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