/* * IBM RTC driver * Copyright (c) 2010 Applied Micro * * Author: Duy Nguyen * * Base on ST M48T86 / Dallas DS12887 RTC driver * * 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. * * This drivers only supports the clock running in BCD and 24H mode. * If it will be ever adapted to binary and 12H mode, care must be taken * to not introduce bugs. */ #include #include #include #include #include #include #include #include #define RTC_REG_SEC 0x00 #define RTC_REG_SECALRM 0x01 #define RTC_REG_MIN 0x02 #define RTC_REG_MINALRM 0x03 #define RTC_REG_HOUR 0x04 #define RTC_REG_HOURALRM 0x05 #define RTC_REG_DOW 0x06 /* 1 = sunday */ #define RTC_REG_DOM 0x07 #define RTC_REG_MONTH 0x08 /* 1 - 12 */ #define RTC_REG_YEAR 0x09 /* 0 - 99 */ #define RTC_REG_A 0x0A #define RTC_REG_B 0x0B #define RTC_REG_C 0x0C #define RTC_REG_D 0x0D #define RTC_REG_B_H24 (1 << 1) #define RTC_REG_B_DM (1 << 2) #define RTC_REG_B_SET (1 << 7) #define RTC_REG_D_VRT (1 << 7) #define RTC_REG_PF 0x80 /* Period */ #define RTC_REG_AF 0x40 /* Alarm */ #define RTC_REG_UF 0x10 /* Update */ #define RTC_DCR_BASE_ADDR 0x300 #define RTC_READ(reg) mfdcr(RTC_DCR_BASE_ADDR + reg) #define RTC_WRITE(val, reg) mtdcr(RTC_DCR_BASE_ADDR + reg, val) /* Debug support */ #define DBG_LEVEL 0 #define RTC_DBG(dev, name, fmt, arg...) \ printk(KERN_DEBUG #name ": " fmt, ## arg) #if DBG_LEVEL > 0 # define DBG(d,f,x...) RTC_DBG(d, ibm-rtc, f, ##x) # define NL "\n" #else # define DBG(f,x...) ((void)0) #endif #if DBG_LEVEL > 1 # define DBG2(d,f,x...) DBG(d,f, ##x) #else # define DBG2(f,x...) ((void)0) #endif /* * FIXME: Temporatorily comment out read/setalarm() * because it make /dev/rtc work wrong. * Enabling it later (if needed) */ #undef CONFIG_IBM_RTC_ALARM struct ibm_rtc_instance { void __iomem *ioaddr; int irq; struct rtc_device *rtc; struct of_device *ofdev; spinlock_t lock; /* serialize the NVRAM and RTC access */ }; static int ibm_rtc_read_time(struct device *dev, struct rtc_time *tm) { unsigned char reg; //struct platform_device *pdev = to_platform_device(dev); DBG2(dev, "ibm_rtc_read_time" NL); reg = RTC_READ(RTC_REG_B); if (reg & RTC_REG_B_DM) { /* data (binary) mode */ tm->tm_sec = RTC_READ(RTC_REG_SEC); tm->tm_min = RTC_READ(RTC_REG_MIN); tm->tm_hour = RTC_READ(RTC_REG_HOUR) & 0x3F; tm->tm_mday = RTC_READ(RTC_REG_DOM); /* tm_mon is 0-11 */ tm->tm_mon = RTC_READ(RTC_REG_MONTH) - 1; tm->tm_year = RTC_READ(RTC_REG_YEAR) + 100; tm->tm_wday = RTC_READ(RTC_REG_DOW); } else { /* bcd mode */ tm->tm_sec = bcd2bin(RTC_READ(RTC_REG_SEC)); tm->tm_min = bcd2bin(RTC_READ(RTC_REG_MIN)); tm->tm_hour = bcd2bin(RTC_READ(RTC_REG_HOUR) & 0x3F); tm->tm_mday = bcd2bin(RTC_READ(RTC_REG_DOM)); /* tm_mon is 0-11 */ tm->tm_mon = bcd2bin(RTC_READ(RTC_REG_MONTH)) - 1; tm->tm_year = bcd2bin(RTC_READ(RTC_REG_YEAR)) + 100; tm->tm_wday = bcd2bin(RTC_READ(RTC_REG_DOW)); } /* correct the hour if the clock is in 12h mode */ if (!(reg & RTC_REG_B_H24)) if (RTC_READ(RTC_REG_HOUR) & 0x80) tm->tm_hour += 12; return 0; } static int ibm_rtc_set_time(struct device *dev, struct rtc_time *tm) { unsigned char reg; //struct platform_device *pdev = to_platform_device(dev); DBG2(dev, "ibm_rtc_set_time" NL); reg = RTC_READ(RTC_REG_B); /* update flag and 24h mode */ reg |= RTC_REG_B_SET | RTC_REG_B_H24; RTC_WRITE(reg, RTC_REG_B); if (reg & RTC_REG_B_DM) { /* data (binary) mode */ RTC_WRITE(tm->tm_sec, RTC_REG_SEC); RTC_WRITE(tm->tm_min, RTC_REG_MIN); RTC_WRITE(tm->tm_hour, RTC_REG_HOUR); RTC_WRITE(tm->tm_mday, RTC_REG_DOM); RTC_WRITE(tm->tm_mon + 1, RTC_REG_MONTH); RTC_WRITE(tm->tm_year % 100, RTC_REG_YEAR); RTC_WRITE(tm->tm_wday, RTC_REG_DOW); } else { /* bcd mode */ RTC_WRITE(bin2bcd(tm->tm_sec), RTC_REG_SEC); RTC_WRITE(bin2bcd(tm->tm_min), RTC_REG_MIN); RTC_WRITE(bin2bcd(tm->tm_hour), RTC_REG_HOUR); RTC_WRITE(bin2bcd(tm->tm_mday), RTC_REG_DOM); RTC_WRITE(bin2bcd(tm->tm_mon + 1), RTC_REG_MONTH); RTC_WRITE(bin2bcd(tm->tm_year % 100), RTC_REG_YEAR); RTC_WRITE(bin2bcd(tm->tm_wday), RTC_REG_DOW); } /* update ended */ reg &= ~RTC_REG_B_SET; RTC_WRITE(reg, RTC_REG_B); return 0; } #if defined(CONFIG_IBM_RTC_ALARM) /* * Read alarm time and date in RTC */ static int ibm_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { unsigned char reg; //struct platform_device *pdev = to_platform_device(dev); struct rtc_time *tm = &alrm->time; DBG2(dev, "ibm_rtc_read_time" NL); reg = RTC_READ(RTC_REG_B); if (reg & RTC_REG_B_DM) { /* data (binary) mode */ tm->tm_sec = RTC_READ(RTC_REG_SECALRM); tm->tm_min = RTC_READ(RTC_REG_MINALRM); tm->tm_hour = RTC_READ(RTC_REG_HOURALRM) & 0x3F; tm->tm_mday = RTC_READ(RTC_REG_DOM); /* tm_mon is 0-11 */ tm->tm_mon = RTC_READ(RTC_REG_MONTH) - 1; tm->tm_year = RTC_READ(RTC_REG_YEAR) + 100; tm->tm_wday = RTC_READ(RTC_REG_DOW); } else { /* bcd mode */ tm->tm_sec = bcd2bin(RTC_READ(RTC_REG_SECALRM)); tm->tm_min = bcd2bin(RTC_READ(RTC_REG_MINALRM)); tm->tm_hour = bcd2bin(RTC_READ(RTC_REG_HOURALRM) & 0x3F); tm->tm_mday = bcd2bin(RTC_READ(RTC_REG_DOM)); /* tm_mon is 0-11 */ tm->tm_mon = bcd2bin(RTC_READ(RTC_REG_MONTH)) - 1; tm->tm_year = bcd2bin(RTC_READ(RTC_REG_YEAR)) + 100; tm->tm_wday = bcd2bin(RTC_READ(RTC_REG_DOW)); } /* correct the hour if the clock is in 12h mode */ if (!(reg & RTC_REG_B_H24)) if (RTC_READ(RTC_REG_HOUR) & 0x80) tm->tm_hour += 12; return 0; } /* * Set alarm in RTC */ static int ibm_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { unsigned char reg; struct platform_device *pdev = to_platform_device(dev); struct ibm_rtc_instance *rtc = platform_get_drvdata(pdev); struct rtc_time *tm = &alrm->time; /* If no irq, we don't support ALARM */ if (rtc->irq == NO_IRQ) return -EIO; reg = RTC_READ(RTC_REG_B); /* update flag and 24h mode */ reg |= RTC_REG_B_SET | RTC_REG_B_H24; RTC_WRITE(reg, RTC_REG_B); if (reg & RTC_REG_B_DM) { /* data (binary) mode */ RTC_WRITE(tm->tm_sec, RTC_REG_SECALRM); RTC_WRITE(tm->tm_min, RTC_REG_MINALRM); RTC_WRITE(tm->tm_hour, RTC_REG_HOURALRM); RTC_WRITE(tm->tm_mday, RTC_REG_DOM); RTC_WRITE(tm->tm_mon + 1, RTC_REG_MONTH); RTC_WRITE(tm->tm_year % 100, RTC_REG_YEAR); RTC_WRITE(tm->tm_wday, RTC_REG_DOW); } else { /* bcd mode */ RTC_WRITE(bin2bcd(tm->tm_sec), RTC_REG_SECALRM); RTC_WRITE(bin2bcd(tm->tm_min), RTC_REG_MINALRM); RTC_WRITE(bin2bcd(tm->tm_hour), RTC_REG_HOURALRM); RTC_WRITE(bin2bcd(tm->tm_mday), RTC_REG_DOM); RTC_WRITE(bin2bcd(tm->tm_mon + 1), RTC_REG_MONTH); RTC_WRITE(bin2bcd(tm->tm_year % 100), RTC_REG_YEAR); RTC_WRITE(bin2bcd(tm->tm_wday), RTC_REG_DOW); } /* update ended */ reg &= ~RTC_REG_B_SET; RTC_WRITE(reg, RTC_REG_B); return 0; } #endif //CONFIG_IBM_RTC_ALARM /* * Handle commands from user-space */ static int ibm_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { unsigned char r; struct platform_device *pdev = to_platform_device(dev); struct ibm_rtc_instance *rtc = platform_get_drvdata(pdev); unsigned long flags; int ret = 0; spin_lock_irqsave(&rtc->lock, flags); r = RTC_READ(RTC_REG_B); switch (cmd) { case RTC_AIE_OFF: /* alarm interrupt off */ r &= ~RTC_REG_AF; break; case RTC_AIE_ON: /* alarm interrupt on */ r |= RTC_REG_AF; break; case RTC_UIE_OFF: /* update interrupt off */ r &= ~RTC_REG_UF; break; case RTC_UIE_ON: /* update interrupt on */ r |= RTC_REG_UF; break; case RTC_PIE_OFF: /* periodic interrupt off */ r &= ~RTC_REG_PF; break; case RTC_PIE_ON: /* periodic interrupt on */ r |= RTC_REG_PF; break; default: ret = -ENOIOCTLCMD; break; } RTC_WRITE(r, RTC_REG_B); spin_unlock_irqrestore(&rtc->lock, flags); return ret; } static int ibm_rtc_proc(struct device *dev, struct seq_file *seq) { unsigned char reg; //struct platform_device *pdev = to_platform_device(dev); DBG(dev, "ibm_rtc_proc" NL); reg = RTC_READ(RTC_REG_B); seq_printf(seq, "mode\t\t: %s\n", (reg & RTC_REG_B_DM) ? "binary" : "bcd"); reg = RTC_READ(RTC_REG_D); seq_printf(seq, "battery\t\t: %s\n", (reg & RTC_REG_D_VRT) ? "ok" : "exhausted"); return 0; } /* * IRQ handler for the RTC */ static irqreturn_t ibm_rtc_interrupt(int irq, void *dev_id) { unsigned char reg; struct platform_device *pdev = to_platform_device((struct device *)dev_id); struct ibm_rtc_instance *dev = platform_get_drvdata(pdev); unsigned char events = RTC_IRQF; /* * read and clear interrupt */ spin_lock(&dev->lock); reg = RTC_READ(RTC_REG_C); spin_unlock(&dev->lock); DBG(dev, "RTC_REG_C = %04x" NL, reg); if (reg & RTC_REG_PF) events|= RTC_PF; if (reg & RTC_REG_AF) events|= RTC_AF; if (reg & RTC_REG_UF) events|= RTC_UF; rtc_update_irq(dev->rtc, 1, events); return IRQ_HANDLED; } static const struct rtc_class_ops ibm_rtc_ops = { .ioctl = ibm_rtc_ioctl, .read_time = ibm_rtc_read_time, .set_time = ibm_rtc_set_time, #if defined(CONFIG_IBM_RTC_ALARM) .read_alarm = ibm_rtc_read_alarm, .set_alarm = ibm_rtc_set_alarm, #endif .proc = ibm_rtc_proc, }; static int ibm_rtc_probe(struct of_device *ofdev, const struct of_device_id *match) { unsigned char reg; struct platform_device *pdev = &ofdev->dev; struct ibm_rtc_instance *dev = platform_get_drvdata(pdev); struct device_node *np = ofdev->node; struct rtc_device *rtc; int err; DBG(dev, "ibm_rtc_probe" NL); /* * Skip unused/unwired RTC. */ if (of_get_property(np, "unused", NULL) || !of_device_is_available(np)) return -ENODEV; /* Allocate RTC device */ dev = kmalloc(sizeof(struct ibm_rtc_instance), GFP_KERNEL); if (dev == NULL) { dev_err(&ofdev->dev, "kmalloc failed for dev\n"); err = -ENOMEM; goto out; } memset(dev, 0, sizeof(struct ibm_rtc_instance)); rtc = rtc_device_register("ibm_rtc", &ofdev->dev, &ibm_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) return PTR_ERR(rtc); dev->rtc = rtc; dev->ofdev = ofdev; /* Try to get irq number. We also can work in * the mode without IRQ. */ dev->irq = irq_of_parse_and_map(np, 0); if (dev->irq == NO_IRQ) { printk(KERN_ERR "%s: Can't map main interrupt\n", np->full_name); err = -ENODEV; goto out; } if (dev->irq != NO_IRQ) { err = request_irq(dev->irq, ibm_rtc_interrupt, IRQF_SHARED, "IBM RTC", &ofdev->dev); if (err) goto out; } dev_set_drvdata(&ofdev->dev, dev); /* read battery status */ reg = RTC_READ(RTC_REG_D); dev_info(&ofdev->dev, "battery %s\n", (reg & RTC_REG_D_VRT) ? "ok" : "exhausted"); return 0; out: return err; } static int ibm_rtc_remove(struct of_device *ofdev) { struct platform_device *pdev = &ofdev->dev; struct ibm_rtc_instance *dev = platform_get_drvdata(pdev); struct rtc_device *rtc = dev->rtc; DBG(dev, "ibm_rtc_remove" NL); dev_set_drvdata(&ofdev->dev, NULL); if (rtc) rtc_device_unregister(rtc); return 0; } static const struct of_device_id ibm_rtc_match[] = { { .compatible = "ibm,rtc", }, {} }; static struct of_platform_driver ibm_rtc_platform_driver = { .name = "ibm-rtc", .match_table = ibm_rtc_match, .probe = ibm_rtc_probe, .remove = ibm_rtc_remove, }; static int __init ibm_rtc_init(void) { return of_register_platform_driver(&ibm_rtc_platform_driver); } static void __exit ibm_rtc_exit(void) { of_unregister_platform_driver(&ibm_rtc_platform_driver); } MODULE_AUTHOR("Duy Nguyen "); MODULE_DESCRIPTION("IBM RTC driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_VERSION); MODULE_ALIAS("platform:ibm-rtc"); module_init(ibm_rtc_init); module_exit(ibm_rtc_exit);