pwmcmds: Add Kconfig option to allow boards to disable hardware PWM commands

Some boards may not support hardware based PWM.  Update the build so
that those commands do not need to be compiled if they are not
available.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

5 files changed, 85 insertions, 70 deletions

diff --git a/src/Kconfig b/src/Kconfig
index 0445685e..db265c96 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -21,6 +21,9 @@ config HAVE_GPIO_ADC
 config HAVE_GPIO_SPI
     bool
     default n
+config HAVE_GPIO_HARD_PWM
+    bool
+    default n
 
 config INLINE_STEPPER_HACK
     # Enables gcc to inline stepper_event() into the main timer irq handler
diff --git a/src/Makefile b/src/Makefile
index 5c7dc085..b4a4c33e 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -3,3 +3,4 @@
 src-y += sched.c command.c stepper.c basecmd.c gpiocmds.c endstop.c
 src-$(CONFIG_HAVE_GPIO_ADC) += adccmds.c
 src-$(CONFIG_HAVE_GPIO_SPI) += spicmds.c
+src-$(CONFIG_HAVE_GPIO_HARD_PWM) += pwmcmds.c
diff --git a/src/avr/Kconfig b/src/avr/Kconfig
index efc8484a..8d5d4522 100644
--- a/src/avr/Kconfig
+++ b/src/avr/Kconfig
@@ -7,6 +7,7 @@ config AVR_SELECT
     default y
     select HAVE_GPIO_ADC
     select HAVE_GPIO_SPI
+    select HAVE_GPIO_HARD_PWM
 
 config BOARD_DIRECTORY
     string
diff --git a/src/gpiocmds.c b/src/gpiocmds.c
index 283d3d2e..70608a6f 100644
--- a/src/gpiocmds.c
+++ b/src/gpiocmds.c
@@ -4,12 +4,11 @@
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
-#include <stddef.h> // offsetof
 #include "basecmd.h" // alloc_oid
-#include "board/gpio.h" // struct gpio
+#include "board/gpio.h" // struct gpio_out
 #include "board/irq.h" // irq_save
 #include "command.h" // DECL_COMMAND
-#include "sched.h" // DECL_TASK
+#include "sched.h" // sched_timer
 
 
 /****************************************************************
@@ -87,73 +86,6 @@ DECL_COMMAND(command_set_digital_out, "set_digital_out pin=%u value=%c");
 
 
 /****************************************************************
- * Hardware PWM pins
- ****************************************************************/
-
-struct pwm_out_s {
-    struct timer timer;
-    struct gpio_pwm pin;
-    uint32_t max_duration;
-    uint8_t value, default_value;
-};
-
-static uint8_t
-pwm_event(struct timer *timer)
-{
-    struct pwm_out_s *p = container_of(timer, struct pwm_out_s, timer);
-    gpio_pwm_write(p->pin, p->value);
-    if (p->value == p->default_value || !p->max_duration)
-        return SF_DONE;
-    p->timer.waketime += p->max_duration;
-    p->timer.func = digital_end_event;
-    return SF_RESCHEDULE;
-}
-
-void
-command_config_pwm_out(uint32_t *args)
-{
-    struct pwm_out_s *p = alloc_oid(args[0], command_config_pwm_out, sizeof(*p));
-    p->default_value = args[3];
-    p->pin = gpio_pwm_setup(args[1], args[2], p->default_value);
-    p->max_duration = args[4];
-}
-DECL_COMMAND(command_config_pwm_out,
-             "config_pwm_out oid=%c pin=%u cycle_ticks=%u default_value=%c"
-             " max_duration=%u");
-
-void
-command_schedule_pwm_out(uint32_t *args)
-{
-    struct pwm_out_s *p = lookup_oid(args[0], command_config_pwm_out);
-    sched_del_timer(&p->timer);
-    p->timer.func = pwm_event;
-    p->timer.waketime = args[1];
-    p->value = args[2];
-    sched_timer(&p->timer);
-}
-DECL_COMMAND(command_schedule_pwm_out,
-             "schedule_pwm_out oid=%c clock=%u value=%c");
-
-static void
-pwm_shutdown(void)
-{
-    uint8_t i;
-    struct pwm_out_s *p;
-    foreach_oid(i, p, command_config_pwm_out) {
-        gpio_pwm_write(p->pin, p->default_value);
-    }
-}
-DECL_SHUTDOWN(pwm_shutdown);
-
-void
-command_set_pwm_out(uint32_t *args)
-{
-    gpio_pwm_setup(args[0], args[1], args[2]);
-}
-DECL_COMMAND(command_set_pwm_out, "set_pwm_out pin=%u cycle_ticks=%u value=%c");
-
-
-/****************************************************************
  * Soft PWM output pins
  ****************************************************************/
 
diff --git a/src/pwmcmds.c b/src/pwmcmds.c
new file mode 100644
index 00000000..bc9fec03
--- /dev/null
+++ b/src/pwmcmds.c
@@ -0,0 +1,78 @@
+// Commands for controlling hardware based pulse-width-modulator pins
+//
+// Copyright (C) 2016  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "basecmd.h" // alloc_oid
+#include "board/gpio.h" // struct gpio_pwm
+#include "command.h" // DECL_COMMAND
+#include "sched.h" // sched_timer
+
+struct pwm_out_s {
+    struct timer timer;
+    struct gpio_pwm pin;
+    uint32_t max_duration;
+    uint8_t value, default_value;
+};
+
+static uint8_t
+pwm_end_event(struct timer *timer)
+{
+    shutdown("Missed scheduling of next hard pwm event");
+}
+
+static uint8_t
+pwm_event(struct timer *timer)
+{
+    struct pwm_out_s *p = container_of(timer, struct pwm_out_s, timer);
+    gpio_pwm_write(p->pin, p->value);
+    if (p->value == p->default_value || !p->max_duration)
+        return SF_DONE;
+    p->timer.waketime += p->max_duration;
+    p->timer.func = pwm_end_event;
+    return SF_RESCHEDULE;
+}
+
+void
+command_config_pwm_out(uint32_t *args)
+{
+    struct pwm_out_s *p = alloc_oid(args[0], command_config_pwm_out, sizeof(*p));
+    p->default_value = args[3];
+    p->pin = gpio_pwm_setup(args[1], args[2], p->default_value);
+    p->max_duration = args[4];
+}
+DECL_COMMAND(command_config_pwm_out,
+             "config_pwm_out oid=%c pin=%u cycle_ticks=%u default_value=%c"
+             " max_duration=%u");
+
+void
+command_schedule_pwm_out(uint32_t *args)
+{
+    struct pwm_out_s *p = lookup_oid(args[0], command_config_pwm_out);
+    sched_del_timer(&p->timer);
+    p->timer.func = pwm_event;
+    p->timer.waketime = args[1];
+    p->value = args[2];
+    sched_timer(&p->timer);
+}
+DECL_COMMAND(command_schedule_pwm_out,
+             "schedule_pwm_out oid=%c clock=%u value=%c");
+
+static void
+pwm_shutdown(void)
+{
+    uint8_t i;
+    struct pwm_out_s *p;
+    foreach_oid(i, p, command_config_pwm_out) {
+        gpio_pwm_write(p->pin, p->default_value);
+    }
+}
+DECL_SHUTDOWN(pwm_shutdown);
+
+void
+command_set_pwm_out(uint32_t *args)
+{
+    gpio_pwm_setup(args[0], args[1], args[2]);
+}
+DECL_COMMAND(command_set_pwm_out, "set_pwm_out pin=%u cycle_ticks=%u value=%c");