Commit | Line | Data |
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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 | 2 | /* ------------------------------------------------------------------------ * |
c6e8bb2c | 3 | * i2c-parport-light.c I2C bus over parallel port * |
1da177e4 | 4 | * ------------------------------------------------------------------------ * |
7c81c60f | 5 | Copyright (C) 2003-2010 Jean Delvare <jdelvare@suse.de> |
07da0372 | 6 | |
1da177e4 LT |
7 | Based on older i2c-velleman.c driver |
8 | Copyright (C) 1995-2000 Simon G. Vogl | |
9 | With some changes from: | |
10 | Frodo Looijaard <frodol@dds.nl> | |
96de0e25 | 11 | Kyösti Mälkki <kmalkki@cc.hut.fi> |
07da0372 | 12 | |
1da177e4 LT |
13 | * ------------------------------------------------------------------------ */ |
14 | ||
1da177e4 LT |
15 | #include <linux/kernel.h> |
16 | #include <linux/module.h> | |
17 | #include <linux/init.h> | |
6d376fcc | 18 | #include <linux/delay.h> |
c6e8bb2c | 19 | #include <linux/platform_device.h> |
1da177e4 LT |
20 | #include <linux/ioport.h> |
21 | #include <linux/i2c.h> | |
22 | #include <linux/i2c-algo-bit.h> | |
927ab2f8 | 23 | #include <linux/i2c-smbus.h> |
21782180 | 24 | #include <linux/io.h> |
1da177e4 LT |
25 | #include "i2c-parport.h" |
26 | ||
27 | #define DEFAULT_BASE 0x378 | |
c6e8bb2c JD |
28 | #define DRVNAME "i2c-parport-light" |
29 | ||
30 | static struct platform_device *pdev; | |
1da177e4 LT |
31 | |
32 | static u16 base; | |
c78babcc | 33 | module_param_hw(base, ushort, ioport, 0); |
1da177e4 LT |
34 | MODULE_PARM_DESC(base, "Base I/O address"); |
35 | ||
927ab2f8 | 36 | static int irq; |
c78babcc | 37 | module_param_hw(irq, int, irq, 0); |
927ab2f8 JD |
38 | MODULE_PARM_DESC(irq, "IRQ (optional)"); |
39 | ||
1da177e4 LT |
40 | /* ----- Low-level parallel port access ----------------------------------- */ |
41 | ||
42 | static inline void port_write(unsigned char p, unsigned char d) | |
43 | { | |
44 | outb(d, base+p); | |
45 | } | |
46 | ||
47 | static inline unsigned char port_read(unsigned char p) | |
48 | { | |
49 | return inb(base+p); | |
50 | } | |
51 | ||
52 | /* ----- Unified line operation functions --------------------------------- */ | |
53 | ||
54 | static inline void line_set(int state, const struct lineop *op) | |
55 | { | |
56 | u8 oldval = port_read(op->port); | |
57 | ||
58 | /* Touch only the bit(s) needed */ | |
59 | if ((op->inverted && !state) || (!op->inverted && state)) | |
60 | port_write(op->port, oldval | op->val); | |
61 | else | |
62 | port_write(op->port, oldval & ~op->val); | |
63 | } | |
64 | ||
65 | static inline int line_get(const struct lineop *op) | |
66 | { | |
67 | u8 oldval = port_read(op->port); | |
68 | ||
69 | return ((op->inverted && (oldval & op->val) != op->val) | |
70 | || (!op->inverted && (oldval & op->val) == op->val)); | |
71 | } | |
72 | ||
73 | /* ----- I2C algorithm call-back functions and structures ----------------- */ | |
74 | ||
75 | static void parport_setscl(void *data, int state) | |
76 | { | |
77 | line_set(state, &adapter_parm[type].setscl); | |
78 | } | |
79 | ||
80 | static void parport_setsda(void *data, int state) | |
81 | { | |
82 | line_set(state, &adapter_parm[type].setsda); | |
83 | } | |
84 | ||
85 | static int parport_getscl(void *data) | |
86 | { | |
87 | return line_get(&adapter_parm[type].getscl); | |
88 | } | |
89 | ||
90 | static int parport_getsda(void *data) | |
91 | { | |
92 | return line_get(&adapter_parm[type].getsda); | |
93 | } | |
94 | ||
95 | /* Encapsulate the functions above in the correct structure | |
96 | Note that getscl will be set to NULL by the attaching code for adapters | |
97 | that cannot read SCL back */ | |
98 | static struct i2c_algo_bit_data parport_algo_data = { | |
99 | .setsda = parport_setsda, | |
100 | .setscl = parport_setscl, | |
101 | .getsda = parport_getsda, | |
102 | .getscl = parport_getscl, | |
103 | .udelay = 50, | |
1da177e4 | 104 | .timeout = HZ, |
07da0372 | 105 | }; |
1da177e4 | 106 | |
c6e8bb2c | 107 | /* ----- Driver registration ---------------------------------------------- */ |
1da177e4 LT |
108 | |
109 | static struct i2c_adapter parport_adapter = { | |
110 | .owner = THIS_MODULE, | |
111 | .class = I2C_CLASS_HWMON, | |
1da177e4 LT |
112 | .algo_data = &parport_algo_data, |
113 | .name = "Parallel port adapter (light)", | |
114 | }; | |
115 | ||
927ab2f8 JD |
116 | /* SMBus alert support */ |
117 | static struct i2c_smbus_alert_setup alert_data = { | |
927ab2f8 JD |
118 | }; |
119 | static struct i2c_client *ara; | |
120 | static struct lineop parport_ctrl_irq = { | |
121 | .val = (1 << 4), | |
07da0372 | 122 | .port = PORT_CTRL, |
927ab2f8 JD |
123 | }; |
124 | ||
0b255e92 | 125 | static int i2c_parport_probe(struct platform_device *pdev) |
c6e8bb2c JD |
126 | { |
127 | int err; | |
c6e8bb2c JD |
128 | |
129 | /* Reset hardware to a sane state (SCL and SDA high) */ | |
130 | parport_setsda(NULL, 1); | |
131 | parport_setscl(NULL, 1); | |
132 | /* Other init if needed (power on...) */ | |
6d376fcc | 133 | if (adapter_parm[type].init.val) { |
c6e8bb2c | 134 | line_set(1, &adapter_parm[type].init); |
6d376fcc JD |
135 | /* Give powered devices some time to settle */ |
136 | msleep(100); | |
137 | } | |
c6e8bb2c JD |
138 | |
139 | parport_adapter.dev.parent = &pdev->dev; | |
140 | err = i2c_bit_add_bus(&parport_adapter); | |
927ab2f8 | 141 | if (err) { |
c6e8bb2c | 142 | dev_err(&pdev->dev, "Unable to register with I2C\n"); |
927ab2f8 JD |
143 | return err; |
144 | } | |
145 | ||
146 | /* Setup SMBus alert if supported */ | |
147 | if (adapter_parm[type].smbus_alert && irq) { | |
148 | alert_data.irq = irq; | |
149 | ara = i2c_setup_smbus_alert(&parport_adapter, &alert_data); | |
150 | if (ara) | |
151 | line_set(1, &parport_ctrl_irq); | |
152 | else | |
153 | dev_warn(&pdev->dev, "Failed to register ARA client\n"); | |
154 | } | |
155 | ||
156 | return 0; | |
c6e8bb2c JD |
157 | } |
158 | ||
0b255e92 | 159 | static int i2c_parport_remove(struct platform_device *pdev) |
c6e8bb2c | 160 | { |
927ab2f8 JD |
161 | if (ara) { |
162 | line_set(0, &parport_ctrl_irq); | |
163 | i2c_unregister_device(ara); | |
164 | ara = NULL; | |
165 | } | |
c6e8bb2c JD |
166 | i2c_del_adapter(&parport_adapter); |
167 | ||
168 | /* Un-init if needed (power off...) */ | |
169 | if (adapter_parm[type].init.val) | |
170 | line_set(0, &adapter_parm[type].init); | |
171 | ||
c6e8bb2c JD |
172 | return 0; |
173 | } | |
174 | ||
175 | static struct platform_driver i2c_parport_driver = { | |
176 | .driver = { | |
c6e8bb2c JD |
177 | .name = DRVNAME, |
178 | }, | |
179 | .probe = i2c_parport_probe, | |
0b255e92 | 180 | .remove = i2c_parport_remove, |
c6e8bb2c JD |
181 | }; |
182 | ||
183 | static int __init i2c_parport_device_add(u16 address) | |
184 | { | |
c6e8bb2c JD |
185 | int err; |
186 | ||
187 | pdev = platform_device_alloc(DRVNAME, -1); | |
188 | if (!pdev) { | |
189 | err = -ENOMEM; | |
190 | printk(KERN_ERR DRVNAME ": Device allocation failed\n"); | |
191 | goto exit; | |
192 | } | |
193 | ||
c6e8bb2c JD |
194 | err = platform_device_add(pdev); |
195 | if (err) { | |
196 | printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n", | |
197 | err); | |
198 | goto exit_device_put; | |
199 | } | |
200 | ||
201 | return 0; | |
202 | ||
203 | exit_device_put: | |
204 | platform_device_put(pdev); | |
205 | exit: | |
206 | return err; | |
207 | } | |
1da177e4 LT |
208 | |
209 | static int __init i2c_parport_init(void) | |
210 | { | |
c6e8bb2c JD |
211 | int err; |
212 | ||
e97b81dd | 213 | if (type < 0) { |
c6e8bb2c | 214 | printk(KERN_ERR DRVNAME ": adapter type unspecified\n"); |
e97b81dd MH |
215 | return -ENODEV; |
216 | } | |
217 | ||
218 | if (type >= ARRAY_SIZE(adapter_parm)) { | |
c6e8bb2c | 219 | printk(KERN_ERR DRVNAME ": invalid type (%d)\n", type); |
e97b81dd | 220 | return -ENODEV; |
1da177e4 | 221 | } |
7e3d7db5 | 222 | |
1da177e4 | 223 | if (base == 0) { |
c6e8bb2c | 224 | pr_info(DRVNAME ": using default base 0x%x\n", DEFAULT_BASE); |
1da177e4 LT |
225 | base = DEFAULT_BASE; |
226 | } | |
227 | ||
9def2556 JD |
228 | if (!request_region(base, 3, DRVNAME)) |
229 | return -EBUSY; | |
230 | ||
927ab2f8 JD |
231 | if (irq != 0) |
232 | pr_info(DRVNAME ": using irq %d\n", irq); | |
233 | ||
07da0372 | 234 | if (!adapter_parm[type].getscl.val) |
1da177e4 LT |
235 | parport_algo_data.getscl = NULL; |
236 | ||
c6e8bb2c JD |
237 | /* Sets global pdev as a side effect */ |
238 | err = i2c_parport_device_add(base); | |
239 | if (err) | |
9def2556 | 240 | goto exit_release; |
1da177e4 | 241 | |
c6e8bb2c JD |
242 | err = platform_driver_register(&i2c_parport_driver); |
243 | if (err) | |
244 | goto exit_device; | |
7e3d7db5 | 245 | |
1da177e4 | 246 | return 0; |
c6e8bb2c JD |
247 | |
248 | exit_device: | |
249 | platform_device_unregister(pdev); | |
9def2556 JD |
250 | exit_release: |
251 | release_region(base, 3); | |
c6e8bb2c | 252 | return err; |
1da177e4 LT |
253 | } |
254 | ||
255 | static void __exit i2c_parport_exit(void) | |
256 | { | |
c6e8bb2c JD |
257 | platform_driver_unregister(&i2c_parport_driver); |
258 | platform_device_unregister(pdev); | |
9def2556 | 259 | release_region(base, 3); |
1da177e4 LT |
260 | } |
261 | ||
7c81c60f | 262 | MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); |
1da177e4 LT |
263 | MODULE_DESCRIPTION("I2C bus over parallel port (light)"); |
264 | MODULE_LICENSE("GPL"); | |
265 | ||
266 | module_init(i2c_parport_init); | |
267 | module_exit(i2c_parport_exit); |