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16#include <linux/i2c.h>
17#include <linux/bcd.h>
18#include <linux/rtc.h>
19#include <linux/slab.h>
20#include <linux/module.h>
21#include <linux/of.h>
22
23#define DRV_VERSION "0.0.1"
24
25#define PCF2127_REG_CTRL1 (0x00)
26#define PCF2127_REG_CTRL2 (0x01)
27#define PCF2127_REG_CTRL3 (0x02)
28#define PCF2127_REG_SC (0x03)
29#define PCF2127_REG_MN (0x04)
30#define PCF2127_REG_HR (0x05)
31#define PCF2127_REG_DM (0x06)
32#define PCF2127_REG_DW (0x07)
33#define PCF2127_REG_MO (0x08)
34#define PCF2127_REG_YR (0x09)
35
36static struct i2c_driver pcf2127_driver;
37
38struct pcf2127 {
39 struct rtc_device *rtc;
40 int voltage_low;
41};
42
43
44
45
46
47static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
48{
49 struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
50 unsigned char buf[10] = { PCF2127_REG_CTRL1 };
51
52
53 if (i2c_master_send(client, buf, 1) != 1 ||
54 i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) {
55 dev_err(&client->dev, "%s: read error\n", __func__);
56 return -EIO;
57 }
58
59 if (buf[PCF2127_REG_CTRL3] & 0x04) {
60 pcf2127->voltage_low = 1;
61 dev_info(&client->dev,
62 "low voltage detected, date/time is not reliable.\n");
63 }
64
65 dev_dbg(&client->dev,
66 "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, "
67 "sec=%02x, min=%02x, hr=%02x, "
68 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
69 __func__,
70 buf[0], buf[1], buf[2],
71 buf[3], buf[4], buf[5],
72 buf[6], buf[7], buf[8], buf[9]);
73
74
75 tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
76 tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
77 tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F);
78 tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
79 tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
80 tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1;
81 tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
82 if (tm->tm_year < 70)
83 tm->tm_year += 100;
84
85 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
86 "mday=%d, mon=%d, year=%d, wday=%d\n",
87 __func__,
88 tm->tm_sec, tm->tm_min, tm->tm_hour,
89 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
90
91
92
93
94 if (rtc_valid_tm(tm) < 0)
95 dev_err(&client->dev, "retrieved date/time is not valid.\n");
96
97 return 0;
98}
99
100static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
101{
102 unsigned char buf[8];
103 int i = 0, err;
104
105 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
106 "mday=%d, mon=%d, year=%d, wday=%d\n",
107 __func__,
108 tm->tm_sec, tm->tm_min, tm->tm_hour,
109 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
110
111
112 buf[i++] = PCF2127_REG_SC;
113
114
115 buf[i++] = bin2bcd(tm->tm_sec);
116 buf[i++] = bin2bcd(tm->tm_min);
117 buf[i++] = bin2bcd(tm->tm_hour);
118 buf[i++] = bin2bcd(tm->tm_mday);
119 buf[i++] = tm->tm_wday & 0x07;
120
121
122 buf[i++] = bin2bcd(tm->tm_mon + 1);
123
124
125 buf[i++] = bin2bcd(tm->tm_year % 100);
126
127
128 err = i2c_master_send(client, buf, i);
129 if (err != i) {
130 dev_err(&client->dev,
131 "%s: err=%d", __func__, err);
132 return -EIO;
133 }
134
135 return 0;
136}
137
138#ifdef CONFIG_RTC_INTF_DEV
139static int pcf2127_rtc_ioctl(struct device *dev,
140 unsigned int cmd, unsigned long arg)
141{
142 struct pcf2127 *pcf2127 = i2c_get_clientdata(to_i2c_client(dev));
143
144 switch (cmd) {
145 case RTC_VL_READ:
146 if (pcf2127->voltage_low)
147 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
148
149 if (copy_to_user((void __user *)arg, &pcf2127->voltage_low,
150 sizeof(int)))
151 return -EFAULT;
152 return 0;
153 default:
154 return -ENOIOCTLCMD;
155 }
156}
157#else
158#define pcf2127_rtc_ioctl NULL
159#endif
160
161static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
162{
163 return pcf2127_get_datetime(to_i2c_client(dev), tm);
164}
165
166static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
167{
168 return pcf2127_set_datetime(to_i2c_client(dev), tm);
169}
170
171static const struct rtc_class_ops pcf2127_rtc_ops = {
172 .ioctl = pcf2127_rtc_ioctl,
173 .read_time = pcf2127_rtc_read_time,
174 .set_time = pcf2127_rtc_set_time,
175};
176
177static int pcf2127_probe(struct i2c_client *client,
178 const struct i2c_device_id *id)
179{
180 struct pcf2127 *pcf2127;
181
182 dev_dbg(&client->dev, "%s\n", __func__);
183
184 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
185 return -ENODEV;
186
187 pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127),
188 GFP_KERNEL);
189 if (!pcf2127)
190 return -ENOMEM;
191
192 dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
193
194 i2c_set_clientdata(client, pcf2127);
195
196 pcf2127->rtc = devm_rtc_device_register(&client->dev,
197 pcf2127_driver.driver.name,
198 &pcf2127_rtc_ops, THIS_MODULE);
199
200 if (IS_ERR(pcf2127->rtc))
201 return PTR_ERR(pcf2127->rtc);
202
203 return 0;
204}
205
206static const struct i2c_device_id pcf2127_id[] = {
207 { "pcf2127", 0 },
208 { }
209};
210MODULE_DEVICE_TABLE(i2c, pcf2127_id);
211
212#ifdef CONFIG_OF
213static const struct of_device_id pcf2127_of_match[] = {
214 { .compatible = "nxp,pcf2127" },
215 {}
216};
217MODULE_DEVICE_TABLE(of, pcf2127_of_match);
218#endif
219
220static struct i2c_driver pcf2127_driver = {
221 .driver = {
222 .name = "rtc-pcf2127",
223 .owner = THIS_MODULE,
224 .of_match_table = of_match_ptr(pcf2127_of_match),
225 },
226 .probe = pcf2127_probe,
227 .id_table = pcf2127_id,
228};
229
230module_i2c_driver(pcf2127_driver);
231
232MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
233MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
234MODULE_LICENSE("GPL");
235MODULE_VERSION(DRV_VERSION);
236
