patch-2.4.22 linux-2.4.22/arch/mips/lasat/ds1603.c

• Lines: 175
• Date: 2003-08-25 04:44:40.000000000 -0700
• Orig file: linux-2.4.21/arch/mips/lasat/ds1603.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.21/arch/mips/lasat/ds1603.c linux-2.4.22/arch/mips/lasat/ds1603.c
@@ -0,0 +1,174 @@
+/* 
+ * Dallas Semiconductors 1603 RTC driver 
+ *
+ * Brian Murphy <brian@murphy.dk> 
+ *
+ */
+#include <linux/kernel.h>
+#include <asm/lasat/lasat.h>
+#include <linux/delay.h>
+#include <asm/lasat/ds1603.h>
+
+#include "ds1603.h"
+
+#define READ_TIME_CMD 0x81
+#define SET_TIME_CMD 0x80
+#define TRIMMER_SET_CMD 0xC0
+#define TRIMMER_VALUE_MASK 0x38
+#define TRIMMER_SHIFT 3
+
+struct ds_defs *ds1603 = NULL;
+
+/* HW specific register functions */
+static void rtc_reg_write(unsigned long val) 
+{
+	*ds1603->reg = val;
+}
+
+static unsigned long rtc_reg_read(void) 
+{
+	unsigned long tmp = *ds1603->reg;
+	return tmp;
+}
+
+static unsigned long rtc_datareg_read(void)
+{
+	unsigned long tmp = *ds1603->data_reg;
+	return tmp;
+}
+
+static void rtc_nrst_high(void)
+{
+	rtc_reg_write(rtc_reg_read() | ds1603->rst);
+}
+
+static void rtc_nrst_low(void)
+{
+	rtc_reg_write(rtc_reg_read() & ~ds1603->rst);
+}
+
+static void rtc_cycle_clock(unsigned long data)
+{
+	data |= ds1603->clk;
+	rtc_reg_write(data);
+	ndelay(250);
+	if (ds1603->data_reversed)
+		data &= ~ds1603->data;
+	else
+		data |= ds1603->data;
+	data &= ~ds1603->clk;
+	rtc_reg_write(data);
+	ndelay(250 + ds1603->huge_delay);
+}
+
+static void rtc_write_databit(unsigned int bit)
+{
+	unsigned long data = rtc_reg_read();
+	if (ds1603->data_reversed)
+		bit = !bit;
+	if (bit)
+		data |= ds1603->data;
+	else
+		data &= ~ds1603->data;
+
+	rtc_reg_write(data);
+	ndelay(50 + ds1603->huge_delay);
+	rtc_cycle_clock(data);
+}
+
+static unsigned int rtc_read_databit(void)
+{
+	unsigned int data;
+
+	data = (rtc_datareg_read() & (1 << ds1603->data_read_shift)) 
+		>> ds1603->data_read_shift;
+	rtc_cycle_clock(rtc_reg_read());
+	return data;
+}
+
+static void rtc_write_byte(unsigned int byte)
+{
+	int i;
+
+	for (i = 0; i<=7; i++) {
+		rtc_write_databit(byte & 1L);
+		byte >>= 1;
+	}
+}
+
+static void rtc_write_word(unsigned long word)
+{
+	int i;
+
+	for (i = 0; i<=31; i++) {
+		rtc_write_databit(word & 1L);
+		word >>= 1;
+	}
+}
+
+static unsigned long rtc_read_word(void)
+{
+	int i;
+	unsigned long word = 0;
+	unsigned long shift = 0;
+
+	for (i = 0; i<=31; i++) {
+		word |= rtc_read_databit() << shift;
+		shift++;
+	}
+	return word;
+}
+
+static void rtc_init_op(void)
+{
+	rtc_nrst_high();
+
+	rtc_reg_write(rtc_reg_read() & ~ds1603->clk);
+
+	ndelay(50);
+}
+
+static void rtc_end_op(void)
+{
+	rtc_nrst_low();
+	ndelay(1000);
+}
+
+/* interface */
+unsigned long ds1603_read(void)
+{
+	unsigned long word;
+	rtc_init_op();
+	rtc_write_byte(READ_TIME_CMD);
+	word = rtc_read_word();
+	rtc_end_op();
+	return word;
+}
+
+int ds1603_set(unsigned long time)
+{
+	rtc_init_op();
+	rtc_write_byte(SET_TIME_CMD);
+	rtc_write_word(time);
+	rtc_end_op();
+
+	return 0;
+}
+
+void ds1603_set_trimmer(unsigned int trimval)
+{
+	rtc_init_op();
+	rtc_write_byte(((trimval << TRIMMER_SHIFT) & TRIMMER_VALUE_MASK)
+			| (TRIMMER_SET_CMD));
+	rtc_end_op();
+}
+
+void ds1603_disable(void)
+{
+	ds1603_set_trimmer(TRIMMER_DISABLE_RTC);
+}
+
+void ds1603_enable(void)
+{
+	ds1603_set_trimmer(TRIMMER_DEFAULT);
+}