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14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/device.h>
18#include <linux/mutex.h>
19#include <linux/i2c.h>
20#include <linux/gpio.h>
21#include <linux/of.h>
22#include <linux/of_gpio.h>
23#include <linux/slab.h>
24#include <linux/kthread.h>
25#include <linux/reboot.h>
26#include <asm/prom.h>
27#include <asm/machdep.h>
28
29
30
31
32
33#define MCU_REG_CTRL 0x20
34#define MCU_CTRL_POFF 0x40
35#define MCU_CTRL_BTN 0x80
36
37#define MCU_NUM_GPIO 2
38
39struct mcu {
40 struct mutex lock;
41 struct i2c_client *client;
42 struct gpio_chip gc;
43 u8 reg_ctrl;
44};
45
46static struct mcu *glob_mcu;
47
48struct task_struct *shutdown_thread;
49static int shutdown_thread_fn(void *data)
50{
51 int ret;
52 struct mcu *mcu = glob_mcu;
53
54 while (!kthread_should_stop()) {
55 ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
56 if (ret < 0)
57 pr_err("MCU status reg read failed.\n");
58 mcu->reg_ctrl = ret;
59
60
61 if (mcu->reg_ctrl & MCU_CTRL_BTN) {
62 i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL,
63 mcu->reg_ctrl & ~MCU_CTRL_BTN);
64
65 ctrl_alt_del();
66 }
67
68 set_current_state(TASK_INTERRUPTIBLE);
69 schedule_timeout(HZ);
70 }
71
72 return 0;
73}
74
75static ssize_t show_status(struct device *d,
76 struct device_attribute *attr, char *buf)
77{
78 int ret;
79 struct mcu *mcu = glob_mcu;
80
81 ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
82 if (ret < 0)
83 return -ENODEV;
84 mcu->reg_ctrl = ret;
85
86 return sprintf(buf, "%02x\n", ret);
87}
88static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
89
90static void mcu_power_off(void)
91{
92 struct mcu *mcu = glob_mcu;
93
94 pr_info("Sending power-off request to the MCU...\n");
95 mutex_lock(&mcu->lock);
96 i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL,
97 mcu->reg_ctrl | MCU_CTRL_POFF);
98 mutex_unlock(&mcu->lock);
99}
100
101static void mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
102{
103 struct mcu *mcu = container_of(gc, struct mcu, gc);
104 u8 bit = 1 << (4 + gpio);
105
106 mutex_lock(&mcu->lock);
107 if (val)
108 mcu->reg_ctrl &= ~bit;
109 else
110 mcu->reg_ctrl |= bit;
111
112 i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, mcu->reg_ctrl);
113 mutex_unlock(&mcu->lock);
114}
115
116static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
117{
118 mcu_gpio_set(gc, gpio, val);
119 return 0;
120}
121
122static int mcu_gpiochip_add(struct mcu *mcu)
123{
124 struct device_node *np;
125 struct gpio_chip *gc = &mcu->gc;
126
127 np = of_find_compatible_node(NULL, NULL, "fsl,mcu-mpc8349emitx");
128 if (!np)
129 return -ENODEV;
130
131 gc->owner = THIS_MODULE;
132 gc->label = np->full_name;
133 gc->can_sleep = 1;
134 gc->ngpio = MCU_NUM_GPIO;
135 gc->base = -1;
136 gc->set = mcu_gpio_set;
137 gc->direction_output = mcu_gpio_dir_out;
138 gc->of_node = np;
139
140 return gpiochip_add(gc);
141}
142
143static int mcu_gpiochip_remove(struct mcu *mcu)
144{
145 return gpiochip_remove(&mcu->gc);
146}
147
148static int __devinit mcu_probe(struct i2c_client *client,
149 const struct i2c_device_id *id)
150{
151 struct mcu *mcu;
152 int ret;
153
154 mcu = kzalloc(sizeof(*mcu), GFP_KERNEL);
155 if (!mcu)
156 return -ENOMEM;
157
158 mutex_init(&mcu->lock);
159 mcu->client = client;
160 i2c_set_clientdata(client, mcu);
161
162 ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
163 if (ret < 0)
164 goto err;
165 mcu->reg_ctrl = ret;
166
167 ret = mcu_gpiochip_add(mcu);
168 if (ret)
169 goto err;
170
171
172 if (!ppc_md.power_off) {
173 glob_mcu = mcu;
174 ppc_md.power_off = mcu_power_off;
175 dev_info(&client->dev, "will provide power-off service\n");
176 }
177
178 if (device_create_file(&client->dev, &dev_attr_status))
179 dev_err(&client->dev,
180 "couldn't create device file for status\n");
181
182 shutdown_thread = kthread_run(shutdown_thread_fn, NULL,
183 "mcu-i2c-shdn");
184
185 return 0;
186err:
187 kfree(mcu);
188 return ret;
189}
190
191static int __devexit mcu_remove(struct i2c_client *client)
192{
193 struct mcu *mcu = i2c_get_clientdata(client);
194 int ret;
195
196 kthread_stop(shutdown_thread);
197
198 device_remove_file(&client->dev, &dev_attr_status);
199
200 if (glob_mcu == mcu) {
201 ppc_md.power_off = NULL;
202 glob_mcu = NULL;
203 }
204
205 ret = mcu_gpiochip_remove(mcu);
206 if (ret)
207 return ret;
208 i2c_set_clientdata(client, NULL);
209 kfree(mcu);
210 return 0;
211}
212
213static const struct i2c_device_id mcu_ids[] = {
214 { "mcu-mpc8349emitx", },
215 {},
216};
217MODULE_DEVICE_TABLE(i2c, mcu_ids);
218
219static struct of_device_id mcu_of_match_table[] __devinitdata = {
220 { .compatible = "fsl,mcu-mpc8349emitx", },
221 { },
222};
223
224static struct i2c_driver mcu_driver = {
225 .driver = {
226 .name = "mcu-mpc8349emitx",
227 .owner = THIS_MODULE,
228 .of_match_table = mcu_of_match_table,
229 },
230 .probe = mcu_probe,
231 .remove = __devexit_p(mcu_remove),
232 .id_table = mcu_ids,
233};
234
235static int __init mcu_init(void)
236{
237 return i2c_add_driver(&mcu_driver);
238}
239module_init(mcu_init);
240
241static void __exit mcu_exit(void)
242{
243 i2c_del_driver(&mcu_driver);
244}
245module_exit(mcu_exit);
246
247MODULE_DESCRIPTION("Power Management and GPIO expander driver for "
248 "MPC8349E-mITX-compatible MCU");
249MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
250MODULE_LICENSE("GPL");
251
