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 }; 40 41 static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload, 42 unsigned short *delete) 43 { 44 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data; 45 unsigned long comp; 46 47 comp = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP); 48 49 if (preload) 50 *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK) 51 >> EP93XX_RTC_SWCOMP_INT_SHIFT; 52 53 if (delete) 54 *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK) 55 >> EP93XX_RTC_SWCOMP_DEL_SHIFT; 56 57 return 0; 58 } 59 60 static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm) 61 { 62 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data; 63 unsigned long time; 64 65 time = __raw_readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA); 66 67 rtc_time_to_tm(time, tm); 68 return 0; 69 } 70 71 static int ep93xx_rtc_set_mmss(struct device *dev, unsigned long secs) 72 { 73 struct ep93xx_rtc *ep93xx_rtc = dev->platform_data; 74 75 __raw_writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD); 76 return 0; 77 } 78 79 static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq) 80 { 81 unsigned short preload, delete; 82 83 ep93xx_rtc_get_swcomp(dev, &preload, &delete); 84 85 seq_printf(seq, "preload\t\t: %d\n", preload); 86 seq_printf(seq, "delete\t\t: %d\n", delete); 87 88 return 0; 89 } 90 91 static const struct rtc_class_ops ep93xx_rtc_ops = { 92 .read_time = ep93xx_rtc_read_time, 93 .set_mmss = ep93xx_rtc_set_mmss, 94 .proc = ep93xx_rtc_proc, 95 }; 96 97 static ssize_t ep93xx_rtc_show_comp_preload(struct device *dev, 98 struct device_attribute *attr, char *buf) 99 { 100 unsigned short preload; 101 102 ep93xx_rtc_get_swcomp(dev, &preload, NULL); 103 104 return sprintf(buf, "%d\n", preload); 105 } 106 static DEVICE_ATTR(comp_preload, S_IRUGO, ep93xx_rtc_show_comp_preload, NULL); 107 108 static ssize_t ep93xx_rtc_show_comp_delete(struct device *dev, 109 struct device_attribute *attr, char *buf) 110 { 111 unsigned short delete; 112 113 ep93xx_rtc_get_swcomp(dev, NULL, &delete); 114 115 return sprintf(buf, "%d\n", delete); 116 } 117 static DEVICE_ATTR(comp_delete, S_IRUGO, ep93xx_rtc_show_comp_delete, NULL); 118 119 static struct attribute *ep93xx_rtc_attrs[] = { 120 &dev_attr_comp_preload.attr, 121 &dev_attr_comp_delete.attr, 122 NULL 123 }; 124 125 static const struct attribute_group ep93xx_rtc_sysfs_files = { 126 .attrs = ep93xx_rtc_attrs, 127 }; 128 129 static int __init ep93xx_rtc_probe(struct platform_device *pdev) 130 { 131 struct ep93xx_rtc *ep93xx_rtc; 132 struct resource *res; 133 struct rtc_device *rtc; 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 if (!res) 142 return -ENXIO; 143 144 if (!devm_request_mem_region(&pdev->dev, res->start, 145 resource_size(res), pdev->name)) 146 return -EBUSY; 147 148 ep93xx_rtc->mmio_base = devm_ioremap(&pdev->dev, res->start, 149 resource_size(res)); 150 if (!ep93xx_rtc->mmio_base) 151 return -ENXIO; 152 153 pdev->dev.platform_data = ep93xx_rtc; 154 155 rtc = rtc_device_register(pdev->name, 156 &pdev->dev, &ep93xx_rtc_ops, THIS_MODULE); 157 if (IS_ERR(rtc)) { 158 err = PTR_ERR(rtc); 159 goto exit; 160 } 161 162 platform_set_drvdata(pdev, rtc); 163 164 err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files); 165 if (err) 166 goto fail; 167 168 return 0; 169 170 fail: 171 platform_set_drvdata(pdev, NULL); 172 rtc_device_unregister(rtc); 173 exit: 174 pdev->dev.platform_data = NULL; 175 return err; 176 } 177 178 static int __exit ep93xx_rtc_remove(struct platform_device *pdev) 179 { 180 struct rtc_device *rtc = platform_get_drvdata(pdev); 181 182 sysfs_remove_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files); 183 platform_set_drvdata(pdev, NULL); 184 rtc_device_unregister(rtc); 185 pdev->dev.platform_data = NULL; 186 187 return 0; 188 } 189 190 /* work with hotplug and coldplug */ 191 MODULE_ALIAS("platform:ep93xx-rtc"); 192 193 static struct platform_driver ep93xx_rtc_driver = { 194 .driver = { 195 .name = "ep93xx-rtc", 196 .owner = THIS_MODULE, 197 }, 198 .remove = __exit_p(ep93xx_rtc_remove), 199 }; 200 201 static int __init ep93xx_rtc_init(void) 202 { 203 return platform_driver_probe(&ep93xx_rtc_driver, ep93xx_rtc_probe); 204 } 205 206 static void __exit ep93xx_rtc_exit(void) 207 { 208 platform_driver_unregister(&ep93xx_rtc_driver); 209 } 210 211 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 212 MODULE_DESCRIPTION("EP93XX RTC driver"); 213 MODULE_LICENSE("GPL"); 214 MODULE_VERSION(DRV_VERSION); 215 216 module_init(ep93xx_rtc_init); 217 module_exit(ep93xx_rtc_exit); 218