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