1 /* 2 * Driver for the RTC in Marvell SoCs. 3 * 4 * This file is licensed under the terms of the GNU General Public 5 * License version 2. This program is licensed "as is" without any 6 * warranty of any kind, whether express or implied. 7 */ 8 9 #include <linux/init.h> 10 #include <linux/kernel.h> 11 #include <linux/rtc.h> 12 #include <linux/bcd.h> 13 #include <linux/io.h> 14 #include <linux/platform_device.h> 15 16 17 #define RTC_TIME_REG_OFFS 0 18 #define RTC_SECONDS_OFFS 0 19 #define RTC_MINUTES_OFFS 8 20 #define RTC_HOURS_OFFS 16 21 #define RTC_WDAY_OFFS 24 22 #define RTC_HOURS_12H_MODE (1 << 22) /* 12 hours mode */ 23 24 #define RTC_DATE_REG_OFFS 4 25 #define RTC_MDAY_OFFS 0 26 #define RTC_MONTH_OFFS 8 27 #define RTC_YEAR_OFFS 16 28 29 30 struct rtc_plat_data { 31 struct rtc_device *rtc; 32 void __iomem *ioaddr; 33 }; 34 35 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm) 36 { 37 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 38 void __iomem *ioaddr = pdata->ioaddr; 39 u32 rtc_reg; 40 41 rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) | 42 (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) | 43 (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) | 44 (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS); 45 writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS); 46 47 rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) | 48 (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) | 49 (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS); 50 writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS); 51 52 return 0; 53 } 54 55 static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm) 56 { 57 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 58 void __iomem *ioaddr = pdata->ioaddr; 59 u32 rtc_time, rtc_date; 60 unsigned int year, month, day, hour, minute, second, wday; 61 62 rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS); 63 rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS); 64 65 second = rtc_time & 0x7f; 66 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f; 67 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */ 68 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7; 69 70 day = rtc_date & 0x3f; 71 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f; 72 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff; 73 74 tm->tm_sec = bcd2bin(second); 75 tm->tm_min = bcd2bin(minute); 76 tm->tm_hour = bcd2bin(hour); 77 tm->tm_mday = bcd2bin(day); 78 tm->tm_wday = bcd2bin(wday); 79 tm->tm_mon = bcd2bin(month) - 1; 80 /* hw counts from year 2000, but tm_year is relative to 1900 */ 81 tm->tm_year = bcd2bin(year) + 100; 82 83 return rtc_valid_tm(tm); 84 } 85 86 static const struct rtc_class_ops mv_rtc_ops = { 87 .read_time = mv_rtc_read_time, 88 .set_time = mv_rtc_set_time, 89 }; 90 91 static int __init mv_rtc_probe(struct platform_device *pdev) 92 { 93 struct resource *res; 94 struct rtc_plat_data *pdata; 95 resource_size_t size; 96 u32 rtc_time; 97 98 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 99 if (!res) 100 return -ENODEV; 101 102 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 103 if (!pdata) 104 return -ENOMEM; 105 106 size = resource_size(res); 107 if (!devm_request_mem_region(&pdev->dev, res->start, size, 108 pdev->name)) 109 return -EBUSY; 110 111 pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size); 112 if (!pdata->ioaddr) 113 return -ENOMEM; 114 115 /* make sure the 24 hours mode is enabled */ 116 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); 117 if (rtc_time & RTC_HOURS_12H_MODE) { 118 dev_err(&pdev->dev, "24 Hours mode not supported.\n"); 119 return -EINVAL; 120 } 121 122 platform_set_drvdata(pdev, pdata); 123 pdata->rtc = rtc_device_register(pdev->name, &pdev->dev, 124 &mv_rtc_ops, THIS_MODULE); 125 if (IS_ERR(pdata->rtc)) 126 return PTR_ERR(pdata->rtc); 127 128 return 0; 129 } 130 131 static int __exit mv_rtc_remove(struct platform_device *pdev) 132 { 133 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 134 135 rtc_device_unregister(pdata->rtc); 136 return 0; 137 } 138 139 static struct platform_driver mv_rtc_driver = { 140 .remove = __exit_p(mv_rtc_remove), 141 .driver = { 142 .name = "rtc-mv", 143 .owner = THIS_MODULE, 144 }, 145 }; 146 147 static __init int mv_init(void) 148 { 149 return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe); 150 } 151 152 static __exit void mv_exit(void) 153 { 154 platform_driver_unregister(&mv_rtc_driver); 155 } 156 157 module_init(mv_init); 158 module_exit(mv_exit); 159 160 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>"); 161 MODULE_DESCRIPTION("Marvell RTC driver"); 162 MODULE_LICENSE("GPL"); 163 MODULE_ALIAS("platform:rtc-mv"); 164