--- /dev/null
+/* drivers/rtc/rtc-r9701.c
+ *
+ * Driver for Epson RTC-9701JE
+ *
+ * Copyright (C) 2008 Magnus Damm
+ *
+ * Based on drivers/rtc/rtc-max6902.c
+ *
+ * Copyright (C) 2006 8D Technologies inc.
+ * Copyright (C) 2004 Compulab Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/rtc.h>
+#include <linux/spi/spi.h>
+#include <linux/bcd.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+
+#define RSECCNT 0x00 /* Second Counter */
+#define RMINCNT 0x01 /* Minute Counter */
+#define RHRCNT 0x02 /* Hour Counter */
+#define RWKCNT 0x03 /* Week Counter */
+#define RDAYCNT 0x04 /* Day Counter */
+#define RMONCNT 0x05 /* Month Counter */
+#define RYRCNT 0x06 /* Year Counter */
+#define R100CNT 0x07 /* Y100 Counter */
+#define RMINAR 0x08 /* Minute Alarm */
+#define RHRAR 0x09 /* Hour Alarm */
+#define RWKAR 0x0a /* Week/Day Alarm */
+#define RTIMCNT 0x0c /* Interval Timer */
+#define REXT 0x0d /* Extension Register */
+#define RFLAG 0x0e /* RTC Flag Register */
+#define RCR 0x0f /* RTC Control Register */
+
+static int write_reg(struct device *dev, int address, unsigned char data)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ unsigned char buf[2];
+
+ buf[0] = address & 0x7f;
+ buf[1] = data;
+
+ return spi_write(spi, buf, ARRAY_SIZE(buf));
+}
+
+static int read_regs(struct device *dev, unsigned char *regs, int no_regs)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ u8 txbuf[1], rxbuf[1];
+ int k, ret;
+
+ ret = 0;
+
+ for (k = 0; ret == 0 && k < no_regs; k++) {
+ txbuf[0] = 0x80 | regs[k];
+ ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
+ regs[k] = rxbuf[0];
+ }
+
+ return ret;
+}
+
+static int r9701_get_datetime(struct device *dev, struct rtc_time *dt)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ unsigned long time;
+ int ret;
+ unsigned char buf[] = { RSECCNT, RMINCNT, RHRCNT,
+ RDAYCNT, RMONCNT, RYRCNT };
+
+ ret = read_regs(&spi->dev, buf, ARRAY_SIZE(buf));
+ if (ret)
+ return ret;
+
+ memset(dt, 0, sizeof(*dt));
+
+ dt->tm_sec = BCD2BIN(buf[0]); /* RSECCNT */
+ dt->tm_min = BCD2BIN(buf[1]); /* RMINCNT */
+ dt->tm_hour = BCD2BIN(buf[2]); /* RHRCNT */
+
+ dt->tm_mday = BCD2BIN(buf[3]); /* RDAYCNT */
+ dt->tm_mon = BCD2BIN(buf[4]) - 1; /* RMONCNT */
+ dt->tm_year = BCD2BIN(buf[5]) + 100; /* RYRCNT */
+
+ /* the rtc device may contain illegal values on power up
+ * according to the data sheet. make sure they are valid.
+ */
+
+ ret = rtc_valid_tm(dt);
+ if (ret)
+ return ret;
+
+ /* don't bother with yday, wday and isdst.
+ * let the rtc core calculate them for us.
+ */
+
+ rtc_tm_to_time(dt, &time);
+ rtc_time_to_tm(time, dt);
+ return 0;
+}
+
+static int r9701_set_datetime(struct device *dev, struct rtc_time *dt)
+{
+ int ret, year;
+
+ year = dt->tm_year + 1900;
+ if (year >= 2100 || year < 2000)
+ return -EINVAL;
+
+ ret = write_reg(dev, RHRCNT, BIN2BCD(dt->tm_hour));
+ ret |= write_reg(dev, RMINCNT, BIN2BCD(dt->tm_min));
+ ret |= write_reg(dev, RSECCNT, BIN2BCD(dt->tm_sec));
+ ret |= write_reg(dev, RDAYCNT, BIN2BCD(dt->tm_mday));
+ ret |= write_reg(dev, RMONCNT, BIN2BCD(dt->tm_mon + 1));
+ ret |= write_reg(dev, RYRCNT, BIN2BCD(dt->tm_year - 100));
+ ret |= write_reg(dev, RWKCNT, 1 << dt->tm_wday);
+
+ return ret;
+}
+
+static const struct rtc_class_ops r9701_rtc_ops = {
+ .read_time = r9701_get_datetime,
+ .set_time = r9701_set_datetime,
+};
+
+static int __devinit r9701_probe(struct spi_device *spi)
+{
+ struct rtc_device *rtc;
+ unsigned char tmp;
+ int res;
+
+ rtc = rtc_device_register("r9701",
+ &spi->dev, &r9701_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ dev_set_drvdata(&spi->dev, rtc);
+
+ spi->mode = SPI_MODE_3;
+ spi->bits_per_word = 8;
+ spi_setup(spi);
+
+ tmp = R100CNT;
+ res = read_regs(&spi->dev, &tmp, 1);
+ if (res || tmp != 0x20) {
+ rtc_device_unregister(rtc);
+ return res;
+ }
+
+ return 0;
+}
+
+static int __devexit r9701_remove(struct spi_device *spi)
+{
+ struct rtc_device *rtc = dev_get_drvdata(&spi->dev);
+
+ rtc_device_unregister(rtc);
+ return 0;
+}
+
+static struct spi_driver r9701_driver = {
+ .driver = {
+ .name = "rtc-r9701",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = r9701_probe,
+ .remove = __devexit_p(r9701_remove),
+};
+
+static __init int r9701_init(void)
+{
+ return spi_register_driver(&r9701_driver);
+}
+module_init(r9701_init);
+
+static __exit void r9701_exit(void)
+{
+ spi_unregister_driver(&r9701_driver);
+}
+module_exit(r9701_exit);
+
+MODULE_DESCRIPTION("r9701 spi RTC driver");
+MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-stable.git / commitdiff