i2c-algo-pca: Add PCA9665 support
[linux-2.6.git] / 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/errno.h>
19 #include <linux/i2c.h>
20 #include <linux/interrupt.h>
21 #include <linux/platform_device.h>
22 #include <linux/i2c-algo-pca.h>
23 #include <linux/i2c-pca-platform.h>
24 #include <linux/gpio.h>
25
26 #include <asm/irq.h>
27 #include <asm/io.h>
28
29 #define res_len(r)              ((r)->end - (r)->start + 1)
30
31 struct i2c_pca_pf_data {
32         void __iomem                    *reg_base;
33         int                             irq;    /* if 0, use polling */
34         int                             gpio;
35         wait_queue_head_t               wait;
36         struct i2c_adapter              adap;
37         struct i2c_algo_pca_data        algo_data;
38         unsigned long                   io_base;
39         unsigned long                   io_size;
40 };
41
42 /* Read/Write functions for different register alignments */
43
44 static int i2c_pca_pf_readbyte8(void *pd, int reg)
45 {
46         struct i2c_pca_pf_data *i2c = pd;
47         return ioread8(i2c->reg_base + reg);
48 }
49
50 static int i2c_pca_pf_readbyte16(void *pd, int reg)
51 {
52         struct i2c_pca_pf_data *i2c = pd;
53         return ioread8(i2c->reg_base + reg * 2);
54 }
55
56 static int i2c_pca_pf_readbyte32(void *pd, int reg)
57 {
58         struct i2c_pca_pf_data *i2c = pd;
59         return ioread8(i2c->reg_base + reg * 4);
60 }
61
62 static void i2c_pca_pf_writebyte8(void *pd, int reg, int val)
63 {
64         struct i2c_pca_pf_data *i2c = pd;
65         iowrite8(val, i2c->reg_base + reg);
66 }
67
68 static void i2c_pca_pf_writebyte16(void *pd, int reg, int val)
69 {
70         struct i2c_pca_pf_data *i2c = pd;
71         iowrite8(val, i2c->reg_base + reg * 2);
72 }
73
74 static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
75 {
76         struct i2c_pca_pf_data *i2c = pd;
77         iowrite8(val, i2c->reg_base + reg * 4);
78 }
79
80
81 static int i2c_pca_pf_waitforcompletion(void *pd)
82 {
83         struct i2c_pca_pf_data *i2c = pd;
84         int ret = 0;
85
86         if (i2c->irq) {
87                 ret = wait_event_interruptible(i2c->wait,
88                         i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
89                         & I2C_PCA_CON_SI);
90         } else {
91                 /*
92                  * Do polling...
93                  * XXX: Could get stuck in extreme cases!
94                  *      Maybe add timeout, but using irqs is preferred anyhow.
95                  */
96                 while ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
97                                 & I2C_PCA_CON_SI) == 0)
98                         udelay(100);
99         }
100
101         return ret;
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         i2c->adap.timeout = platform_data->timeout;
181
182         i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed;
183         i2c->algo_data.data = i2c;
184
185         switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
186         case IORESOURCE_MEM_32BIT:
187                 i2c->algo_data.write_byte = i2c_pca_pf_writebyte32;
188                 i2c->algo_data.read_byte = i2c_pca_pf_readbyte32;
189                 break;
190         case IORESOURCE_MEM_16BIT:
191                 i2c->algo_data.write_byte = i2c_pca_pf_writebyte16;
192                 i2c->algo_data.read_byte = i2c_pca_pf_readbyte16;
193                 break;
194         case IORESOURCE_MEM_8BIT:
195         default:
196                 i2c->algo_data.write_byte = i2c_pca_pf_writebyte8;
197                 i2c->algo_data.read_byte = i2c_pca_pf_readbyte8;
198                 break;
199         }
200
201         i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion;
202
203         i2c->gpio = platform_data->gpio;
204         i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset;
205
206         /* Use gpio_is_valid() when in mainline */
207         if (i2c->gpio > -1) {
208                 ret = gpio_request(i2c->gpio, i2c->adap.name);
209                 if (ret == 0) {
210                         gpio_direction_output(i2c->gpio, 1);
211                         i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;
212                 } else {
213                         printk(KERN_WARNING "%s: Registering gpio failed!\n",
214                                 i2c->adap.name);
215                         i2c->gpio = ret;
216                 }
217         }
218
219         if (irq) {
220                 ret = request_irq(irq, i2c_pca_pf_handler,
221                         IRQF_TRIGGER_FALLING, i2c->adap.name, i2c);
222                 if (ret)
223                         goto e_reqirq;
224         }
225
226         if (i2c_pca_add_numbered_bus(&i2c->adap) < 0) {
227                 ret = -ENODEV;
228                 goto e_adapt;
229         }
230
231         platform_set_drvdata(pdev, i2c);
232
233         printk(KERN_INFO "%s registered.\n", i2c->adap.name);
234
235         return 0;
236
237 e_adapt:
238         if (irq)
239                 free_irq(irq, i2c);
240 e_reqirq:
241         if (i2c->gpio > -1)
242                 gpio_free(i2c->gpio);
243
244         iounmap(i2c->reg_base);
245 e_remap:
246         kfree(i2c);
247 e_alloc:
248         release_mem_region(res->start, res_len(res));
249 e_print:
250         printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret);
251         return ret;
252 }
253
254 static int __devexit i2c_pca_pf_remove(struct platform_device *pdev)
255 {
256         struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev);
257         platform_set_drvdata(pdev, NULL);
258
259         i2c_del_adapter(&i2c->adap);
260
261         if (i2c->irq)
262                 free_irq(i2c->irq, i2c);
263
264         if (i2c->gpio > -1)
265                 gpio_free(i2c->gpio);
266
267         iounmap(i2c->reg_base);
268         release_mem_region(i2c->io_base, i2c->io_size);
269         kfree(i2c);
270
271         return 0;
272 }
273
274 static struct platform_driver i2c_pca_pf_driver = {
275         .probe = i2c_pca_pf_probe,
276         .remove = __devexit_p(i2c_pca_pf_remove),
277         .driver = {
278                 .name = "i2c-pca-platform",
279                 .owner = THIS_MODULE,
280         },
281 };
282
283 static int __init i2c_pca_pf_init(void)
284 {
285         return platform_driver_register(&i2c_pca_pf_driver);
286 }
287
288 static void __exit i2c_pca_pf_exit(void)
289 {
290         platform_driver_unregister(&i2c_pca_pf_driver);
291 }
292
293 MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
294 MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");
295 MODULE_LICENSE("GPL");
296
297 module_init(i2c_pca_pf_init);
298 module_exit(i2c_pca_pf_exit);
299