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2018-04-20	Update OPNFV Sphinx Theme	Trevor Bramwell	1	-0/+7

/* * 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 rtc_tm, *alarm_tm = &alarm->time; unsigned long rtc_secs, alarm_secs; 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); alarm_tm->tm_wday = -1; /* * The alarm section does not store year/month. We use the ones in rtc * section as a basis and increment month and then year if needed to get * alarm after current time. */ ret = _isl12057_rtc_read_time(dev, &rtc_tm); if (ret) goto err_unlock; alarm_tm->tm_year = rtc_tm.tm_year; alarm_tm->tm_mon = rtc_tm.tm_mon; 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_secs < rtc_secs) { if (alarm_tm->tm_mon == 11) { alarm_tm->tm_mon = 0; alarm_tm->tm_year += 1; } else { alarm_tm->tm_mon += 1; } } 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");