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 17 #define EP93XX_RTC_DATA 0x000 18 #define EP93XX_RTC_MATCH 0x004 19 #define EP93XX_RTC_STATUS 0x008 20 #define EP93XX_RTC_STATUS_INTR (1<<0) 21 #define EP93XX_RTC_LOAD 0x00C 22 #define EP93XX_RTC_CONTROL 0x010 23 #define EP93XX_RTC_CONTROL_MIE (1<<0) 24 #define EP93XX_RTC_SWCOMP 0x108 25 #define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f0000 26 #define EP93XX_RTC_SWCOMP_DEL_SHIFT 16 27 #define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff 28 #define EP93XX_RTC_SWCOMP_INT_SHIFT 0 29 30 #define DRV_VERSION "0.3" 31 32 /* 33 * struct device dev.platform_data is used to store our private data 34 * because struct rtc_device does not have a variable to hold it. 35 */ 36 struct ep93xx_rtc { 37 void __iomem *mmio_base; 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->platform_data; 44 unsigned long comp; 45 46 comp = __raw_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->platform_data; 62 unsigned long time; 63 64 time = __raw_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->platform_data; 73 74 __raw_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); 117 118 119 static int __init ep93xx_rtc_probe(struct platform_device *pdev) 120 { 121 struct ep93xx_rtc *ep93xx_rtc; 122 struct resource *res; 123 struct rtc_device *rtc; 124 int err; 125 126 ep93xx_rtc = kzalloc(sizeof(struct ep93xx_rtc), GFP_KERNEL); 127 if (ep93xx_rtc == NULL) 128 return -ENOMEM; 129 130 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 131 if (res == NULL) 132 return -ENXIO; 133 134 res = request_mem_region(res->start, resource_size(res), pdev->name); 135 if (res == NULL) 136 return -EBUSY; 137 138 ep93xx_rtc->mmio_base = ioremap(res->start, resource_size(res)); 139 if (ep93xx_rtc->mmio_base == NULL) { 140 err = -ENXIO; 141 goto fail; 142 } 143 144 pdev->dev.platform_data = ep93xx_rtc; 145 146 rtc = rtc_device_register(pdev->name, 147 &pdev->dev, &ep93xx_rtc_ops, THIS_MODULE); 148 if (IS_ERR(rtc)) { 149 err = PTR_ERR(rtc); 150 goto fail; 151 } 152 153 platform_set_drvdata(pdev, rtc); 154 155 err = device_create_file(&pdev->dev, &dev_attr_comp_preload); 156 if (err) 157 goto fail; 158 err = device_create_file(&pdev->dev, &dev_attr_comp_delete); 159 if (err) { 160 device_remove_file(&pdev->dev, &dev_attr_comp_preload); 161 goto fail; 162 } 163 164 return 0; 165 166 fail: 167 if (ep93xx_rtc->mmio_base) { 168 iounmap(ep93xx_rtc->mmio_base); 169 pdev->dev.platform_data = NULL; 170 } 171 release_mem_region(res->start, resource_size(res)); 172 return err; 173 } 174 175 static int __exit ep93xx_rtc_remove(struct platform_device *pdev) 176 { 177 struct rtc_device *rtc = platform_get_drvdata(pdev); 178 struct ep93xx_rtc *ep93xx_rtc = pdev->dev.platform_data; 179 struct resource *res; 180 181 /* cleanup sysfs */ 182 device_remove_file(&pdev->dev, &dev_attr_comp_delete); 183 device_remove_file(&pdev->dev, &dev_attr_comp_preload); 184 185 rtc_device_unregister(rtc); 186 187 iounmap(ep93xx_rtc->mmio_base); 188 pdev->dev.platform_data = NULL; 189 190 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 191 release_mem_region(res->start, resource_size(res)); 192 193 platform_set_drvdata(pdev, NULL); 194 195 return 0; 196 } 197 198 /* work with hotplug and coldplug */ 199 MODULE_ALIAS("platform:ep93xx-rtc"); 200 201 static struct platform_driver ep93xx_rtc_driver = { 202 .driver = { 203 .name = "ep93xx-rtc", 204 .owner = THIS_MODULE, 205 }, 206 .remove = __exit_p(ep93xx_rtc_remove), 207 }; 208 209 static int __init ep93xx_rtc_init(void) 210 { 211 return platform_driver_probe(&ep93xx_rtc_driver, ep93xx_rtc_probe); 212 } 213 214 static void __exit ep93xx_rtc_exit(void) 215 { 216 platform_driver_unregister(&ep93xx_rtc_driver); 217 } 218 219 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); 220 MODULE_DESCRIPTION("EP93XX RTC driver"); 221 MODULE_LICENSE("GPL"); 222 MODULE_VERSION(DRV_VERSION); 223 224 module_init(ep93xx_rtc_init); 225 module_exit(ep93xx_rtc_exit); 226