Mälkki <kmalkki@cc.hut.fi> |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 11 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | This program is free software; you can redistribute it and/or modify |
| 13 | it under the terms of the GNU General Public License as published by |
| 14 | the Free Software Foundation; either version 2 of the License, or |
| 15 | (at your option) any later version. |
| 16 | |
| 17 | This program is distributed in the hope that it will be useful, |
| 18 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | GNU General Public License for more details. |
| 21 | |
| 22 | You should have received a copy of the GNU General Public License |
| 23 | along with this program; if not, write to the Free Software |
| 24 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 25 | * ------------------------------------------------------------------------ */ |
| 26 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include <linux/kernel.h> |
| 28 | #include <linux/module.h> |
| 29 | #include <linux/init.h> |
Jean Delvare | 6d376fc | 2010-03-02 12:23:41 +0100 | [diff] [blame] | 30 | #include <linux/delay.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | #include <linux/parport.h> |
| 32 | #include <linux/i2c.h> |
| 33 | #include <linux/i2c-algo-bit.h> |
Jean Delvare | 3585925 | 2010-03-02 12:23:44 +0100 | [diff] [blame] | 34 | #include <linux/i2c-smbus.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 35 | #include <linux/slab.h> |
Jean Delvare | 56acc7a | 2011-05-01 18:18:49 +0200 | [diff] [blame] | 36 | #include <linux/list.h> |
| 37 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | #include "i2c-parport.h" |
| 39 | |
| 40 | /* ----- Device list ------------------------------------------------------ */ |
| 41 | |
| 42 | struct i2c_par { |
| 43 | struct pardevice *pdev; |
| 44 | struct i2c_adapter adapter; |
| 45 | struct i2c_algo_bit_data algo_data; |
Jean Delvare | 3585925 | 2010-03-02 12:23:44 +0100 | [diff] [blame] | 46 | struct i2c_smbus_alert_setup alert_data; |
| 47 | struct i2c_client *ara; |
Jean Delvare | 56acc7a | 2011-05-01 18:18:49 +0200 | [diff] [blame] | 48 | struct list_head node; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | }; |
| 50 | |
Jean Delvare | 56acc7a | 2011-05-01 18:18:49 +0200 | [diff] [blame] | 51 | static LIST_HEAD(adapter_list); |
| 52 | static DEFINE_MUTEX(adapter_list_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
| 54 | /* ----- Low-level parallel port access ----------------------------------- */ |
| 55 | |
| 56 | static void port_write_data(struct parport *p, unsigned char d) |
| 57 | { |
| 58 | parport_write_data(p, d); |
| 59 | } |
| 60 | |
| 61 | static void port_write_control(struct parport *p, unsigned char d) |
| 62 | { |
| 63 | parport_write_control(p, d); |
| 64 | } |
| 65 | |
| 66 | static unsigned char port_read_data(struct parport *p) |
| 67 | { |
| 68 | return parport_read_data(p); |
| 69 | } |
| 70 | |
| 71 | static unsigned char port_read_status(struct parport *p) |
| 72 | { |
| 73 | return parport_read_status(p); |
| 74 | } |
| 75 | |
| 76 | static unsigned char port_read_control(struct parport *p) |
| 77 | { |
| 78 | return parport_read_control(p); |
| 79 | } |
| 80 | |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 81 | static void (* const port_write[])(struct parport *, unsigned char) = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | port_write_data, |
| 83 | NULL, |
| 84 | port_write_control, |
| 85 | }; |
| 86 | |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 87 | static unsigned char (* const port_read[])(struct parport *) = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | port_read_data, |
| 89 | port_read_status, |
| 90 | port_read_control, |
| 91 | }; |
| 92 | |
| 93 | /* ----- Unified line operation functions --------------------------------- */ |
| 94 | |
| 95 | static inline void line_set(struct parport *data, int state, |
| 96 | const struct lineop *op) |
| 97 | { |
| 98 | u8 oldval = port_read[op->port](data); |
| 99 | |
| 100 | /* Touch only the bit(s) needed */ |
| 101 | if ((op->inverted && !state) || (!op->inverted && state)) |
| 102 | port_write[op->port](data, oldval | op->val); |
| 103 | else |
| 104 | port_write[op->port](data, oldval & ~op->val); |
| 105 | } |
| 106 | |
| 107 | static inline int line_get(struct parport *data, |
| 108 | const struct lineop *op) |
| 109 | { |
| 110 | u8 oldval = port_read[op->port](data); |
| 111 | |
| 112 | return ((op->inverted && (oldval & op->val) != op->val) |
| 113 | || (!op->inverted && (oldval & op->val) == op->val)); |
| 114 | } |
| 115 | |
| 116 | /* ----- I2C algorithm call-back functions and structures ----------------- */ |
| 117 | |
| 118 | static void parport_setscl(void *data, int state) |
| 119 | { |
| 120 | line_set((struct parport *) data, state, &adapter_parm[type].setscl); |
| 121 | } |
| 122 | |
| 123 | static void parport_setsda(void *data, int state) |
| 124 | { |
| 125 | line_set((struct parport *) data, state, &adapter_parm[type].setsda); |
| 126 | } |
| 127 | |
| 128 | static int parport_getscl(void *data) |
| 129 | { |
| 130 | return line_get((struct parport *) data, &adapter_parm[type].getscl); |
| 131 | } |
| 132 | |
| 133 | static int parport_getsda(void *data) |
| 134 | { |
| 135 | return line_get((struct parport *) data, &adapter_parm[type].getsda); |
| 136 | } |
| 137 | |
| 138 | /* Encapsulate the functions above in the correct structure. |
| 139 | Note that this is only a template, from which the real structures are |
| 140 | copied. The attaching code will set getscl to NULL for adapters that |
Tobias Klauser | 614e24b | 2005-05-19 21:39:06 +0200 | [diff] [blame] | 141 | cannot read SCL back, and will also make the data field point to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | the parallel port structure. */ |
Jean Delvare | bfdcad9 | 2010-05-21 18:40:57 +0200 | [diff] [blame] | 143 | static const struct i2c_algo_bit_data parport_algo_data = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | .setsda = parport_setsda, |
| 145 | .setscl = parport_setscl, |
| 146 | .getsda = parport_getsda, |
| 147 | .getscl = parport_getscl, |
Jean Delvare | 3af07bd | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 148 | .udelay = 10, /* ~50 kbps */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | .timeout = HZ, |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 150 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | |
| 152 | /* ----- I2c and parallel port call-back functions and structures --------- */ |
| 153 | |
Jean Delvare | 7fe442a | 2012-10-05 22:23:53 +0200 | [diff] [blame] | 154 | static void i2c_parport_irq(void *data) |
Jean Delvare | 3585925 | 2010-03-02 12:23:44 +0100 | [diff] [blame] | 155 | { |
| 156 | struct i2c_par *adapter = data; |
| 157 | struct i2c_client *ara = adapter->ara; |
| 158 | |
| 159 | if (ara) { |
| 160 | dev_dbg(&ara->dev, "SMBus alert received\n"); |
| 161 | i2c_handle_smbus_alert(ara); |
| 162 | } else |
| 163 | dev_dbg(&adapter->adapter.dev, |
| 164 | "SMBus alert received but no ARA client!\n"); |
| 165 | } |
| 166 | |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 167 | static void i2c_parport_attach(struct parport *port) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | { |
| 169 | struct i2c_par *adapter; |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 170 | |
Deepak Saxena | 5263ebb | 2005-10-17 23:09:43 +0200 | [diff] [blame] | 171 | adapter = kzalloc(sizeof(struct i2c_par), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | if (adapter == NULL) { |
Deepak Saxena | 5263ebb | 2005-10-17 23:09:43 +0200 | [diff] [blame] | 173 | printk(KERN_ERR "i2c-parport: Failed to kzalloc\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | return; |
| 175 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | |
| 177 | pr_debug("i2c-parport: attaching to %s\n", port->name); |
Jean Delvare | 3585925 | 2010-03-02 12:23:44 +0100 | [diff] [blame] | 178 | parport_disable_irq(port); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | adapter->pdev = parport_register_device(port, "i2c-parport", |
Jean Delvare | 3585925 | 2010-03-02 12:23:44 +0100 | [diff] [blame] | 180 | NULL, NULL, i2c_parport_irq, PARPORT_FLAG_EXCL, adapter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | if (!adapter->pdev) { |
| 182 | printk(KERN_ERR "i2c-parport: Unable to register with parport\n"); |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 183 | goto err_free; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | } |
| 185 | |
| 186 | /* Fill the rest of the structure */ |
Jean Delvare | cacf226 | 2007-05-01 23:26:29 +0200 | [diff] [blame] | 187 | adapter->adapter.owner = THIS_MODULE; |
| 188 | adapter->adapter.class = I2C_CLASS_HWMON; |
Jean Delvare | cacf226 | 2007-05-01 23:26:29 +0200 | [diff] [blame] | 189 | strlcpy(adapter->adapter.name, "Parallel port adapter", |
| 190 | sizeof(adapter->adapter.name)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | adapter->algo_data = parport_algo_data; |
Jean Delvare | 3af07bd | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 192 | /* Slow down if we can't sense SCL */ |
| 193 | if (!adapter_parm[type].getscl.val) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | adapter->algo_data.getscl = NULL; |
Jean Delvare | 3af07bd | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 195 | adapter->algo_data.udelay = 50; /* ~10 kbps */ |
| 196 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | adapter->algo_data.data = port; |
| 198 | adapter->adapter.algo_data = &adapter->algo_data; |
David Brownell | da67529 | 2007-05-08 00:27:42 -0700 | [diff] [blame] | 199 | adapter->adapter.dev.parent = port->physport->dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | |
| 201 | if (parport_claim_or_block(adapter->pdev) < 0) { |
| 202 | printk(KERN_ERR "i2c-parport: Could not claim parallel port\n"); |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 203 | goto err_unregister; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | } |
| 205 | |
| 206 | /* Reset hardware to a sane state (SCL and SDA high) */ |
| 207 | parport_setsda(port, 1); |
| 208 | parport_setscl(port, 1); |
| 209 | /* Other init if needed (power on...) */ |
Jean Delvare | 6d376fc | 2010-03-02 12:23:41 +0100 | [diff] [blame] | 210 | if (adapter_parm[type].init.val) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | line_set(port, 1, &adapter_parm[type].init); |
Jean Delvare | 6d376fc | 2010-03-02 12:23:41 +0100 | [diff] [blame] | 212 | /* Give powered devices some time to settle */ |
| 213 | msleep(100); |
| 214 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | if (i2c_bit_add_bus(&adapter->adapter) < 0) { |
| 217 | printk(KERN_ERR "i2c-parport: Unable to register with I2C\n"); |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 218 | goto err_unregister; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 219 | } |
| 220 | |
Jean Delvare | 3585925 | 2010-03-02 12:23:44 +0100 | [diff] [blame] | 221 | /* Setup SMBus alert if supported */ |
| 222 | if (adapter_parm[type].smbus_alert) { |
| 223 | adapter->alert_data.alert_edge_triggered = 1; |
| 224 | adapter->ara = i2c_setup_smbus_alert(&adapter->adapter, |
| 225 | &adapter->alert_data); |
| 226 | if (adapter->ara) |
| 227 | parport_enable_irq(port); |
| 228 | else |
| 229 | printk(KERN_WARNING "i2c-parport: Failed to register " |
| 230 | "ARA client\n"); |
| 231 | } |
| 232 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | /* Add the new adapter to the list */ |
Jean Delvare | 56acc7a | 2011-05-01 18:18:49 +0200 | [diff] [blame] | 234 | mutex_lock(&adapter_list_lock); |
| 235 | list_add_tail(&adapter->node, &adapter_list); |
| 236 | mutex_unlock(&adapter_list_lock); |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 237 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 239 | err_unregister: |
Jean Delvare | 7b964f733 | 2008-11-28 15:24:39 +0100 | [diff] [blame] | 240 | parport_release(adapter->pdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | parport_unregister_device(adapter->pdev); |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 242 | err_free: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | kfree(adapter); |
| 244 | } |
| 245 | |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 246 | static void i2c_parport_detach(struct parport *port) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | { |
Jean Delvare | 56acc7a | 2011-05-01 18:18:49 +0200 | [diff] [blame] | 248 | struct i2c_par *adapter, *_n; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | |
| 250 | /* Walk the list */ |
Jean Delvare | 56acc7a | 2011-05-01 18:18:49 +0200 | [diff] [blame] | 251 | mutex_lock(&adapter_list_lock); |
| 252 | list_for_each_entry_safe(adapter, _n, &adapter_list, node) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | if (adapter->pdev->port == port) { |
Jean Delvare | 3585925 | 2010-03-02 12:23:44 +0100 | [diff] [blame] | 254 | if (adapter->ara) { |
| 255 | parport_disable_irq(port); |
| 256 | i2c_unregister_device(adapter->ara); |
| 257 | } |
Jean Delvare | 3af07bd | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 258 | i2c_del_adapter(&adapter->adapter); |
| 259 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | /* Un-init if needed (power off...) */ |
| 261 | if (adapter_parm[type].init.val) |
| 262 | line_set(port, 0, &adapter_parm[type].init); |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 263 | |
Jean Delvare | 7b964f733 | 2008-11-28 15:24:39 +0100 | [diff] [blame] | 264 | parport_release(adapter->pdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | parport_unregister_device(adapter->pdev); |
Jean Delvare | 56acc7a | 2011-05-01 18:18:49 +0200 | [diff] [blame] | 266 | list_del(&adapter->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | kfree(adapter); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | } |
| 269 | } |
Jean Delvare | 56acc7a | 2011-05-01 18:18:49 +0200 | [diff] [blame] | 270 | mutex_unlock(&adapter_list_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | } |
| 272 | |
Jean Delvare | 6c129be | 2005-10-08 00:17:35 +0200 | [diff] [blame] | 273 | static struct parport_driver i2c_parport_driver = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | .name = "i2c-parport", |
| 275 | .attach = i2c_parport_attach, |
| 276 | .detach = i2c_parport_detach, |
| 277 | }; |
| 278 | |
| 279 | /* ----- Module loading, unloading and information ------------------------ */ |
| 280 | |
| 281 | static int __init i2c_parport_init(void) |
| 282 | { |
Mark M. Hoffman | e97b81d | 2006-03-23 16:50:25 +0100 | [diff] [blame] | 283 | if (type < 0) { |
| 284 | printk(KERN_WARNING "i2c-parport: adapter type unspecified\n"); |
| 285 | return -ENODEV; |
| 286 | } |
| 287 | |
| 288 | if (type >= ARRAY_SIZE(adapter_parm)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | printk(KERN_WARNING "i2c-parport: invalid type (%d)\n", type); |
Mark M. Hoffman | e97b81d | 2006-03-23 16:50:25 +0100 | [diff] [blame] | 290 | return -ENODEV; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | } |
Tobias Klauser | 7e3d7db | 2006-01-09 23:19:51 +0100 | [diff] [blame] | 292 | |
Jean Delvare | 6c129be | 2005-10-08 00:17:35 +0200 | [diff] [blame] | 293 | return parport_register_driver(&i2c_parport_driver); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | } |
| 295 | |
| 296 | static void __exit i2c_parport_exit(void) |
| 297 | { |
Jean Delvare | 6c129be | 2005-10-08 00:17:35 +0200 | [diff] [blame] | 298 | parport_unregister_driver(&i2c_parport_driver); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | } |
| 300 | |
Jean Delvare | 7c81c60f | 2014-01-29 20:40:08 +0100 | [diff] [blame] | 301 | MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | MODULE_DESCRIPTION("I2C bus over parallel port"); |
| 303 | MODULE_LICENSE("GPL"); |
| 304 | |
| 305 | module_init(i2c_parport_init); |
| 306 | module_exit(i2c_parport_exit); |