Merge branch 'linus' into tracing/core
[linux-2.6] / drivers / i2c / busses / i2c-pca-platform.c
1 /*
2  *  i2c_pca_platform.c
3  *
4  *  Platform driver for the PCA9564 I2C controller.
5  *
6  *  Copyright (C) 2008 Pengutronix
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License version 2 as
10  *  published by the Free Software Foundation.
11
12  */
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/delay.h>
18 #include <linux/jiffies.h>
19 #include <linux/errno.h>
20 #include <linux/i2c.h>
21 #include <linux/interrupt.h>
22 #include <linux/platform_device.h>
23 #include <linux/i2c-algo-pca.h>
24 #include <linux/i2c-pca-platform.h>
25 #include <linux/gpio.h>
26
27 #include <asm/irq.h>
28 #include <asm/io.h>
29
30 #define res_len(r)              ((r)->end - (r)->start + 1)
31
32 struct i2c_pca_pf_data {
33         void __iomem                    *reg_base;
34         int                             irq;    /* if 0, use polling */
35         int                             gpio;
36         wait_queue_head_t               wait;
37         struct i2c_adapter              adap;
38         struct i2c_algo_pca_data        algo_data;
39         unsigned long                   io_base;
40         unsigned long                   io_size;
41 };
42
43 /* Read/Write functions for different register alignments */
44
45 static int i2c_pca_pf_readbyte8(void *pd, int reg)
46 {
47         struct i2c_pca_pf_data *i2c = pd;
48         return ioread8(i2c->reg_base + reg);
49 }
50
51 static int i2c_pca_pf_readbyte16(void *pd, int reg)
52 {
53         struct i2c_pca_pf_data *i2c = pd;
54         return ioread8(i2c->reg_base + reg * 2);
55 }
56
57 static int i2c_pca_pf_readbyte32(void *pd, int reg)
58 {
59         struct i2c_pca_pf_data *i2c = pd;
60         return ioread8(i2c->reg_base + reg * 4);
61 }
62
63 static void i2c_pca_pf_writebyte8(void *pd, int reg, int val)
64 {
65         struct i2c_pca_pf_data *i2c = pd;
66         iowrite8(val, i2c->reg_base + reg);
67 }
68
69 static void i2c_pca_pf_writebyte16(void *pd, int reg, int val)
70 {
71         struct i2c_pca_pf_data *i2c = pd;
72         iowrite8(val, i2c->reg_base + reg * 2);
73 }
74
75 static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
76 {
77         struct i2c_pca_pf_data *i2c = pd;
78         iowrite8(val, i2c->reg_base + reg * 4);
79 }
80
81
82 static int i2c_pca_pf_waitforcompletion(void *pd)
83 {
84         struct i2c_pca_pf_data *i2c = pd;
85         long ret = ~0;
86         unsigned long timeout;
87
88         if (i2c->irq) {
89                 ret = wait_event_interruptible_timeout(i2c->wait,
90                         i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
91                         & I2C_PCA_CON_SI, i2c->adap.timeout);
92         } else {
93                 /* Do polling */
94                 timeout = jiffies + i2c->adap.timeout;
95                 while (((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
96                                 & I2C_PCA_CON_SI) == 0)
97                                 && (ret = time_before(jiffies, timeout)))
98                         udelay(100);
99         }
100
101         return ret > 0;
102 }
103
104 static void i2c_pca_pf_dummyreset(void *pd)
105 {
106         struct i2c_pca_pf_data *i2c = pd;
107         printk(KERN_WARNING "%s: No reset-pin found. Chip may get stuck!\n",
108                 i2c->adap.name);
109 }
110
111 static void i2c_pca_pf_resetchip(void *pd)
112 {
113         struct i2c_pca_pf_data *i2c = pd;
114
115         gpio_set_value(i2c->gpio, 0);
116         ndelay(100);
117         gpio_set_value(i2c->gpio, 1);
118 }
119
120 static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id)
121 {
122         struct i2c_pca_pf_data *i2c = dev_id;
123
124         if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
125                 return IRQ_NONE;
126
127         wake_up_interruptible(&i2c->wait);
128
129         return IRQ_HANDLED;
130 }
131
132
133 static int __devinit i2c_pca_pf_probe(struct platform_device *pdev)
134 {
135         struct i2c_pca_pf_data *i2c;
136         struct resource *res;
137         struct i2c_pca9564_pf_platform_data *platform_data =
138                                 pdev->dev.platform_data;
139         int ret = 0;
140         int irq;
141
142         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
143         irq = platform_get_irq(pdev, 0);
144         /* If irq is 0, we do polling. */
145
146         if (res == NULL) {
147                 ret = -ENODEV;
148                 goto e_print;
149         }
150
151         if (!request_mem_region(res->start, res_len(res), res->name)) {
152                 ret = -ENOMEM;
153                 goto e_print;
154         }
155
156         i2c = kzalloc(sizeof(struct i2c_pca_pf_data), GFP_KERNEL);
157         if (!i2c) {
158                 ret = -ENOMEM;
159                 goto e_alloc;
160         }
161
162         init_waitqueue_head(&i2c->wait);
163
164         i2c->reg_base = ioremap(res->start, res_len(res));
165         if (!i2c->reg_base) {
166                 ret = -ENOMEM;
167                 goto e_remap;
168         }
169         i2c->io_base = res->start;
170         i2c->io_size = res_len(res);
171         i2c->irq = irq;
172
173         i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0;
174         i2c->adap.owner = THIS_MODULE;
175         snprintf(i2c->adap.name, sizeof(i2c->adap.name),
176                  "PCA9564/PCA9665 at 0x%08lx",
177                  (unsigned long) res->start);
178         i2c->adap.algo_data = &i2c->algo_data;
179         i2c->adap.dev.parent = &pdev->dev;
180
181         if (platform_data) {
182                 i2c->adap.timeout = platform_data->timeout;
183                 i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed;
184                 i2c->gpio = platform_data->gpio;
185         } else {
186                 i2c->adap.timeout = HZ;
187                 i2c->algo_data.i2c_clock = 59000;
188                 i2c->gpio = -1;
189         }
190
191         i2c->algo_data.data = i2c;
192         i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion;
193         i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset;
194
195         switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
196         case IORESOURCE_MEM_32BIT:
197                 i2c->algo_data.write_byte = i2c_pca_pf_writebyte32;
198                 i2c->algo_data.read_byte = i2c_pca_pf_readbyte32;
199                 break;
200         case IORESOURCE_MEM_16BIT:
201                 i2c->algo_data.write_byte = i2c_pca_pf_writebyte16;
202                 i2c->algo_data.read_byte = i2c_pca_pf_readbyte16;
203                 break;
204         case IORESOURCE_MEM_8BIT:
205         default:
206                 i2c->algo_data.write_byte = i2c_pca_pf_writebyte8;
207                 i2c->algo_data.read_byte = i2c_pca_pf_readbyte8;
208                 break;
209         }
210
211         /* Use gpio_is_valid() when in mainline */
212         if (i2c->gpio > -1) {
213                 ret = gpio_request(i2c->gpio, i2c->adap.name);
214                 if (ret == 0) {
215                         gpio_direction_output(i2c->gpio, 1);
216                         i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;
217                 } else {
218                         printk(KERN_WARNING "%s: Registering gpio failed!\n",
219                                 i2c->adap.name);
220                         i2c->gpio = ret;
221                 }
222         }
223
224         if (irq) {
225                 ret = request_irq(irq, i2c_pca_pf_handler,
226                         IRQF_TRIGGER_FALLING, i2c->adap.name, i2c);
227                 if (ret)
228                         goto e_reqirq;
229         }
230
231         if (i2c_pca_add_numbered_bus(&i2c->adap) < 0) {
232                 ret = -ENODEV;
233                 goto e_adapt;
234         }
235
236         platform_set_drvdata(pdev, i2c);
237
238         printk(KERN_INFO "%s registered.\n", i2c->adap.name);
239
240         return 0;
241
242 e_adapt:
243         if (irq)
244                 free_irq(irq, i2c);
245 e_reqirq:
246         if (i2c->gpio > -1)
247                 gpio_free(i2c->gpio);
248
249         iounmap(i2c->reg_base);
250 e_remap:
251         kfree(i2c);
252 e_alloc:
253         release_mem_region(res->start, res_len(res));
254 e_print:
255         printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret);
256         return ret;
257 }
258
259 static int __devexit i2c_pca_pf_remove(struct platform_device *pdev)
260 {
261         struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev);
262         platform_set_drvdata(pdev, NULL);
263
264         i2c_del_adapter(&i2c->adap);
265
266         if (i2c->irq)
267                 free_irq(i2c->irq, i2c);
268
269         if (i2c->gpio > -1)
270                 gpio_free(i2c->gpio);
271
272         iounmap(i2c->reg_base);
273         release_mem_region(i2c->io_base, i2c->io_size);
274         kfree(i2c);
275
276         return 0;
277 }
278
279 static struct platform_driver i2c_pca_pf_driver = {
280         .probe = i2c_pca_pf_probe,
281         .remove = __devexit_p(i2c_pca_pf_remove),
282         .driver = {
283                 .name = "i2c-pca-platform",
284                 .owner = THIS_MODULE,
285         },
286 };
287
288 static int __init i2c_pca_pf_init(void)
289 {
290         return platform_driver_register(&i2c_pca_pf_driver);
291 }
292
293 static void __exit i2c_pca_pf_exit(void)
294 {
295         platform_driver_unregister(&i2c_pca_pf_driver);
296 }
297
298 MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
299 MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");
300 MODULE_LICENSE("GPL");
301
302 module_init(i2c_pca_pf_init);
303 module_exit(i2c_pca_pf_exit);
304