]> nv-tegra.nvidia Code Review - linux-2.6.git/commitdiff
[PATCH] RTC: add rtc-rs5c348 driver
authorAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Wed, 28 Jun 2006 11:26:47 +0000 (04:26 -0700)
committerLinus Torvalds <torvalds@g5.osdl.org>
Wed, 28 Jun 2006 21:59:04 +0000 (14:59 -0700)
Add an SPI driver for the Ricoh RS5C348 RTC chip.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-rs5c348.c [new file with mode: 0644]

index bccff400b198d6e0da250fd483a551ad60d992bd..f2fc81a9074d8af26c79940f87ddaa8c98712999 100644 (file)
@@ -162,6 +162,16 @@ config RTC_DRV_PCF8583
          This driver can also be built as a module. If so, the module
          will be called rtc-pcf8583.
 
+config RTC_DRV_RS5C348
+       tristate "Ricoh RS5C348A/B"
+       depends on RTC_CLASS && SPI
+       help
+         If you say yes here you get support for the
+         Ricoh RS5C348A and RS5C348B RTC chips.
+
+         This driver can also be built as a module. If so, the module
+         will be called rtc-rs5c348.
+
 config RTC_DRV_RS5C372
        tristate "Ricoh RS5C372A/B"
        depends on RTC_CLASS && I2C
index 900d210dd1a24e017b46801251b5bdcea46e4407..da5e38774e130f444f1eb43f31740f5bae404abe 100644 (file)
@@ -19,6 +19,7 @@ obj-$(CONFIG_RTC_DRV_DS1742)  += rtc-ds1742.o
 obj-$(CONFIG_RTC_DRV_PCF8563)  += rtc-pcf8563.o
 obj-$(CONFIG_RTC_DRV_PCF8583)  += rtc-pcf8583.o
 obj-$(CONFIG_RTC_DRV_RS5C372)  += rtc-rs5c372.o
+obj-$(CONFIG_RTC_DRV_RS5C348)  += rtc-rs5c348.o
 obj-$(CONFIG_RTC_DRV_M48T86)   += rtc-m48t86.o
 obj-$(CONFIG_RTC_DRV_DS1553)   += rtc-ds1553.o
 obj-$(CONFIG_RTC_DRV_EP93XX)   += rtc-ep93xx.o
diff --git a/drivers/rtc/rtc-rs5c348.c b/drivers/rtc/rtc-rs5c348.c
new file mode 100644 (file)
index 0000000..0964d1d
--- /dev/null
@@ -0,0 +1,246 @@
+/*
+ * A SPI driver for the Ricoh RS5C348 RTC
+ *
+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ *
+ * 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.
+ *
+ * The board specific init code should provide characteristics of this
+ * device:
+ *     Mode 1 (High-Active, Shift-Then-Sample), High Avtive CS
+ */
+
+#include <linux/bcd.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/rtc.h>
+#include <linux/workqueue.h>
+#include <linux/spi/spi.h>
+
+#define DRV_VERSION "0.1"
+
+#define RS5C348_REG_SECS       0
+#define RS5C348_REG_MINS       1
+#define RS5C348_REG_HOURS      2
+#define RS5C348_REG_WDAY       3
+#define RS5C348_REG_DAY        4
+#define RS5C348_REG_MONTH      5
+#define RS5C348_REG_YEAR       6
+#define RS5C348_REG_CTL1       14
+#define RS5C348_REG_CTL2       15
+
+#define RS5C348_SECS_MASK      0x7f
+#define RS5C348_MINS_MASK      0x7f
+#define RS5C348_HOURS_MASK     0x3f
+#define RS5C348_WDAY_MASK      0x03
+#define RS5C348_DAY_MASK       0x3f
+#define RS5C348_MONTH_MASK     0x1f
+
+#define RS5C348_BIT_PM 0x20    /* REG_HOURS */
+#define RS5C348_BIT_Y2K        0x80    /* REG_MONTH */
+#define RS5C348_BIT_24H        0x20    /* REG_CTL1 */
+#define RS5C348_BIT_XSTP       0x10    /* REG_CTL2 */
+#define RS5C348_BIT_VDET       0x40    /* REG_CTL2 */
+
+#define RS5C348_CMD_W(addr)    (((addr) << 4) | 0x08)  /* single write */
+#define RS5C348_CMD_R(addr)    (((addr) << 4) | 0x0c)  /* single read */
+#define RS5C348_CMD_MW(addr)   (((addr) << 4) | 0x00)  /* burst write */
+#define RS5C348_CMD_MR(addr)   (((addr) << 4) | 0x04)  /* burst read */
+
+struct rs5c348_plat_data {
+       struct rtc_device *rtc;
+       int rtc_24h;
+};
+
+static int
+rs5c348_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       struct rs5c348_plat_data *pdata = spi->dev.platform_data;
+       u8 txbuf[5+7], *txp;
+       int ret;
+
+       /* Transfer 5 bytes before writing SEC.  This gives 31us for carry. */
+       txp = txbuf;
+       txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
+       txbuf[1] = 0;   /* dummy */
+       txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
+       txbuf[3] = 0;   /* dummy */
+       txbuf[4] = RS5C348_CMD_MW(RS5C348_REG_SECS); /* cmd, sec, ... */
+       txp = &txbuf[5];
+       txp[RS5C348_REG_SECS] = BIN2BCD(tm->tm_sec);
+       txp[RS5C348_REG_MINS] = BIN2BCD(tm->tm_min);
+       if (pdata->rtc_24h) {
+               txp[RS5C348_REG_HOURS] = BIN2BCD(tm->tm_hour);
+       } else {
+               /* hour 0 is AM12, noon is PM12 */
+               txp[RS5C348_REG_HOURS] = BIN2BCD((tm->tm_hour + 11) % 12 + 1) |
+                       (tm->tm_hour >= 12 ? RS5C348_BIT_PM : 0);
+       }
+       txp[RS5C348_REG_WDAY] = BIN2BCD(tm->tm_wday);
+       txp[RS5C348_REG_DAY] = BIN2BCD(tm->tm_mday);
+       txp[RS5C348_REG_MONTH] = BIN2BCD(tm->tm_mon + 1) |
+               (tm->tm_year >= 100 ? RS5C348_BIT_Y2K : 0);
+       txp[RS5C348_REG_YEAR] = BIN2BCD(tm->tm_year % 100);
+       /* write in one transfer to avoid data inconsistency */
+       ret = spi_write_then_read(spi, txbuf, sizeof(txbuf), NULL, 0);
+       udelay(62);     /* Tcsr 62us */
+       return ret;
+}
+
+static int
+rs5c348_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       struct rs5c348_plat_data *pdata = spi->dev.platform_data;
+       u8 txbuf[5], rxbuf[7];
+       int ret;
+
+       /* Transfer 5 byte befores reading SEC.  This gives 31us for carry. */
+       txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
+       txbuf[1] = 0;   /* dummy */
+       txbuf[2] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
+       txbuf[3] = 0;   /* dummy */
+       txbuf[4] = RS5C348_CMD_MR(RS5C348_REG_SECS); /* cmd, sec, ... */
+
+       /* read in one transfer to avoid data inconsistency */
+       ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
+                                 rxbuf, sizeof(rxbuf));
+       udelay(62);     /* Tcsr 62us */
+       if (ret < 0)
+               return ret;
+
+       tm->tm_sec = BCD2BIN(rxbuf[RS5C348_REG_SECS] & RS5C348_SECS_MASK);
+       tm->tm_min = BCD2BIN(rxbuf[RS5C348_REG_MINS] & RS5C348_MINS_MASK);
+       tm->tm_hour = BCD2BIN(rxbuf[RS5C348_REG_HOURS] & RS5C348_HOURS_MASK);
+       if (!pdata->rtc_24h) {
+               tm->tm_hour %= 12;
+               if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM)
+                       tm->tm_hour += 12;
+       }
+       tm->tm_wday = BCD2BIN(rxbuf[RS5C348_REG_WDAY] & RS5C348_WDAY_MASK);
+       tm->tm_mday = BCD2BIN(rxbuf[RS5C348_REG_DAY] & RS5C348_DAY_MASK);
+       tm->tm_mon =
+               BCD2BIN(rxbuf[RS5C348_REG_MONTH] & RS5C348_MONTH_MASK) - 1;
+       /* year is 1900 + tm->tm_year */
+       tm->tm_year = BCD2BIN(rxbuf[RS5C348_REG_YEAR]) +
+               ((rxbuf[RS5C348_REG_MONTH] & RS5C348_BIT_Y2K) ? 100 : 0);
+
+       if (rtc_valid_tm(tm) < 0) {
+               dev_err(&spi->dev, "retrieved date/time is not valid.\n");
+               rtc_time_to_tm(0, tm);
+       }
+
+       return 0;
+}
+
+static struct rtc_class_ops rs5c348_rtc_ops = {
+       .read_time      = rs5c348_rtc_read_time,
+       .set_time       = rs5c348_rtc_set_time,
+};
+
+static struct spi_driver rs5c348_driver;
+
+static int __devinit rs5c348_probe(struct spi_device *spi)
+{
+       int ret;
+       struct rtc_device *rtc;
+       struct rs5c348_plat_data *pdata;
+
+       pdata = kzalloc(sizeof(struct rs5c348_plat_data), GFP_KERNEL);
+       if (!pdata)
+               return -ENOMEM;
+       spi->dev.platform_data = pdata;
+
+       /* Check D7 of SECOND register */
+       ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_SECS));
+       if (ret < 0 || (ret & 0x80)) {
+               dev_err(&spi->dev, "not found.\n");
+               goto kfree_exit;
+       }
+
+       dev_info(&spi->dev, "chip found, driver version " DRV_VERSION "\n");
+       dev_info(&spi->dev, "spiclk %u KHz.\n",
+                (spi->max_speed_hz + 500) / 1000);
+
+       /* turn RTC on if it was not on */
+       ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
+       if (ret < 0)
+               goto kfree_exit;
+       if (ret & (RS5C348_BIT_XSTP | RS5C348_BIT_VDET)) {
+               u8 buf[2];
+               if (ret & RS5C348_BIT_VDET)
+                       dev_warn(&spi->dev, "voltage-low detected.\n");
+               buf[0] = RS5C348_CMD_W(RS5C348_REG_CTL2);
+               buf[1] = 0;
+               ret = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0);
+               if (ret < 0)
+                       goto kfree_exit;
+       }
+
+       ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL1));
+       if (ret < 0)
+               goto kfree_exit;
+       if (ret & RS5C348_BIT_24H)
+               pdata->rtc_24h = 1;
+
+       rtc = rtc_device_register(rs5c348_driver.driver.name, &spi->dev,
+                                 &rs5c348_rtc_ops, THIS_MODULE);
+
+       if (IS_ERR(rtc)) {
+               ret = PTR_ERR(rtc);
+               goto kfree_exit;
+       }
+
+       pdata->rtc = rtc;
+
+       return 0;
+ kfree_exit:
+       kfree(pdata);
+       return ret;
+}
+
+static int __devexit rs5c348_remove(struct spi_device *spi)
+{
+       struct rs5c348_plat_data *pdata = spi->dev.platform_data;
+       struct rtc_device *rtc = pdata->rtc;
+
+       if (rtc)
+               rtc_device_unregister(rtc);
+       kfree(pdata);
+       return 0;
+}
+
+static struct spi_driver rs5c348_driver = {
+       .driver = {
+               .name   = "rs5c348",
+               .bus    = &spi_bus_type,
+               .owner  = THIS_MODULE,
+       },
+       .probe  = rs5c348_probe,
+       .remove = __devexit_p(rs5c348_remove),
+};
+
+static __init int rs5c348_init(void)
+{
+       return spi_register_driver(&rs5c348_driver);
+}
+
+static __exit void rs5c348_exit(void)
+{
+       spi_unregister_driver(&rs5c348_driver);
+}
+
+module_init(rs5c348_init);
+module_exit(rs5c348_exit);
+
+MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
+MODULE_DESCRIPTION("Ricoh RS5C348 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);