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 #define DRV_VERSION "0.3" 32 33 /* 34 * struct device dev.platform_data is used to store our private data 35 * because struct rtc_device does not have a variable to hold it. 36 */ 37 struct ep93xx_rtc { 38 void __iomem *mmio_base; 39 struct rtc_device *rtc; 40 }; 41 42 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload, 43 unsigned short *delete) 44 { 45 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data; 46 unsigned long comp; 47 48 comp = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP); 49 50 if (preload) 51 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK) 52 >> EP93XX_RTC_SWCOMP_INT_SHIFT; 53 54 if (delete) 55 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK) 56 >> EP93XX_RTC_SWCOMP_DEL_SHIFT; 57 58 return 0; 59 } 60 61 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm) 62 { 63 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data; 64 unsigned long time; 65 66 time = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA); 67 68 rtc_time_to_tm(time, tm); 69 return 0; 70 } 71 72 static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs) 73 { 74 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data; 75 76 __raw_writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD); 77 return 0; 78 } 79 80 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq) 81 { 82 unsigned short preload, delete; 83 84 ep93xx_rtc_get_swcomp(dev, &preload, &delete); 85 86 seq_printf(seq, "preload\t\t: %d\n", preload); 87 seq_printf(seq, "delete\t\t: %d\n", delete); 88 89 return 0; 90 } 91 92 static const struct rtc_class_ops ep93xx_rtc_ops = { 93 .read_time = ep93xx_rtc_read_time, 94 .set_mmss = ep93xx_rtc_set_mmss, 95 .proc = ep93xx_rtc_proc, 96 }; 97 98 static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev, 99 struct device_attribute *attr, char *buf) 100 { 101 unsigned short preload; 102 103 ep93xx_rtc_get_swcomp(dev, &preload, NULL); 104 105 return sprintf(buf, "%d\n", preload); 106 } 107 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL); 108 109 static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev, 110 struct device_attribute *attr, char *buf) 111 { 112 unsigned short delete; 113 114 ep93xx_rtc_get_swcomp(dev, NULL, &delete); 115 116 return sprintf(buf, "%d\n", delete); 117 } 118 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL); 119 120 static struct attribute *ep93xx_rtc_attrs[] = { 121 &dev_attr_comp_preload.attr, 122 &dev_attr_comp_delete.attr, 123 NULL 124 }; 125 126 static const struct attribute_group ep93xx_rtc_sysfs_files = { 127 .attrs = ep93xx_rtc_attrs, 128 }; 129 130 static int ep93xx_rtc_probe(struct platform_device *pdev) 131 { 132 struct ep93xx_rtc *ep93xx_rtc; 133 struct resource *res; 134 int err; 135 136 ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL); 137 if (!ep93xx_rtc) 138 return -ENOMEM; 139 140 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 141 ep93xx_rtc->mmio_base = devm_ioremap_resource(&pdev->dev, res); 142 if (IS_ERR(ep93xx_rtc->mmio_base)) 143 return PTR_ERR(ep93xx_rtc->mmio_base); 144 145 pdev->dev.platform_data = ep93xx_rtc; 146 platform_set_drvdata(pdev, ep93xx_rtc); 147 148 ep93xx_rtc->rtc = devm_rtc_device_register(&pdev->dev, 149 pdev->name, &ep93xx_rtc_ops, THIS_MODULE); 150 if (IS_ERR(ep93xx_rtc->rtc)) { 151 err = PTR_ERR(ep93xx_rtc->rtc); 152 goto exit; 153 } 154 155 err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files); 156 if (err) 157 goto exit; 158 159 return 0; 160 161 exit: 162 pdev->dev.platform_data = NULL; 163 return err; 164 } 165 166 static int ep93xx_rtc_remove(struct platform_device *pdev) 167 { 168 sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files); 169 pdev->dev.platform_data = NULL; 170 171 return 0; 172 } 173 174 static struct platform_driver ep93xx_rtc_driver = { 175 .driver = { 176 .name = "ep93xx-rtc", 177 .owner = THIS_MODULE, 178 }, 179 .probe = ep93xx_rtc_probe, 180 .remove = ep93xx_rtc_remove, 181 }; 182 183 module_platform_driver(ep93xx_rtc_driver); 184 185 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 186 MODULE_DESCRIPTION("EP93XX RTC driver"); 187 MODULE_LICENSE("GPL"); 188 MODULE_VERSION(DRV_VERSION); 189 MODULE_ALIAS("platform:ep93xx-rtc"); 190