1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * A driver for the RTC embedded in the Cirrus Logic EP93XX processors 4 * Copyright (c) 2006 Tower Technologies 5 * 6 * Author: Alessandro Zummo <a.zummo@towertech.it> 7 */ 8 9 #include <linux/module.h> 10 #include <linux/rtc.h> 11 #include <linux/platform_device.h> 12 #include <linux/io.h> 13 #include <linux/gfp.h> 14 15 #define EP93XX_RTC_DATA 0x000 16 #define EP93XX_RTC_MATCH 0x004 17 #define EP93XX_RTC_STATUS 0x008 18 #define EP93XX_RTC_STATUS_INTR BIT(0) 19 #define EP93XX_RTC_LOAD 0x00C 20 #define EP93XX_RTC_CONTROL 0x010 21 #define EP93XX_RTC_CONTROL_MIE BIT(0) 22 #define EP93XX_RTC_SWCOMP 0x108 23 #define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f0000 24 #define EP93XX_RTC_SWCOMP_DEL_SHIFT 16 25 #define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff 26 #define EP93XX_RTC_SWCOMP_INT_SHIFT 0 27 28 struct ep93xx_rtc { 29 void __iomem *mmio_base; 30 struct rtc_device *rtc; 31 }; 32 33 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload, 34 unsigned short *delete) 35 { 36 struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev); 37 unsigned long comp; 38 39 comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP); 40 41 if (preload) 42 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK) 43 >> EP93XX_RTC_SWCOMP_INT_SHIFT; 44 45 if (delete) 46 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK) 47 >> EP93XX_RTC_SWCOMP_DEL_SHIFT; 48 49 return 0; 50 } 51 52 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm) 53 { 54 struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev); 55 unsigned long time; 56 57 time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA); 58 59 rtc_time64_to_tm(time, tm); 60 return 0; 61 } 62 63 static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm) 64 { 65 struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev); 66 unsigned long secs = rtc_tm_to_time64(tm); 67 68 writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD); 69 return 0; 70 } 71 72 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq) 73 { 74 unsigned short preload, delete; 75 76 ep93xx_rtc_get_swcomp(dev, &preload, &delete); 77 78 seq_printf(seq, "preload\t\t: %d\n", preload); 79 seq_printf(seq, "delete\t\t: %d\n", delete); 80 81 return 0; 82 } 83 84 static const struct rtc_class_ops ep93xx_rtc_ops = { 85 .read_time = ep93xx_rtc_read_time, 86 .set_time = ep93xx_rtc_set_time, 87 .proc = ep93xx_rtc_proc, 88 }; 89 90 static ssize_t comp_preload_show(struct device *dev, 91 struct device_attribute *attr, char *buf) 92 { 93 unsigned short preload; 94 95 ep93xx_rtc_get_swcomp(dev->parent, &preload, NULL); 96 97 return sprintf(buf, "%d\n", preload); 98 } 99 static DEVICE_ATTR_RO(comp_preload); 100 101 static ssize_t comp_delete_show(struct device *dev, 102 struct device_attribute *attr, char *buf) 103 { 104 unsigned short delete; 105 106 ep93xx_rtc_get_swcomp(dev->parent, NULL, &delete); 107 108 return sprintf(buf, "%d\n", delete); 109 } 110 static DEVICE_ATTR_RO(comp_delete); 111 112 static struct attribute *ep93xx_rtc_attrs[] = { 113 &dev_attr_comp_preload.attr, 114 &dev_attr_comp_delete.attr, 115 NULL 116 }; 117 118 static const struct attribute_group ep93xx_rtc_sysfs_files = { 119 .attrs = ep93xx_rtc_attrs, 120 }; 121 122 static int ep93xx_rtc_probe(struct platform_device *pdev) 123 { 124 struct ep93xx_rtc *ep93xx_rtc; 125 int err; 126 127 ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL); 128 if (!ep93xx_rtc) 129 return -ENOMEM; 130 131 ep93xx_rtc->mmio_base = devm_platform_ioremap_resource(pdev, 0); 132 if (IS_ERR(ep93xx_rtc->mmio_base)) 133 return PTR_ERR(ep93xx_rtc->mmio_base); 134 135 platform_set_drvdata(pdev, ep93xx_rtc); 136 137 ep93xx_rtc->rtc = devm_rtc_allocate_device(&pdev->dev); 138 if (IS_ERR(ep93xx_rtc->rtc)) 139 return PTR_ERR(ep93xx_rtc->rtc); 140 141 ep93xx_rtc->rtc->ops = &ep93xx_rtc_ops; 142 ep93xx_rtc->rtc->range_max = U32_MAX; 143 144 err = rtc_add_group(ep93xx_rtc->rtc, &ep93xx_rtc_sysfs_files); 145 if (err) 146 return err; 147 148 return rtc_register_device(ep93xx_rtc->rtc); 149 } 150 151 static struct platform_driver ep93xx_rtc_driver = { 152 .driver = { 153 .name = "ep93xx-rtc", 154 }, 155 .probe = ep93xx_rtc_probe, 156 }; 157 158 module_platform_driver(ep93xx_rtc_driver); 159 160 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 161 MODULE_DESCRIPTION("EP93XX RTC driver"); 162 MODULE_LICENSE("GPL"); 163 MODULE_ALIAS("platform:ep93xx-rtc"); 164