mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 13:56:40 +07:00
9d1d4f9eab
Having a RTC that doesn't maintain proper time across a reboot is one thing. But a RTC that doesn't work at all and only causes timeouts is another. Tested-by: Martin Michlmayr <tbm@cyrius.com> Signed-off-by: Nicolas Pitre <nico@marvell.com>
175 lines
4.3 KiB
C
175 lines
4.3 KiB
C
/*
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* Driver for the RTC in Marvell SoCs.
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <linux/io.h>
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#include <linux/platform_device.h>
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#include <linux/delay.h>
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#define RTC_TIME_REG_OFFS 0
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#define RTC_SECONDS_OFFS 0
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#define RTC_MINUTES_OFFS 8
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#define RTC_HOURS_OFFS 16
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#define RTC_WDAY_OFFS 24
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#define RTC_HOURS_12H_MODE (1 << 22) /* 12 hours mode */
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#define RTC_DATE_REG_OFFS 4
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#define RTC_MDAY_OFFS 0
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#define RTC_MONTH_OFFS 8
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#define RTC_YEAR_OFFS 16
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struct rtc_plat_data {
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struct rtc_device *rtc;
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void __iomem *ioaddr;
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};
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static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct rtc_plat_data *pdata = dev_get_drvdata(dev);
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void __iomem *ioaddr = pdata->ioaddr;
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u32 rtc_reg;
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rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
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(bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
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(bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
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(bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
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writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
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rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
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(bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
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(bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS);
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writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
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return 0;
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}
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static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct rtc_plat_data *pdata = dev_get_drvdata(dev);
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void __iomem *ioaddr = pdata->ioaddr;
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u32 rtc_time, rtc_date;
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unsigned int year, month, day, hour, minute, second, wday;
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rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
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rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
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second = rtc_time & 0x7f;
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minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
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hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */
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wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
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day = rtc_date & 0x3f;
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month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
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year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
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tm->tm_sec = bcd2bin(second);
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tm->tm_min = bcd2bin(minute);
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tm->tm_hour = bcd2bin(hour);
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tm->tm_mday = bcd2bin(day);
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tm->tm_wday = bcd2bin(wday);
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tm->tm_mon = bcd2bin(month) - 1;
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/* hw counts from year 2000, but tm_year is relative to 1900 */
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tm->tm_year = bcd2bin(year) + 100;
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return rtc_valid_tm(tm);
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}
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static const struct rtc_class_ops mv_rtc_ops = {
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.read_time = mv_rtc_read_time,
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.set_time = mv_rtc_set_time,
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};
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static int __init mv_rtc_probe(struct platform_device *pdev)
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{
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struct resource *res;
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struct rtc_plat_data *pdata;
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resource_size_t size;
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u32 rtc_time;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENODEV;
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pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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size = resource_size(res);
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if (!devm_request_mem_region(&pdev->dev, res->start, size,
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pdev->name))
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return -EBUSY;
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pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size);
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if (!pdata->ioaddr)
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return -ENOMEM;
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/* make sure the 24 hours mode is enabled */
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rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
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if (rtc_time & RTC_HOURS_12H_MODE) {
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dev_err(&pdev->dev, "24 Hours mode not supported.\n");
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return -EINVAL;
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}
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/* make sure it is actually functional */
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if (rtc_time == 0x01000000) {
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ssleep(1);
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rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
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if (rtc_time == 0x01000000) {
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dev_err(&pdev->dev, "internal RTC not ticking\n");
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return -ENODEV;
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}
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}
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platform_set_drvdata(pdev, pdata);
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pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
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&mv_rtc_ops, THIS_MODULE);
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if (IS_ERR(pdata->rtc))
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return PTR_ERR(pdata->rtc);
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return 0;
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}
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static int __exit mv_rtc_remove(struct platform_device *pdev)
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{
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struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
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rtc_device_unregister(pdata->rtc);
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return 0;
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}
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static struct platform_driver mv_rtc_driver = {
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.remove = __exit_p(mv_rtc_remove),
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.driver = {
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.name = "rtc-mv",
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.owner = THIS_MODULE,
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},
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};
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static __init int mv_init(void)
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{
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return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe);
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}
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static __exit void mv_exit(void)
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{
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platform_driver_unregister(&mv_rtc_driver);
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}
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module_init(mv_init);
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module_exit(mv_exit);
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MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
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MODULE_DESCRIPTION("Marvell RTC driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:rtc-mv");
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