led: new module

This module controls the blinking of the user LED.

6 files changed, 168 insertions, 5 deletions

diff --git a/Makefile b/Makefile
index 5b13655..d1688a2 100644
--- a/Makefile
+++ b/Makefile
@@ -181,6 +181,7 @@ SOURCES = \
 	src/cpu_asm.S \
 	src/flash.c \
 	src/gpio.c \
+	src/led.c \
 	src/main.c \
 	src/mem.c \
 	src/mutex.c \
diff --git a/src/gpio.c b/src/gpio.c
index fa368c7..a545c69 100644
--- a/src/gpio.c
+++ b/src/gpio.c
@@ -20,6 +20,7 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <stdbool.h>
 #include <stdint.h>
 
 #include "gpio.h"
@@ -50,14 +51,14 @@ gpio_compute_location(unsigned int io, unsigned int nr_bits,
 }
 
 static void
-gpio_set(volatile struct gpio_regs *regs, unsigned int io,
-         uint32_t af, uint32_t speed, uint32_t pupd)
+gpio_set_af(volatile struct gpio_regs *regs, unsigned int io,
+            uint32_t af, uint32_t speed, uint32_t pupd)
 {
     uint32_t shift, mask, value;
     volatile uint32_t *reg;
 
     gpio_compute_location(io, 2, &shift, &mask);
-    value = (af == 0) ? 1 : 2;
+    value = (af == 15) ? 1 : 2;
     regs->moder &= ~mask;
     regs->moder |= value << shift;
 
@@ -81,9 +82,37 @@ gpio_set(volatile struct gpio_regs *regs, unsigned int io,
     *reg |= af << shift;
 }
 
+static void
+gpio_set_output(volatile struct gpio_regs *regs, unsigned int io, bool high)
+{
+    uint32_t shift, mask;
+
+    gpio_set_af(gpio_c_regs, io, 15, 0, 0);
+
+    gpio_compute_location(io, 1, &shift, &mask);
+
+    if (high) {
+        regs->odr |= high << shift;
+    } else {
+        regs->odr &= ~mask;
+    }
+}
+
 void
 gpio_setup(void)
 {
-    gpio_set(gpio_c_regs, 6, 8, 1, 1);
-    gpio_set(gpio_c_regs, 7, 8, 1, 1);
+    gpio_set_af(gpio_c_regs, 6, 8, 1, 1); /* UART6 TX */
+    gpio_set_af(gpio_c_regs, 7, 8, 1, 1); /* UART6 RX */
+}
+
+void
+gpio_led_on(void)
+{
+    gpio_set_output(gpio_c_regs, 13, true);
+}
+
+void
+gpio_led_off(void)
+{
+    gpio_set_output(gpio_c_regs, 13, false);
 }
diff --git a/src/gpio.h b/src/gpio.h
index 4330b9c..363497b 100644
--- a/src/gpio.h
+++ b/src/gpio.h
@@ -28,4 +28,7 @@
  */
 void gpio_setup(void);
 
+void gpio_led_on(void);
+void gpio_led_off(void);
+
 #endif /* _GPIO_H */
diff --git a/src/led.c b/src/led.c
new file mode 100644
index 0000000..3a49f77
--- /dev/null
+++ b/src/led.c
@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2018 Richard Braun.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <lib/shell.h>
+
+#include "gpio.h"
+#include "led.h"
+#include "thread.h"
+#include "timer.h"
+
+#define LED_BLINK_INTERVAL THREAD_SCHED_FREQ
+
+static struct timer led_timer;
+static bool led_on;
+static volatile bool led_blinking_enabled;
+
+static void
+led_shell_blink(int argc, char **argv)
+{
+    bool enabled;
+
+    if (argc != 2) {
+        goto error;
+    }
+
+    if (strcmp(argv[1], "on") == 0) {
+        enabled = true;
+    } else if (strcmp(argv[1], "off") == 0) {
+        enabled = false;
+    } else {
+        goto error;
+    }
+
+    led_blinking_enabled = enabled;
+
+    return;
+
+error:
+    printf("led: error: invalid arguments\n");
+}
+
+static struct shell_cmd led_shell_cmds[] = {
+    SHELL_CMD_INITIALIZER("led_blink", led_shell_blink,
+        "led_blink <on|off>",
+        "control led blinking"),
+};
+
+static void
+led_toggle(void *arg)
+{
+    (void)arg;
+
+    if (led_blinking_enabled) {
+        if (led_on) {
+            gpio_led_off();
+        } else {
+            gpio_led_on();
+        }
+    }
+
+    led_on = !led_on;
+    timer_schedule(&led_timer, timer_get_time(&led_timer) + LED_BLINK_INTERVAL);
+}
+
+void
+led_setup(void)
+{
+    gpio_led_off();
+    led_on = false;
+    led_blinking_enabled = true;
+
+    SHELL_REGISTER_CMDS(led_shell_cmds);
+
+    timer_init(&led_timer, led_toggle, NULL);
+    timer_schedule(&led_timer, timer_now() + LED_BLINK_INTERVAL);
+}
diff --git a/src/led.h b/src/led.h
new file mode 100644
index 0000000..e25efb4
--- /dev/null
+++ b/src/led.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2018 Richard Braun.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _LED_H
+#define _LED_H
+
+void led_setup(void);
+
+#endif /* _LED_H */
diff --git a/src/main.c b/src/main.c
index aa64234..d06afc0 100644
--- a/src/main.c
+++ b/src/main.c
@@ -26,6 +26,7 @@
 #include <lib/shell.h>
 
 #include "cpu.h"
+#include "led.h"
 #include "main.h"
 #include "mem.h"
 #include "panic.h"
@@ -51,6 +52,7 @@ main(void)
     thread_setup();
     timer_setup();
     shell_setup();
+    led_setup();
     sw_setup();
 
     printf("X1 " QUOTE(VERSION) "\n\n");