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/mod_devicetable.h> 11 #include <linux/rtc.h> 12 #include <linux/platform_device.h> 13 #include <linux/io.h> 14 #include <linux/gfp.h> 15 16 #define EP93XX_RTC_DATA 0x000 17 #define EP93XX_RTC_MATCH 0x004 18 #define EP93XX_RTC_STATUS 0x008 19 #define EP93XX_RTC_STATUS_INTR BIT(0) 20 #define EP93XX_RTC_LOAD 0x00C 21 #define EP93XX_RTC_CONTROL 0x010 22 #define EP93XX_RTC_CONTROL_MIE BIT(0) 23 #define EP93XX_RTC_SWCOMP 0x108 24 #define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f0000 25 #define EP93XX_RTC_SWCOMP_DEL_SHIFT 16 26 #define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff 27 #define EP93XX_RTC_SWCOMP_INT_SHIFT 0 28 29 struct ep93xx_rtc { 30 void __iomem *mmio_base; 31 struct rtc_device *rtc; 32 }; 33 34 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload, 35 unsigned short *delete) 36 { 37 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev); 38 unsigned long comp; 39 40 comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP); 41 42 if (preload) 43 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK) 44 >> EP93XX_RTC_SWCOMP_INT_SHIFT; 45 46 if (delete) 47 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK) 48 >> EP93XX_RTC_SWCOMP_DEL_SHIFT; 49 50 return 0; 51 } 52 53 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm) 54 { 55 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev); 56 unsigned long time; 57 58 time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA); 59 60 rtc_time64_to_tm(time, tm); 61 return 0; 62 } 63 64 static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm) 65 { 66 struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev); 67 unsigned long secs = rtc_tm_to_time64(tm); 68 69 writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD); 70 return 0; 71 } 72 73 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq) 74 { 75 unsigned short preload, delete; 76 77 ep93xx_rtc_get_swcomp(dev, &preload, &delete); 78 79 seq_printf(seq, "preload\t\t: %d\n", preload); 80 seq_printf(seq, "delete\t\t: %d\n", delete); 81 82 return 0; 83 } 84 85 static const struct rtc_class_ops ep93xx_rtc_ops = { 86 .read_time = ep93xx_rtc_read_time, 87 .set_time = ep93xx_rtc_set_time, 88 .proc = ep93xx_rtc_proc, 89 }; 90 91 static ssize_t comp_preload_show(struct device *dev, 92 struct device_attribute *attr, char *buf) 93 { 94 unsigned short preload; 95 96 ep93xx_rtc_get_swcomp(dev->parent, &preload, NULL); 97 98 return sprintf(buf, "%d\n", preload); 99 } 100 static DEVICE_ATTR_RO(comp_preload); 101 102 static ssize_t comp_delete_show(struct device *dev, 103 struct device_attribute *attr, char *buf) 104 { 105 unsigned short delete; 106 107 ep93xx_rtc_get_swcomp(dev->parent, NULL, &delete); 108 109 return sprintf(buf, "%d\n", delete); 110 } 111 static DEVICE_ATTR_RO(comp_delete); 112 113 static struct attribute *ep93xx_rtc_attrs[] = { 114 &dev_attr_comp_preload.attr, 115 &dev_attr_comp_delete.attr, 116 NULL 117 }; 118 119 static const struct attribute_group ep93xx_rtc_sysfs_files = { 120 .attrs = ep93xx_rtc_attrs, 121 }; 122 123 static int ep93xx_rtc_probe(struct platform_device *pdev) 124 { 125 struct ep93xx_rtc *ep93xx_rtc; 126 int err; 127 128 ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL); 129 if (!ep93xx_rtc) 130 return -ENOMEM; 131 132 ep93xx_rtc->mmio_base = devm_platform_ioremap_resource(pdev, 0); 133 if (IS_ERR(ep93xx_rtc->mmio_base)) 134 return PTR_ERR(ep93xx_rtc->mmio_base); 135 136 platform_set_drvdata(pdev, ep93xx_rtc); 137 138 ep93xx_rtc->rtc = devm_rtc_allocate_device(&pdev->dev); 139 if (IS_ERR(ep93xx_rtc->rtc)) 140 return PTR_ERR(ep93xx_rtc->rtc); 141 142 ep93xx_rtc->rtc->ops = &ep93xx_rtc_ops; 143 ep93xx_rtc->rtc->range_max = U32_MAX; 144 145 err = rtc_add_group(ep93xx_rtc->rtc, &ep93xx_rtc_sysfs_files); 146 if (err) 147 return err; 148 149 return devm_rtc_register_device(ep93xx_rtc->rtc); 150 } 151 152 static const struct of_device_id ep93xx_rtc_of_ids[] = { 153 { .compatible = "cirrus,ep9301-rtc" }, 154 { /* sentinel */ } 155 }; 156 MODULE_DEVICE_TABLE(of, ep93xx_rtc_of_ids); 157 158 static struct platform_driver ep93xx_rtc_driver = { 159 .driver = { 160 .name = "ep93xx-rtc", 161 .of_match_table = ep93xx_rtc_of_ids, 162 }, 163 .probe = ep93xx_rtc_probe, 164 }; 165 166 module_platform_driver(ep93xx_rtc_driver); 167 168 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 169 MODULE_DESCRIPTION("EP93XX RTC driver"); 170 MODULE_LICENSE("GPL"); 171 MODULE_ALIAS("platform:ep93xx-rtc"); 172