/* * ST M48T59 RTC driver * * Copyright (c) 2007 Wind River Systems, Inc. * * Author: Mark Zhan <rongkai.zhan@windriver.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/io.h> #include <linux/device.h> #include <linux/platform_device.h> #include <linux/rtc.h> #include <linux/rtc/m48t59.h> #include <linux/bcd.h> #ifndef NO_IRQ #define NO_IRQ (-1) #endif #define M48T59_READ(reg) pdata->read_byte(dev, reg) #define M48T59_WRITE(val, reg) pdata->write_byte(dev, 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; unsigned int size; /* iomem size */ 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 platform_device *pdev = to_platform_device(dev); struct m48t59_private *m48t59 = platform_get_drvdata(pdev); writeb(val, m48t59->ioaddr+ofs); } static u8 m48t59_mem_readb(struct device *dev, u32 ofs) { struct platform_device *pdev = to_platform_device(dev); struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 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 platform_device *pdev = to_platform_device(dev); struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 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 ((val & M48T59_WDAY_CEB) && (val & M48T59_WDAY_CB)) { dev_dbg(dev, "Century bit is enabled\n"); tm->tm_year += 100; /* one century */ } 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 %04d-%02d-%02d %02d/%02d/%02d\n", tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec); return 0; } static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct platform_device *pdev = to_platform_device(dev); struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = platform_get_drvdata(pdev); unsigned long flags; u8 val = 0; dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n", tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec); 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(tm->tm_year % 100), M48T59_YEAR); if (tm->tm_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 platform_device *pdev = to_platform_device(dev); struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 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)); /* 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 %04d-%02d-%02d %02d/%02d/%02d\n", tm->tm_year + 1900, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec); return 0; } /* * Set alarm time and date in RTC */ static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) { struct platform_device *pdev = to_platform_device(dev); struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = platform_get_drvdata(pdev); struct rtc_time *tm = &alrm->time; u8 mday, hour, min, sec; unsigned long flags; /* If no irq, we don't support ALARM */ if (m48t59->irq == NO_IRQ) return -EIO; /* * 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", tm->tm_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_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { struct platform_device *pdev = to_platform_device(dev); struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = platform_get_drvdata(pdev); unsigned long flags; int ret = 0; spin_lock_irqsave(&m48t59->lock, flags); switch (cmd) { case RTC_AIE_OFF: /* alarm interrupt off */ M48T59_WRITE(0x00, M48T59_INTR); break; case RTC_AIE_ON: /* alarm interrupt on */ M48T59_WRITE(M48T59_INTR_AFE, M48T59_INTR); break; default: ret = -ENOIOCTLCMD; break; } spin_unlock_irqrestore(&m48t59->lock, flags); return ret; } static int m48t59_rtc_proc(struct device *dev, struct seq_file *seq) { struct platform_device *pdev = to_platform_device(dev); struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 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 platform_device *pdev = to_platform_device(dev); struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = platform_get_drvdata(pdev); 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 = { .ioctl = m48t59_rtc_ioctl, .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, }; static ssize_t m48t59_nvram_read(struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t size) { struct device *dev = container_of(kobj, struct device, kobj); struct platform_device *pdev = to_platform_device(dev); struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = platform_get_drvdata(pdev); ssize_t cnt = 0; unsigned long flags; for (; size > 0 && pos < M48T59_NVRAM_SIZE; cnt++, size--) { spin_lock_irqsave(&m48t59->lock, flags); *buf++ = M48T59_READ(cnt); spin_unlock_irqrestore(&m48t59->lock, flags); } return cnt; } static ssize_t m48t59_nvram_write(struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t size) { struct device *dev = container_of(kobj, struct device, kobj); struct platform_device *pdev = to_platform_device(dev); struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = platform_get_drvdata(pdev); ssize_t cnt = 0; unsigned long flags; for (; size > 0 && pos < M48T59_NVRAM_SIZE; cnt++, size--) { spin_lock_irqsave(&m48t59->lock, flags); M48T59_WRITE(*buf++, cnt); spin_unlock_irqrestore(&m48t59->lock, flags); } return cnt; } static struct bin_attribute m48t59_nvram_attr = { .attr = { .name = "nvram", .mode = S_IRUGO | S_IWUSR, .owner = THIS_MODULE, }, .read = m48t59_nvram_read, .write = m48t59_nvram_write, .size = M48T59_NVRAM_SIZE, }; static int __devinit m48t59_rtc_probe(struct platform_device *pdev) { struct m48t59_plat_data *pdata = pdev->dev.platform_data; struct m48t59_private *m48t59 = NULL; struct resource *res; int ret = -ENOMEM; /* 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 = kzalloc(sizeof(*pdata), GFP_KERNEL); if (!pdata) return -ENOMEM; /* Ensure we only kmalloc platform data once */ pdev->dev.platform_data = pdata; } /* 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 = kzalloc(sizeof(*m48t59), GFP_KERNEL); if (!m48t59) return -ENOMEM; m48t59->size = res->end - res->start + 1; m48t59->ioaddr = ioremap(res->start, m48t59->size); if (!m48t59->ioaddr) goto out; /* Try to get irq number. We also can work in * the mode without IRQ. */ m48t59->irq = platform_get_irq(pdev, 0); if (m48t59->irq < 0) m48t59->irq = NO_IRQ; if (m48t59->irq != NO_IRQ) { ret = request_irq(m48t59->irq, m48t59_rtc_interrupt, IRQF_SHARED, "rtc-m48t59", &pdev->dev); if (ret) goto out; } m48t59->rtc = rtc_device_register("m48t59", &pdev->dev, &m48t59_rtc_ops, THIS_MODULE); if (IS_ERR(m48t59->rtc)) { ret = PTR_ERR(m48t59->rtc); goto out; } ret = sysfs_create_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); if (ret) goto out; spin_lock_init(&m48t59->lock); platform_set_drvdata(pdev, m48t59); return 0; out: if (!IS_ERR(m48t59->rtc)) rtc_device_unregister(m48t59->rtc); if (m48t59->irq != NO_IRQ) free_irq(m48t59->irq, &pdev->dev); if (m48t59->ioaddr) iounmap(m48t59->ioaddr); if (m48t59) kfree(m48t59); return ret; } static int __devexit m48t59_rtc_remove(struct platform_device *pdev) { struct m48t59_private *m48t59 = platform_get_drvdata(pdev); sysfs_remove_bin_file(&pdev->dev.kobj, &m48t59_nvram_attr); if (!IS_ERR(m48t59->rtc)) rtc_device_unregister(m48t59->rtc); if (m48t59->ioaddr) iounmap(m48t59->ioaddr); if (m48t59->irq != NO_IRQ) free_irq(m48t59->irq, &pdev->dev); platform_set_drvdata(pdev, NULL); kfree(m48t59); return 0; } /* work with hotplug and coldplug */ MODULE_ALIAS("platform:rtc-m48t59"); static struct platform_driver m48t59_rtc_driver = { .driver = { .name = "rtc-m48t59", .owner = THIS_MODULE, }, .probe = m48t59_rtc_probe, .remove = __devexit_p(m48t59_rtc_remove), }; static int __init m48t59_rtc_init(void) { return platform_driver_register(&m48t59_rtc_driver); } static void __exit m48t59_rtc_exit(void) { platform_driver_unregister(&m48t59_rtc_driver); } module_init(m48t59_rtc_init); module_exit(m48t59_rtc_exit); MODULE_AUTHOR("Mark Zhan <rongkai.zhan@windriver.com>"); MODULE_DESCRIPTION("M48T59 RTC driver"); MODULE_LICENSE("GPL");