diff options
Diffstat (limited to 'drivers/rtc/rtc-ds1343.c')
| -rw-r--r-- | drivers/rtc/rtc-ds1343.c | 621 |
1 files changed, 621 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c new file mode 100644 index 000000000..5208da4cf --- /dev/null +++ b/drivers/rtc/rtc-ds1343.c @@ -0,0 +1,621 @@ +/* rtc-ds1343.c + * + * Driver for Dallas Semiconductor DS1343 Low Current, SPI Compatible + * Real Time Clock + * + * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com> + * Ankur Srivastava <sankurece@gmail.com> : DS1343 Nvram Support + * + * 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/init.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/device.h> +#include <linux/spi/spi.h> +#include <linux/regmap.h> +#include <linux/rtc.h> +#include <linux/bcd.h> +#include <linux/pm.h> +#include <linux/pm_wakeirq.h> +#include <linux/slab.h> + +#define DALLAS_MAXIM_DS1343 0 +#define DALLAS_MAXIM_DS1344 1 + +/* RTC DS1343 Registers */ +#define DS1343_SECONDS_REG 0x00 +#define DS1343_MINUTES_REG 0x01 +#define DS1343_HOURS_REG 0x02 +#define DS1343_DAY_REG 0x03 +#define DS1343_DATE_REG 0x04 +#define DS1343_MONTH_REG 0x05 +#define DS1343_YEAR_REG 0x06 +#define DS1343_ALM0_SEC_REG 0x07 +#define DS1343_ALM0_MIN_REG 0x08 +#define DS1343_ALM0_HOUR_REG 0x09 +#define DS1343_ALM0_DAY_REG 0x0A +#define DS1343_ALM1_SEC_REG 0x0B +#define DS1343_ALM1_MIN_REG 0x0C +#define DS1343_ALM1_HOUR_REG 0x0D +#define DS1343_ALM1_DAY_REG 0x0E +#define DS1343_CONTROL_REG 0x0F +#define DS1343_STATUS_REG 0x10 +#define DS1343_TRICKLE_REG 0x11 +#define DS1343_NVRAM 0x20 + +#define DS1343_NVRAM_LEN 96 + +/* DS1343 Control Registers bits */ +#define DS1343_EOSC 0x80 +#define DS1343_DOSF 0x20 +#define DS1343_EGFIL 0x10 +#define DS1343_SQW 0x08 +#define DS1343_INTCN 0x04 +#define DS1343_A1IE 0x02 +#define DS1343_A0IE 0x01 + +/* DS1343 Status Registers bits */ +#define DS1343_OSF 0x80 +#define DS1343_IRQF1 0x02 +#define DS1343_IRQF0 0x01 + +/* DS1343 Trickle Charger Registers bits */ +#define DS1343_TRICKLE_MAGIC 0xa0 +#define DS1343_TRICKLE_DS1 0x08 +#define DS1343_TRICKLE_1K 0x01 +#define DS1343_TRICKLE_2K 0x02 +#define DS1343_TRICKLE_4K 0x03 + +static const struct spi_device_id ds1343_id[] = { + { "ds1343", DALLAS_MAXIM_DS1343 }, + { "ds1344", DALLAS_MAXIM_DS1344 }, + { } +}; +MODULE_DEVICE_TABLE(spi, ds1343_id); + +struct ds1343_priv { + struct spi_device *spi; + struct rtc_device *rtc; + struct regmap *map; + struct mutex mutex; + unsigned int irqen; + int irq; + int alarm_sec; + int alarm_min; + int alarm_hour; + int alarm_mday; +}; + +static int ds1343_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) +{ + switch (cmd) { +#ifdef RTC_SET_CHARGE + case RTC_SET_CHARGE: + { + int val; + + if (copy_from_user(&val, (int __user *)arg, sizeof(int))) + return -EFAULT; + + return regmap_write(priv->map, DS1343_TRICKLE_REG, val); + } + break; +#endif + } + + return -ENOIOCTLCMD; +} + +static ssize_t ds1343_show_glitchfilter(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ds1343_priv *priv = dev_get_drvdata(dev); + int glitch_filt_status, data; + + regmap_read(priv->map, DS1343_CONTROL_REG, &data); + + glitch_filt_status = !!(data & DS1343_EGFIL); + + if (glitch_filt_status) + return sprintf(buf, "enabled\n"); + else + return sprintf(buf, "disabled\n"); +} + +static ssize_t ds1343_store_glitchfilter(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ds1343_priv *priv = dev_get_drvdata(dev); + int data; + + regmap_read(priv->map, DS1343_CONTROL_REG, &data); + + if (strncmp(buf, "enabled", 7) == 0) + data |= DS1343_EGFIL; + + else if (strncmp(buf, "disabled", 8) == 0) + data &= ~(DS1343_EGFIL); + + else + return -EINVAL; + + regmap_write(priv->map, DS1343_CONTROL_REG, data); + + return count; +} + +static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter, + ds1343_store_glitchfilter); + +static int ds1343_nvram_write(void *priv, unsigned int off, void *val, + size_t bytes) +{ + struct ds1343_priv *ds1343 = priv; + + return regmap_bulk_write(ds1343->map, DS1343_NVRAM + off, val, bytes); +} + +static int ds1343_nvram_read(void *priv, unsigned int off, void *val, + size_t bytes) +{ + struct ds1343_priv *ds1343 = priv; + + return regmap_bulk_read(ds1343->map, DS1343_NVRAM + off, val, bytes); +} + +static ssize_t ds1343_show_tricklecharger(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ds1343_priv *priv = dev_get_drvdata(dev); + int data; + char *diodes = "disabled", *resistors = " "; + + regmap_read(priv->map, DS1343_TRICKLE_REG, &data); + + if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) { + switch (data & 0x0c) { + case DS1343_TRICKLE_DS1: + diodes = "one diode,"; + break; + + default: + diodes = "no diode,"; + break; + } + + switch (data & 0x03) { + case DS1343_TRICKLE_1K: + resistors = "1k Ohm"; + break; + + case DS1343_TRICKLE_2K: + resistors = "2k Ohm"; + break; + + case DS1343_TRICKLE_4K: + resistors = "4k Ohm"; + break; + + default: + diodes = "disabled"; + break; + } + } + + return sprintf(buf, "%s %s\n", diodes, resistors); +} + +static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL); + +static int ds1343_sysfs_register(struct device *dev) +{ + int err; + + err = device_create_file(dev, &dev_attr_glitch_filter); + if (err) + return err; + + err = device_create_file(dev, &dev_attr_trickle_charger); + if (!err) + return 0; + + device_remove_file(dev, &dev_attr_glitch_filter); + + return err; +} + +static void ds1343_sysfs_unregister(struct device *dev) +{ + device_remove_file(dev, &dev_attr_glitch_filter); + device_remove_file(dev, &dev_attr_trickle_charger); +} + +static int ds1343_read_time(struct device *dev, struct rtc_time *dt) +{ + struct ds1343_priv *priv = dev_get_drvdata(dev); + unsigned char buf[7]; + int res; + + res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7); + if (res) + return res; + + dt->tm_sec = bcd2bin(buf[0]); + dt->tm_min = bcd2bin(buf[1]); + dt->tm_hour = bcd2bin(buf[2] & 0x3F); + dt->tm_wday = bcd2bin(buf[3]) - 1; + dt->tm_mday = bcd2bin(buf[4]); + dt->tm_mon = bcd2bin(buf[5] & 0x1F) - 1; + dt->tm_year = bcd2bin(buf[6]) + 100; /* year offset from 1900 */ + + return 0; +} + +static int ds1343_set_time(struct device *dev, struct rtc_time *dt) +{ + struct ds1343_priv *priv = dev_get_drvdata(dev); + int res; + + res = regmap_write(priv->map, DS1343_SECONDS_REG, + bin2bcd(dt->tm_sec)); + if (res) + return res; + + res = regmap_write(priv->map, DS1343_MINUTES_REG, + bin2bcd(dt->tm_min)); + if (res) + return res; + + res = regmap_write(priv->map, DS1343_HOURS_REG, + bin2bcd(dt->tm_hour) & 0x3F); + if (res) + return res; + + res = regmap_write(priv->map, DS1343_DAY_REG, + bin2bcd(dt->tm_wday + 1)); + if (res) + return res; + + res = regmap_write(priv->map, DS1343_DATE_REG, + bin2bcd(dt->tm_mday)); + if (res) + return res; + + res = regmap_write(priv->map, DS1343_MONTH_REG, + bin2bcd(dt->tm_mon + 1)); + if (res) + return res; + + dt->tm_year %= 100; + + res = regmap_write(priv->map, DS1343_YEAR_REG, + bin2bcd(dt->tm_year)); + if (res) + return res; + + return 0; +} + +static int ds1343_update_alarm(struct device *dev) +{ + struct ds1343_priv *priv = dev_get_drvdata(dev); + unsigned int control, stat; + unsigned char buf[4]; + int res = 0; + + res = regmap_read(priv->map, DS1343_CONTROL_REG, &control); + if (res) + return res; + + res = regmap_read(priv->map, DS1343_STATUS_REG, &stat); + if (res) + return res; + + control &= ~(DS1343_A0IE); + stat &= ~(DS1343_IRQF0); + + res = regmap_write(priv->map, DS1343_CONTROL_REG, control); + if (res) + return res; + + res = regmap_write(priv->map, DS1343_STATUS_REG, stat); + if (res) + return res; + + buf[0] = priv->alarm_sec < 0 || (priv->irqen & RTC_UF) ? + 0x80 : bin2bcd(priv->alarm_sec) & 0x7F; + buf[1] = priv->alarm_min < 0 || (priv->irqen & RTC_UF) ? + 0x80 : bin2bcd(priv->alarm_min) & 0x7F; + buf[2] = priv->alarm_hour < 0 || (priv->irqen & RTC_UF) ? + 0x80 : bin2bcd(priv->alarm_hour) & 0x3F; + buf[3] = priv->alarm_mday < 0 || (priv->irqen & RTC_UF) ? + 0x80 : bin2bcd(priv->alarm_mday) & 0x7F; + + res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4); + if (res) + return res; + + if (priv->irqen) { + control |= DS1343_A0IE; + res = regmap_write(priv->map, DS1343_CONTROL_REG, control); + } + + return res; +} + +static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct ds1343_priv *priv = dev_get_drvdata(dev); + int res = 0; + unsigned int stat; + + if (priv->irq <= 0) + return -EINVAL; + + mutex_lock(&priv->mutex); + + res = regmap_read(priv->map, DS1343_STATUS_REG, &stat); + if (res) + goto out; + + alarm->enabled = !!(priv->irqen & RTC_AF); + alarm->pending = !!(stat & DS1343_IRQF0); + + alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec; + alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min; + alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour; + alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday; + +out: + mutex_unlock(&priv->mutex); + return res; +} + +static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct ds1343_priv *priv = dev_get_drvdata(dev); + int res = 0; + + if (priv->irq <= 0) + return -EINVAL; + + mutex_lock(&priv->mutex); + + priv->alarm_sec = alarm->time.tm_sec; + priv->alarm_min = alarm->time.tm_min; + priv->alarm_hour = alarm->time.tm_hour; + priv->alarm_mday = alarm->time.tm_mday; + + if (alarm->enabled) + priv->irqen |= RTC_AF; + + res = ds1343_update_alarm(dev); + + mutex_unlock(&priv->mutex); + + return res; +} + +static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct ds1343_priv *priv = dev_get_drvdata(dev); + int res = 0; + + if (priv->irq <= 0) + return -EINVAL; + + mutex_lock(&priv->mutex); + + if (enabled) + priv->irqen |= RTC_AF; + else + priv->irqen &= ~RTC_AF; + + res = ds1343_update_alarm(dev); + + mutex_unlock(&priv->mutex); + + return res; +} + +static irqreturn_t ds1343_thread(int irq, void *dev_id) +{ + struct ds1343_priv *priv = dev_id; + unsigned int stat, control; + int res = 0; + + mutex_lock(&priv->mutex); + + res = regmap_read(priv->map, DS1343_STATUS_REG, &stat); + if (res) + goto out; + + if (stat & DS1343_IRQF0) { + stat &= ~DS1343_IRQF0; + regmap_write(priv->map, DS1343_STATUS_REG, stat); + + res = regmap_read(priv->map, DS1343_CONTROL_REG, &control); + if (res) + goto out; + + control &= ~DS1343_A0IE; + regmap_write(priv->map, DS1343_CONTROL_REG, control); + + rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF); + } + +out: + mutex_unlock(&priv->mutex); + return IRQ_HANDLED; +} + +static const struct rtc_class_ops ds1343_rtc_ops = { + .ioctl = ds1343_ioctl, + .read_time = ds1343_read_time, + .set_time = ds1343_set_time, + .read_alarm = ds1343_read_alarm, + .set_alarm = ds1343_set_alarm, + .alarm_irq_enable = ds1343_alarm_irq_enable, +}; + +static int ds1343_probe(struct spi_device *spi) +{ + struct ds1343_priv *priv; + struct regmap_config config = { .reg_bits = 8, .val_bits = 8, + .write_flag_mask = 0x80, }; + unsigned int data; + int res; + struct nvmem_config nvmem_cfg = { + .name = "ds1343-", + .word_size = 1, + .stride = 1, + .size = DS1343_NVRAM_LEN, + .reg_read = ds1343_nvram_read, + .reg_write = ds1343_nvram_write, + }; + + priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->spi = spi; + mutex_init(&priv->mutex); + + /* RTC DS1347 works in spi mode 3 and + * its chip select is active high + */ + spi->mode = SPI_MODE_3 | SPI_CS_HIGH; + spi->bits_per_word = 8; + res = spi_setup(spi); + if (res) + return res; + + spi_set_drvdata(spi, priv); + + priv->map = devm_regmap_init_spi(spi, &config); + + if (IS_ERR(priv->map)) { + dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n"); + return PTR_ERR(priv->map); + } + + res = regmap_read(priv->map, DS1343_SECONDS_REG, &data); + if (res) + return res; + + regmap_read(priv->map, DS1343_CONTROL_REG, &data); + data |= DS1343_INTCN; + data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE); + regmap_write(priv->map, DS1343_CONTROL_REG, data); + + regmap_read(priv->map, DS1343_STATUS_REG, &data); + data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0); + regmap_write(priv->map, DS1343_STATUS_REG, data); + + priv->rtc = devm_rtc_allocate_device(&spi->dev); + if (IS_ERR(priv->rtc)) + return PTR_ERR(priv->rtc); + + priv->rtc->nvram_old_abi = true; + priv->rtc->ops = &ds1343_rtc_ops; + + res = rtc_register_device(priv->rtc); + if (res) + return res; + + nvmem_cfg.priv = priv; + rtc_nvmem_register(priv->rtc, &nvmem_cfg); + + priv->irq = spi->irq; + + if (priv->irq >= 0) { + res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, + ds1343_thread, IRQF_ONESHOT, + "ds1343", priv); + if (res) { + priv->irq = -1; + dev_err(&spi->dev, + "unable to request irq for rtc ds1343\n"); + } else { + device_init_wakeup(&spi->dev, true); + dev_pm_set_wake_irq(&spi->dev, spi->irq); + } + } + + res = ds1343_sysfs_register(&spi->dev); + if (res) + dev_err(&spi->dev, + "unable to create sysfs entries for rtc ds1343\n"); + + return 0; +} + +static int ds1343_remove(struct spi_device *spi) +{ + struct ds1343_priv *priv = spi_get_drvdata(spi); + + if (spi->irq) { + mutex_lock(&priv->mutex); + priv->irqen &= ~RTC_AF; + mutex_unlock(&priv->mutex); + + dev_pm_clear_wake_irq(&spi->dev); + device_init_wakeup(&spi->dev, false); + devm_free_irq(&spi->dev, spi->irq, priv); + } + + spi_set_drvdata(spi, NULL); + + ds1343_sysfs_unregister(&spi->dev); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP + +static int ds1343_suspend(struct device *dev) +{ + struct spi_device *spi = to_spi_device(dev); + + if (spi->irq >= 0 && device_may_wakeup(dev)) + enable_irq_wake(spi->irq); + + return 0; +} + +static int ds1343_resume(struct device *dev) +{ + struct spi_device *spi = to_spi_device(dev); + + if (spi->irq >= 0 && device_may_wakeup(dev)) + disable_irq_wake(spi->irq); + + return 0; +} + +#endif + +static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume); + +static struct spi_driver ds1343_driver = { + .driver = { + .name = "ds1343", + .pm = &ds1343_pm, + }, + .probe = ds1343_probe, + .remove = ds1343_remove, + .id_table = ds1343_id, +}; + +module_spi_driver(ds1343_driver); + +MODULE_DESCRIPTION("DS1343 RTC SPI Driver"); +MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>," + "Ankur Srivastava <sankurece@gmail.com>"); +MODULE_LICENSE("GPL v2"); |