1 /* 2 * A driver for the RTC embedded in the Cirrus Logic EP93XX processors 3 * Copyright (c) 2006 Tower Technologies 4 * 5 * Author: Alessandro Zummo <a.zummo@towertech.it> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/rtc.h> 14 #include <linux/platform_device.h> 15 #include <linux/io.h> 16 #include <linux/gfp.h> 17 18 #define EP93XX_RTC_DATA 0x000 19 #define EP93XX_RTC_MATCH 0x004 20 #define EP93XX_RTC_STATUS 0x008 21 #define EP93XX_RTC_STATUS_INTR (1<<0) 22 #define EP93XX_RTC_LOAD 0x00C 23 #define EP93XX_RTC_CONTROL 0x010 24 #define EP93XX_RTC_CONTROL_MIE (1<<0) 25 #define EP93XX_RTC_SWCOMP 0x108 26 #define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f0000 27 #define EP93XX_RTC_SWCOMP_DEL_SHIFT 16 28 #define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff 29 #define EP93XX_RTC_SWCOMP_INT_SHIFT 0 30 31 /* 32 * struct device dev.platform_data is used to store our private data 33 * because struct rtc_device does not have a variable to hold it. 34 */ 35 struct ep93xx_rtc { 36 void __iomem *mmio_base; 37 struct rtc_device *rtc; 38 }; 39 40 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload, 41 unsigned short *delete) 42 { 43 struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev); 44 unsigned long comp; 45 46 comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP); 47 48 if (preload) 49 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK) 50 >> EP93XX_RTC_SWCOMP_INT_SHIFT; 51 52 if (delete) 53 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK) 54 >> EP93XX_RTC_SWCOMP_DEL_SHIFT; 55 56 return 0; 57 } 58 59 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm) 60 { 61 struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev); 62 unsigned long time; 63 64 time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA); 65 66 rtc_time_to_tm(time, tm); 67 return 0; 68 } 69 70 static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs) 71 { 72 struct ep93xx_rtc *ep93xx_rtc = dev_get_platdata(dev); 73 74 writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD); 75 return 0; 76 } 77 78 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq) 79 { 80 unsigned short preload, delete; 81 82 ep93xx_rtc_get_swcomp(dev, &preload, &delete); 83 84 seq_printf(seq, "preload\t\t: %d\n", preload); 85 seq_printf(seq, "delete\t\t: %d\n", delete); 86 87 return 0; 88 } 89 90 static const struct rtc_class_ops ep93xx_rtc_ops = { 91 .read_time = ep93xx_rtc_read_time, 92 .set_mmss = ep93xx_rtc_set_mmss, 93 .proc = ep93xx_rtc_proc, 94 }; 95 96 static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev, 97 struct device_attribute *attr, char *buf) 98 { 99 unsigned short preload; 100 101 ep93xx_rtc_get_swcomp(dev, &preload, NULL); 102 103 return sprintf(buf, "%d\n", preload); 104 } 105 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL); 106 107 static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev, 108 struct device_attribute *attr, char *buf) 109 { 110 unsigned short delete; 111 112 ep93xx_rtc_get_swcomp(dev, NULL, &delete); 113 114 return sprintf(buf, "%d\n", delete); 115 } 116 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL); 117 118 static struct attribute *ep93xx_rtc_attrs[] = { 119 &dev_attr_comp_preload.attr, 120 &dev_attr_comp_delete.attr, 121 NULL 122 }; 123 124 static const struct attribute_group ep93xx_rtc_sysfs_files = { 125 .attrs = ep93xx_rtc_attrs, 126 }; 127 128 static int ep93xx_rtc_probe(struct platform_device *pdev) 129 { 130 struct ep93xx_rtc *ep93xx_rtc; 131 struct resource *res; 132 int err; 133 134 ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL); 135 if (!ep93xx_rtc) 136 return -ENOMEM; 137 138 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 139 ep93xx_rtc->mmio_base = devm_ioremap_resource(&pdev->dev, res); 140 if (IS_ERR(ep93xx_rtc->mmio_base)) 141 return PTR_ERR(ep93xx_rtc->mmio_base); 142 143 pdev->dev.platform_data = ep93xx_rtc; 144 platform_set_drvdata(pdev, ep93xx_rtc); 145 146 ep93xx_rtc->rtc = devm_rtc_device_register(&pdev->dev, 147 pdev->name, &ep93xx_rtc_ops, THIS_MODULE); 148 if (IS_ERR(ep93xx_rtc->rtc)) { 149 err = PTR_ERR(ep93xx_rtc->rtc); 150 goto exit; 151 } 152 153 err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files); 154 if (err) 155 goto exit; 156 157 return 0; 158 159 exit: 160 pdev->dev.platform_data = NULL; 161 return err; 162 } 163 164 static int ep93xx_rtc_remove(struct platform_device *pdev) 165 { 166 sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files); 167 pdev->dev.platform_data = NULL; 168 169 return 0; 170 } 171 172 static struct platform_driver ep93xx_rtc_driver = { 173 .driver = { 174 .name = "ep93xx-rtc", 175 }, 176 .probe = ep93xx_rtc_probe, 177 .remove = ep93xx_rtc_remove, 178 }; 179 180 module_platform_driver(ep93xx_rtc_driver); 181 182 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 183 MODULE_DESCRIPTION("EP93XX RTC driver"); 184 MODULE_LICENSE("GPL"); 185 MODULE_ALIAS("platform:ep93xx-rtc"); 186