1 /* 2 * Freescale STMP37XX/STMP378X Real Time Clock driver 3 * 4 * Copyright (c) 2007 Sigmatel, Inc. 5 * Peter Hartley, <peter.hartley@sigmatel.com> 6 * 7 * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved. 8 * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. 9 */ 10 11 /* 12 * The code contained herein is licensed under the GNU General Public 13 * License. You may obtain a copy of the GNU General Public License 14 * Version 2 or later at the following locations: 15 * 16 * http://www.opensource.org/licenses/gpl-license.html 17 * http://www.gnu.org/copyleft/gpl.html 18 */ 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/init.h> 22 #include <linux/platform_device.h> 23 #include <linux/interrupt.h> 24 #include <linux/rtc.h> 25 #include <linux/slab.h> 26 27 #include <mach/platform.h> 28 #include <mach/stmp3xxx.h> 29 #include <mach/regs-rtc.h> 30 31 struct stmp3xxx_rtc_data { 32 struct rtc_device *rtc; 33 unsigned irq_count; 34 void __iomem *io; 35 int irq_alarm, irq_1msec; 36 }; 37 38 static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data) 39 { 40 /* 41 * The datasheet doesn't say which way round the 42 * NEW_REGS/STALE_REGS bitfields go. In fact it's 0x1=P0, 43 * 0x2=P1, .., 0x20=P5, 0x40=ALARM, 0x80=SECONDS 44 */ 45 while (__raw_readl(rtc_data->io + HW_RTC_STAT) & 46 BF(0x80, RTC_STAT_STALE_REGS)) 47 cpu_relax(); 48 } 49 50 /* Time read/write */ 51 static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) 52 { 53 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); 54 55 stmp3xxx_wait_time(rtc_data); 56 rtc_time_to_tm(__raw_readl(rtc_data->io + HW_RTC_SECONDS), rtc_tm); 57 return 0; 58 } 59 60 static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t) 61 { 62 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); 63 64 __raw_writel(t, rtc_data->io + HW_RTC_SECONDS); 65 stmp3xxx_wait_time(rtc_data); 66 return 0; 67 } 68 69 /* interrupt(s) handler */ 70 static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id) 71 { 72 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id); 73 u32 status; 74 u32 events = 0; 75 76 status = __raw_readl(rtc_data->io + HW_RTC_CTRL) & 77 (BM_RTC_CTRL_ALARM_IRQ | BM_RTC_CTRL_ONEMSEC_IRQ); 78 79 if (status & BM_RTC_CTRL_ALARM_IRQ) { 80 stmp3xxx_clearl(BM_RTC_CTRL_ALARM_IRQ, 81 rtc_data->io + HW_RTC_CTRL); 82 events |= RTC_AF | RTC_IRQF; 83 } 84 85 if (status & BM_RTC_CTRL_ONEMSEC_IRQ) { 86 stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ, 87 rtc_data->io + HW_RTC_CTRL); 88 if (++rtc_data->irq_count % 1000 == 0) { 89 events |= RTC_UF | RTC_IRQF; 90 rtc_data->irq_count = 0; 91 } 92 } 93 94 if (events) 95 rtc_update_irq(rtc_data->rtc, 1, events); 96 97 return IRQ_HANDLED; 98 } 99 100 static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled) 101 { 102 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); 103 void __iomem *p = rtc_data->io + HW_RTC_PERSISTENT0, 104 *ctl = rtc_data->io + HW_RTC_CTRL; 105 106 if (enabled) { 107 stmp3xxx_setl(BM_RTC_PERSISTENT0_ALARM_EN | 108 BM_RTC_PERSISTENT0_ALARM_WAKE_EN, p); 109 stmp3xxx_setl(BM_RTC_CTRL_ALARM_IRQ_EN, ctl); 110 } else { 111 stmp3xxx_clearl(BM_RTC_PERSISTENT0_ALARM_EN | 112 BM_RTC_PERSISTENT0_ALARM_WAKE_EN, p); 113 stmp3xxx_clearl(BM_RTC_CTRL_ALARM_IRQ_EN, ctl); 114 } 115 return 0; 116 } 117 118 static int stmp3xxx_update_irq_enable(struct device *dev, unsigned int enabled) 119 { 120 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); 121 122 if (enabled) 123 stmp3xxx_setl(BM_RTC_CTRL_ONEMSEC_IRQ_EN, 124 rtc_data->io + HW_RTC_CTRL); 125 else 126 stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ_EN, 127 rtc_data->io + HW_RTC_CTRL); 128 return 0; 129 } 130 131 static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 132 { 133 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); 134 135 rtc_time_to_tm(__raw_readl(rtc_data->io + HW_RTC_ALARM), &alm->time); 136 return 0; 137 } 138 139 static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 140 { 141 unsigned long t; 142 struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); 143 144 rtc_tm_to_time(&alm->time, &t); 145 __raw_writel(t, rtc_data->io + HW_RTC_ALARM); 146 return 0; 147 } 148 149 static struct rtc_class_ops stmp3xxx_rtc_ops = { 150 .alarm_irq_enable = 151 stmp3xxx_alarm_irq_enable, 152 .update_irq_enable = 153 stmp3xxx_update_irq_enable, 154 .read_time = stmp3xxx_rtc_gettime, 155 .set_mmss = stmp3xxx_rtc_set_mmss, 156 .read_alarm = stmp3xxx_rtc_read_alarm, 157 .set_alarm = stmp3xxx_rtc_set_alarm, 158 }; 159 160 static int stmp3xxx_rtc_remove(struct platform_device *pdev) 161 { 162 struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev); 163 164 if (!rtc_data) 165 return 0; 166 167 stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ_EN | BM_RTC_CTRL_ALARM_IRQ_EN, 168 rtc_data->io + HW_RTC_CTRL); 169 free_irq(rtc_data->irq_alarm, &pdev->dev); 170 free_irq(rtc_data->irq_1msec, &pdev->dev); 171 rtc_device_unregister(rtc_data->rtc); 172 iounmap(rtc_data->io); 173 kfree(rtc_data); 174 175 return 0; 176 } 177 178 static int stmp3xxx_rtc_probe(struct platform_device *pdev) 179 { 180 struct stmp3xxx_rtc_data *rtc_data; 181 struct resource *r; 182 int err; 183 184 rtc_data = kzalloc(sizeof *rtc_data, GFP_KERNEL); 185 if (!rtc_data) 186 return -ENOMEM; 187 188 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 189 if (!r) { 190 dev_err(&pdev->dev, "failed to get resource\n"); 191 err = -ENXIO; 192 goto out_free; 193 } 194 195 rtc_data->io = ioremap(r->start, resource_size(r)); 196 if (!rtc_data->io) { 197 dev_err(&pdev->dev, "ioremap failed\n"); 198 err = -EIO; 199 goto out_free; 200 } 201 202 rtc_data->irq_alarm = platform_get_irq(pdev, 0); 203 rtc_data->irq_1msec = platform_get_irq(pdev, 1); 204 205 if (!(__raw_readl(HW_RTC_STAT + rtc_data->io) & 206 BM_RTC_STAT_RTC_PRESENT)) { 207 dev_err(&pdev->dev, "no device onboard\n"); 208 err = -ENODEV; 209 goto out_remap; 210 } 211 212 stmp3xxx_reset_block(rtc_data->io, true); 213 stmp3xxx_clearl(BM_RTC_PERSISTENT0_ALARM_EN | 214 BM_RTC_PERSISTENT0_ALARM_WAKE_EN | 215 BM_RTC_PERSISTENT0_ALARM_WAKE, 216 rtc_data->io + HW_RTC_PERSISTENT0); 217 rtc_data->rtc = rtc_device_register(pdev->name, &pdev->dev, 218 &stmp3xxx_rtc_ops, THIS_MODULE); 219 if (IS_ERR(rtc_data->rtc)) { 220 err = PTR_ERR(rtc_data->rtc); 221 goto out_remap; 222 } 223 224 rtc_data->irq_count = 0; 225 err = request_irq(rtc_data->irq_alarm, stmp3xxx_rtc_interrupt, 226 IRQF_DISABLED, "RTC alarm", &pdev->dev); 227 if (err) { 228 dev_err(&pdev->dev, "Cannot claim IRQ%d\n", 229 rtc_data->irq_alarm); 230 goto out_irq_alarm; 231 } 232 err = request_irq(rtc_data->irq_1msec, stmp3xxx_rtc_interrupt, 233 IRQF_DISABLED, "RTC tick", &pdev->dev); 234 if (err) { 235 dev_err(&pdev->dev, "Cannot claim IRQ%d\n", 236 rtc_data->irq_1msec); 237 goto out_irq1; 238 } 239 240 platform_set_drvdata(pdev, rtc_data); 241 242 return 0; 243 244 out_irq1: 245 free_irq(rtc_data->irq_alarm, &pdev->dev); 246 out_irq_alarm: 247 stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ_EN | BM_RTC_CTRL_ALARM_IRQ_EN, 248 rtc_data->io + HW_RTC_CTRL); 249 rtc_device_unregister(rtc_data->rtc); 250 out_remap: 251 iounmap(rtc_data->io); 252 out_free: 253 kfree(rtc_data); 254 return err; 255 } 256 257 #ifdef CONFIG_PM 258 static int stmp3xxx_rtc_suspend(struct platform_device *dev, pm_message_t state) 259 { 260 return 0; 261 } 262 263 static int stmp3xxx_rtc_resume(struct platform_device *dev) 264 { 265 struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(dev); 266 267 stmp3xxx_reset_block(rtc_data->io, true); 268 stmp3xxx_clearl(BM_RTC_PERSISTENT0_ALARM_EN | 269 BM_RTC_PERSISTENT0_ALARM_WAKE_EN | 270 BM_RTC_PERSISTENT0_ALARM_WAKE, 271 rtc_data->io + HW_RTC_PERSISTENT0); 272 return 0; 273 } 274 #else 275 #define stmp3xxx_rtc_suspend NULL 276 #define stmp3xxx_rtc_resume NULL 277 #endif 278 279 static struct platform_driver stmp3xxx_rtcdrv = { 280 .probe = stmp3xxx_rtc_probe, 281 .remove = stmp3xxx_rtc_remove, 282 .suspend = stmp3xxx_rtc_suspend, 283 .resume = stmp3xxx_rtc_resume, 284 .driver = { 285 .name = "stmp3xxx-rtc", 286 .owner = THIS_MODULE, 287 }, 288 }; 289 290 static int __init stmp3xxx_rtc_init(void) 291 { 292 return platform_driver_register(&stmp3xxx_rtcdrv); 293 } 294 295 static void __exit stmp3xxx_rtc_exit(void) 296 { 297 platform_driver_unregister(&stmp3xxx_rtcdrv); 298 } 299 300 module_init(stmp3xxx_rtc_init); 301 module_exit(stmp3xxx_rtc_exit); 302 303 MODULE_DESCRIPTION("STMP3xxx RTC Driver"); 304 MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com>"); 305 MODULE_LICENSE("GPL"); 306