--- /dev/null
+/*
+ * RTC routines for RICOH Rx5C348 SPI chip.
+ * Copyright (C) 2000-2001 Toshiba Corporation
+ *
+ * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
+ * terms of the GNU General Public License version 2. This program is
+ * licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/rtc.h>
+#include <linux/time.h>
+#include <linux/bcd.h>
+#include <asm/time.h>
+#include <asm/tx4938/spi.h>
+
+#define EPOCH 2000
+
+/* registers */
+#define Rx5C348_REG_SECOND 0
+#define Rx5C348_REG_MINUTE 1
+#define Rx5C348_REG_HOUR 2
+#define Rx5C348_REG_WEEK 3
+#define Rx5C348_REG_DAY 4
+#define Rx5C348_REG_MONTH 5
+#define Rx5C348_REG_YEAR 6
+#define Rx5C348_REG_ADJUST 7
+#define Rx5C348_REG_ALARM_W_MIN 8
+#define Rx5C348_REG_ALARM_W_HOUR 9
+#define Rx5C348_REG_ALARM_W_WEEK 10
+#define Rx5C348_REG_ALARM_D_MIN 11
+#define Rx5C348_REG_ALARM_D_HOUR 12
+#define Rx5C348_REG_CTL1 14
+#define Rx5C348_REG_CTL2 15
+
+/* register bits */
+#define Rx5C348_BIT_PM 0x20 /* REG_HOUR */
+#define Rx5C348_BIT_Y2K 0x80 /* REG_MONTH */
+#define Rx5C348_BIT_24H 0x20 /* REG_CTL1 */
+#define Rx5C348_BIT_XSTP 0x10 /* REG_CTL2 */
+
+/* commands */
+#define Rx5C348_CMD_W(addr) (((addr) << 4) | 0x08) /* single write */
+#define Rx5C348_CMD_R(addr) (((addr) << 4) | 0x0c) /* single read */
+#define Rx5C348_CMD_MW(addr) (((addr) << 4) | 0x00) /* burst write */
+#define Rx5C348_CMD_MR(addr) (((addr) << 4) | 0x04) /* burst read */
+
+static struct spi_dev_desc srtc_dev_desc = {
+ .baud = 1000000, /* 1.0Mbps @ Vdd 2.0V */
+ .tcss = 31,
+ .tcsh = 1,
+ .tcsr = 62,
+ /* 31us for Tcss (62us for Tcsr) is required for carry operation) */
+ .byteorder = 1, /* MSB-First */
+ .polarity = 0, /* High-Active */
+ .phase = 1, /* Shift-Then-Sample */
+
+};
+static int srtc_chipid;
+static int srtc_24h;
+
+static inline int
+spi_rtc_io(unsigned char *inbuf, unsigned char *outbuf, unsigned int count)
+{
+ unsigned char *inbufs[1], *outbufs[1];
+ unsigned int incounts[2], outcounts[2];
+ inbufs[0] = inbuf;
+ incounts[0] = count;
+ incounts[1] = 0;
+ outbufs[0] = outbuf;
+ outcounts[0] = count;
+ outcounts[1] = 0;
+ return txx9_spi_io(srtc_chipid, &srtc_dev_desc,
+ inbufs, incounts, outbufs, outcounts, 0);
+}
+
+/* RTC-dependent code for time.c */
+
+static int
+rtc_rx5c348_set_time(unsigned long t)
+{
+ unsigned char inbuf[8];
+ struct rtc_time tm;
+ u8 year, month, day, hour, minute, second, century;
+
+ /* convert */
+ to_tm(t, &tm);
+
+ year = tm.tm_year % 100;
+ month = tm.tm_mon+1; /* tm_mon starts from 0 to 11 */
+ day = tm.tm_mday;
+ hour = tm.tm_hour;
+ minute = tm.tm_min;
+ second = tm.tm_sec;
+ century = tm.tm_year / 100;
+
+ inbuf[0] = Rx5C348_CMD_MW(Rx5C348_REG_SECOND);
+ BIN_TO_BCD(second);
+ inbuf[1] = second;
+ BIN_TO_BCD(minute);
+ inbuf[2] = minute;
+
+ if (srtc_24h) {
+ BIN_TO_BCD(hour);
+ inbuf[3] = hour;
+ } else {
+ /* hour 0 is AM12, noon is PM12 */
+ inbuf[3] = 0;
+ if (hour >= 12)
+ inbuf[3] = Rx5C348_BIT_PM;
+ hour = (hour + 11) % 12 + 1;
+ BIN_TO_BCD(hour);
+ inbuf[3] |= hour;
+ }
+ inbuf[4] = 0; /* ignore week */
+ BIN_TO_BCD(day);
+ inbuf[5] = day;
+ BIN_TO_BCD(month);
+ inbuf[6] = month;
+ if (century >= 20)
+ inbuf[6] |= Rx5C348_BIT_Y2K;
+ BIN_TO_BCD(year);
+ inbuf[7] = year;
+ /* write in one transfer to avoid data inconsistency */
+ return spi_rtc_io(inbuf, NULL, 8);
+}
+
+static unsigned long
+rtc_rx5c348_get_time(void)
+{
+ unsigned char inbuf[8], outbuf[8];
+ unsigned int year, month, day, hour, minute, second;
+
+ inbuf[0] = Rx5C348_CMD_MR(Rx5C348_REG_SECOND);
+ memset(inbuf + 1, 0, 7);
+ /* read in one transfer to avoid data inconsistency */
+ if (spi_rtc_io(inbuf, outbuf, 8))
+ return 0;
+ second = outbuf[1];
+ BCD_TO_BIN(second);
+ minute = outbuf[2];
+ BCD_TO_BIN(minute);
+ if (srtc_24h) {
+ hour = outbuf[3];
+ BCD_TO_BIN(hour);
+ } else {
+ hour = outbuf[3] & ~Rx5C348_BIT_PM;
+ BCD_TO_BIN(hour);
+ hour %= 12;
+ if (outbuf[3] & Rx5C348_BIT_PM)
+ hour += 12;
+ }
+ day = outbuf[5];
+ BCD_TO_BIN(day);
+ month = outbuf[6] & ~Rx5C348_BIT_Y2K;
+ BCD_TO_BIN(month);
+ year = outbuf[7];
+ BCD_TO_BIN(year);
+ year += EPOCH;
+
+ return mktime(year, month, day, hour, minute, second);
+}
+
+void __init
+rtc_rx5c348_init(int chipid)
+{
+ unsigned char inbuf[2], outbuf[2];
+ srtc_chipid = chipid;
+ /* turn on RTC if it is not on */
+ inbuf[0] = Rx5C348_CMD_R(Rx5C348_REG_CTL2);
+ inbuf[1] = 0;
+ spi_rtc_io(inbuf, outbuf, 2);
+ if (outbuf[1] & Rx5C348_BIT_XSTP) {
+ inbuf[0] = Rx5C348_CMD_W(Rx5C348_REG_CTL2);
+ inbuf[1] = 0;
+ spi_rtc_io(inbuf, NULL, 2);
+ }
+
+ inbuf[0] = Rx5C348_CMD_R(Rx5C348_REG_CTL1);
+ inbuf[1] = 0;
+ spi_rtc_io(inbuf, outbuf, 2);
+ if (outbuf[1] & Rx5C348_BIT_24H)
+ srtc_24h = 1;
+
+ /* set the function pointers */
+ rtc_mips_get_time = rtc_rx5c348_get_time;
+ rtc_mips_set_time = rtc_rx5c348_set_time;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff