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Linux/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                 .owner  = THIS_MODULE,
291         },
292 };
293 
294 module_platform_driver_probe(tx4939_rtc_driver, tx4939_rtc_probe);
295 
296 MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
297 MODULE_DESCRIPTION("TX4939 internal RTC driver");
298 MODULE_LICENSE("GPL");
299 MODULE_ALIAS("platform:tx4939rtc");
300 

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