/* rtc-bq4802.c: TI BQ4802 RTC driver. * * Copyright (C) 2008 David S. Miller <davem@davemloft.net> */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/io.h> #include <linux/platform_device.h> #include <linux/rtc.h> #include <linux/bcd.h> #include <linux/slab.h> MODULE_AUTHOR("David S. Miller <davem@davemloft.net>"); MODULE_DESCRIPTION("TI BQ4802 RTC driver"); MODULE_LICENSE("GPL"); struct bq4802 { void __iomem *regs; unsigned long ioport; struct rtc_device *rtc; spinlock_t lock; struct resource *r; u8 (*read)(struct bq4802 *, int); void (*write)(struct bq4802 *, int, u8); }; static u8 bq4802_read_io(struct bq4802 *p, int off) { return inb(p->ioport + off); } static void bq4802_write_io(struct bq4802 *p, int off, u8 val) { outb(val, p->ioport + off); } static u8 bq4802_read_mem(struct bq4802 *p, int off) { return readb(p->regs + off); } static void bq4802_write_mem(struct bq4802 *p, int off, u8 val) { writeb(val, p->regs + off); } static int bq4802_read_time(struct device *dev, struct rtc_time *tm) { struct platform_device *pdev = to_platform_device(dev); struct bq4802 *p = platform_get_drvdata(pdev); unsigned long flags; unsigned int century; u8 val; spin_lock_irqsave(&p->lock, flags); val = p->read(p, 0x0e); p->write(p, 0xe, val | 0x08); tm->tm_sec = p->read(p, 0x00); tm->tm_min = p->read(p, 0x02); tm->tm_hour = p->read(p, 0x04); tm->tm_mday = p->read(p, 0x06); tm->tm_mon = p->read(p, 0x09); tm->tm_year = p->read(p, 0x0a); tm->tm_wday = p->read(p, 0x08); century = p->read(p, 0x0f); p->write(p, 0x0e, val); spin_unlock_irqrestore(&p->lock, flags); tm->tm_sec = bcd2bin(tm->tm_sec); tm->tm_min = bcd2bin(tm->tm_min); tm->tm_hour = bcd2bin(tm->tm_hour); tm->tm_mday = bcd2bin(tm->tm_mday); tm->tm_mon = bcd2bin(tm->tm_mon); tm->tm_year = bcd2bin(tm->tm_year); tm->tm_wday = bcd2bin(tm->tm_wday); century = bcd2bin(century); tm->tm_year += (century * 100); tm->tm_year -= 1900; tm->tm_mon--; return 0; } static int bq4802_set_time(struct device *dev, struct rtc_time *tm) { struct platform_device *pdev = to_platform_device(dev); struct bq4802 *p = platform_get_drvdata(pdev); u8 sec, min, hrs, day, mon, yrs, century, val; unsigned long flags; unsigned int year; year = tm->tm_year + 1900; century = year / 100; yrs = year % 100; mon = tm->tm_mon + 1; /* tm_mon starts at zero */ day = tm->tm_mday; hrs = tm->tm_hour; min = tm->tm_min; sec = tm->tm_sec; sec = bin2bcd(sec); min = bin2bcd(min); hrs = bin2bcd(hrs); day = bin2bcd(day); mon = bin2bcd(mon); yrs = bin2bcd(yrs); century = bin2bcd(century); spin_lock_irqsave(&p->lock, flags); val = p->read(p, 0x0e); p->write(p, 0x0e, val | 0x08); p->write(p, 0x00, sec); p->write(p, 0x02, min); p->write(p, 0x04, hrs); p->write(p, 0x06, day); p->write(p, 0x09, mon); p->write(p, 0x0a, yrs); p->write(p, 0x0f, century); p->write(p, 0x0e, val); spin_unlock_irqrestore(&p->lock, flags); return 0; } static const struct rtc_class_ops bq4802_ops = { .read_time = bq4802_read_time, .set_time = bq4802_set_time, }; static int bq4802_probe(struct platform_device *pdev) { struct bq4802 *p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL); int err = -ENOMEM; if (!p) goto out; spin_lock_init(&p->lock); p->r = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!p->r) { p->r = platform_get_resource(pdev, IORESOURCE_IO, 0); err = -EINVAL; if (!p->r) goto out; } if (p->r->flags & IORESOURCE_IO) { p->ioport = p->r->start; p->read = bq4802_read_io; p->write = bq4802_write_io; } else if (p->r->flags & IORESOURCE_MEM) { p->regs = devm_ioremap(&pdev->dev, p->r->start, resource_size(p->r)); p->read = bq4802_read_mem; p->write = bq4802_write_mem; } else { err = -EINVAL; goto out; } platform_set_drvdata(pdev, p); p->rtc = devm_rtc_device_register(&pdev->dev, "bq4802", &bq4802_ops, THIS_MODULE); if (IS_ERR(p->rtc)) { err = PTR_ERR(p->rtc); goto out; } err = 0; out: return err; } /* work with hotplug and coldplug */ MODULE_ALIAS("platform:rtc-bq4802"); static struct platform_driver bq4802_driver = { .driver = { .name = "rtc-bq4802", .owner = THIS_MODULE, }, .probe = bq4802_probe, }; module_platform_driver(bq4802_driver);