+++ /dev/null
-/*
- * rtc-isl12057 - Driver for Intersil ISL12057 I2C Real Time Clock
- *
- * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
- *
- * This work is largely based on Intersil ISL1208 driver developed by
- * Hebert Valerio Riedel <hvr@gnu.org>.
- *
- * Detailed datasheet on which this development is based is available here:
- *
- * http://natisbad.org/NAS2/refs/ISL12057.pdf
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/rtc.h>
-#include <linux/i2c.h>
-#include <linux/bcd.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
-#include <linux/regmap.h>
-
-#define DRV_NAME "rtc-isl12057"
-
-/* RTC section */
-#define ISL12057_REG_RTC_SC 0x00 /* Seconds */
-#define ISL12057_REG_RTC_MN 0x01 /* Minutes */
-#define ISL12057_REG_RTC_HR 0x02 /* Hours */
-#define ISL12057_REG_RTC_HR_PM BIT(5) /* AM/PM bit in 12h format */
-#define ISL12057_REG_RTC_HR_MIL BIT(6) /* 24h/12h format */
-#define ISL12057_REG_RTC_DW 0x03 /* Day of the Week */
-#define ISL12057_REG_RTC_DT 0x04 /* Date */
-#define ISL12057_REG_RTC_MO 0x05 /* Month */
-#define ISL12057_REG_RTC_MO_CEN BIT(7) /* Century bit */
-#define ISL12057_REG_RTC_YR 0x06 /* Year */
-#define ISL12057_RTC_SEC_LEN 7
-
-/* Alarm 1 section */
-#define ISL12057_REG_A1_SC 0x07 /* Alarm 1 Seconds */
-#define ISL12057_REG_A1_MN 0x08 /* Alarm 1 Minutes */
-#define ISL12057_REG_A1_HR 0x09 /* Alarm 1 Hours */
-#define ISL12057_REG_A1_HR_PM BIT(5) /* AM/PM bit in 12h format */
-#define ISL12057_REG_A1_HR_MIL BIT(6) /* 24h/12h format */
-#define ISL12057_REG_A1_DWDT 0x0A /* Alarm 1 Date / Day of the week */
-#define ISL12057_REG_A1_DWDT_B BIT(6) /* DW / DT selection bit */
-#define ISL12057_A1_SEC_LEN 4
-
-/* Alarm 2 section */
-#define ISL12057_REG_A2_MN 0x0B /* Alarm 2 Minutes */
-#define ISL12057_REG_A2_HR 0x0C /* Alarm 2 Hours */
-#define ISL12057_REG_A2_DWDT 0x0D /* Alarm 2 Date / Day of the week */
-#define ISL12057_A2_SEC_LEN 3
-
-/* Control/Status registers */
-#define ISL12057_REG_INT 0x0E
-#define ISL12057_REG_INT_A1IE BIT(0) /* Alarm 1 interrupt enable bit */
-#define ISL12057_REG_INT_A2IE BIT(1) /* Alarm 2 interrupt enable bit */
-#define ISL12057_REG_INT_INTCN BIT(2) /* Interrupt control enable bit */
-#define ISL12057_REG_INT_RS1 BIT(3) /* Freq out control bit 1 */
-#define ISL12057_REG_INT_RS2 BIT(4) /* Freq out control bit 2 */
-#define ISL12057_REG_INT_EOSC BIT(7) /* Oscillator enable bit */
-
-#define ISL12057_REG_SR 0x0F
-#define ISL12057_REG_SR_A1F BIT(0) /* Alarm 1 interrupt bit */
-#define ISL12057_REG_SR_A2F BIT(1) /* Alarm 2 interrupt bit */
-#define ISL12057_REG_SR_OSF BIT(7) /* Oscillator failure bit */
-
-/* Register memory map length */
-#define ISL12057_MEM_MAP_LEN 0x10
-
-struct isl12057_rtc_data {
- struct rtc_device *rtc;
- struct regmap *regmap;
- struct mutex lock;
- int irq;
-};
-
-static void isl12057_rtc_regs_to_tm(struct rtc_time *tm, u8 *regs)
-{
- tm->tm_sec = bcd2bin(regs[ISL12057_REG_RTC_SC]);
- tm->tm_min = bcd2bin(regs[ISL12057_REG_RTC_MN]);
-
- if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_MIL) { /* AM/PM */
- tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x1f);
- if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_PM)
- tm->tm_hour += 12;
- } else { /* 24 hour mode */
- tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x3f);
- }
-
- tm->tm_mday = bcd2bin(regs[ISL12057_REG_RTC_DT]);
- tm->tm_wday = bcd2bin(regs[ISL12057_REG_RTC_DW]) - 1; /* starts at 1 */
- tm->tm_mon = bcd2bin(regs[ISL12057_REG_RTC_MO] & 0x1f) - 1; /* ditto */
- tm->tm_year = bcd2bin(regs[ISL12057_REG_RTC_YR]) + 100;
-
- /* Check if years register has overflown from 99 to 00 */
- if (regs[ISL12057_REG_RTC_MO] & ISL12057_REG_RTC_MO_CEN)
- tm->tm_year += 100;
-}
-
-static int isl12057_rtc_tm_to_regs(u8 *regs, struct rtc_time *tm)
-{
- u8 century_bit;
-
- /*
- * The clock has an 8 bit wide bcd-coded register for the year.
- * It also has a century bit encoded in MO flag which provides
- * information about overflow of year register from 99 to 00.
- * tm_year is an offset from 1900 and we are interested in the
- * 2000-2199 range, so any value less than 100 or larger than
- * 299 is invalid.
- */
- if (tm->tm_year < 100 || tm->tm_year > 299)
- return -EINVAL;
-
- century_bit = (tm->tm_year > 199) ? ISL12057_REG_RTC_MO_CEN : 0;
-
- regs[ISL12057_REG_RTC_SC] = bin2bcd(tm->tm_sec);
- regs[ISL12057_REG_RTC_MN] = bin2bcd(tm->tm_min);
- regs[ISL12057_REG_RTC_HR] = bin2bcd(tm->tm_hour); /* 24-hour format */
- regs[ISL12057_REG_RTC_DT] = bin2bcd(tm->tm_mday);
- regs[ISL12057_REG_RTC_MO] = bin2bcd(tm->tm_mon + 1) | century_bit;
- regs[ISL12057_REG_RTC_YR] = bin2bcd(tm->tm_year % 100);
- regs[ISL12057_REG_RTC_DW] = bin2bcd(tm->tm_wday + 1);
-
- return 0;
-}
-
-/*
- * Try and match register bits w/ fixed null values to see whether we
- * are dealing with an ISL12057. Note: this function is called early
- * during init and hence does need mutex protection.
- */
-static int isl12057_i2c_validate_chip(struct regmap *regmap)
-{
- u8 regs[ISL12057_MEM_MAP_LEN];
- static const u8 mask[ISL12057_MEM_MAP_LEN] = { 0x80, 0x80, 0x80, 0xf8,
- 0xc0, 0x60, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x60, 0x7c };
- int ret, i;
-
- ret = regmap_bulk_read(regmap, 0, regs, ISL12057_MEM_MAP_LEN);
- if (ret)
- return ret;
-
- for (i = 0; i < ISL12057_MEM_MAP_LEN; ++i) {
- if (regs[i] & mask[i]) /* check if bits are cleared */
- return -ENODEV;
- }
-
- return 0;
-}
-
-static int _isl12057_rtc_clear_alarm(struct device *dev)
-{
- struct isl12057_rtc_data *data = dev_get_drvdata(dev);
- int ret;
-
- ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
- ISL12057_REG_SR_A1F, 0);
- if (ret)
- dev_err(dev, "%s: clearing alarm failed (%d)\n", __func__, ret);
-
- return ret;
-}
-
-static int _isl12057_rtc_update_alarm(struct device *dev, int enable)
-{
- struct isl12057_rtc_data *data = dev_get_drvdata(dev);
- int ret;
-
- ret = regmap_update_bits(data->regmap, ISL12057_REG_INT,
- ISL12057_REG_INT_A1IE,
- enable ? ISL12057_REG_INT_A1IE : 0);
- if (ret)
- dev_err(dev, "%s: changing alarm interrupt flag failed (%d)\n",
- __func__, ret);
-
- return ret;
-}
-
-/*
- * Note: as we only read from device and do not perform any update, there is
- * no need for an equivalent function which would try and get driver's main
- * lock. Here, it is safe for everyone if we just use regmap internal lock
- * on the device when reading.
- */
-static int _isl12057_rtc_read_time(struct device *dev, struct rtc_time *tm)
-{
- struct isl12057_rtc_data *data = dev_get_drvdata(dev);
- u8 regs[ISL12057_RTC_SEC_LEN];
- unsigned int sr;
- int ret;
-
- ret = regmap_read(data->regmap, ISL12057_REG_SR, &sr);
- if (ret) {
- dev_err(dev, "%s: unable to read oscillator status flag (%d)\n",
- __func__, ret);
- goto out;
- } else {
- if (sr & ISL12057_REG_SR_OSF) {
- ret = -ENODATA;
- goto out;
- }
- }
-
- ret = regmap_bulk_read(data->regmap, ISL12057_REG_RTC_SC, regs,
- ISL12057_RTC_SEC_LEN);
- if (ret)
- dev_err(dev, "%s: unable to read RTC time section (%d)\n",
- __func__, ret);
-
-out:
- if (ret)
- return ret;
-
- isl12057_rtc_regs_to_tm(tm, regs);
-
- return rtc_valid_tm(tm);
-}
-
-static int isl12057_rtc_update_alarm(struct device *dev, int enable)
-{
- struct isl12057_rtc_data *data = dev_get_drvdata(dev);
- int ret;
-
- mutex_lock(&data->lock);
- ret = _isl12057_rtc_update_alarm(dev, enable);
- mutex_unlock(&data->lock);
-
- return ret;
-}
-
-static int isl12057_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
-{
- struct isl12057_rtc_data *data = dev_get_drvdata(dev);
- struct rtc_time *alarm_tm = &alarm->time;
- u8 regs[ISL12057_A1_SEC_LEN];
- unsigned int ir;
- int ret;
-
- mutex_lock(&data->lock);
- ret = regmap_bulk_read(data->regmap, ISL12057_REG_A1_SC, regs,
- ISL12057_A1_SEC_LEN);
- if (ret) {
- dev_err(dev, "%s: reading alarm section failed (%d)\n",
- __func__, ret);
- goto err_unlock;
- }
-
- alarm_tm->tm_sec = bcd2bin(regs[0] & 0x7f);
- alarm_tm->tm_min = bcd2bin(regs[1] & 0x7f);
- alarm_tm->tm_hour = bcd2bin(regs[2] & 0x3f);
- alarm_tm->tm_mday = bcd2bin(regs[3] & 0x3f);
-
- ret = regmap_read(data->regmap, ISL12057_REG_INT, &ir);
- if (ret) {
- dev_err(dev, "%s: reading alarm interrupt flag failed (%d)\n",
- __func__, ret);
- goto err_unlock;
- }
-
- alarm->enabled = !!(ir & ISL12057_REG_INT_A1IE);
-
-err_unlock:
- mutex_unlock(&data->lock);
-
- return ret;
-}
-
-static int isl12057_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
-{
- struct isl12057_rtc_data *data = dev_get_drvdata(dev);
- struct rtc_time *alarm_tm = &alarm->time;
- unsigned long rtc_secs, alarm_secs;
- u8 regs[ISL12057_A1_SEC_LEN];
- struct rtc_time rtc_tm;
- int ret, enable = 1;
-
- mutex_lock(&data->lock);
- ret = _isl12057_rtc_read_time(dev, &rtc_tm);
- if (ret)
- goto err_unlock;
-
- ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
- if (ret)
- goto err_unlock;
-
- ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
- if (ret)
- goto err_unlock;
-
- /* If alarm time is before current time, disable the alarm */
- if (!alarm->enabled || alarm_secs <= rtc_secs) {
- enable = 0;
- } else {
- /*
- * Chip only support alarms up to one month in the future. Let's
- * return an error if we get something after that limit.
- * Comparison is done by incrementing rtc_tm month field by one
- * and checking alarm value is still below.
- */
- if (rtc_tm.tm_mon == 11) { /* handle year wrapping */
- rtc_tm.tm_mon = 0;
- rtc_tm.tm_year += 1;
- } else {
- rtc_tm.tm_mon += 1;
- }
-
- ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
- if (ret)
- goto err_unlock;
-
- if (alarm_secs > rtc_secs) {
- dev_err(dev, "%s: max for alarm is one month (%d)\n",
- __func__, ret);
- ret = -EINVAL;
- goto err_unlock;
- }
- }
-
- /* Disable the alarm before modifying it */
- ret = _isl12057_rtc_update_alarm(dev, 0);
- if (ret < 0) {
- dev_err(dev, "%s: unable to disable the alarm (%d)\n",
- __func__, ret);
- goto err_unlock;
- }
-
- /* Program alarm registers */
- regs[0] = bin2bcd(alarm_tm->tm_sec) & 0x7f;
- regs[1] = bin2bcd(alarm_tm->tm_min) & 0x7f;
- regs[2] = bin2bcd(alarm_tm->tm_hour) & 0x3f;
- regs[3] = bin2bcd(alarm_tm->tm_mday) & 0x3f;
-
- ret = regmap_bulk_write(data->regmap, ISL12057_REG_A1_SC, regs,
- ISL12057_A1_SEC_LEN);
- if (ret < 0) {
- dev_err(dev, "%s: writing alarm section failed (%d)\n",
- __func__, ret);
- goto err_unlock;
- }
-
- /* Enable or disable alarm */
- ret = _isl12057_rtc_update_alarm(dev, enable);
-
-err_unlock:
- mutex_unlock(&data->lock);
-
- return ret;
-}
-
-static int isl12057_rtc_set_time(struct device *dev, struct rtc_time *tm)
-{
- struct isl12057_rtc_data *data = dev_get_drvdata(dev);
- u8 regs[ISL12057_RTC_SEC_LEN];
- int ret;
-
- ret = isl12057_rtc_tm_to_regs(regs, tm);
- if (ret)
- return ret;
-
- mutex_lock(&data->lock);
- ret = regmap_bulk_write(data->regmap, ISL12057_REG_RTC_SC, regs,
- ISL12057_RTC_SEC_LEN);
- if (ret) {
- dev_err(dev, "%s: unable to write RTC time section (%d)\n",
- __func__, ret);
- goto out;
- }
-
- /*
- * Now that RTC time has been updated, let's clear oscillator
- * failure flag, if needed.
- */
- ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
- ISL12057_REG_SR_OSF, 0);
- if (ret < 0)
- dev_err(dev, "%s: unable to clear osc. failure bit (%d)\n",
- __func__, ret);
-
-out:
- mutex_unlock(&data->lock);
-
- return ret;
-}
-
-/*
- * Check current RTC status and enable/disable what needs to be. Return 0 if
- * everything went ok and a negative value upon error. Note: this function
- * is called early during init and hence does need mutex protection.
- */
-static int isl12057_check_rtc_status(struct device *dev, struct regmap *regmap)
-{
- int ret;
-
- /* Enable oscillator if not already running */
- ret = regmap_update_bits(regmap, ISL12057_REG_INT,
- ISL12057_REG_INT_EOSC, 0);
- if (ret < 0) {
- dev_err(dev, "%s: unable to enable oscillator (%d)\n",
- __func__, ret);
- return ret;
- }
-
- /* Clear alarm bit if needed */
- ret = regmap_update_bits(regmap, ISL12057_REG_SR,
- ISL12057_REG_SR_A1F, 0);
- if (ret < 0) {
- dev_err(dev, "%s: unable to clear alarm bit (%d)\n",
- __func__, ret);
- return ret;
- }
-
- return 0;
-}
-
-#ifdef CONFIG_OF
-/*
- * One would expect the device to be marked as a wakeup source only
- * when an IRQ pin of the RTC is routed to an interrupt line of the
- * CPU. In practice, such an IRQ pin can be connected to a PMIC and
- * this allows the device to be powered up when RTC alarm rings. This
- * is for instance the case on ReadyNAS 102, 104 and 2120. On those
- * devices with no IRQ driectly connected to the SoC, the RTC chip
- * can be forced as a wakeup source by stating that explicitly in
- * the device's .dts file using the "wakeup-source" boolean property.
- * This will guarantee 'wakealarm' sysfs entry is available on the device.
- *
- * The function below returns 1, i.e. the capability of the chip to
- * wakeup the device, based on IRQ availability or if the boolean
- * property has been set in the .dts file. Otherwise, it returns 0.
- */
-
-static bool isl12057_can_wakeup_machine(struct device *dev)
-{
- struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-
- return data->irq || of_property_read_bool(dev->of_node, "wakeup-source")
- || of_property_read_bool(dev->of_node, /* legacy */
- "isil,irq2-can-wakeup-machine");
-}
-#else
-static bool isl12057_can_wakeup_machine(struct device *dev)
-{
- struct isl12057_rtc_data *data = dev_get_drvdata(dev);
-
- return !!data->irq;
-}
-#endif
-
-static int isl12057_rtc_alarm_irq_enable(struct device *dev,
- unsigned int enable)
-{
- struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
- int ret = -ENOTTY;
-
- if (rtc_data->irq)
- ret = isl12057_rtc_update_alarm(dev, enable);
-
- return ret;
-}
-
-static irqreturn_t isl12057_rtc_interrupt(int irq, void *data)
-{
- struct i2c_client *client = data;
- struct isl12057_rtc_data *rtc_data = dev_get_drvdata(&client->dev);
- struct rtc_device *rtc = rtc_data->rtc;
- int ret, handled = IRQ_NONE;
- unsigned int sr;
-
- ret = regmap_read(rtc_data->regmap, ISL12057_REG_SR, &sr);
- if (!ret && (sr & ISL12057_REG_SR_A1F)) {
- dev_dbg(&client->dev, "RTC alarm!\n");
-
- rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
-
- /* Acknowledge and disable the alarm */
- _isl12057_rtc_clear_alarm(&client->dev);
- _isl12057_rtc_update_alarm(&client->dev, 0);
-
- handled = IRQ_HANDLED;
- }
-
- return handled;
-}
-
-static const struct rtc_class_ops rtc_ops = {
- .read_time = _isl12057_rtc_read_time,
- .set_time = isl12057_rtc_set_time,
- .read_alarm = isl12057_rtc_read_alarm,
- .set_alarm = isl12057_rtc_set_alarm,
- .alarm_irq_enable = isl12057_rtc_alarm_irq_enable,
-};
-
-static const struct regmap_config isl12057_rtc_regmap_config = {
- .reg_bits = 8,
- .val_bits = 8,
-};
-
-static int isl12057_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
-{
- struct device *dev = &client->dev;
- struct isl12057_rtc_data *data;
- struct regmap *regmap;
- int ret;
-
- if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
- I2C_FUNC_SMBUS_BYTE_DATA |
- I2C_FUNC_SMBUS_I2C_BLOCK))
- return -ENODEV;
-
- regmap = devm_regmap_init_i2c(client, &isl12057_rtc_regmap_config);
- if (IS_ERR(regmap)) {
- ret = PTR_ERR(regmap);
- dev_err(dev, "%s: regmap allocation failed (%d)\n",
- __func__, ret);
- return ret;
- }
-
- ret = isl12057_i2c_validate_chip(regmap);
- if (ret)
- return ret;
-
- ret = isl12057_check_rtc_status(dev, regmap);
- if (ret)
- return ret;
-
- data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
- mutex_init(&data->lock);
- data->regmap = regmap;
- dev_set_drvdata(dev, data);
-
- if (client->irq > 0) {
- ret = devm_request_threaded_irq(dev, client->irq, NULL,
- isl12057_rtc_interrupt,
- IRQF_SHARED|IRQF_ONESHOT,
- DRV_NAME, client);
- if (!ret)
- data->irq = client->irq;
- else
- dev_err(dev, "%s: irq %d unavailable (%d)\n", __func__,
- client->irq, ret);
- }
-
- if (isl12057_can_wakeup_machine(dev))
- device_init_wakeup(dev, true);
-
- data->rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops,
- THIS_MODULE);
- ret = PTR_ERR_OR_ZERO(data->rtc);
- if (ret) {
- dev_err(dev, "%s: unable to register RTC device (%d)\n",
- __func__, ret);
- goto err;
- }
-
- /* We cannot support UIE mode if we do not have an IRQ line */
- if (!data->irq)
- data->rtc->uie_unsupported = 1;
-
-err:
- return ret;
-}
-
-static int isl12057_remove(struct i2c_client *client)
-{
- if (isl12057_can_wakeup_machine(&client->dev))
- device_init_wakeup(&client->dev, false);
-
- return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int isl12057_rtc_suspend(struct device *dev)
-{
- struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
-
- if (rtc_data->irq && device_may_wakeup(dev))
- return enable_irq_wake(rtc_data->irq);
-
- return 0;
-}
-
-static int isl12057_rtc_resume(struct device *dev)
-{
- struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
-
- if (rtc_data->irq && device_may_wakeup(dev))
- return disable_irq_wake(rtc_data->irq);
-
- return 0;
-}
-#endif
-
-static SIMPLE_DEV_PM_OPS(isl12057_rtc_pm_ops, isl12057_rtc_suspend,
- isl12057_rtc_resume);
-
-#ifdef CONFIG_OF
-static const struct of_device_id isl12057_dt_match[] = {
- { .compatible = "isl,isl12057" }, /* for backward compat., don't use */
- { .compatible = "isil,isl12057" },
- { },
-};
-MODULE_DEVICE_TABLE(of, isl12057_dt_match);
-#endif
-
-static const struct i2c_device_id isl12057_id[] = {
- { "isl12057", 0 },
- { }
-};
-MODULE_DEVICE_TABLE(i2c, isl12057_id);
-
-static struct i2c_driver isl12057_driver = {
- .driver = {
- .name = DRV_NAME,
- .pm = &isl12057_rtc_pm_ops,
- .of_match_table = of_match_ptr(isl12057_dt_match),
- },
- .probe = isl12057_probe,
- .remove = isl12057_remove,
- .id_table = isl12057_id,
-};
-module_i2c_driver(isl12057_driver);
-
-MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
-MODULE_DESCRIPTION("Intersil ISL12057 RTC driver");
-MODULE_LICENSE("GPL");
projects / deliverable / linux.git / commitdiff
