| /* |
| * I2C client/driver for the ST M41T00 family of i2c rtc chips. |
| * |
| * Author: Mark A. Greer <mgreer@mvista.com> |
| * |
| * 2005, 2006 (c) MontaVista Software, Inc. This file is licensed under |
| * the terms of the GNU General Public License version 2. This program |
| * is licensed "as is" without any warranty of any kind, whether express |
| * or implied. |
| */ |
| /* |
| * This i2c client/driver wedges between the drivers/char/genrtc.c RTC |
| * interface and the SMBus interface of the i2c subsystem. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/interrupt.h> |
| #include <linux/i2c.h> |
| #include <linux/rtc.h> |
| #include <linux/bcd.h> |
| #include <linux/workqueue.h> |
| #include <linux/platform_device.h> |
| #include <linux/m41t00.h> |
| #include <asm/time.h> |
| #include <asm/rtc.h> |
| |
| static struct i2c_driver m41t00_driver; |
| static struct i2c_client *save_client; |
| |
| static unsigned short ignore[] = { I2C_CLIENT_END }; |
| static unsigned short normal_addr[] = { I2C_CLIENT_END, I2C_CLIENT_END }; |
| |
| static struct i2c_client_address_data addr_data = { |
| .normal_i2c = normal_addr, |
| .probe = ignore, |
| .ignore = ignore, |
| }; |
| |
| struct m41t00_chip_info { |
| u8 type; |
| char *name; |
| u8 read_limit; |
| u8 sec; /* Offsets for chip regs */ |
| u8 min; |
| u8 hour; |
| u8 day; |
| u8 mon; |
| u8 year; |
| u8 alarm_mon; |
| u8 alarm_hour; |
| u8 sqw; |
| u8 sqw_freq; |
| }; |
| |
| static struct m41t00_chip_info m41t00_chip_info_tbl[] = { |
| { |
| .type = M41T00_TYPE_M41T00, |
| .name = "m41t00", |
| .read_limit = 5, |
| .sec = 0, |
| .min = 1, |
| .hour = 2, |
| .day = 4, |
| .mon = 5, |
| .year = 6, |
| }, |
| { |
| .type = M41T00_TYPE_M41T81, |
| .name = "m41t81", |
| .read_limit = 1, |
| .sec = 1, |
| .min = 2, |
| .hour = 3, |
| .day = 5, |
| .mon = 6, |
| .year = 7, |
| .alarm_mon = 0xa, |
| .alarm_hour = 0xc, |
| .sqw = 0x13, |
| }, |
| { |
| .type = M41T00_TYPE_M41T85, |
| .name = "m41t85", |
| .read_limit = 1, |
| .sec = 1, |
| .min = 2, |
| .hour = 3, |
| .day = 5, |
| .mon = 6, |
| .year = 7, |
| .alarm_mon = 0xa, |
| .alarm_hour = 0xc, |
| .sqw = 0x13, |
| }, |
| }; |
| static struct m41t00_chip_info *m41t00_chip; |
| |
| ulong |
| m41t00_get_rtc_time(void) |
| { |
| s32 sec, min, hour, day, mon, year; |
| s32 sec1, min1, hour1, day1, mon1, year1; |
| u8 reads = 0; |
| u8 buf[8], msgbuf[1] = { 0 }; /* offset into rtc's regs */ |
| struct i2c_msg msgs[] = { |
| { |
| .addr = save_client->addr, |
| .flags = 0, |
| .len = 1, |
| .buf = msgbuf, |
| }, |
| { |
| .addr = save_client->addr, |
| .flags = I2C_M_RD, |
| .len = 8, |
| .buf = buf, |
| }, |
| }; |
| |
| sec = min = hour = day = mon = year = 0; |
| |
| do { |
| if (i2c_transfer(save_client->adapter, msgs, 2) < 0) |
| goto read_err; |
| |
| sec1 = sec; |
| min1 = min; |
| hour1 = hour; |
| day1 = day; |
| mon1 = mon; |
| year1 = year; |
| |
| sec = buf[m41t00_chip->sec] & 0x7f; |
| min = buf[m41t00_chip->min] & 0x7f; |
| hour = buf[m41t00_chip->hour] & 0x3f; |
| day = buf[m41t00_chip->day] & 0x3f; |
| mon = buf[m41t00_chip->mon] & 0x1f; |
| year = buf[m41t00_chip->year]; |
| } while ((++reads < m41t00_chip->read_limit) && ((sec != sec1) |
| || (min != min1) || (hour != hour1) || (day != day1) |
| || (mon != mon1) || (year != year1))); |
| |
| if ((m41t00_chip->read_limit > 1) && ((sec != sec1) || (min != min1) |
| || (hour != hour1) || (day != day1) || (mon != mon1) |
| || (year != year1))) |
| goto read_err; |
| |
| sec = BCD2BIN(sec); |
| min = BCD2BIN(min); |
| hour = BCD2BIN(hour); |
| day = BCD2BIN(day); |
| mon = BCD2BIN(mon); |
| year = BCD2BIN(year); |
| |
| year += 1900; |
| if (year < 1970) |
| year += 100; |
| |
| return mktime(year, mon, day, hour, min, sec); |
| |
| read_err: |
| dev_err(&save_client->dev, "m41t00_get_rtc_time: Read error\n"); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(m41t00_get_rtc_time); |
| |
| static void |
| m41t00_set(void *arg) |
| { |
| struct rtc_time tm; |
| int nowtime = *(int *)arg; |
| s32 sec, min, hour, day, mon, year; |
| u8 wbuf[9], *buf = &wbuf[1], msgbuf[1] = { 0 }; |
| struct i2c_msg msgs[] = { |
| { |
| .addr = save_client->addr, |
| .flags = 0, |
| .len = 1, |
| .buf = msgbuf, |
| }, |
| { |
| .addr = save_client->addr, |
| .flags = I2C_M_RD, |
| .len = 8, |
| .buf = buf, |
| }, |
| }; |
| |
| to_tm(nowtime, &tm); |
| tm.tm_year = (tm.tm_year - 1900) % 100; |
| |
| sec = BIN2BCD(tm.tm_sec); |
| min = BIN2BCD(tm.tm_min); |
| hour = BIN2BCD(tm.tm_hour); |
| day = BIN2BCD(tm.tm_mday); |
| mon = BIN2BCD(tm.tm_mon); |
| year = BIN2BCD(tm.tm_year); |
| |
| /* Read reg values into buf[0..7]/wbuf[1..8] */ |
| if (i2c_transfer(save_client->adapter, msgs, 2) < 0) { |
| dev_err(&save_client->dev, "m41t00_set: Read error\n"); |
| return; |
| } |
| |
| wbuf[0] = 0; /* offset into rtc's regs */ |
| buf[m41t00_chip->sec] = (buf[m41t00_chip->sec] & ~0x7f) | (sec & 0x7f); |
| buf[m41t00_chip->min] = (buf[m41t00_chip->min] & ~0x7f) | (min & 0x7f); |
| buf[m41t00_chip->hour] = (buf[m41t00_chip->hour] & ~0x3f) | (hour& 0x3f); |
| buf[m41t00_chip->day] = (buf[m41t00_chip->day] & ~0x3f) | (day & 0x3f); |
| buf[m41t00_chip->mon] = (buf[m41t00_chip->mon] & ~0x1f) | (mon & 0x1f); |
| |
| if (i2c_master_send(save_client, wbuf, 9) < 0) |
| dev_err(&save_client->dev, "m41t00_set: Write error\n"); |
| } |
| |
| static ulong new_time; |
| static struct workqueue_struct *m41t00_wq; |
| static DECLARE_WORK(m41t00_work, m41t00_set, &new_time); |
| |
| int |
| m41t00_set_rtc_time(ulong nowtime) |
| { |
| new_time = nowtime; |
| |
| if (in_interrupt()) |
| queue_work(m41t00_wq, &m41t00_work); |
| else |
| m41t00_set(&new_time); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(m41t00_set_rtc_time); |
| |
| /* |
| ***************************************************************************** |
| * |
| * platform_data Driver Interface |
| * |
| ***************************************************************************** |
| */ |
| static int __init |
| m41t00_platform_probe(struct platform_device *pdev) |
| { |
| struct m41t00_platform_data *pdata; |
| int i; |
| |
| if (pdev && (pdata = pdev->dev.platform_data)) { |
| normal_addr[0] = pdata->i2c_addr; |
| |
| for (i=0; i<ARRAY_SIZE(m41t00_chip_info_tbl); i++) |
| if (m41t00_chip_info_tbl[i].type == pdata->type) { |
| m41t00_chip = &m41t00_chip_info_tbl[i]; |
| m41t00_chip->sqw_freq = pdata->sqw_freq; |
| return 0; |
| } |
| } |
| return -ENODEV; |
| } |
| |
| static int __exit |
| m41t00_platform_remove(struct platform_device *pdev) |
| { |
| return 0; |
| } |
| |
| static struct platform_driver m41t00_platform_driver = { |
| .probe = m41t00_platform_probe, |
| .remove = m41t00_platform_remove, |
| .driver = { |
| .owner = THIS_MODULE, |
| .name = M41T00_DRV_NAME, |
| }, |
| }; |
| |
| /* |
| ***************************************************************************** |
| * |
| * Driver Interface |
| * |
| ***************************************************************************** |
| */ |
| static int |
| m41t00_probe(struct i2c_adapter *adap, int addr, int kind) |
| { |
| struct i2c_client *client; |
| int rc; |
| |
| if (!i2c_check_functionality(adap, I2C_FUNC_I2C |
| | I2C_FUNC_SMBUS_BYTE_DATA)) |
| return 0; |
| |
| client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); |
| if (!client) |
| return -ENOMEM; |
| |
| strlcpy(client->name, m41t00_chip->name, I2C_NAME_SIZE); |
| client->addr = addr; |
| client->adapter = adap; |
| client->driver = &m41t00_driver; |
| |
| if ((rc = i2c_attach_client(client))) |
| goto attach_err; |
| |
| if (m41t00_chip->type != M41T00_TYPE_M41T00) { |
| /* If asked, disable SQW, set SQW frequency & re-enable */ |
| if (m41t00_chip->sqw_freq) |
| if (((rc = i2c_smbus_read_byte_data(client, |
| m41t00_chip->alarm_mon)) < 0) |
| || ((rc = i2c_smbus_write_byte_data(client, |
| m41t00_chip->alarm_mon, rc & ~0x40)) <0) |
| || ((rc = i2c_smbus_write_byte_data(client, |
| m41t00_chip->sqw, |
| m41t00_chip->sqw_freq)) < 0) |
| || ((rc = i2c_smbus_write_byte_data(client, |
| m41t00_chip->alarm_mon, rc | 0x40)) <0)) |
| goto sqw_err; |
| |
| /* Make sure HT (Halt Update) bit is cleared */ |
| if ((rc = i2c_smbus_read_byte_data(client, |
| m41t00_chip->alarm_hour)) < 0) |
| goto ht_err; |
| |
| if (rc & 0x40) |
| if ((rc = i2c_smbus_write_byte_data(client, |
| m41t00_chip->alarm_hour, rc & ~0x40))<0) |
| goto ht_err; |
| } |
| |
| /* Make sure ST (stop) bit is cleared */ |
| if ((rc = i2c_smbus_read_byte_data(client, m41t00_chip->sec)) < 0) |
| goto st_err; |
| |
| if (rc & 0x80) |
| if ((rc = i2c_smbus_write_byte_data(client, m41t00_chip->sec, |
| rc & ~0x80)) < 0) |
| goto st_err; |
| |
| m41t00_wq = create_singlethread_workqueue(m41t00_chip->name); |
| save_client = client; |
| return 0; |
| |
| st_err: |
| dev_err(&client->dev, "m41t00_probe: Can't clear ST bit\n"); |
| goto attach_err; |
| ht_err: |
| dev_err(&client->dev, "m41t00_probe: Can't clear HT bit\n"); |
| goto attach_err; |
| sqw_err: |
| dev_err(&client->dev, "m41t00_probe: Can't set SQW Frequency\n"); |
| attach_err: |
| kfree(client); |
| return rc; |
| } |
| |
| static int |
| m41t00_attach(struct i2c_adapter *adap) |
| { |
| return i2c_probe(adap, &addr_data, m41t00_probe); |
| } |
| |
| static int |
| m41t00_detach(struct i2c_client *client) |
| { |
| int rc; |
| |
| if ((rc = i2c_detach_client(client)) == 0) { |
| kfree(client); |
| destroy_workqueue(m41t00_wq); |
| } |
| return rc; |
| } |
| |
| static struct i2c_driver m41t00_driver = { |
| .driver = { |
| .name = M41T00_DRV_NAME, |
| }, |
| .id = I2C_DRIVERID_STM41T00, |
| .attach_adapter = m41t00_attach, |
| .detach_client = m41t00_detach, |
| }; |
| |
| static int __init |
| m41t00_init(void) |
| { |
| int rc; |
| |
| if (!(rc = platform_driver_register(&m41t00_platform_driver))) |
| rc = i2c_add_driver(&m41t00_driver); |
| return rc; |
| } |
| |
| static void __exit |
| m41t00_exit(void) |
| { |
| i2c_del_driver(&m41t00_driver); |
| platform_driver_unregister(&m41t00_platform_driver); |
| } |
| |
| module_init(m41t00_init); |
| module_exit(m41t00_exit); |
| |
| MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>"); |
| MODULE_DESCRIPTION("ST Microelectronics M41T00 RTC I2C Client Driver"); |
| MODULE_LICENSE("GPL"); |