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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 <asm/prom.h>
24#include <asm/machdep.h>
25
26
27
28
29
30#define MCU_REG_CTRL 0x20
31#define MCU_CTRL_POFF 0x40
32
33#define MCU_NUM_GPIO 2
34
35struct mcu {
36 struct mutex lock;
37 struct device_node *np;
38 struct i2c_client *client;
39 struct of_gpio_chip of_gc;
40 u8 reg_ctrl;
41};
42
43static struct mcu *glob_mcu;
44
45static void mcu_power_off(void)
46{
47 struct mcu *mcu = glob_mcu;
48
49 pr_info("Sending power-off request to the MCU...\n");
50 mutex_lock(&mcu->lock);
51 i2c_smbus_write_byte_data(glob_mcu->client, MCU_REG_CTRL,
52 mcu->reg_ctrl | MCU_CTRL_POFF);
53 mutex_unlock(&mcu->lock);
54}
55
56static void mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
57{
58 struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
59 struct mcu *mcu = container_of(of_gc, struct mcu, of_gc);
60 u8 bit = 1 << (4 + gpio);
61
62 mutex_lock(&mcu->lock);
63 if (val)
64 mcu->reg_ctrl &= ~bit;
65 else
66 mcu->reg_ctrl |= bit;
67
68 i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, mcu->reg_ctrl);
69 mutex_unlock(&mcu->lock);
70}
71
72static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
73{
74 mcu_gpio_set(gc, gpio, val);
75 return 0;
76}
77
78static int mcu_gpiochip_add(struct mcu *mcu)
79{
80 struct device_node *np;
81 struct of_gpio_chip *of_gc = &mcu->of_gc;
82 struct gpio_chip *gc = &of_gc->gc;
83 int ret;
84
85 np = of_find_compatible_node(NULL, NULL, "fsl,mcu-mpc8349emitx");
86 if (!np)
87 return -ENODEV;
88
89 gc->owner = THIS_MODULE;
90 gc->label = np->full_name;
91 gc->can_sleep = 1;
92 gc->ngpio = MCU_NUM_GPIO;
93 gc->base = -1;
94 gc->set = mcu_gpio_set;
95 gc->direction_output = mcu_gpio_dir_out;
96 of_gc->gpio_cells = 2;
97 of_gc->xlate = of_gpio_simple_xlate;
98
99 np->data = of_gc;
100 mcu->np = np;
101
102
103
104
105
106 ret = gpiochip_add(gc);
107 if (ret)
108 of_node_put(np);
109 return ret;
110}
111
112static int mcu_gpiochip_remove(struct mcu *mcu)
113{
114 int ret;
115
116 ret = gpiochip_remove(&mcu->of_gc.gc);
117 if (ret)
118 return ret;
119 of_node_put(mcu->np);
120
121 return 0;
122}
123
124static int __devinit mcu_probe(struct i2c_client *client,
125 const struct i2c_device_id *id)
126{
127 struct mcu *mcu;
128 int ret;
129
130 mcu = kzalloc(sizeof(*mcu), GFP_KERNEL);
131 if (!mcu)
132 return -ENOMEM;
133
134 mutex_init(&mcu->lock);
135 mcu->client = client;
136 i2c_set_clientdata(client, mcu);
137
138 ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
139 if (ret < 0)
140 goto err;
141 mcu->reg_ctrl = ret;
142
143 ret = mcu_gpiochip_add(mcu);
144 if (ret)
145 goto err;
146
147
148 if (!ppc_md.power_off) {
149 glob_mcu = mcu;
150 ppc_md.power_off = mcu_power_off;
151 dev_info(&client->dev, "will provide power-off service\n");
152 }
153
154 return 0;
155err:
156 kfree(mcu);
157 return ret;
158}
159
160static int __devexit mcu_remove(struct i2c_client *client)
161{
162 struct mcu *mcu = i2c_get_clientdata(client);
163 int ret;
164
165 if (glob_mcu == mcu) {
166 ppc_md.power_off = NULL;
167 glob_mcu = NULL;
168 }
169
170 ret = mcu_gpiochip_remove(mcu);
171 if (ret)
172 return ret;
173 i2c_set_clientdata(client, NULL);
174 kfree(mcu);
175 return 0;
176}
177
178static const struct i2c_device_id mcu_ids[] = {
179 { "mcu-mpc8349emitx", },
180 {},
181};
182MODULE_DEVICE_TABLE(i2c, mcu_ids);
183
184static struct i2c_driver mcu_driver = {
185 .driver = {
186 .name = "mcu-mpc8349emitx",
187 .owner = THIS_MODULE,
188 },
189 .probe = mcu_probe,
190 .remove = __devexit_p(mcu_remove),
191 .id_table = mcu_ids,
192};
193
194static int __init mcu_init(void)
195{
196 return i2c_add_driver(&mcu_driver);
197}
198module_init(mcu_init);
199
200static void __exit mcu_exit(void)
201{
202 i2c_del_driver(&mcu_driver);
203}
204module_exit(mcu_exit);
205
206MODULE_DESCRIPTION("Power Management and GPIO expander driver for "
207 "MPC8349E-mITX-compatible MCU");
208MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
209MODULE_LICENSE("GPL");
210
