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