| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * ST M48T59 RTC driver |
| * |
| * Copyright (c) 2007 Wind River Systems, Inc. |
| * |
| * Author: Mark Zhan <rongkai.zhan@windriver.com> |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/io.h> |
| #include <linux/device.h> |
| #include <linux/platform_device.h> |
| #include <linux/rtc.h> |
| #include <linux/rtc/m48t59.h> |
| #include <linux/bcd.h> |
| #include <linux/slab.h> |
| |
| #ifndef NO_IRQ |
| #define NO_IRQ (-1) |
| #endif |
| |
| #define M48T59_READ(reg) (pdata->read_byte(dev, pdata->offset + reg)) |
| #define M48T59_WRITE(val, reg) \ |
| (pdata->write_byte(dev, pdata->offset + reg, val)) |
| |
| #define M48T59_SET_BITS(mask, reg) \ |
| M48T59_WRITE((M48T59_READ(reg) | (mask)), (reg)) |
| #define M48T59_CLEAR_BITS(mask, reg) \ |
| M48T59_WRITE((M48T59_READ(reg) & ~(mask)), (reg)) |
| |
| struct m48t59_private { |
| void __iomem *ioaddr; |
| int irq; |
| struct rtc_device *rtc; |
| spinlock_t lock; /* serialize the NVRAM and RTC access */ |
| }; |
| |
| /* |
| * This is the generic access method when the chip is memory-mapped |
| */ |
| static void |
| m48t59_mem_writeb(struct device *dev, u32 ofs, u8 val) |
| { |
| struct m48t59_private *m48t59 = dev_get_drvdata(dev); |
| |
| writeb(val, m48t59->ioaddr+ofs); |
| } |
| |
| static u8 |
| m48t59_mem_readb(struct device *dev, u32 ofs) |
| { |
| struct m48t59_private *m48t59 = dev_get_drvdata(dev); |
| |
| return readb(m48t59->ioaddr+ofs); |
| } |
| |
| /* |
| * NOTE: M48T59 only uses BCD mode |
| */ |
| static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| { |
| struct m48t59_plat_data *pdata = dev_get_platdata(dev); |
| struct m48t59_private *m48t59 = dev_get_drvdata(dev); |
| unsigned long flags; |
| u8 val; |
| |
| spin_lock_irqsave(&m48t59->lock, flags); |
| /* Issue the READ command */ |
| M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL); |
| |
| tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)); |
| /* tm_mon is 0-11 */ |
| tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1; |
| tm->tm_mday = bcd2bin(M48T59_READ(M48T59_MDAY)); |
| |
| val = M48T59_READ(M48T59_WDAY); |
| if ((pdata->type == M48T59RTC_TYPE_M48T59) && |
| (val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) { |
| dev_dbg(dev, "Century bit is enabled\n"); |
| tm->tm_year += 100; /* one century */ |
| } |
| #ifdef CONFIG_SPARC |
| /* Sun SPARC machines count years since 1968 */ |
| tm->tm_year += 68; |
| #endif |
| |
| tm->tm_wday = bcd2bin(val & 0x07); |
| tm->tm_hour = bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F); |
| tm->tm_min = bcd2bin(M48T59_READ(M48T59_MIN) & 0x7F); |
| tm->tm_sec = bcd2bin(M48T59_READ(M48T59_SEC) & 0x7F); |
| |
| /* Clear the READ bit */ |
| M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL); |
| spin_unlock_irqrestore(&m48t59->lock, flags); |
| |
| dev_dbg(dev, "RTC read time %ptR\n", tm); |
| return 0; |
| } |
| |
| static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm) |
| { |
| struct m48t59_plat_data *pdata = dev_get_platdata(dev); |
| struct m48t59_private *m48t59 = dev_get_drvdata(dev); |
| unsigned long flags; |
| u8 val = 0; |
| int year = tm->tm_year; |
| |
| #ifdef CONFIG_SPARC |
| /* Sun SPARC machines count years since 1968 */ |
| year -= 68; |
| #endif |
| |
| dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n", |
| year + 1900, tm->tm_mon, tm->tm_mday, |
| tm->tm_hour, tm->tm_min, tm->tm_sec); |
| |
| if (year < 0) |
| return -EINVAL; |
| |
| spin_lock_irqsave(&m48t59->lock, flags); |
| /* Issue the WRITE command */ |
| M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); |
| |
| M48T59_WRITE((bin2bcd(tm->tm_sec) & 0x7F), M48T59_SEC); |
| M48T59_WRITE((bin2bcd(tm->tm_min) & 0x7F), M48T59_MIN); |
| M48T59_WRITE((bin2bcd(tm->tm_hour) & 0x3F), M48T59_HOUR); |
| M48T59_WRITE((bin2bcd(tm->tm_mday) & 0x3F), M48T59_MDAY); |
| /* tm_mon is 0-11 */ |
| M48T59_WRITE((bin2bcd(tm->tm_mon + 1) & 0x1F), M48T59_MONTH); |
| M48T59_WRITE(bin2bcd(year % 100), M48T59_YEAR); |
| |
| if (pdata->type == M48T59RTC_TYPE_M48T59 && (year >= 100)) |
| val = (M48T59_WDAY_CEB | M48T59_WDAY_CB); |
| val |= (bin2bcd(tm->tm_wday) & 0x07); |
| M48T59_WRITE(val, M48T59_WDAY); |
| |
| /* Clear the WRITE bit */ |
| M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); |
| spin_unlock_irqrestore(&m48t59->lock, flags); |
| return 0; |
| } |
| |
| /* |
| * Read alarm time and date in RTC |
| */ |
| static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) |
| { |
| struct m48t59_plat_data *pdata = dev_get_platdata(dev); |
| struct m48t59_private *m48t59 = dev_get_drvdata(dev); |
| struct rtc_time *tm = &alrm->time; |
| unsigned long flags; |
| u8 val; |
| |
| /* If no irq, we don't support ALARM */ |
| if (m48t59->irq == NO_IRQ) |
| return -EIO; |
| |
| spin_lock_irqsave(&m48t59->lock, flags); |
| /* Issue the READ command */ |
| M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL); |
| |
| tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)); |
| #ifdef CONFIG_SPARC |
| /* Sun SPARC machines count years since 1968 */ |
| tm->tm_year += 68; |
| #endif |
| /* tm_mon is 0-11 */ |
| tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1; |
| |
| val = M48T59_READ(M48T59_WDAY); |
| if ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) |
| tm->tm_year += 100; /* one century */ |
| |
| tm->tm_mday = bcd2bin(M48T59_READ(M48T59_ALARM_DATE)); |
| tm->tm_hour = bcd2bin(M48T59_READ(M48T59_ALARM_HOUR)); |
| tm->tm_min = bcd2bin(M48T59_READ(M48T59_ALARM_MIN)); |
| tm->tm_sec = bcd2bin(M48T59_READ(M48T59_ALARM_SEC)); |
| |
| /* Clear the READ bit */ |
| M48T59_CLEAR_BITS(M48T59_CNTL_READ, M48T59_CNTL); |
| spin_unlock_irqrestore(&m48t59->lock, flags); |
| |
| dev_dbg(dev, "RTC read alarm time %ptR\n", tm); |
| return rtc_valid_tm(tm); |
| } |
| |
| /* |
| * Set alarm time and date in RTC |
| */ |
| static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) |
| { |
| struct m48t59_plat_data *pdata = dev_get_platdata(dev); |
| struct m48t59_private *m48t59 = dev_get_drvdata(dev); |
| struct rtc_time *tm = &alrm->time; |
| u8 mday, hour, min, sec; |
| unsigned long flags; |
| int year = tm->tm_year; |
| |
| #ifdef CONFIG_SPARC |
| /* Sun SPARC machines count years since 1968 */ |
| year -= 68; |
| #endif |
| |
| /* If no irq, we don't support ALARM */ |
| if (m48t59->irq == NO_IRQ) |
| return -EIO; |
| |
| if (year < 0) |
| return -EINVAL; |
| |
| /* |
| * 0xff means "always match" |
| */ |
| mday = tm->tm_mday; |
| mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff; |
| if (mday == 0xff) |
| mday = M48T59_READ(M48T59_MDAY); |
| |
| hour = tm->tm_hour; |
| hour = (hour < 24) ? bin2bcd(hour) : 0x00; |
| |
| min = tm->tm_min; |
| min = (min < 60) ? bin2bcd(min) : 0x00; |
| |
| sec = tm->tm_sec; |
| sec = (sec < 60) ? bin2bcd(sec) : 0x00; |
| |
| spin_lock_irqsave(&m48t59->lock, flags); |
| /* Issue the WRITE command */ |
| M48T59_SET_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); |
| |
| M48T59_WRITE(mday, M48T59_ALARM_DATE); |
| M48T59_WRITE(hour, M48T59_ALARM_HOUR); |
| M48T59_WRITE(min, M48T59_ALARM_MIN); |
| M48T59_WRITE(sec, M48T59_ALARM_SEC); |
| |
| /* Clear the WRITE bit */ |
| M48T59_CLEAR_BITS(M48T59_CNTL_WRITE, M48T59_CNTL); |
| spin_unlock_irqrestore(&m48t59->lock, flags); |
| |
| dev_dbg(dev, "RTC set alarm time %04d-%02d-%02d %02d/%02d/%02d\n", |
| year + 1900, tm->tm_mon, tm->tm_mday, |
| tm->tm_hour, tm->tm_min, tm->tm_sec); |
| return 0; |
| } |
| |
| /* |
| * Handle commands from user-space |
| */ |
| static int m48t59_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) |
| { |
| struct m48t59_plat_data *pdata = dev_get_platdata(dev); |
| struct m48t59_private *m48t59 = dev_get_drvdata(dev); |
| unsigned long flags; |
| |
| spin_lock_irqsave(&m48t59->lock, flags); |
| if (enabled) |
| M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR); |
| else |
| M48T59_WRITE(0x00, M48T59_INTR); |
| spin_unlock_irqrestore(&m48t59->lock, flags); |
| |
| return 0; |
| } |
| |
| static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq) |
| { |
| struct m48t59_plat_data *pdata = dev_get_platdata(dev); |
| struct m48t59_private *m48t59 = dev_get_drvdata(dev); |
| unsigned long flags; |
| u8 val; |
| |
| spin_lock_irqsave(&m48t59->lock, flags); |
| val = M48T59_READ(M48T59_FLAGS); |
| spin_unlock_irqrestore(&m48t59->lock, flags); |
| |
| seq_printf(seq, "battery\t\t: %s\n", |
| (val & M48T59_FLAGS_BF) ? "low" : "normal"); |
| return 0; |
| } |
| |
| /* |
| * IRQ handler for the RTC |
| */ |
| static irqreturn_t m48t59_rtc_interrupt(int irq, void *dev_id) |
| { |
| struct device *dev = (struct device *)dev_id; |
| struct m48t59_plat_data *pdata = dev_get_platdata(dev); |
| struct m48t59_private *m48t59 = dev_get_drvdata(dev); |
| u8 event; |
| |
| spin_lock(&m48t59->lock); |
| event = M48T59_READ(M48T59_FLAGS); |
| spin_unlock(&m48t59->lock); |
| |
| if (event & M48T59_FLAGS_AF) { |
| rtc_update_irq(m48t59->rtc, 1, (RTC_AF | RTC_IRQF)); |
| return IRQ_HANDLED; |
| } |
| |
| return IRQ_NONE; |
| } |
| |
| static const struct rtc_class_ops m48t59_rtc_ops = { |
| .read_time = m48t59_rtc_read_time, |
| .set_time = m48t59_rtc_set_time, |
| .read_alarm = m48t59_rtc_readalarm, |
| .set_alarm = m48t59_rtc_setalarm, |
| .proc = m48t59_rtc_proc, |
| .alarm_irq_enable = m48t59_rtc_alarm_irq_enable, |
| }; |
| |
| static int m48t59_nvram_read(void *priv, unsigned int offset, void *val, |
| size_t size) |
| { |
| struct platform_device *pdev = priv; |
| struct device *dev = &pdev->dev; |
| struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev); |
| struct m48t59_private *m48t59 = platform_get_drvdata(pdev); |
| ssize_t cnt = 0; |
| unsigned long flags; |
| u8 *buf = val; |
| |
| spin_lock_irqsave(&m48t59->lock, flags); |
| |
| for (; cnt < size; cnt++) |
| *buf++ = M48T59_READ(cnt); |
| |
| spin_unlock_irqrestore(&m48t59->lock, flags); |
| |
| return 0; |
| } |
| |
| static int m48t59_nvram_write(void *priv, unsigned int offset, void *val, |
| size_t size) |
| { |
| struct platform_device *pdev = priv; |
| struct device *dev = &pdev->dev; |
| struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev); |
| struct m48t59_private *m48t59 = platform_get_drvdata(pdev); |
| ssize_t cnt = 0; |
| unsigned long flags; |
| u8 *buf = val; |
| |
| spin_lock_irqsave(&m48t59->lock, flags); |
| |
| for (; cnt < size; cnt++) |
| M48T59_WRITE(*buf++, cnt); |
| |
| spin_unlock_irqrestore(&m48t59->lock, flags); |
| |
| return 0; |
| } |
| |
| static int m48t59_rtc_probe(struct platform_device *pdev) |
| { |
| struct m48t59_plat_data *pdata = dev_get_platdata(&pdev->dev); |
| struct m48t59_private *m48t59 = NULL; |
| struct resource *res; |
| int ret = -ENOMEM; |
| struct nvmem_config nvmem_cfg = { |
| .name = "m48t59-", |
| .word_size = 1, |
| .stride = 1, |
| .reg_read = m48t59_nvram_read, |
| .reg_write = m48t59_nvram_write, |
| .priv = pdev, |
| }; |
| |
| /* This chip could be memory-mapped or I/O-mapped */ |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (!res) { |
| res = platform_get_resource(pdev, IORESOURCE_IO, 0); |
| if (!res) |
| return -EINVAL; |
| } |
| |
| if (res->flags & IORESOURCE_IO) { |
| /* If we are I/O-mapped, the platform should provide |
| * the operations accessing chip registers. |
| */ |
| if (!pdata || !pdata->write_byte || !pdata->read_byte) |
| return -EINVAL; |
| } else if (res->flags & IORESOURCE_MEM) { |
| /* we are memory-mapped */ |
| if (!pdata) { |
| pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), |
| GFP_KERNEL); |
| if (!pdata) |
| return -ENOMEM; |
| /* Ensure we only kmalloc platform data once */ |
| pdev->dev.platform_data = pdata; |
| } |
| if (!pdata->type) |
| pdata->type = M48T59RTC_TYPE_M48T59; |
| |
| /* Try to use the generic memory read/write ops */ |
| if (!pdata->write_byte) |
| pdata->write_byte = m48t59_mem_writeb; |
| if (!pdata->read_byte) |
| pdata->read_byte = m48t59_mem_readb; |
| } |
| |
| m48t59 = devm_kzalloc(&pdev->dev, sizeof(*m48t59), GFP_KERNEL); |
| if (!m48t59) |
| return -ENOMEM; |
| |
| m48t59->ioaddr = pdata->ioaddr; |
| |
| if (!m48t59->ioaddr) { |
| /* ioaddr not mapped externally */ |
| m48t59->ioaddr = devm_ioremap(&pdev->dev, res->start, |
| resource_size(res)); |
| if (!m48t59->ioaddr) |
| return ret; |
| } |
| |
| /* Try to get irq number. We also can work in |
| * the mode without IRQ. |
| */ |
| m48t59->irq = platform_get_irq_optional(pdev, 0); |
| if (m48t59->irq <= 0) |
| m48t59->irq = NO_IRQ; |
| |
| if (m48t59->irq != NO_IRQ) { |
| ret = devm_request_irq(&pdev->dev, m48t59->irq, |
| m48t59_rtc_interrupt, IRQF_SHARED, |
| "rtc-m48t59", &pdev->dev); |
| if (ret) |
| return ret; |
| } |
| |
| m48t59->rtc = devm_rtc_allocate_device(&pdev->dev); |
| if (IS_ERR(m48t59->rtc)) |
| return PTR_ERR(m48t59->rtc); |
| |
| switch (pdata->type) { |
| case M48T59RTC_TYPE_M48T59: |
| pdata->offset = 0x1ff0; |
| break; |
| case M48T59RTC_TYPE_M48T02: |
| clear_bit(RTC_FEATURE_ALARM, m48t59->rtc->features); |
| pdata->offset = 0x7f0; |
| break; |
| case M48T59RTC_TYPE_M48T08: |
| clear_bit(RTC_FEATURE_ALARM, m48t59->rtc->features); |
| pdata->offset = 0x1ff0; |
| break; |
| default: |
| dev_err(&pdev->dev, "Unknown RTC type\n"); |
| return -ENODEV; |
| } |
| |
| spin_lock_init(&m48t59->lock); |
| platform_set_drvdata(pdev, m48t59); |
| |
| m48t59->rtc->ops = &m48t59_rtc_ops; |
| m48t59->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900; |
| m48t59->rtc->range_max = RTC_TIMESTAMP_END_2099; |
| |
| nvmem_cfg.size = pdata->offset; |
| ret = devm_rtc_nvmem_register(m48t59->rtc, &nvmem_cfg); |
| if (ret) |
| return ret; |
| |
| ret = devm_rtc_register_device(m48t59->rtc); |
| if (ret) |
| return ret; |
| |
| return 0; |
| } |
| |
| /* work with hotplug and coldplug */ |
| MODULE_ALIAS("platform:rtc-m48t59"); |
| |
| static struct platform_driver m48t59_rtc_driver = { |
| .driver = { |
| .name = "rtc-m48t59", |
| }, |
| .probe = m48t59_rtc_probe, |
| }; |
| |
| module_platform_driver(m48t59_rtc_driver); |
| |
| MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>"); |
| MODULE_DESCRIPTION("M48T59/M48T02/M48T08 RTC driver"); |
| MODULE_LICENSE("GPL"); |