// SPDX-License-Identifier: GPL-2.0-only
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/* rtc-bq4802.c: TI BQ4802 RTC driver.
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*
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* Copyright (C) 2008 David S. Miller <davem@davemloft.net>
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/platform_device.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <linux/slab.h>
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MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
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MODULE_DESCRIPTION("TI BQ4802 RTC driver");
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MODULE_LICENSE("GPL");
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struct bq4802 {
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void __iomem *regs;
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unsigned long ioport;
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struct rtc_device *rtc;
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spinlock_t lock;
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struct resource *r;
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u8 (*read)(struct bq4802 *, int);
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void (*write)(struct bq4802 *, int, u8);
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};
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static u8 bq4802_read_io(struct bq4802 *p, int off)
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{
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return inb(p->ioport + off);
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}
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static void bq4802_write_io(struct bq4802 *p, int off, u8 val)
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{
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outb(val, p->ioport + off);
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}
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static u8 bq4802_read_mem(struct bq4802 *p, int off)
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{
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return readb(p->regs + off);
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}
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static void bq4802_write_mem(struct bq4802 *p, int off, u8 val)
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{
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writeb(val, p->regs + off);
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}
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static int bq4802_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct bq4802 *p = dev_get_drvdata(dev);
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unsigned long flags;
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unsigned int century;
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u8 val;
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spin_lock_irqsave(&p->lock, flags);
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val = p->read(p, 0x0e);
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p->write(p, 0xe, val | 0x08);
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tm->tm_sec = p->read(p, 0x00);
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tm->tm_min = p->read(p, 0x02);
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tm->tm_hour = p->read(p, 0x04);
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tm->tm_mday = p->read(p, 0x06);
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tm->tm_mon = p->read(p, 0x09);
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tm->tm_year = p->read(p, 0x0a);
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tm->tm_wday = p->read(p, 0x08);
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century = p->read(p, 0x0f);
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p->write(p, 0x0e, val);
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spin_unlock_irqrestore(&p->lock, flags);
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tm->tm_sec = bcd2bin(tm->tm_sec);
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tm->tm_min = bcd2bin(tm->tm_min);
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tm->tm_hour = bcd2bin(tm->tm_hour);
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tm->tm_mday = bcd2bin(tm->tm_mday);
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tm->tm_mon = bcd2bin(tm->tm_mon);
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tm->tm_year = bcd2bin(tm->tm_year);
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tm->tm_wday = bcd2bin(tm->tm_wday);
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century = bcd2bin(century);
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tm->tm_year += (century * 100);
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tm->tm_year -= 1900;
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tm->tm_mon--;
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return 0;
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}
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static int bq4802_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct bq4802 *p = dev_get_drvdata(dev);
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u8 sec, min, hrs, day, mon, yrs, century, val;
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unsigned long flags;
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unsigned int year;
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year = tm->tm_year + 1900;
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century = year / 100;
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yrs = year % 100;
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mon = tm->tm_mon + 1; /* tm_mon starts at zero */
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day = tm->tm_mday;
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hrs = tm->tm_hour;
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min = tm->tm_min;
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sec = tm->tm_sec;
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sec = bin2bcd(sec);
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min = bin2bcd(min);
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hrs = bin2bcd(hrs);
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day = bin2bcd(day);
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mon = bin2bcd(mon);
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yrs = bin2bcd(yrs);
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century = bin2bcd(century);
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spin_lock_irqsave(&p->lock, flags);
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val = p->read(p, 0x0e);
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p->write(p, 0x0e, val | 0x08);
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p->write(p, 0x00, sec);
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p->write(p, 0x02, min);
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p->write(p, 0x04, hrs);
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p->write(p, 0x06, day);
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p->write(p, 0x09, mon);
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p->write(p, 0x0a, yrs);
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p->write(p, 0x0f, century);
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p->write(p, 0x0e, val);
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spin_unlock_irqrestore(&p->lock, flags);
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return 0;
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}
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static const struct rtc_class_ops bq4802_ops = {
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.read_time = bq4802_read_time,
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.set_time = bq4802_set_time,
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};
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static int bq4802_probe(struct platform_device *pdev)
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{
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struct bq4802 *p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
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int err = -ENOMEM;
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if (!p)
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goto out;
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spin_lock_init(&p->lock);
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p->r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!p->r) {
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p->r = platform_get_resource(pdev, IORESOURCE_IO, 0);
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err = -EINVAL;
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if (!p->r)
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goto out;
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}
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if (p->r->flags & IORESOURCE_IO) {
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p->ioport = p->r->start;
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p->read = bq4802_read_io;
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p->write = bq4802_write_io;
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} else if (p->r->flags & IORESOURCE_MEM) {
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p->regs = devm_ioremap(&pdev->dev, p->r->start,
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resource_size(p->r));
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if (!p->regs){
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err = -ENOMEM;
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goto out;
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}
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p->read = bq4802_read_mem;
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p->write = bq4802_write_mem;
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} else {
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err = -EINVAL;
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goto out;
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}
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platform_set_drvdata(pdev, p);
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p->rtc = devm_rtc_device_register(&pdev->dev, "bq4802",
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&bq4802_ops, THIS_MODULE);
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if (IS_ERR(p->rtc)) {
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err = PTR_ERR(p->rtc);
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goto out;
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}
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err = 0;
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out:
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return err;
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}
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/* work with hotplug and coldplug */
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MODULE_ALIAS("platform:rtc-bq4802");
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static struct platform_driver bq4802_driver = {
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.driver = {
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.name = "rtc-bq4802",
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},
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.probe = bq4802_probe,
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};
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module_platform_driver(bq4802_driver);
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