Add support for setting and reading timer (#8)

* Add ioctl command for reading and writing BM8563_TIMER_CONTROL
* Add ioctl command for reading and writing BM8563_TIMER
* Add unit tests for reading and writing timer

uint8_t count = 10;
uint8_t control = BM8563_TIMER_ENABLE | BM8563_TIMER_1HZ;

bm8563_ioctl(&bm, BM8563_TIMER_WRITE, &count);
bm8563_ioctl(&bm, BM8563_TIMER_CONTROL_WRITE, &control);

CHANGELOG.md

@@ -5,6 +5,7 @@ All notable changes to this project will be documented in this file, in reverse
 ## [0.5.0](https://github.com/tuupola/bm8563/compare/0.4.0...master) - unreleased
 
 ### Added
+- Support for reading and writing timers ([#8](https://github.com/tuupola/bm8563/pull/8)).
 - Support for reading and writing control status registers ([#5](https://github.com/tuupola/bm8563/pull/5)).
 - Support for reading and writing alarms ([#4](https://github.com/tuupola/bm8563/pull/4), [#5](https://github.com/tuupola/bm8563/pull/5)).
 - Support for low voltage warnings ([#3](https://github.com/tuupola/bm8563/pull/3)).

README.md

@@ -126,6 +126,44 @@ bm8563_init(&bm);
 bm8563_ioctl(&bm, BM8563_ALARM_READ, &rtc_alarm);
 ```
 
+## Set RTC timer
+
+```c
+#include "bm8563.h"
+#include "user_i2c.h"
+
+uint8_t count, control;
+bm8563_t bm;
+
+/* Add pointers to user provided functions. */
+bm.read = &user_i2c_read;
+bm.write = &user_i2c_write;
+
+bm8563_init(&bm);
+
+/* Create a 10 second timer. */
+count = 10;
+control = BM8563_TIMER_ENABLE | BM8563_TIMER_1HZ;
+
+bm8563_ioctl(&bm, BM8563_TIMER_WRITE, &count);
+bm8563_ioctl(&bm, BM8563_TIMER_CONTROL_WRITE, &control);
+
+/* Prints "Timer!" every 10 seconds. */
+while (1) {
+    bm8563_ioctl(&bm, BM8563_CONTROL_STATUS2_READ, &control);
+    /* Check for timer flag. */
+    if (control & BM8563_TF) {
+        printf("Timer!\n");
+
+        /* Clear timer flag. */
+        tmp &= ~BM8563_TF;
+        bm8563_ioctl(&bm, BM8563_CONTROL_STATUS2_WRITE, &tmp);
+    }
+}
+
+```
+
+
 ## License
 
 The MIT License (MIT). Please see [License File](LICENSE.txt) for more information.

bm8563.c

@@ -254,13 +254,17 @@ bm8563_err_t bm8563_ioctl(const bm8563_t *bm, int16_t command, void *buffer)
 
     case BM8563_CONTROL_STATUS1_READ:
     case BM8563_CONTROL_STATUS2_READ:
+    case BM8563_TIMER_CONTROL_READ:
+    case BM8563_TIMER_READ:
         return bm->read(
             bm->handle, BM8563_ADDRESS, reg, (uint8_t *)buffer, 1
         );
         break;
 
     case BM8563_CONTROL_STATUS1_WRITE:
     case BM8563_CONTROL_STATUS2_WRITE:
+    case BM8563_TIMER_CONTROL_WRITE:
+    case BM8563_TIMER_WRITE:
         return bm->write(
             bm->handle, BM8563_ADDRESS, reg, (uint8_t *)buffer, 1
         );

bm8563.h

@@ -70,13 +70,25 @@ extern "C" {
 #define BM8563_ALARM_NONE       (0xff)
 #define BM8563_ALARM_SIZE       (0x04)
 
+#define BM8563_TIMER_CONTROL    (0x0e)
+#define BM8563_TIMER_ENABLE     (0b10000000)
+#define BM8563_TIMER_4_096KHZ   (0b00000000)
+#define BM8563_TIMER_64HZ       (0b00000001)
+#define BM8563_TIMER_1HZ        (0b00000010)
+#define BM8563_TIMER_1_60HZ     (0b00000011)
+#define BM8563_TIMER            (0x0f)
+
 /* IOCTL commands */
 #define BM8563_ALARM_SET        (0x0900)
 #define BM8563_ALARM_READ       (0x0901)
 #define BM8563_CONTROL_STATUS1_READ     (0x0000)
 #define BM8563_CONTROL_STATUS1_WRITE    (0x0001)
 #define BM8563_CONTROL_STATUS2_READ     (0x0100)
 #define BM8563_CONTROL_STATUS2_WRITE    (0x0101)
+#define BM8563_TIMER_CONTROL_READ       (0x0e00)
+#define BM8563_TIMER_CONTROL_WRITE      (0x0e01)
+#define BM8563_TIMER_READ               (0x0f00)
+#define BM8563_TIMER_WRITE              (0x0f01)
 
 /* Status codes. */
 #define BM8563_ERROR_NOTTY      (-1)

tests/unit.c

@@ -155,6 +155,29 @@ TEST should_read_and_write_alarm(void) {
     PASS();
 }
 
+TEST should_read_and_write_timer(void) {
+    uint8_t count = 10;
+    uint8_t reg =  BM8563_TIMER_ENABLE | BM8563_TIMER_1HZ;
+
+    bm8563_t bm;
+    bm.read = &mock_i2c_read;
+    bm.write = &mock_i2c_write;
+
+    ASSERT(BM8563_OK == bm8563_init(&bm));
+    ASSERT(BM8563_OK == bm8563_ioctl(&bm, BM8563_TIMER_WRITE, &count));
+    ASSERT(BM8563_OK == bm8563_ioctl(&bm, BM8563_TIMER_CONTROL_WRITE, &reg));
+
+    count = 0;
+    reg = 0;
+
+    ASSERT(BM8563_OK == bm8563_ioctl(&bm, BM8563_TIMER_READ, &count));
+    ASSERT(BM8563_OK == bm8563_ioctl(&bm, BM8563_TIMER_CONTROL_READ, &reg));
+    ASSERT(10 == count);
+    ASSERT((BM8563_TIMER_ENABLE | BM8563_TIMER_1HZ) == reg);
+
+    PASS();
+}
+
 GREATEST_MAIN_DEFS();
 
 int main(int argc, char **argv) {
@@ -168,6 +191,7 @@ int main(int argc, char **argv) {
     RUN_TEST(should_read_and_write_time);
     RUN_TEST(should_handle_century);
     RUN_TEST(should_read_and_write_alarm);
+    RUN_TEST(should_read_and_write_timer);
 
     GREATEST_MAIN_END();
 }