diff options
Diffstat (limited to 'drivers/rtc/rtc-rx8025.c')
-rw-r--r-- | drivers/rtc/rtc-rx8025.c | 688 |
1 files changed, 688 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rx8025.c b/drivers/rtc/rtc-rx8025.c new file mode 100644 index 00000000000..b1a29bcfdf1 --- /dev/null +++ b/drivers/rtc/rtc-rx8025.c @@ -0,0 +1,688 @@ +/* + * Driver for Epson's RTC module RX-8025 SA/NB + * + * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com> + * + * Copyright (C) 2005 by Digi International Inc. + * All rights reserved. + * + * Modified by fengjh at rising.com.cn + * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors> + * 2006.11 + * + * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com> + * Converted to new style by Wolfgang Grandegger <wg@grandegger.com> + * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com> + * + * 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/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/bcd.h> +#include <linux/i2c.h> +#include <linux/list.h> +#include <linux/rtc.h> + +/* Register definitions */ +#define RX8025_REG_SEC 0x00 +#define RX8025_REG_MIN 0x01 +#define RX8025_REG_HOUR 0x02 +#define RX8025_REG_WDAY 0x03 +#define RX8025_REG_MDAY 0x04 +#define RX8025_REG_MONTH 0x05 +#define RX8025_REG_YEAR 0x06 +#define RX8025_REG_DIGOFF 0x07 +#define RX8025_REG_ALWMIN 0x08 +#define RX8025_REG_ALWHOUR 0x09 +#define RX8025_REG_ALWWDAY 0x0a +#define RX8025_REG_ALDMIN 0x0b +#define RX8025_REG_ALDHOUR 0x0c +/* 0x0d is reserved */ +#define RX8025_REG_CTRL1 0x0e +#define RX8025_REG_CTRL2 0x0f + +#define RX8025_BIT_CTRL1_CT (7 << 0) +/* 1 Hz periodic level irq */ +#define RX8025_BIT_CTRL1_CT_1HZ 4 +#define RX8025_BIT_CTRL1_TEST (1 << 3) +#define RX8025_BIT_CTRL1_1224 (1 << 5) +#define RX8025_BIT_CTRL1_DALE (1 << 6) +#define RX8025_BIT_CTRL1_WALE (1 << 7) + +#define RX8025_BIT_CTRL2_DAFG (1 << 0) +#define RX8025_BIT_CTRL2_WAFG (1 << 1) +#define RX8025_BIT_CTRL2_CTFG (1 << 2) +#define RX8025_BIT_CTRL2_PON (1 << 4) +#define RX8025_BIT_CTRL2_XST (1 << 5) +#define RX8025_BIT_CTRL2_VDET (1 << 6) + +/* Clock precision adjustment */ +#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */ +#define RX8025_ADJ_DATA_MAX 62 +#define RX8025_ADJ_DATA_MIN -62 + +static const struct i2c_device_id rx8025_id[] = { + { "rx8025", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, rx8025_id); + +struct rx8025_data { + struct i2c_client *client; + struct rtc_device *rtc; + struct work_struct work; + u8 ctrl1; + unsigned exiting:1; +}; + +static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value) +{ + int ret = i2c_smbus_read_byte_data(client, (number << 4) | 0x08); + + if (ret < 0) { + dev_err(&client->dev, "Unable to read register #%d\n", number); + return ret; + } + + *value = ret; + return 0; +} + +static int rx8025_read_regs(struct i2c_client *client, + int number, u8 length, u8 *values) +{ + int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) | 0x08, + length, values); + + if (ret != length) { + dev_err(&client->dev, "Unable to read registers #%d..#%d\n", + number, number + length - 1); + return ret < 0 ? ret : -EIO; + } + + return 0; +} + +static int rx8025_write_reg(struct i2c_client *client, int number, u8 value) +{ + int ret = i2c_smbus_write_byte_data(client, number << 4, value); + + if (ret) + dev_err(&client->dev, "Unable to write register #%d\n", + number); + + return ret; +} + +static int rx8025_write_regs(struct i2c_client *client, + int number, u8 length, u8 *values) +{ + int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) | 0x08, + length, values); + + if (ret) + dev_err(&client->dev, "Unable to write registers #%d..#%d\n", + number, number + length - 1); + + return ret; +} + +static irqreturn_t rx8025_irq(int irq, void *dev_id) +{ + struct i2c_client *client = dev_id; + struct rx8025_data *rx8025 = i2c_get_clientdata(client); + + disable_irq_nosync(irq); + schedule_work(&rx8025->work); + return IRQ_HANDLED; +} + +static void rx8025_work(struct work_struct *work) +{ + struct rx8025_data *rx8025 = container_of(work, struct rx8025_data, + work); + struct i2c_client *client = rx8025->client; + struct mutex *lock = &rx8025->rtc->ops_lock; + u8 status; + + mutex_lock(lock); + + if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status)) + goto out; + + if (!(status & RX8025_BIT_CTRL2_XST)) + dev_warn(&client->dev, "Oscillation stop was detected," + "you may have to readjust the clock\n"); + + if (status & RX8025_BIT_CTRL2_CTFG) { + /* periodic */ + status &= ~RX8025_BIT_CTRL2_CTFG; + local_irq_disable(); + rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF); + local_irq_enable(); + } + + if (status & RX8025_BIT_CTRL2_DAFG) { + /* alarm */ + status &= RX8025_BIT_CTRL2_DAFG; + if (rx8025_write_reg(client, RX8025_REG_CTRL1, + rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE)) + goto out; + local_irq_disable(); + rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF); + local_irq_enable(); + } + + /* acknowledge IRQ */ + rx8025_write_reg(client, RX8025_REG_CTRL2, + status | RX8025_BIT_CTRL2_XST); + +out: + if (!rx8025->exiting) + enable_irq(client->irq); + + mutex_unlock(lock); +} + +static int rx8025_get_time(struct device *dev, struct rtc_time *dt) +{ + struct rx8025_data *rx8025 = dev_get_drvdata(dev); + u8 date[7]; + int err; + + err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date); + if (err) + return err; + + dev_dbg(dev, "%s: read 0x%02x 0x%02x " + "0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__, + date[0], date[1], date[2], date[3], date[4], + date[5], date[6]); + + dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f); + dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f); + if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224) + dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f); + else + dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12 + + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0); + + dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f); + dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1; + dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]); + + if (dt->tm_year < 70) + dt->tm_year += 100; + + dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__, + dt->tm_sec, dt->tm_min, dt->tm_hour, + dt->tm_mday, dt->tm_mon, dt->tm_year); + + return rtc_valid_tm(dt); +} + +static int rx8025_set_time(struct device *dev, struct rtc_time *dt) +{ + struct rx8025_data *rx8025 = dev_get_drvdata(dev); + u8 date[7]; + + /* + * BUG: The HW assumes every year that is a multiple of 4 to be a leap + * year. Next time this is wrong is 2100, which will not be a leap + * year. + */ + + /* + * Here the read-only bits are written as "0". I'm not sure if that + * is sound. + */ + date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec); + date[RX8025_REG_MIN] = bin2bcd(dt->tm_min); + if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224) + date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour); + else + date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0) + | bin2bcd((dt->tm_hour + 11) % 12 + 1); + + date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday); + date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday); + date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1); + date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100); + + dev_dbg(dev, + "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", + __func__, + date[0], date[1], date[2], date[3], date[4], date[5], date[6]); + + return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date); +} + +static int rx8025_init_client(struct i2c_client *client, int *need_reset) +{ + struct rx8025_data *rx8025 = i2c_get_clientdata(client); + u8 ctrl[2], ctrl2; + int need_clear = 0; + int err; + + err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl); + if (err) + goto out; + + /* Keep test bit zero ! */ + rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST; + + if (ctrl[1] & RX8025_BIT_CTRL2_PON) { + dev_warn(&client->dev, "power-on reset was detected, " + "you may have to readjust the clock\n"); + *need_reset = 1; + } + + if (ctrl[1] & RX8025_BIT_CTRL2_VDET) { + dev_warn(&client->dev, "a power voltage drop was detected, " + "you may have to readjust the clock\n"); + *need_reset = 1; + } + + if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) { + dev_warn(&client->dev, "Oscillation stop was detected," + "you may have to readjust the clock\n"); + *need_reset = 1; + } + + if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) { + dev_warn(&client->dev, "Alarm was detected\n"); + need_clear = 1; + } + + if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG)) + need_clear = 1; + + if (*need_reset || need_clear) { + ctrl2 = ctrl[0]; + ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET | + RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG | + RX8025_BIT_CTRL2_DAFG); + ctrl2 |= RX8025_BIT_CTRL2_XST; + + err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2); + } +out: + return err; +} + +/* Alarm support */ +static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct rx8025_data *rx8025 = dev_get_drvdata(dev); + struct i2c_client *client = rx8025->client; + u8 ctrl2, ald[2]; + int err; + + if (client->irq <= 0) + return -EINVAL; + + err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald); + if (err) + return err; + + err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2); + if (err) + return err; + + dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n", + __func__, ald[0], ald[1], ctrl2); + + /* Hardware alarms precision is 1 minute! */ + t->time.tm_sec = 0; + t->time.tm_min = bcd2bin(ald[0] & 0x7f); + if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224) + t->time.tm_hour = bcd2bin(ald[1] & 0x3f); + else + t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12 + + (ald[1] & 0x20 ? 12 : 0); + + t->time.tm_wday = -1; + t->time.tm_mday = -1; + t->time.tm_mon = -1; + t->time.tm_year = -1; + + dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n", + __func__, + t->time.tm_sec, t->time.tm_min, t->time.tm_hour, + t->time.tm_mday, t->time.tm_mon, t->time.tm_year); + t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE); + t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled; + + return err; +} + +static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct i2c_client *client = to_i2c_client(dev); + struct rx8025_data *rx8025 = dev_get_drvdata(dev); + u8 ald[2]; + int err; + + if (client->irq <= 0) + return -EINVAL; + + /* Hardware alarm precision is 1 minute! */ + ald[0] = bin2bcd(t->time.tm_min); + if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224) + ald[1] = bin2bcd(t->time.tm_hour); + else + ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0) + | bin2bcd((t->time.tm_hour + 11) % 12 + 1); + + dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]); + + if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) { + rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE; + err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1, + rx8025->ctrl1); + if (err) + return err; + } + err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald); + if (err) + return err; + + if (t->enabled) { + rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE; + err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1, + rx8025->ctrl1); + if (err) + return err; + } + + return 0; +} + +static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct rx8025_data *rx8025 = dev_get_drvdata(dev); + u8 ctrl1; + int err; + + ctrl1 = rx8025->ctrl1; + if (enabled) + ctrl1 |= RX8025_BIT_CTRL1_DALE; + else + ctrl1 &= ~RX8025_BIT_CTRL1_DALE; + + if (ctrl1 != rx8025->ctrl1) { + rx8025->ctrl1 = ctrl1; + err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1, + rx8025->ctrl1); + if (err) + return err; + } + return 0; +} + +static int rx8025_irq_set_state(struct device *dev, int enabled) +{ + struct i2c_client *client = to_i2c_client(dev); + struct rx8025_data *rx8025 = i2c_get_clientdata(client); + int ctrl1; + int err; + + if (client->irq <= 0) + return -ENXIO; + + ctrl1 = rx8025->ctrl1 & ~RX8025_BIT_CTRL1_CT; + if (enabled) + ctrl1 |= RX8025_BIT_CTRL1_CT_1HZ; + if (ctrl1 != rx8025->ctrl1) { + rx8025->ctrl1 = ctrl1; + err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1, + rx8025->ctrl1); + if (err) + return err; + } + + return 0; +} + +static struct rtc_class_ops rx8025_rtc_ops = { + .read_time = rx8025_get_time, + .set_time = rx8025_set_time, + .read_alarm = rx8025_read_alarm, + .set_alarm = rx8025_set_alarm, + .alarm_irq_enable = rx8025_alarm_irq_enable, + .irq_set_state = rx8025_irq_set_state, +}; + +/* + * Clock precision adjustment support + * + * According to the RX8025 SA/NB application manual the frequency and + * temperature charateristics can be approximated using the following + * equation: + * + * df = a * (ut - t)**2 + * + * df: Frequency deviation in any temperature + * a : Coefficient = (-35 +-5) * 10**-9 + * ut: Ultimate temperature in degree = +25 +-5 degree + * t : Any temperature in degree + * + * Note that the clock adjustment in ppb must be entered (which is + * the negative value of the deviation). + */ +static int rx8025_get_clock_adjust(struct device *dev, int *adj) +{ + struct i2c_client *client = to_i2c_client(dev); + u8 digoff; + int err; + + err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff); + if (err) + return err; + + *adj = digoff >= 64 ? digoff - 128 : digoff; + if (*adj > 0) + (*adj)--; + *adj *= -RX8025_ADJ_RESOLUTION; + + return 0; +} + +static int rx8025_set_clock_adjust(struct device *dev, int adj) +{ + struct i2c_client *client = to_i2c_client(dev); + u8 digoff; + int err; + + adj /= -RX8025_ADJ_RESOLUTION; + if (adj > RX8025_ADJ_DATA_MAX) + adj = RX8025_ADJ_DATA_MAX; + else if (adj < RX8025_ADJ_DATA_MIN) + adj = RX8025_ADJ_DATA_MIN; + else if (adj > 0) + adj++; + else if (adj < 0) + adj += 128; + digoff = adj; + + err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff); + if (err) + return err; + + dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff); + + return 0; +} + +static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int err, adj; + + err = rx8025_get_clock_adjust(dev, &adj); + if (err) + return err; + + return sprintf(buf, "%d\n", adj); +} + +static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int adj, err; + + if (sscanf(buf, "%i", &adj) != 1) + return -EINVAL; + + err = rx8025_set_clock_adjust(dev, adj); + + return err ? err : count; +} + +static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR, + rx8025_sysfs_show_clock_adjust, + rx8025_sysfs_store_clock_adjust); + +static int rx8025_sysfs_register(struct device *dev) +{ + return device_create_file(dev, &dev_attr_clock_adjust_ppb); +} + +static void rx8025_sysfs_unregister(struct device *dev) +{ + device_remove_file(dev, &dev_attr_clock_adjust_ppb); +} + +static int __devinit rx8025_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); + struct rx8025_data *rx8025; + int err, need_reset = 0; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA + | I2C_FUNC_SMBUS_I2C_BLOCK)) { + dev_err(&adapter->dev, + "doesn't support required functionality\n"); + err = -EIO; + goto errout; + } + + rx8025 = kzalloc(sizeof(*rx8025), GFP_KERNEL); + if (!rx8025) { + dev_err(&adapter->dev, "failed to alloc memory\n"); + err = -ENOMEM; + goto errout; + } + + rx8025->client = client; + i2c_set_clientdata(client, rx8025); + INIT_WORK(&rx8025->work, rx8025_work); + + err = rx8025_init_client(client, &need_reset); + if (err) + goto errout_free; + + if (need_reset) { + struct rtc_time tm; + dev_info(&client->dev, + "bad conditions detected, resetting date\n"); + rtc_time_to_tm(0, &tm); /* 1970/1/1 */ + rx8025_set_time(&client->dev, &tm); + } + + rx8025->rtc = rtc_device_register(client->name, &client->dev, + &rx8025_rtc_ops, THIS_MODULE); + if (IS_ERR(rx8025->rtc)) { + err = PTR_ERR(rx8025->rtc); + dev_err(&client->dev, "unable to register the class device\n"); + goto errout_free; + } + + if (client->irq > 0) { + dev_info(&client->dev, "IRQ %d supplied\n", client->irq); + err = request_irq(client->irq, rx8025_irq, + 0, "rx8025", client); + if (err) { + dev_err(&client->dev, "unable to request IRQ\n"); + goto errout_reg; + } + } + + rx8025->rtc->irq_freq = 1; + rx8025->rtc->max_user_freq = 1; + + err = rx8025_sysfs_register(&client->dev); + if (err) + goto errout_irq; + + return 0; + +errout_irq: + if (client->irq > 0) + free_irq(client->irq, client); + +errout_reg: + rtc_device_unregister(rx8025->rtc); + +errout_free: + i2c_set_clientdata(client, NULL); + kfree(rx8025); + +errout: + dev_err(&adapter->dev, "probing for rx8025 failed\n"); + return err; +} + +static int __devexit rx8025_remove(struct i2c_client *client) +{ + struct rx8025_data *rx8025 = i2c_get_clientdata(client); + struct mutex *lock = &rx8025->rtc->ops_lock; + + if (client->irq > 0) { + mutex_lock(lock); + rx8025->exiting = 1; + mutex_unlock(lock); + + free_irq(client->irq, client); + flush_scheduled_work(); + } + + rx8025_sysfs_unregister(&client->dev); + rtc_device_unregister(rx8025->rtc); + i2c_set_clientdata(client, NULL); + kfree(rx8025); + return 0; +} + +static struct i2c_driver rx8025_driver = { + .driver = { + .name = "rtc-rx8025", + .owner = THIS_MODULE, + }, + .probe = rx8025_probe, + .remove = __devexit_p(rx8025_remove), + .id_table = rx8025_id, +}; + +static int __init rx8025_init(void) +{ + return i2c_add_driver(&rx8025_driver); +} + +static void __exit rx8025_exit(void) +{ + i2c_del_driver(&rx8025_driver); +} + +MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); +MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver"); +MODULE_LICENSE("GPL"); + +module_init(rx8025_init); +module_exit(rx8025_exit); |