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 #include <linux/delay.h> 16 17 18 #define RTC_TIME_REG_OFFS 0 19 #define RTC_SECONDS_OFFS 0 20 #define RTC_MINUTES_OFFS 8 21 #define RTC_HOURS_OFFS 16 22 #define RTC_WDAY_OFFS 24 23 #define RTC_HOURS_12H_MODE (1 << 22) /* 12 hours mode */ 24 25 #define RTC_DATE_REG_OFFS 4 26 #define RTC_MDAY_OFFS 0 27 #define RTC_MONTH_OFFS 8 28 #define RTC_YEAR_OFFS 16 29 30 31 struct rtc_plat_data { 32 struct rtc_device *rtc; 33 void __iomem *ioaddr; 34 }; 35 36 static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm) 37 { 38 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 39 void __iomem *ioaddr = pdata->ioaddr; 40 u32 rtc_reg; 41 42 rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) | 43 (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) | 44 (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) | 45 (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS); 46 writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS); 47 48 rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) | 49 (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) | 50 (bin2bcd(tm->tm_year % 100) << RTC_YEAR_OFFS); 51 writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS); 52 53 return 0; 54 } 55 56 static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm) 57 { 58 struct rtc_plat_data *pdata = dev_get_drvdata(dev); 59 void __iomem *ioaddr = pdata->ioaddr; 60 u32 rtc_time, rtc_date; 61 unsigned int year, month, day, hour, minute, second, wday; 62 63 rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS); 64 rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS); 65 66 second = rtc_time & 0x7f; 67 minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f; 68 hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hours mode */ 69 wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7; 70 71 day = rtc_date & 0x3f; 72 month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f; 73 year = (rtc_date >> RTC_YEAR_OFFS) & 0xff; 74 75 tm->tm_sec = bcd2bin(second); 76 tm->tm_min = bcd2bin(minute); 77 tm->tm_hour = bcd2bin(hour); 78 tm->tm_mday = bcd2bin(day); 79 tm->tm_wday = bcd2bin(wday); 80 tm->tm_mon = bcd2bin(month) - 1; 81 /* hw counts from year 2000, but tm_year is relative to 1900 */ 82 tm->tm_year = bcd2bin(year) + 100; 83 84 return rtc_valid_tm(tm); 85 } 86 87 static const struct rtc_class_ops mv_rtc_ops = { 88 .read_time = mv_rtc_read_time, 89 .set_time = mv_rtc_set_time, 90 }; 91 92 static int __init mv_rtc_probe(struct platform_device *pdev) 93 { 94 struct resource *res; 95 struct rtc_plat_data *pdata; 96 resource_size_t size; 97 u32 rtc_time; 98 99 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 100 if (!res) 101 return -ENODEV; 102 103 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 104 if (!pdata) 105 return -ENOMEM; 106 107 size = resource_size(res); 108 if (!devm_request_mem_region(&pdev->dev, res->start, size, 109 pdev->name)) 110 return -EBUSY; 111 112 pdata->ioaddr = devm_ioremap(&pdev->dev, res->start, size); 113 if (!pdata->ioaddr) 114 return -ENOMEM; 115 116 /* make sure the 24 hours mode is enabled */ 117 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); 118 if (rtc_time & RTC_HOURS_12H_MODE) { 119 dev_err(&pdev->dev, "24 Hours mode not supported.\n"); 120 return -EINVAL; 121 } 122 123 /* make sure it is actually functional */ 124 if (rtc_time == 0x01000000) { 125 ssleep(1); 126 rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); 127 if (rtc_time == 0x01000000) { 128 dev_err(&pdev->dev, "internal RTC not ticking\n"); 129 return -ENODEV; 130 } 131 } 132 133 platform_set_drvdata(pdev, pdata); 134 pdata->rtc = rtc_device_register(pdev->name, &pdev->dev, 135 &mv_rtc_ops, THIS_MODULE); 136 if (IS_ERR(pdata->rtc)) 137 return PTR_ERR(pdata->rtc); 138 139 return 0; 140 } 141 142 static int __exit mv_rtc_remove(struct platform_device *pdev) 143 { 144 struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 145 146 rtc_device_unregister(pdata->rtc); 147 return 0; 148 } 149 150 static struct platform_driver mv_rtc_driver = { 151 .remove = __exit_p(mv_rtc_remove), 152 .driver = { 153 .name = "rtc-mv", 154 .owner = THIS_MODULE, 155 }, 156 }; 157 158 static __init int mv_init(void) 159 { 160 return platform_driver_probe(&mv_rtc_driver, mv_rtc_probe); 161 } 162 163 static __exit void mv_exit(void) 164 { 165 platform_driver_unregister(&mv_rtc_driver); 166 } 167 168 module_init(mv_init); 169 module_exit(mv_exit); 170 171 MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>"); 172 MODULE_DESCRIPTION("Marvell RTC driver"); 173 MODULE_LICENSE("GPL"); 174 MODULE_ALIAS("platform:rtc-mv"); 175