diff options
Diffstat (limited to 'kernel/drivers/rtc/rtc-pcf8563.c')
| -rw-r--r-- | kernel/drivers/rtc/rtc-pcf8563.c | 503 |
1 files changed, 503 insertions, 0 deletions
diff --git a/kernel/drivers/rtc/rtc-pcf8563.c b/kernel/drivers/rtc/rtc-pcf8563.c new file mode 100644 index 000000000..0ba7e5992 --- /dev/null +++ b/kernel/drivers/rtc/rtc-pcf8563.c @@ -0,0 +1,503 @@ +/* + * An I2C driver for the Philips PCF8563 RTC + * Copyright 2005-06 Tower Technologies + * + * Author: Alessandro Zummo <a.zummo@towertech.it> + * Maintainers: http://www.nslu2-linux.org/ + * + * based on the other drivers in this same directory. + * + * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf + * + * 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. + */ + +#include <linux/i2c.h> +#include <linux/bcd.h> +#include <linux/rtc.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/err.h> + +#define DRV_VERSION "0.4.3" + +#define PCF8563_REG_ST1 0x00 /* status */ +#define PCF8563_REG_ST2 0x01 +#define PCF8563_BIT_AIE (1 << 1) +#define PCF8563_BIT_AF (1 << 3) +#define PCF8563_BITS_ST2_N (7 << 5) + +#define PCF8563_REG_SC 0x02 /* datetime */ +#define PCF8563_REG_MN 0x03 +#define PCF8563_REG_HR 0x04 +#define PCF8563_REG_DM 0x05 +#define PCF8563_REG_DW 0x06 +#define PCF8563_REG_MO 0x07 +#define PCF8563_REG_YR 0x08 + +#define PCF8563_REG_AMN 0x09 /* alarm */ + +#define PCF8563_REG_CLKO 0x0D /* clock out */ +#define PCF8563_REG_TMRC 0x0E /* timer control */ +#define PCF8563_TMRC_ENABLE BIT(7) +#define PCF8563_TMRC_4096 0 +#define PCF8563_TMRC_64 1 +#define PCF8563_TMRC_1 2 +#define PCF8563_TMRC_1_60 3 +#define PCF8563_TMRC_MASK 3 + +#define PCF8563_REG_TMR 0x0F /* timer */ + +#define PCF8563_SC_LV 0x80 /* low voltage */ +#define PCF8563_MO_C 0x80 /* century */ + +static struct i2c_driver pcf8563_driver; + +struct pcf8563 { + struct rtc_device *rtc; + /* + * The meaning of MO_C bit varies by the chip type. + * From PCF8563 datasheet: this bit is toggled when the years + * register overflows from 99 to 00 + * 0 indicates the century is 20xx + * 1 indicates the century is 19xx + * From RTC8564 datasheet: this bit indicates change of + * century. When the year digit data overflows from 99 to 00, + * this bit is set. By presetting it to 0 while still in the + * 20th century, it will be set in year 2000, ... + * There seems no reliable way to know how the system use this + * bit. So let's do it heuristically, assuming we are live in + * 1970...2069. + */ + int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ + int voltage_low; /* incicates if a low_voltage was detected */ + + struct i2c_client *client; +}; + +static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg, + unsigned char length, unsigned char *buf) +{ + struct i2c_msg msgs[] = { + {/* setup read ptr */ + .addr = client->addr, + .len = 1, + .buf = ®, + }, + { + .addr = client->addr, + .flags = I2C_M_RD, + .len = length, + .buf = buf + }, + }; + + if ((i2c_transfer(client->adapter, msgs, 2)) != 2) { + dev_err(&client->dev, "%s: read error\n", __func__); + return -EIO; + } + + return 0; +} + +static int pcf8563_write_block_data(struct i2c_client *client, + unsigned char reg, unsigned char length, + unsigned char *buf) +{ + int i, err; + + for (i = 0; i < length; i++) { + unsigned char data[2] = { reg + i, buf[i] }; + + err = i2c_master_send(client, data, sizeof(data)); + if (err != sizeof(data)) { + dev_err(&client->dev, + "%s: err=%d addr=%02x, data=%02x\n", + __func__, err, data[0], data[1]); + return -EIO; + } + } + + return 0; +} + +static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on) +{ + unsigned char buf; + int err; + + err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf); + if (err < 0) + return err; + + if (on) + buf |= PCF8563_BIT_AIE; + else + buf &= ~PCF8563_BIT_AIE; + + buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N); + + err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf); + if (err < 0) { + dev_err(&client->dev, "%s: write error\n", __func__); + return -EIO; + } + + return 0; +} + +static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en, + unsigned char *pen) +{ + unsigned char buf; + int err; + + err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf); + if (err) + return err; + + if (en) + *en = !!(buf & PCF8563_BIT_AIE); + if (pen) + *pen = !!(buf & PCF8563_BIT_AF); + + return 0; +} + +static irqreturn_t pcf8563_irq(int irq, void *dev_id) +{ + struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id); + int err; + char pending; + + err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending); + if (err) + return IRQ_NONE; + + if (pending) { + rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF); + pcf8563_set_alarm_mode(pcf8563->client, 1); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +/* + * In the routines that deal directly with the pcf8563 hardware, we use + * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. + */ +static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) +{ + struct pcf8563 *pcf8563 = i2c_get_clientdata(client); + unsigned char buf[9]; + int err; + + err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf); + if (err) + return err; + + if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) { + pcf8563->voltage_low = 1; + dev_info(&client->dev, + "low voltage detected, date/time is not reliable.\n"); + } + + dev_dbg(&client->dev, + "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " + "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", + __func__, + buf[0], buf[1], buf[2], buf[3], + buf[4], buf[5], buf[6], buf[7], + buf[8]); + + + tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F); + tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F); + tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */ + tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F); + tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; + tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ + tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]); + if (tm->tm_year < 70) + tm->tm_year += 100; /* assume we are in 1970...2069 */ + /* detect the polarity heuristically. see note above. */ + pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ? + (tm->tm_year >= 100) : (tm->tm_year < 100); + + dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " + "mday=%d, mon=%d, year=%d, wday=%d\n", + __func__, + tm->tm_sec, tm->tm_min, tm->tm_hour, + tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); + + /* the clock can give out invalid datetime, but we cannot return + * -EINVAL otherwise hwclock will refuse to set the time on bootup. + */ + if (rtc_valid_tm(tm) < 0) + dev_err(&client->dev, "retrieved date/time is not valid.\n"); + + return 0; +} + +static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) +{ + struct pcf8563 *pcf8563 = i2c_get_clientdata(client); + unsigned char buf[9]; + + dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " + "mday=%d, mon=%d, year=%d, wday=%d\n", + __func__, + tm->tm_sec, tm->tm_min, tm->tm_hour, + tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); + + /* hours, minutes and seconds */ + buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec); + buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min); + buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour); + + buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday); + + /* month, 1 - 12 */ + buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1); + + /* year and century */ + buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100); + if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100)) + buf[PCF8563_REG_MO] |= PCF8563_MO_C; + + buf[PCF8563_REG_DW] = tm->tm_wday & 0x07; + + return pcf8563_write_block_data(client, PCF8563_REG_SC, + 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC); +} + +#ifdef CONFIG_RTC_INTF_DEV +static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) +{ + struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev)); + struct rtc_time tm; + + switch (cmd) { + case RTC_VL_READ: + if (pcf8563->voltage_low) + dev_info(dev, "low voltage detected, date/time is not reliable.\n"); + + if (copy_to_user((void __user *)arg, &pcf8563->voltage_low, + sizeof(int))) + return -EFAULT; + return 0; + case RTC_VL_CLR: + /* + * Clear the VL bit in the seconds register in case + * the time has not been set already (which would + * have cleared it). This does not really matter + * because of the cached voltage_low value but do it + * anyway for consistency. + */ + if (pcf8563_get_datetime(to_i2c_client(dev), &tm)) + pcf8563_set_datetime(to_i2c_client(dev), &tm); + + /* Clear the cached value. */ + pcf8563->voltage_low = 0; + + return 0; + default: + return -ENOIOCTLCMD; + } +} +#else +#define pcf8563_rtc_ioctl NULL +#endif + +static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + return pcf8563_get_datetime(to_i2c_client(dev), tm); +} + +static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + return pcf8563_set_datetime(to_i2c_client(dev), tm); +} + +static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm) +{ + struct i2c_client *client = to_i2c_client(dev); + unsigned char buf[4]; + int err; + + err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf); + if (err) + return err; + + dev_dbg(&client->dev, + "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n", + __func__, buf[0], buf[1], buf[2], buf[3]); + + tm->time.tm_min = bcd2bin(buf[0] & 0x7F); + tm->time.tm_hour = bcd2bin(buf[1] & 0x3F); + tm->time.tm_mday = bcd2bin(buf[2] & 0x3F); + tm->time.tm_wday = bcd2bin(buf[3] & 0x7); + tm->time.tm_mon = -1; + tm->time.tm_year = -1; + tm->time.tm_yday = -1; + tm->time.tm_isdst = -1; + + err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending); + if (err < 0) + return err; + + dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d," + " enabled=%d, pending=%d\n", __func__, tm->time.tm_min, + tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday, + tm->enabled, tm->pending); + + return 0; +} + +static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm) +{ + struct i2c_client *client = to_i2c_client(dev); + unsigned char buf[4]; + int err; + unsigned long alarm_time; + + /* The alarm has no seconds, round up to nearest minute */ + if (tm->time.tm_sec) { + rtc_tm_to_time(&tm->time, &alarm_time); + alarm_time += 60-tm->time.tm_sec; + rtc_time_to_tm(alarm_time, &tm->time); + } + + dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d " + "enabled=%d pending=%d\n", __func__, + tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday, + tm->time.tm_mday, tm->enabled, tm->pending); + + buf[0] = bin2bcd(tm->time.tm_min); + buf[1] = bin2bcd(tm->time.tm_hour); + buf[2] = bin2bcd(tm->time.tm_mday); + buf[3] = tm->time.tm_wday & 0x07; + + err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf); + if (err) + return err; + + return pcf8563_set_alarm_mode(client, 1); +} + +static int pcf8563_irq_enable(struct device *dev, unsigned int enabled) +{ + dev_dbg(dev, "%s: en=%d\n", __func__, enabled); + return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled); +} + +static const struct rtc_class_ops pcf8563_rtc_ops = { + .ioctl = pcf8563_rtc_ioctl, + .read_time = pcf8563_rtc_read_time, + .set_time = pcf8563_rtc_set_time, + .read_alarm = pcf8563_rtc_read_alarm, + .set_alarm = pcf8563_rtc_set_alarm, + .alarm_irq_enable = pcf8563_irq_enable, +}; + +static int pcf8563_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct pcf8563 *pcf8563; + int err; + unsigned char buf; + unsigned char alm_pending; + + dev_dbg(&client->dev, "%s\n", __func__); + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -ENODEV; + + pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563), + GFP_KERNEL); + if (!pcf8563) + return -ENOMEM; + + dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n"); + + i2c_set_clientdata(client, pcf8563); + pcf8563->client = client; + device_set_wakeup_capable(&client->dev, 1); + + /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */ + buf = PCF8563_TMRC_1_60; + err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf); + if (err < 0) { + dev_err(&client->dev, "%s: write error\n", __func__); + return err; + } + + err = pcf8563_get_alarm_mode(client, NULL, &alm_pending); + if (err < 0) { + dev_err(&client->dev, "%s: read error\n", __func__); + return err; + } + if (alm_pending) + pcf8563_set_alarm_mode(client, 0); + + pcf8563->rtc = devm_rtc_device_register(&client->dev, + pcf8563_driver.driver.name, + &pcf8563_rtc_ops, THIS_MODULE); + + if (IS_ERR(pcf8563->rtc)) + return PTR_ERR(pcf8563->rtc); + + if (client->irq > 0) { + err = devm_request_threaded_irq(&client->dev, client->irq, + NULL, pcf8563_irq, + IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING, + pcf8563->rtc->name, client); + if (err) { + dev_err(&client->dev, "unable to request IRQ %d\n", + client->irq); + return err; + } + + } + + /* the pcf8563 alarm only supports a minute accuracy */ + pcf8563->rtc->uie_unsupported = 1; + + return 0; +} + +static const struct i2c_device_id pcf8563_id[] = { + { "pcf8563", 0 }, + { "rtc8564", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, pcf8563_id); + +#ifdef CONFIG_OF +static const struct of_device_id pcf8563_of_match[] = { + { .compatible = "nxp,pcf8563" }, + {} +}; +MODULE_DEVICE_TABLE(of, pcf8563_of_match); +#endif + +static struct i2c_driver pcf8563_driver = { + .driver = { + .name = "rtc-pcf8563", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(pcf8563_of_match), + }, + .probe = pcf8563_probe, + .id_table = pcf8563_id, +}; + +module_i2c_driver(pcf8563_driver); + +MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); +MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRV_VERSION); |