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244fbbb8 WS |
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> | |
244fbbb8 WS |
15 | #include <linux/slab.h> |
16 | #include <linux/delay.h> | |
2378bc09 | 17 | #include <linux/jiffies.h> |
244fbbb8 WS |
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> | |
21782180 | 25 | #include <linux/io.h> |
244fbbb8 WS |
26 | |
27 | #include <asm/irq.h> | |
244fbbb8 | 28 | |
244fbbb8 WS |
29 | struct i2c_pca_pf_data { |
30 | void __iomem *reg_base; | |
31 | int irq; /* if 0, use polling */ | |
32 | int gpio; | |
33 | wait_queue_head_t wait; | |
34 | struct i2c_adapter adap; | |
35 | struct i2c_algo_pca_data algo_data; | |
36 | unsigned long io_base; | |
37 | unsigned long io_size; | |
38 | }; | |
39 | ||
40 | /* Read/Write functions for different register alignments */ | |
41 | ||
42 | static int i2c_pca_pf_readbyte8(void *pd, int reg) | |
43 | { | |
44 | struct i2c_pca_pf_data *i2c = pd; | |
45 | return ioread8(i2c->reg_base + reg); | |
46 | } | |
47 | ||
48 | static int i2c_pca_pf_readbyte16(void *pd, int reg) | |
49 | { | |
50 | struct i2c_pca_pf_data *i2c = pd; | |
51 | return ioread8(i2c->reg_base + reg * 2); | |
52 | } | |
53 | ||
54 | static int i2c_pca_pf_readbyte32(void *pd, int reg) | |
55 | { | |
56 | struct i2c_pca_pf_data *i2c = pd; | |
57 | return ioread8(i2c->reg_base + reg * 4); | |
58 | } | |
59 | ||
60 | static void i2c_pca_pf_writebyte8(void *pd, int reg, int val) | |
61 | { | |
62 | struct i2c_pca_pf_data *i2c = pd; | |
63 | iowrite8(val, i2c->reg_base + reg); | |
64 | } | |
65 | ||
66 | static void i2c_pca_pf_writebyte16(void *pd, int reg, int val) | |
67 | { | |
68 | struct i2c_pca_pf_data *i2c = pd; | |
69 | iowrite8(val, i2c->reg_base + reg * 2); | |
70 | } | |
71 | ||
72 | static void i2c_pca_pf_writebyte32(void *pd, int reg, int val) | |
73 | { | |
74 | struct i2c_pca_pf_data *i2c = pd; | |
75 | iowrite8(val, i2c->reg_base + reg * 4); | |
76 | } | |
77 | ||
78 | ||
79 | static int i2c_pca_pf_waitforcompletion(void *pd) | |
80 | { | |
81 | struct i2c_pca_pf_data *i2c = pd; | |
2378bc09 | 82 | unsigned long timeout; |
6abb930a | 83 | long ret; |
244fbbb8 WS |
84 | |
85 | if (i2c->irq) { | |
22f8b269 | 86 | ret = wait_event_timeout(i2c->wait, |
244fbbb8 | 87 | i2c->algo_data.read_byte(i2c, I2C_PCA_CON) |
2378bc09 | 88 | & I2C_PCA_CON_SI, i2c->adap.timeout); |
244fbbb8 | 89 | } else { |
2378bc09 WS |
90 | /* Do polling */ |
91 | timeout = jiffies + i2c->adap.timeout; | |
6abb930a YY |
92 | do { |
93 | ret = time_before(jiffies, timeout); | |
94 | if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON) | |
95 | & I2C_PCA_CON_SI) | |
96 | break; | |
244fbbb8 | 97 | udelay(100); |
6abb930a | 98 | } while (ret); |
244fbbb8 WS |
99 | } |
100 | ||
2378bc09 | 101 | return ret > 0; |
244fbbb8 WS |
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 | ||
22f8b269 | 127 | wake_up(&i2c->wait); |
244fbbb8 WS |
128 | |
129 | return IRQ_HANDLED; | |
130 | } | |
131 | ||
132 | ||
0b255e92 | 133 | static int i2c_pca_pf_probe(struct platform_device *pdev) |
244fbbb8 WS |
134 | { |
135 | struct i2c_pca_pf_data *i2c; | |
136 | struct resource *res; | |
137 | struct i2c_pca9564_pf_platform_data *platform_data = | |
6d4028c6 | 138 | dev_get_platdata(&pdev->dev); |
244fbbb8 WS |
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 | ||
c6ffddea | 151 | if (!request_mem_region(res->start, resource_size(res), res->name)) { |
244fbbb8 WS |
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 | ||
c6ffddea | 164 | i2c->reg_base = ioremap(res->start, resource_size(res)); |
244fbbb8 | 165 | if (!i2c->reg_base) { |
7650da02 | 166 | ret = -ENOMEM; |
244fbbb8 WS |
167 | goto e_remap; |
168 | } | |
169 | i2c->io_base = res->start; | |
c6ffddea | 170 | i2c->io_size = resource_size(res); |
244fbbb8 WS |
171 | i2c->irq = irq; |
172 | ||
44454baa | 173 | i2c->adap.nr = pdev->id; |
244fbbb8 | 174 | i2c->adap.owner = THIS_MODULE; |
eff9ec95 MAC |
175 | snprintf(i2c->adap.name, sizeof(i2c->adap.name), |
176 | "PCA9564/PCA9665 at 0x%08lx", | |
177 | (unsigned long) res->start); | |
244fbbb8 WS |
178 | i2c->adap.algo_data = &i2c->algo_data; |
179 | i2c->adap.dev.parent = &pdev->dev; | |
244fbbb8 | 180 | |
6b110d13 WS |
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 | ||
244fbbb8 | 191 | i2c->algo_data.data = i2c; |
6b110d13 WS |
192 | i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion; |
193 | i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset; | |
244fbbb8 WS |
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 | ||
244fbbb8 WS |
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, | |
32358443 | 226 | IRQF_TRIGGER_FALLING, pdev->name, i2c); |
244fbbb8 WS |
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: | |
c6ffddea | 253 | release_mem_region(res->start, resource_size(res)); |
244fbbb8 | 254 | e_print: |
eff9ec95 | 255 | printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret); |
244fbbb8 WS |
256 | return ret; |
257 | } | |
258 | ||
0b255e92 | 259 | static int i2c_pca_pf_remove(struct platform_device *pdev) |
244fbbb8 WS |
260 | { |
261 | struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev); | |
244fbbb8 WS |
262 | |
263 | i2c_del_adapter(&i2c->adap); | |
264 | ||
265 | if (i2c->irq) | |
266 | free_irq(i2c->irq, i2c); | |
267 | ||
268 | if (i2c->gpio > -1) | |
269 | gpio_free(i2c->gpio); | |
270 | ||
271 | iounmap(i2c->reg_base); | |
272 | release_mem_region(i2c->io_base, i2c->io_size); | |
273 | kfree(i2c); | |
274 | ||
275 | return 0; | |
276 | } | |
277 | ||
278 | static struct platform_driver i2c_pca_pf_driver = { | |
279 | .probe = i2c_pca_pf_probe, | |
0b255e92 | 280 | .remove = i2c_pca_pf_remove, |
244fbbb8 WS |
281 | .driver = { |
282 | .name = "i2c-pca-platform", | |
244fbbb8 WS |
283 | }, |
284 | }; | |
285 | ||
a3664b51 | 286 | module_platform_driver(i2c_pca_pf_driver); |
244fbbb8 | 287 | |
9ef8a0be | 288 | MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>"); |
eff9ec95 | 289 | MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); |
244fbbb8 | 290 | MODULE_LICENSE("GPL"); |