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// GPIO functions on rp2040
//
// Copyright (C) 2021 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU GPLv3 license.
#include <string.h> // ffs
#include "board/irq.h" // irq_save
#include "command.h" // shutdown
#include "gpio.h" // gpio_out_setup
#include "hardware/structs/iobank0.h" // iobank0_hw
#include "hardware/structs/padsbank0.h" // padsbank0_hw
#include "hardware/structs/sio.h" // sio_hw
#include "internal.h" // gpio_peripheral
#include "sched.h" // sched_shutdown
/****************************************************************
* Pin mappings
****************************************************************/
DECL_ENUMERATION_RANGE("pin", "gpio0", 0, 30);
// Set the mode and extended function of a pin
void
gpio_peripheral(uint32_t gpio, int func, int pull_up)
{
padsbank0_hw->io[gpio] = (
PADS_BANK0_GPIO0_IE_BITS
| (PADS_BANK0_GPIO0_DRIVE_VALUE_4MA << PADS_BANK0_GPIO0_DRIVE_MSB)
| (pull_up > 0 ? PADS_BANK0_GPIO0_PUE_BITS : 0)
| (pull_up < 0 ? PADS_BANK0_GPIO0_PDE_BITS : 0));
iobank0_hw->io[gpio].ctrl = func << IO_BANK0_GPIO0_CTRL_FUNCSEL_LSB;
}
// Convert a register and bit location back to an integer pin identifier
static int
mask_to_pin(uint32_t mask)
{
return ffs(mask)-1;
}
/****************************************************************
* General Purpose Input Output (GPIO) pins
****************************************************************/
struct gpio_out
gpio_out_setup(uint8_t pin, uint8_t val)
{
if (pin >= 30)
goto fail;
struct gpio_out g = { .bit=1<<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)
{
int pin = mask_to_pin(g.bit);
irqstatus_t flag = irq_save();
gpio_out_write(g, val);
sio_hw->gpio_oe_set = g.bit;
gpio_peripheral(pin, 5, 0);
irq_restore(flag);
}
void
gpio_out_toggle_noirq(struct gpio_out g)
{
sio_hw->gpio_togl = g.bit;
}
void
gpio_out_toggle(struct gpio_out g)
{
gpio_out_toggle_noirq(g);
}
void
gpio_out_write(struct gpio_out g, uint8_t val)
{
if (val)
sio_hw->gpio_set = g.bit;
else
sio_hw->gpio_clr = g.bit;
}
struct gpio_in
gpio_in_setup(uint8_t pin, int8_t pull_up)
{
if (pin >= 30)
goto fail;
struct gpio_in g = { .bit=1<<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)
{
int pin = mask_to_pin(g.bit);
irqstatus_t flag = irq_save();
gpio_peripheral(pin, 5, pull_up);
sio_hw->gpio_oe_clr = g.bit;
irq_restore(flag);
}
uint8_t
gpio_in_read(struct gpio_in g)
{
return !!(sio_hw->gpio_in & g.bit);
}
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