Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* ------------------------------------------------------------------------ * |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 2 | * i2c-parport-light.c I2C bus over parallel port * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * ------------------------------------------------------------------------ * |
Jean Delvare | 927ab2f | 2010-03-02 12:23:45 +0100 | [diff] [blame] | 4 | Copyright (C) 2003-2010 Jean Delvare <khali@linux-fr.org> |
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-velleman.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> |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 31 | #include <linux/platform_device.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <linux/ioport.h> |
| 33 | #include <linux/i2c.h> |
| 34 | #include <linux/i2c-algo-bit.h> |
Jean Delvare | 927ab2f | 2010-03-02 12:23:45 +0100 | [diff] [blame] | 35 | #include <linux/i2c-smbus.h> |
H Hartley Sweeten | 2178218 | 2010-05-21 18:41:01 +0200 | [diff] [blame] | 36 | #include <linux/io.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include "i2c-parport.h" |
| 38 | |
| 39 | #define DEFAULT_BASE 0x378 |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 40 | #define DRVNAME "i2c-parport-light" |
| 41 | |
| 42 | static struct platform_device *pdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
| 44 | static u16 base; |
| 45 | module_param(base, ushort, 0); |
| 46 | MODULE_PARM_DESC(base, "Base I/O address"); |
| 47 | |
Jean Delvare | 927ab2f | 2010-03-02 12:23:45 +0100 | [diff] [blame] | 48 | static int irq; |
| 49 | module_param(irq, int, 0); |
| 50 | MODULE_PARM_DESC(irq, "IRQ (optional)"); |
| 51 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | /* ----- Low-level parallel port access ----------------------------------- */ |
| 53 | |
| 54 | static inline void port_write(unsigned char p, unsigned char d) |
| 55 | { |
| 56 | outb(d, base+p); |
| 57 | } |
| 58 | |
| 59 | static inline unsigned char port_read(unsigned char p) |
| 60 | { |
| 61 | return inb(base+p); |
| 62 | } |
| 63 | |
| 64 | /* ----- Unified line operation functions --------------------------------- */ |
| 65 | |
| 66 | static inline void line_set(int state, const struct lineop *op) |
| 67 | { |
| 68 | u8 oldval = port_read(op->port); |
| 69 | |
| 70 | /* Touch only the bit(s) needed */ |
| 71 | if ((op->inverted && !state) || (!op->inverted && state)) |
| 72 | port_write(op->port, oldval | op->val); |
| 73 | else |
| 74 | port_write(op->port, oldval & ~op->val); |
| 75 | } |
| 76 | |
| 77 | static inline int line_get(const struct lineop *op) |
| 78 | { |
| 79 | u8 oldval = port_read(op->port); |
| 80 | |
| 81 | return ((op->inverted && (oldval & op->val) != op->val) |
| 82 | || (!op->inverted && (oldval & op->val) == op->val)); |
| 83 | } |
| 84 | |
| 85 | /* ----- I2C algorithm call-back functions and structures ----------------- */ |
| 86 | |
| 87 | static void parport_setscl(void *data, int state) |
| 88 | { |
| 89 | line_set(state, &adapter_parm[type].setscl); |
| 90 | } |
| 91 | |
| 92 | static void parport_setsda(void *data, int state) |
| 93 | { |
| 94 | line_set(state, &adapter_parm[type].setsda); |
| 95 | } |
| 96 | |
| 97 | static int parport_getscl(void *data) |
| 98 | { |
| 99 | return line_get(&adapter_parm[type].getscl); |
| 100 | } |
| 101 | |
| 102 | static int parport_getsda(void *data) |
| 103 | { |
| 104 | return line_get(&adapter_parm[type].getsda); |
| 105 | } |
| 106 | |
| 107 | /* Encapsulate the functions above in the correct structure |
| 108 | Note that getscl will be set to NULL by the attaching code for adapters |
| 109 | that cannot read SCL back */ |
| 110 | static struct i2c_algo_bit_data parport_algo_data = { |
| 111 | .setsda = parport_setsda, |
| 112 | .setscl = parport_setscl, |
| 113 | .getsda = parport_getsda, |
| 114 | .getscl = parport_getscl, |
| 115 | .udelay = 50, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | .timeout = HZ, |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 117 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 119 | /* ----- Driver registration ---------------------------------------------- */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | |
| 121 | static struct i2c_adapter parport_adapter = { |
| 122 | .owner = THIS_MODULE, |
| 123 | .class = I2C_CLASS_HWMON, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | .algo_data = &parport_algo_data, |
| 125 | .name = "Parallel port adapter (light)", |
| 126 | }; |
| 127 | |
Jean Delvare | 927ab2f | 2010-03-02 12:23:45 +0100 | [diff] [blame] | 128 | /* SMBus alert support */ |
| 129 | static struct i2c_smbus_alert_setup alert_data = { |
| 130 | .alert_edge_triggered = 1, |
| 131 | }; |
| 132 | static struct i2c_client *ara; |
| 133 | static struct lineop parport_ctrl_irq = { |
| 134 | .val = (1 << 4), |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 135 | .port = PORT_CTRL, |
Jean Delvare | 927ab2f | 2010-03-02 12:23:45 +0100 | [diff] [blame] | 136 | }; |
| 137 | |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 138 | static int i2c_parport_probe(struct platform_device *pdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | { |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 140 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | |
| 142 | /* Reset hardware to a sane state (SCL and SDA high) */ |
| 143 | parport_setsda(NULL, 1); |
| 144 | parport_setscl(NULL, 1); |
| 145 | /* Other init if needed (power on...) */ |
Jean Delvare | 6d376fc | 2010-03-02 12:23:41 +0100 | [diff] [blame] | 146 | if (adapter_parm[type].init.val) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | line_set(1, &adapter_parm[type].init); |
Jean Delvare | 6d376fc | 2010-03-02 12:23:41 +0100 | [diff] [blame] | 148 | /* Give powered devices some time to settle */ |
| 149 | msleep(100); |
| 150 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 152 | parport_adapter.dev.parent = &pdev->dev; |
| 153 | err = i2c_bit_add_bus(&parport_adapter); |
Jean Delvare | 927ab2f | 2010-03-02 12:23:45 +0100 | [diff] [blame] | 154 | if (err) { |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 155 | dev_err(&pdev->dev, "Unable to register with I2C\n"); |
Jean Delvare | 927ab2f | 2010-03-02 12:23:45 +0100 | [diff] [blame] | 156 | return err; |
| 157 | } |
| 158 | |
| 159 | /* Setup SMBus alert if supported */ |
| 160 | if (adapter_parm[type].smbus_alert && irq) { |
| 161 | alert_data.irq = irq; |
| 162 | ara = i2c_setup_smbus_alert(&parport_adapter, &alert_data); |
| 163 | if (ara) |
| 164 | line_set(1, &parport_ctrl_irq); |
| 165 | else |
| 166 | dev_warn(&pdev->dev, "Failed to register ARA client\n"); |
| 167 | } |
| 168 | |
| 169 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | } |
| 171 | |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 172 | static int i2c_parport_remove(struct platform_device *pdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | { |
Jean Delvare | 927ab2f | 2010-03-02 12:23:45 +0100 | [diff] [blame] | 174 | if (ara) { |
| 175 | line_set(0, &parport_ctrl_irq); |
| 176 | i2c_unregister_device(ara); |
| 177 | ara = NULL; |
| 178 | } |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 179 | i2c_del_adapter(&parport_adapter); |
| 180 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | /* Un-init if needed (power off...) */ |
| 182 | if (adapter_parm[type].init.val) |
| 183 | line_set(0, &adapter_parm[type].init); |
| 184 | |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 185 | return 0; |
| 186 | } |
| 187 | |
| 188 | static struct platform_driver i2c_parport_driver = { |
| 189 | .driver = { |
| 190 | .owner = THIS_MODULE, |
| 191 | .name = DRVNAME, |
| 192 | }, |
| 193 | .probe = i2c_parport_probe, |
Bill Pemberton | 0b255e9 | 2012-11-27 15:59:38 -0500 | [diff] [blame] | 194 | .remove = i2c_parport_remove, |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 195 | }; |
| 196 | |
| 197 | static int __init i2c_parport_device_add(u16 address) |
| 198 | { |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 199 | int err; |
| 200 | |
| 201 | pdev = platform_device_alloc(DRVNAME, -1); |
| 202 | if (!pdev) { |
| 203 | err = -ENOMEM; |
| 204 | printk(KERN_ERR DRVNAME ": Device allocation failed\n"); |
| 205 | goto exit; |
| 206 | } |
| 207 | |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 208 | err = platform_device_add(pdev); |
| 209 | if (err) { |
| 210 | printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n", |
| 211 | err); |
| 212 | goto exit_device_put; |
| 213 | } |
| 214 | |
| 215 | return 0; |
| 216 | |
| 217 | exit_device_put: |
| 218 | platform_device_put(pdev); |
| 219 | exit: |
| 220 | return err; |
| 221 | } |
| 222 | |
| 223 | static int __init i2c_parport_init(void) |
| 224 | { |
| 225 | int err; |
| 226 | |
| 227 | if (type < 0) { |
| 228 | printk(KERN_ERR DRVNAME ": adapter type unspecified\n"); |
| 229 | return -ENODEV; |
| 230 | } |
| 231 | |
| 232 | if (type >= ARRAY_SIZE(adapter_parm)) { |
| 233 | printk(KERN_ERR DRVNAME ": invalid type (%d)\n", type); |
| 234 | return -ENODEV; |
| 235 | } |
| 236 | |
| 237 | if (base == 0) { |
| 238 | pr_info(DRVNAME ": using default base 0x%x\n", DEFAULT_BASE); |
| 239 | base = DEFAULT_BASE; |
| 240 | } |
| 241 | |
Jean Delvare | 9def255 | 2008-10-14 17:30:04 +0200 | [diff] [blame] | 242 | if (!request_region(base, 3, DRVNAME)) |
| 243 | return -EBUSY; |
| 244 | |
Jean Delvare | 927ab2f | 2010-03-02 12:23:45 +0100 | [diff] [blame] | 245 | if (irq != 0) |
| 246 | pr_info(DRVNAME ": using irq %d\n", irq); |
| 247 | |
Jean Delvare | 07da037 | 2011-05-24 20:58:49 +0200 | [diff] [blame] | 248 | if (!adapter_parm[type].getscl.val) |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 249 | parport_algo_data.getscl = NULL; |
| 250 | |
| 251 | /* Sets global pdev as a side effect */ |
| 252 | err = i2c_parport_device_add(base); |
| 253 | if (err) |
Jean Delvare | 9def255 | 2008-10-14 17:30:04 +0200 | [diff] [blame] | 254 | goto exit_release; |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 255 | |
| 256 | err = platform_driver_register(&i2c_parport_driver); |
| 257 | if (err) |
| 258 | goto exit_device; |
| 259 | |
| 260 | return 0; |
| 261 | |
| 262 | exit_device: |
| 263 | platform_device_unregister(pdev); |
Jean Delvare | 9def255 | 2008-10-14 17:30:04 +0200 | [diff] [blame] | 264 | exit_release: |
| 265 | release_region(base, 3); |
Jean Delvare | c6e8bb2 | 2007-05-01 23:26:30 +0200 | [diff] [blame] | 266 | return err; |
| 267 | } |
| 268 | |
| 269 | static void __exit i2c_parport_exit(void) |
| 270 | { |
| 271 | platform_driver_unregister(&i2c_parport_driver); |
| 272 | platform_device_unregister(pdev); |
Jean Delvare | 9def255 | 2008-10-14 17:30:04 +0200 | [diff] [blame] | 273 | release_region(base, 3); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | } |
| 275 | |
| 276 | MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); |
| 277 | MODULE_DESCRIPTION("I2C bus over parallel port (light)"); |
| 278 | MODULE_LICENSE("GPL"); |
| 279 | |
| 280 | module_init(i2c_parport_init); |
| 281 | module_exit(i2c_parport_exit); |