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8#include <linux/delay.h>
9#include <linux/i2c.h>
10#include <linux/mfd/core.h>
11#include <linux/module.h>
12#include <linux/of_device.h>
13#include <linux/reboot.h>
14#include <linux/regmap.h>
15
16#define A500_EC_I2C_ERR_TIMEOUT 500
17#define A500_EC_POWER_CMD_TIMEOUT 1000
18
19
20
21
22
23#define CMD_SHUTDOWN 0x0
24#define CMD_WARM_REBOOT 0x0
25#define CMD_COLD_REBOOT 0x1
26
27enum {
28 REG_CURRENT_NOW = 0x03,
29 REG_SHUTDOWN = 0x52,
30 REG_WARM_REBOOT = 0x54,
31 REG_COLD_REBOOT = 0x55,
32};
33
34static struct i2c_client *a500_ec_client_pm_off;
35
36static int a500_ec_read(void *context, const void *reg_buf, size_t reg_size,
37 void *val_buf, size_t val_sizel)
38{
39 struct i2c_client *client = context;
40 unsigned int reg, retries = 5;
41 u16 *ret_val = val_buf;
42 s32 ret = 0;
43
44 reg = *(u8 *)reg_buf;
45
46 while (retries-- > 0) {
47 ret = i2c_smbus_read_word_data(client, reg);
48 if (ret >= 0)
49 break;
50
51 msleep(A500_EC_I2C_ERR_TIMEOUT);
52 }
53
54 if (ret < 0) {
55 dev_err(&client->dev, "read 0x%x failed: %d\n", reg, ret);
56 return ret;
57 }
58
59 *ret_val = ret;
60
61 if (reg == REG_CURRENT_NOW)
62 fsleep(10000);
63
64 return 0;
65}
66
67static int a500_ec_write(void *context, const void *data, size_t count)
68{
69 struct i2c_client *client = context;
70 unsigned int reg, val, retries = 5;
71 s32 ret = 0;
72
73 reg = *(u8 *)(data + 0);
74 val = *(u16 *)(data + 1);
75
76 while (retries-- > 0) {
77 ret = i2c_smbus_write_word_data(client, reg, val);
78 if (ret >= 0)
79 break;
80
81 msleep(A500_EC_I2C_ERR_TIMEOUT);
82 }
83
84 if (ret < 0) {
85 dev_err(&client->dev, "write 0x%x failed: %d\n", reg, ret);
86 return ret;
87 }
88
89 return 0;
90}
91
92static const struct regmap_config a500_ec_regmap_config = {
93 .name = "KB930",
94 .reg_bits = 8,
95 .val_bits = 16,
96 .max_register = 0xff,
97};
98
99static const struct regmap_bus a500_ec_regmap_bus = {
100 .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
101 .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
102 .write = a500_ec_write,
103 .read = a500_ec_read,
104 .max_raw_read = 2,
105};
106
107static void a500_ec_poweroff(void)
108{
109 i2c_smbus_write_word_data(a500_ec_client_pm_off,
110 REG_SHUTDOWN, CMD_SHUTDOWN);
111
112 mdelay(A500_EC_POWER_CMD_TIMEOUT);
113}
114
115static int a500_ec_restart_notify(struct notifier_block *this,
116 unsigned long reboot_mode, void *data)
117{
118 if (reboot_mode == REBOOT_WARM)
119 i2c_smbus_write_word_data(a500_ec_client_pm_off,
120 REG_WARM_REBOOT, CMD_WARM_REBOOT);
121 else
122 i2c_smbus_write_word_data(a500_ec_client_pm_off,
123 REG_COLD_REBOOT, CMD_COLD_REBOOT);
124
125 mdelay(A500_EC_POWER_CMD_TIMEOUT);
126
127 return NOTIFY_DONE;
128}
129
130static struct notifier_block a500_ec_restart_handler = {
131 .notifier_call = a500_ec_restart_notify,
132 .priority = 200,
133};
134
135static const struct mfd_cell a500_ec_cells[] = {
136 { .name = "acer-a500-iconia-battery", },
137 { .name = "acer-a500-iconia-leds", },
138};
139
140static int a500_ec_probe(struct i2c_client *client)
141{
142 struct regmap *regmap;
143 int err;
144
145 regmap = devm_regmap_init(&client->dev, &a500_ec_regmap_bus,
146 client, &a500_ec_regmap_config);
147 if (IS_ERR(regmap))
148 return PTR_ERR(regmap);
149
150 err = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO,
151 a500_ec_cells, ARRAY_SIZE(a500_ec_cells),
152 NULL, 0, NULL);
153 if (err) {
154 dev_err(&client->dev, "failed to add sub-devices: %d\n", err);
155 return err;
156 }
157
158 if (of_device_is_system_power_controller(client->dev.of_node)) {
159 a500_ec_client_pm_off = client;
160
161 err = register_restart_handler(&a500_ec_restart_handler);
162 if (err)
163 return err;
164
165 if (!pm_power_off)
166 pm_power_off = a500_ec_poweroff;
167 }
168
169 return 0;
170}
171
172static int a500_ec_remove(struct i2c_client *client)
173{
174 if (of_device_is_system_power_controller(client->dev.of_node)) {
175 if (pm_power_off == a500_ec_poweroff)
176 pm_power_off = NULL;
177
178 unregister_restart_handler(&a500_ec_restart_handler);
179 }
180
181 return 0;
182}
183
184static const struct of_device_id a500_ec_match[] = {
185 { .compatible = "acer,a500-iconia-ec" },
186 { }
187};
188MODULE_DEVICE_TABLE(of, a500_ec_match);
189
190static struct i2c_driver a500_ec_driver = {
191 .driver = {
192 .name = "acer-a500-embedded-controller",
193 .of_match_table = a500_ec_match,
194 },
195 .probe_new = a500_ec_probe,
196 .remove = a500_ec_remove,
197};
198module_i2c_driver(a500_ec_driver);
199
200MODULE_DESCRIPTION("Acer Iconia Tab A500 Embedded Controller driver");
201MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
202MODULE_LICENSE("GPL");
203
