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 }; 31 32 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload, 33 unsigned short *delete) 34 { 35 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev); 36 unsigned long comp; 37 38 comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP); 39 40 if (preload) 41 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK) 42 >> EP93XX_RTC_SWCOMP_INT_SHIFT; 43 44 if (delete) 45 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK) 46 >> EP93XX_RTC_SWCOMP_DEL_SHIFT; 47 48 return 0; 49 } 50 51 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm) 52 { 53 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev); 54 unsigned long time; 55 56 time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA); 57 58 rtc_time64_to_tm(time, tm); 59 return 0; 60 } 61 62 static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm) 63 { 64 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev); 65 unsigned long secs = rtc_tm_to_time64(tm); 66 67 writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD); 68 return 0; 69 } 70 71 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq) 72 { 73 unsigned short preload, delete; 74 75 ep93xx_rtc_get_swcomp(dev, &preload, &delete); 76 77 seq_printf(seq, "preload\t\t: %d\n", preload); 78 seq_printf(seq, "delete\t\t: %d\n", delete); 79 80 return 0; 81 } 82 83 static const struct rtc_class_ops ep93xx_rtc_ops = { 84 .read_time = ep93xx_rtc_read_time, 85 .set_time = ep93xx_rtc_set_time, 86 .proc = ep93xx_rtc_proc, 87 }; 88 89 static ssize_t comp_preload_show(struct device *dev, 90 struct device_attribute *attr, char *buf) 91 { 92 unsigned short preload; 93 94 ep93xx_rtc_get_swcomp(dev->parent, &preload, NULL); 95 96 return sprintf(buf, "%d\n", preload); 97 } 98 static DEVICE_ATTR_RO(comp_preload); 99 100 static ssize_t comp_delete_show(struct device *dev, 101 struct device_attribute *attr, char *buf) 102 { 103 unsigned short delete; 104 105 ep93xx_rtc_get_swcomp(dev->parent, NULL, &delete); 106 107 return sprintf(buf, "%d\n", delete); 108 } 109 static DEVICE_ATTR_RO(comp_delete); 110 111 static struct attribute *ep93xx_rtc_attrs[] = { 112 &dev_attr_comp_preload.attr, 113 &dev_attr_comp_delete.attr, 114 NULL 115 }; 116 117 static const struct attribute_group ep93xx_rtc_sysfs_files = { 118 .attrs = ep93xx_rtc_attrs, 119 }; 120 121 static int ep93xx_rtc_probe(struct platform_device *pdev) 122 { 123 struct ep93xx_rtc *ep93xx_rtc; 124 struct rtc_device *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 rtc = devm_rtc_allocate_device(&pdev->dev); 138 if (IS_ERR(rtc)) 139 return PTR_ERR(rtc); 140 141 rtc->ops = &ep93xx_rtc_ops; 142 rtc->range_max = U32_MAX; 143 144 err = rtc_add_group(rtc, &ep93xx_rtc_sysfs_files); 145 if (err) 146 return err; 147 148 return devm_rtc_register_device(rtc); 149 } 150 151 static const struct of_device_id ep93xx_rtc_of_ids[] = { 152 { .compatible = "cirrus,ep9301-rtc" }, 153 { /* sentinel */ } 154 }; 155 MODULE_DEVICE_TABLE(of, ep93xx_rtc_of_ids); 156 157 static struct platform_driver ep93xx_rtc_driver = { 158 .driver = { 159 .name = "ep93xx-rtc", 160 .of_match_table = ep93xx_rtc_of_ids, 161 }, 162 .probe = ep93xx_rtc_probe, 163 }; 164 165 module_platform_driver(ep93xx_rtc_driver); 166 167 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 168 MODULE_DESCRIPTION("EP93XX RTC driver"); 169 MODULE_LICENSE("GPL"); 170 MODULE_ALIAS("platform:ep93xx-rtc"); 171