diff options
Diffstat (limited to 'drivers/rtc/rtc-bq4802.c')
| -rw-r--r-- | drivers/rtc/rtc-bq4802.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-bq4802.c b/drivers/rtc/rtc-bq4802.c new file mode 100644 index 00000000000..541580cb6df --- /dev/null +++ b/drivers/rtc/rtc-bq4802.c @@ -0,0 +1,229 @@ +/* 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> + +MODULE_AUTHOR("David S. Miller <davem@davemloft.net>"); +MODULE_DESCRIPTION("TI BQ4802 RTC driver"); +MODULE_LICENSE("GPL"); + +struct bq4802 { + void __iomem *regs; + 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->regs + off); +} + +static void bq4802_write_io(struct bq4802 *p, int off, u8 val) +{ + return outb(val, p->regs + 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) +{ + return 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); + + BCD_TO_BIN(tm->tm_sec); + BCD_TO_BIN(tm->tm_min); + BCD_TO_BIN(tm->tm_hour); + BCD_TO_BIN(tm->tm_mday); + BCD_TO_BIN(tm->tm_mon); + BCD_TO_BIN(tm->tm_year); + BCD_TO_BIN(tm->tm_wday); + BCD_TO_BIN(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; + + BIN_TO_BCD(sec); + BIN_TO_BCD(min); + BIN_TO_BCD(hrs); + BIN_TO_BCD(day); + BIN_TO_BCD(mon); + BIN_TO_BCD(yrs); + BIN_TO_BCD(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 __devinit bq4802_probe(struct platform_device *pdev) +{ + struct bq4802 *p = kzalloc(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_free; + } + if (p->r->flags & IORESOURCE_IO) { + p->regs = (void __iomem *) p->r->start; + p->read = bq4802_read_io; + p->write = bq4802_write_io; + } else if (p->r->flags & IORESOURCE_MEM) { + p->regs = ioremap(p->r->start, resource_size(p->r)); + p->read = bq4802_read_mem; + p->write = bq4802_write_mem; + } else { + err = -EINVAL; + goto out_free; + } + + p->rtc = rtc_device_register("bq4802", &pdev->dev, + &bq4802_ops, THIS_MODULE); + if (IS_ERR(p->rtc)) { + err = PTR_ERR(p->rtc); + goto out_iounmap; + } + + platform_set_drvdata(pdev, p); + err = 0; +out: + return err; + +out_iounmap: + if (p->r->flags & IORESOURCE_MEM) + iounmap(p->regs); +out_free: + kfree(p); + goto out; +} + +static int __devexit bq4802_remove(struct platform_device *pdev) +{ + struct bq4802 *p = platform_get_drvdata(pdev); + + rtc_device_unregister(p->rtc); + if (p->r->flags & IORESOURCE_MEM) + iounmap(p->regs); + + platform_set_drvdata(pdev, NULL); + + kfree(p); + + return 0; +} + +/* 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, + .remove = __devexit_p(bq4802_remove), +}; + +static int __init bq4802_init(void) +{ + return platform_driver_register(&bq4802_driver); +} + +static void __exit bq4802_exit(void) +{ + platform_driver_unregister(&bq4802_driver); +} + +module_init(bq4802_init); +module_exit(bq4802_exit); |