diff options
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/rtc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/rtc/rtc-pcf8583.c | 394 |
3 files changed, 405 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 725d6b696792..37ee69f57a0b 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -132,6 +132,16 @@ config RTC_DRV_PCF8563 This driver can also be built as a module. If so, the module will be called rtc-pcf8563. +config RTC_DRV_PCF8583 + tristate "Philips PCF8583" + depends on RTC_CLASS && I2C + help + If you say yes here you get support for the + Philips PCF8583 RTC chip. + + This driver can also be built as a module. If so, the module + will be called rtc-pcf8583. + config RTC_DRV_RS5C372 tristate "Ricoh RS5C372A/B" depends on RTC_CLASS && I2C diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index ca8bed53079f..090f197f07e8 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_RTC_DRV_TEST) += rtc-test.o obj-$(CONFIG_RTC_DRV_DS1307) += rtc-ds1307.o obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o +obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o obj-$(CONFIG_RTC_DRV_EP93XX) += rtc-ep93xx.o diff --git a/drivers/rtc/rtc-pcf8583.c b/drivers/rtc/rtc-pcf8583.c new file mode 100644 index 000000000000..b235a30cb661 --- /dev/null +++ b/drivers/rtc/rtc-pcf8583.c @@ -0,0 +1,394 @@ +/* + * drivers/rtc/rtc-pcf8583.c + * + * Copyright (C) 2000 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Driver for PCF8583 RTC & RAM chip + * + * Converted to the generic RTC susbsystem by G. Liakhovetski (2006) + */ +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/mc146818rtc.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/bcd.h> + +struct rtc_mem { + unsigned int loc; + unsigned int nr; + unsigned char *data; +}; + +struct pcf8583 { + struct i2c_client client; + struct rtc_device *rtc; + unsigned char ctrl; +}; + +#define CTRL_STOP 0x80 +#define CTRL_HOLD 0x40 +#define CTRL_32KHZ 0x00 +#define CTRL_MASK 0x08 +#define CTRL_ALARMEN 0x04 +#define CTRL_ALARM 0x02 +#define CTRL_TIMER 0x01 + +static unsigned short normal_i2c[] = { I2C_CLIENT_END }; + +/* Module parameters */ +I2C_CLIENT_INSMOD; + +static struct i2c_driver pcf8583_driver; + +#define get_ctrl(x) ((struct pcf8583 *)i2c_get_clientdata(x))->ctrl +#define set_ctrl(x, v) get_ctrl(x) = v + +#define CMOS_YEAR (64 + 128) +#define CMOS_CHECKSUM (63) + +static int pcf8583_get_datetime(struct i2c_client *client, struct rtc_time *dt) +{ + unsigned char buf[8], addr[1] = { 1 }; + struct i2c_msg msgs[2] = { + { + .addr = client->addr, + .flags = 0, + .len = 1, + .buf = addr, + }, { + .addr = client->addr, + .flags = I2C_M_RD, + .len = 6, + .buf = buf, + } + }; + int ret; + + memset(buf, 0, sizeof(buf)); + + ret = i2c_transfer(client->adapter, msgs, 2); + if (ret == 2) { + dt->tm_year = buf[4] >> 6; + dt->tm_wday = buf[5] >> 5; + + buf[4] &= 0x3f; + buf[5] &= 0x1f; + + dt->tm_sec = BCD_TO_BIN(buf[1]); + dt->tm_min = BCD_TO_BIN(buf[2]); + dt->tm_hour = BCD_TO_BIN(buf[3]); + dt->tm_mday = BCD_TO_BIN(buf[4]); + dt->tm_mon = BCD_TO_BIN(buf[5]); + } + + return ret == 2 ? 0 : -EIO; +} + +static int pcf8583_set_datetime(struct i2c_client *client, struct rtc_time *dt, int datetoo) +{ + unsigned char buf[8]; + int ret, len = 6; + + buf[0] = 0; + buf[1] = get_ctrl(client) | 0x80; + buf[2] = 0; + buf[3] = BIN_TO_BCD(dt->tm_sec); + buf[4] = BIN_TO_BCD(dt->tm_min); + buf[5] = BIN_TO_BCD(dt->tm_hour); + + if (datetoo) { + len = 8; + buf[6] = BIN_TO_BCD(dt->tm_mday) | (dt->tm_year << 6); + buf[7] = BIN_TO_BCD(dt->tm_mon) | (dt->tm_wday << 5); + } + + ret = i2c_master_send(client, (char *)buf, len); + if (ret != len) + return -EIO; + + buf[1] = get_ctrl(client); + ret = i2c_master_send(client, (char *)buf, 2); + + return ret == 2 ? 0 : -EIO; +} + +static int pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl) +{ + *ctrl = get_ctrl(client); + return 0; +} + +static int pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl) +{ + unsigned char buf[2]; + + buf[0] = 0; + buf[1] = *ctrl; + set_ctrl(client, *ctrl); + + return i2c_master_send(client, (char *)buf, 2); +} + +static int pcf8583_read_mem(struct i2c_client *client, struct rtc_mem *mem) +{ + unsigned char addr[1]; + struct i2c_msg msgs[2] = { + { + .addr = client->addr, + .flags = 0, + .len = 1, + .buf = addr, + }, { + .addr = client->addr, + .flags = I2C_M_RD, + .len = mem->nr, + .buf = mem->data, + } + }; + + if (mem->loc < 8) + return -EINVAL; + + addr[0] = mem->loc; + + return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO; +} + +static int pcf8583_write_mem(struct i2c_client *client, struct rtc_mem *mem) +{ + unsigned char addr[1]; + struct i2c_msg msgs[2] = { + { + .addr = client->addr, + .flags = 0, + .len = 1, + .buf = addr, + }, { + .addr = client->addr, + .flags = I2C_M_NOSTART, + .len = mem->nr, + .buf = mem->data, + } + }; + + if (mem->loc < 8) + return -EINVAL; + + addr[0] = mem->loc; + + return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO; +} + +static int pcf8583_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct i2c_client *client = to_i2c_client(dev); + unsigned char ctrl, year[2]; + struct rtc_mem mem = { CMOS_YEAR, sizeof(year), year }; + int real_year, year_offset, err; + + /* + * Ensure that the RTC is running. + */ + pcf8583_get_ctrl(client, &ctrl); + if (ctrl & (CTRL_STOP | CTRL_HOLD)) { + unsigned char new_ctrl = ctrl & ~(CTRL_STOP | CTRL_HOLD); + + printk(KERN_WARNING "RTC: resetting control %02x -> %02x\n", + ctrl, new_ctrl); + + if ((err = pcf8583_set_ctrl(client, &new_ctrl)) < 0) + return err; + } + + if (pcf8583_get_datetime(client, tm) || + pcf8583_read_mem(client, &mem)) + return -EIO; + + real_year = year[0]; + + /* + * The RTC year holds the LSB two bits of the current + * year, which should reflect the LSB two bits of the + * CMOS copy of the year. Any difference indicates + * that we have to correct the CMOS version. + */ + year_offset = tm->tm_year - (real_year & 3); + if (year_offset < 0) + /* + * RTC year wrapped. Adjust it appropriately. + */ + year_offset += 4; + + tm->tm_year = real_year + year_offset + year[1] * 100; + + return 0; +} + +static int pcf8583_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct i2c_client *client = to_i2c_client(dev); + unsigned char year[2], chk; + struct rtc_mem cmos_year = { CMOS_YEAR, sizeof(year), year }; + struct rtc_mem cmos_check = { CMOS_CHECKSUM, 1, &chk }; + int ret; + + /* + * The RTC's own 2-bit year must reflect the least + * significant two bits of the CMOS year. + */ + + ret = pcf8583_set_datetime(client, tm, 1); + if (ret) + return ret; + + ret = pcf8583_read_mem(client, &cmos_check); + if (ret) + return ret; + + ret = pcf8583_read_mem(client, &cmos_year); + if (ret) + return ret; + + chk -= year[1] + year[0]; + + year[1] = tm->tm_year / 100; + year[0] = tm->tm_year % 100; + + chk += year[1] + year[0]; + + ret = pcf8583_write_mem(client, &cmos_year); + + if (ret) + return ret; + + ret = pcf8583_write_mem(client, &cmos_check); + + return ret; +} + +static struct rtc_class_ops pcf8583_rtc_ops = { + .read_time = pcf8583_rtc_read_time, + .set_time = pcf8583_rtc_set_time, +}; + +static int pcf8583_probe(struct i2c_adapter *adap, int addr, int kind); + +static int pcf8583_attach(struct i2c_adapter *adap) +{ + return i2c_probe(adap, &addr_data, pcf8583_probe); +} + +static int pcf8583_detach(struct i2c_client *client) +{ + int err; + struct pcf8583 *pcf = i2c_get_clientdata(client); + struct rtc_device *rtc = pcf->rtc; + + if (rtc) + rtc_device_unregister(rtc); + + if ((err = i2c_detach_client(client))) + return err; + + kfree(pcf); + return 0; +} + +static struct i2c_driver pcf8583_driver = { + .driver = { + .name = "pcf8583", + }, + .id = I2C_DRIVERID_PCF8583, + .attach_adapter = pcf8583_attach, + .detach_client = pcf8583_detach, +}; + +static int pcf8583_probe(struct i2c_adapter *adap, int addr, int kind) +{ + struct pcf8583 *pcf; + struct i2c_client *client; + struct rtc_device *rtc; + unsigned char buf[1], ad[1] = { 0 }; + int err; + struct i2c_msg msgs[2] = { + { + .addr = addr, + .flags = 0, + .len = 1, + .buf = ad, + }, { + .addr = addr, + .flags = I2C_M_RD, + .len = 1, + .buf = buf, + } + }; + + pcf = kzalloc(sizeof(*pcf), GFP_KERNEL); + if (!pcf) + return -ENOMEM; + + client = &pcf->client; + + client->addr = addr; + client->adapter = adap; + client->driver = &pcf8583_driver; + + strlcpy(client->name, pcf8583_driver.driver.name, I2C_NAME_SIZE); + + if (i2c_transfer(client->adapter, msgs, 2) != 2) { + err = -EIO; + goto exit_kfree; + } + + err = i2c_attach_client(client); + + if (err) + goto exit_kfree; + + rtc = rtc_device_register(pcf8583_driver.driver.name, &client->dev, + &pcf8583_rtc_ops, THIS_MODULE); + + if (IS_ERR(rtc)) { + err = PTR_ERR(rtc); + goto exit_detach; + } + + pcf->rtc = rtc; + i2c_set_clientdata(client, pcf); + set_ctrl(client, buf[0]); + + return 0; + +exit_detach: + i2c_detach_client(client); + +exit_kfree: + kfree(pcf); + + return err; +} + +static __init int pcf8583_init(void) +{ + return i2c_add_driver(&pcf8583_driver); +} + +static __exit void pcf8583_exit(void) +{ + i2c_del_driver(&pcf8583_driver); +} + +module_init(pcf8583_init); +module_exit(pcf8583_exit); + +MODULE_AUTHOR("Russell King"); +MODULE_DESCRIPTION("PCF8583 I2C RTC driver"); +MODULE_LICENSE("GPL"); |