1 files changed, 142 insertions, 0 deletions
diff --git a/src/atsam/gpio.c b/src/atsam/gpio.c
new file mode 100644
index 00000000..7e6a1dab
--- /dev/null
+++ b/src/atsam/gpio.c
@@ -0,0 +1,142 @@
+// GPIO functions on sam3/sam4
+//
+// Copyright (C) 2016-2018  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "board/irq.h" // irq_save
+#include "command.h" // shutdown
+#include "compiler.h" // ARRAY_SIZE
+#include "gpio.h" // gpio_out_setup
+#include "internal.h" // gpio_peripheral
+#include "sched.h" // sched_shutdown
+
+static Pio * const digital_regs[] = {
+#if CONFIG_MACH_SAM3X8E
+    PIOA, PIOB, PIOC, PIOD
+#elif CONFIG_MACH_SAM4S8C
+    PIOA, PIOB, PIOC
+#elif CONFIG_MACH_SAM4E8E
+    PIOA, PIOB, PIOC, PIOD, PIOE
+#endif
+};
+
+
+/****************************************************************
+ * Pin multiplexing
+ ****************************************************************/
+
+void
+gpio_peripheral(uint32_t gpio, char ptype, int32_t pull_up)
+{
+    uint32_t bank = GPIO2PORT(gpio), bit = GPIO2BIT(gpio), pt = ptype - 'A';
+    Pio *regs = digital_regs[bank];
+
+#if CONFIG_MACH_SAM3X8E
+    regs->PIO_ABSR = (regs->PIO_ABSR & ~bit) | (pt & 0x01 ? bit : 0);
+#else
+    regs->PIO_ABCDSR[0] = (regs->PIO_ABCDSR[0] & ~bit) | (pt & 0x01 ? bit : 0);
+    regs->PIO_ABCDSR[1] = (regs->PIO_ABCDSR[1] & ~bit) | (pt & 0x02 ? bit : 0);
+#endif
+
+    if (pull_up > 0)
+        regs->PIO_PUER = bit;
+    else
+        regs->PIO_PUDR = bit;
+    regs->PIO_PDR = bit;
+}
+
+
+/****************************************************************
+ * General Purpose Input Output (GPIO) pins
+ ****************************************************************/
+
+struct gpio_out
+gpio_out_setup(uint8_t pin, uint8_t val)
+{
+    if (GPIO2PORT(pin) >= ARRAY_SIZE(digital_regs))
+        goto fail;
+    Pio *regs = digital_regs[GPIO2PORT(pin)];
+    struct gpio_out g = { .regs=regs, .bit=GPIO2BIT(pin) };
+    gpio_out_reset(g, val);
+    return g;
+fail:
+    shutdown("Not an output pin");
+}
+
+void
+gpio_out_reset(struct gpio_out g, uint8_t val)
+{
+    Pio *regs = g.regs;
+    irqstatus_t flag = irq_save();
+    if (val)
+        regs->PIO_SODR = g.bit;
+    else
+        regs->PIO_CODR = g.bit;
+    regs->PIO_OER = g.bit;
+    regs->PIO_OWER = g.bit;
+    regs->PIO_PER = g.bit;
+    regs->PIO_PUDR = g.bit;
+    irq_restore(flag);
+}
+
+void
+gpio_out_toggle_noirq(struct gpio_out g)
+{
+    Pio *regs = g.regs;
+    regs->PIO_ODSR ^= g.bit;
+}
+
+void
+gpio_out_toggle(struct gpio_out g)
+{
+    irqstatus_t flag = irq_save();
+    gpio_out_toggle_noirq(g);
+    irq_restore(flag);
+}
+
+void
+gpio_out_write(struct gpio_out g, uint8_t val)
+{
+    Pio *regs = g.regs;
+    if (val)
+        regs->PIO_SODR = g.bit;
+    else
+        regs->PIO_CODR = g.bit;
+}
+
+
+struct gpio_in
+gpio_in_setup(uint8_t pin, int8_t pull_up)
+{
+    if (GPIO2PORT(pin) >= ARRAY_SIZE(digital_regs))
+        goto fail;
+    uint32_t port = GPIO2PORT(pin);
+    enable_pclock(ID_PIOA + port);
+    struct gpio_in g = { .regs=digital_regs[port], .bit=GPIO2BIT(pin) };
+    gpio_in_reset(g, pull_up);
+    return g;
+fail:
+    shutdown("Not an input pin");
+}
+
+void
+gpio_in_reset(struct gpio_in g, int8_t pull_up)
+{
+    Pio *regs = g.regs;
+    irqstatus_t flag = irq_save();
+    if (pull_up)
+        regs->PIO_PUER = g.bit;
+    else
+        regs->PIO_PUDR = g.bit;
+    regs->PIO_ODR = g.bit;
+    regs->PIO_PER = g.bit;
+    irq_restore(flag);
+}
+
+uint8_t
+gpio_in_read(struct gpio_in g)
+{
+    Pio *regs = g.regs;
+    return !!(regs->PIO_PDSR & g.bit);
+}