drivers/rtc/rtc-tx4939.c

   1 /*
   2  * TX4939 internal RTC driver
   3  * Based on RBTX49xx patch from CELF patch archive.
   4  *
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License.  See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  *
   9  * (C) Copyright TOSHIBA CORPORATION 2005-2007
  10  */
  11 #include <linux/rtc.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/io.h>
  15 #include <asm/txx9/tx4939.h>
  16
  17 struct tx4939rtc_plat_data {
  18         struct rtc_device *rtc;
  19         struct tx4939_rtc_reg __iomem *rtcreg;
  20 };
  21
  22 static struct tx4939rtc_plat_data *get_tx4939rtc_plat_data(struct device *dev)
  23 {
  24         return platform_get_drvdata(to_platform_device(dev));
  25 }
  26
  27 static int tx4939_rtc_cmd(struct tx4939_rtc_reg __iomem *rtcreg, int cmd)
  28 {
  29         int i = 0;
  30
  31         __raw_writel(cmd, &rtcreg->ctl);
  32         /* This might take 30us (next 32.768KHz clock) */
  33         while (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_BUSY) {
  34                 /* timeout on approx. 100us (@ GBUS200MHz) */
  35                 if (i++ > 200 * 100)
  36                         return -EBUSY;
  37                 cpu_relax();
  38         }
  39         return 0;
  40 }
  41
  42 static int tx4939_rtc_set_mmss(struct device *dev, unsigned long secs)
  43 {
  44         struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
  45         struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  46         int i, ret;
  47         unsigned char buf[6];
  48
  49         buf[0] = 0;
  50         buf[1] = 0;
  51         buf[2] = secs;
  52         buf[3] = secs >> 8;
  53         buf[4] = secs >> 16;
  54         buf[5] = secs >> 24;
  55         spin_lock_irq(&pdata->rtc->irq_lock);
  56         __raw_writel(0, &rtcreg->adr);
  57         for (i = 0; i < 6; i++)
  58                 __raw_writel(buf[i], &rtcreg->dat);
  59         ret = tx4939_rtc_cmd(rtcreg,
  60                              TX4939_RTCCTL_COMMAND_SETTIME |
  61                              (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
  62         spin_unlock_irq(&pdata->rtc->irq_lock);
  63         return ret;
  64 }
  65
  66 static int tx4939_rtc_read_time(struct device *dev, struct rtc_time *tm)
  67 {
  68         struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
  69         struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  70         int i, ret;
  71         unsigned long sec;
  72         unsigned char buf[6];
  73
  74         spin_lock_irq(&pdata->rtc->irq_lock);
  75         ret = tx4939_rtc_cmd(rtcreg,
  76                              TX4939_RTCCTL_COMMAND_GETTIME |
  77                              (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
  78         if (ret) {
  79                 spin_unlock_irq(&pdata->rtc->irq_lock);
  80                 return ret;
  81         }
  82         __raw_writel(2, &rtcreg->adr);
  83         for (i = 2; i < 6; i++)
  84                 buf[i] = __raw_readl(&rtcreg->dat);
  85         spin_unlock_irq(&pdata->rtc->irq_lock);
  86         sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
  87         rtc_time_to_tm(sec, tm);
  88         return rtc_valid_tm(tm);
  89 }
  90
  91 static int tx4939_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  92 {
  93         struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
  94         struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  95         int i, ret;
  96         unsigned long sec;
  97         unsigned char buf[6];
  98
  99         if (alrm->time.tm_sec < 0 ||
 100             alrm->time.tm_min < 0 ||
 101             alrm->time.tm_hour < 0 ||
 102             alrm->time.tm_mday < 0 ||
 103             alrm->time.tm_mon < 0 ||
 104             alrm->time.tm_year < 0)
 105                 return -EINVAL;
 106         rtc_tm_to_time(&alrm->time, &sec);
 107         buf[0] = 0;
 108         buf[1] = 0;
 109         buf[2] = sec;
 110         buf[3] = sec >> 8;
 111         buf[4] = sec >> 16;
 112         buf[5] = sec >> 24;
 113         spin_lock_irq(&pdata->rtc->irq_lock);
 114         __raw_writel(0, &rtcreg->adr);
 115         for (i = 0; i < 6; i++)
 116                 __raw_writel(buf[i], &rtcreg->dat);
 117         ret = tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_SETALARM |
 118                              (alrm->enabled ? TX4939_RTCCTL_ALME : 0));
 119         spin_unlock_irq(&pdata->rtc->irq_lock);
 120         return ret;
 121 }
 122
 123 static int tx4939_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 124 {
 125         struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
 126         struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
 127         int i, ret;
 128         unsigned long sec;
 129         unsigned char buf[6];
 130         u32 ctl;
 131
 132         spin_lock_irq(&pdata->rtc->irq_lock);
 133         ret = tx4939_rtc_cmd(rtcreg,
 134                              TX4939_RTCCTL_COMMAND_GETALARM |
 135                              (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
 136         if (ret) {
 137                 spin_unlock_irq(&pdata->rtc->irq_lock);
 138                 return ret;
 139         }
 140         __raw_writel(2, &rtcreg->adr);
 141         for (i = 2; i < 6; i++)
 142                 buf[i] = __raw_readl(&rtcreg->dat);
 143         ctl = __raw_readl(&rtcreg->ctl);
 144         alrm->enabled = (ctl & TX4939_RTCCTL_ALME) ? 1 : 0;
 145         alrm->pending = (ctl & TX4939_RTCCTL_ALMD) ? 1 : 0;
 146         spin_unlock_irq(&pdata->rtc->irq_lock);
 147         sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
 148         rtc_time_to_tm(sec, &alrm->time);
 149         return rtc_valid_tm(&alrm->time);
 150 }
 151
 152 static int tx4939_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 153 {
 154         struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
 155
 156         spin_lock_irq(&pdata->rtc->irq_lock);
 157         tx4939_rtc_cmd(pdata->rtcreg,
 158                        TX4939_RTCCTL_COMMAND_NOP |
 159                        (enabled ? TX4939_RTCCTL_ALME : 0));
 160         spin_unlock_irq(&pdata->rtc->irq_lock);
 161         return 0;
 162 }
 163
 164 static irqreturn_t tx4939_rtc_interrupt(int irq, void *dev_id)
 165 {
 166         struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev_id);
 167         struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
 168         unsigned long events = RTC_IRQF;
 169
 170         spin_lock(&pdata->rtc->irq_lock);
 171         if (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALMD) {
 172                 events |= RTC_AF;
 173                 tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_NOP);
 174         }
 175         spin_unlock(&pdata->rtc->irq_lock);
 176         rtc_update_irq(pdata->rtc, 1, events);
 177         return IRQ_HANDLED;
 178 }
 179
 180 static const struct rtc_class_ops tx4939_rtc_ops = {
 181         .read_time              = tx4939_rtc_read_time,
 182         .read_alarm             = tx4939_rtc_read_alarm,
 183         .set_alarm              = tx4939_rtc_set_alarm,
 184         .set_mmss               = tx4939_rtc_set_mmss,
 185         .alarm_irq_enable       = tx4939_rtc_alarm_irq_enable,
 186 };
 187
 188 static ssize_t tx4939_rtc_nvram_read(struct kobject *kobj,
 189                                      struct bin_attribute *bin_attr,
 190                                      char *buf, loff_t pos, size_t size)
 191 {
 192         struct device *dev = container_of(kobj, struct device, kobj);
 193         struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
 194         struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
 195         ssize_t count;
 196
 197         spin_lock_irq(&pdata->rtc->irq_lock);
 198         for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
 199              count++, size--) {
 200                 __raw_writel(pos++, &rtcreg->adr);
 201                 *buf++ = __raw_readl(&rtcreg->dat);
 202         }
 203         spin_unlock_irq(&pdata->rtc->irq_lock);
 204         return count;
 205 }
 206
 207 static ssize_t tx4939_rtc_nvram_write(struct kobject *kobj,
 208                                       struct bin_attribute *bin_attr,
 209                                       char *buf, loff_t pos, size_t size)
 210 {
 211         struct device *dev = container_of(kobj, struct device, kobj);
 212         struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
 213         struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
 214         ssize_t count;
 215
 216         spin_lock_irq(&pdata->rtc->irq_lock);
 217         for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
 218              count++, size--) {
 219                 __raw_writel(pos++, &rtcreg->adr);
 220                 __raw_writel(*buf++, &rtcreg->dat);
 221         }
 222         spin_unlock_irq(&pdata->rtc->irq_lock);
 223         return count;
 224 }
 225
 226 static struct bin_attribute tx4939_rtc_nvram_attr = {
 227         .attr = {
 228                 .name = "nvram",
 229                 .mode = S_IRUGO | S_IWUSR,
 230         },
 231         .size = TX4939_RTC_REG_RAMSIZE,
 232         .read = tx4939_rtc_nvram_read,
 233         .write = tx4939_rtc_nvram_write,
 234 };
 235
 236 static int __init tx4939_rtc_probe(struct platform_device *pdev)
 237 {
 238         struct rtc_device *rtc;
 239         struct tx4939rtc_plat_data *pdata;
 240         struct resource *res;
 241         int irq, ret;
 242
 243         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 244         if (!res)
 245                 return -ENODEV;
 246         irq = platform_get_irq(pdev, 0);
 247         if (irq < 0)
 248                 return -ENODEV;
 249         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 250         if (!pdata)
 251                 return -ENOMEM;
 252         platform_set_drvdata(pdev, pdata);
 253
 254         if (!devm_request_mem_region(&pdev->dev, res->start,
 255                                      resource_size(res), pdev->name))
 256                 return -EBUSY;
 257         pdata->rtcreg = devm_ioremap(&pdev->dev, res->start,
 258                                      resource_size(res));
 259         if (!pdata->rtcreg)
 260                 return -EBUSY;
 261
 262         tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
 263         if (devm_request_irq(&pdev->dev, irq, tx4939_rtc_interrupt,
 264                              IRQF_DISABLED | IRQF_SHARED,
 265                              pdev->name, &pdev->dev) < 0) {
 266                 return -EBUSY;
 267         }
 268         rtc = rtc_device_register(pdev->name, &pdev->dev,
 269                                   &tx4939_rtc_ops, THIS_MODULE);
 270         if (IS_ERR(rtc))
 271                 return PTR_ERR(rtc);
 272         pdata->rtc = rtc;
 273         ret = sysfs_create_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
 274         if (ret)
 275                 rtc_device_unregister(rtc);
 276         return ret;
 277 }
 278
 279 static int __exit tx4939_rtc_remove(struct platform_device *pdev)
 280 {
 281         struct tx4939rtc_plat_data *pdata = platform_get_drvdata(pdev);
 282         struct rtc_device *rtc = pdata->rtc;
 283
 284         spin_lock_irq(&rtc->irq_lock);
 285         tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
 286         spin_unlock_irq(&rtc->irq_lock);
 287         sysfs_remove_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
 288         rtc_device_unregister(rtc);
 289         platform_set_drvdata(pdev, NULL);
 290         return 0;
 291 }
 292
 293 static struct platform_driver tx4939_rtc_driver = {
 294         .remove         = __exit_p(tx4939_rtc_remove),
 295         .driver         = {
 296                 .name   = "tx4939rtc",
 297                 .owner  = THIS_MODULE,
 298         },
 299 };
 300
 301 static int __init tx4939rtc_init(void)
 302 {
 303         return platform_driver_probe(&tx4939_rtc_driver, tx4939_rtc_probe);
 304 }
 305
 306 static void __exit tx4939rtc_exit(void)
 307 {
 308         platform_driver_unregister(&tx4939_rtc_driver);
 309 }
 310
 311 module_init(tx4939rtc_init);
 312 module_exit(tx4939rtc_exit);
 313
 314 MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
 315 MODULE_DESCRIPTION("TX4939 internal RTC driver");
 316 MODULE_LICENSE("GPL");
 317 MODULE_ALIAS("platform:tx4939rtc");