File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/mips/lasat/ds1603.c b/arch/mips/lasat/ds1603.c
new file mode 100644
index 0000000..c6fd96f
--- /dev/null
+++ b/arch/mips/lasat/ds1603.c
@@ -0,0 +1,184 @@
+/*
+ * 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 <asm/time.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;
+
+/* 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);
+ lasat_ndelay(250);
+ if (ds1603->data_reversed)
+ data &= ~ds1603->data;
+ else
+ data |= ds1603->data;
+ data &= ~ds1603->clk;
+ rtc_reg_write(data);
+ lasat_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);
+ lasat_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);
+
+ lasat_ndelay(50);
+}
+
+static void rtc_end_op(void)
+{
+ rtc_nrst_low();
+ lasat_ndelay(1000);
+}
+
+void read_persistent_clock(struct timespec *ts)
+{
+ unsigned long word;
+ unsigned long flags;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ rtc_init_op();
+ rtc_write_byte(READ_TIME_CMD);
+ word = rtc_read_word();
+ rtc_end_op();
+ spin_unlock_irqrestore(&rtc_lock, flags);
+
+ ts->tv_sec = word;
+ ts->tv_nsec = 0;
+}
+
+int rtc_mips_set_mmss(unsigned long time)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ rtc_init_op();
+ rtc_write_byte(SET_TIME_CMD);
+ rtc_write_word(time);
+ rtc_end_op();
+ spin_unlock_irqrestore(&rtc_lock, flags);
+
+ 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);
+}