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// GPIO functions on PRU
//
// Copyright (C) 2017 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU GPLv3 license.
#include "board/io.h" // readl
#include "command.h" // shutdown
#include "compiler.h" // ARRAY_SIZE
#include "gpio.h" // gpio_out_setup
#include "internal.h" // ADC
#include "sched.h" // sched_shutdown
/****************************************************************
* Pin mappings
****************************************************************/
#define GPIO(PORT, NUM) ((PORT) * 32 + (NUM))
#define GPIO2PORT(PIN) ((PIN) / 32)
#define GPIO2BIT(PIN) (1<<((PIN) % 32))
struct gpio_regs {
uint32_t pad_0[77];
volatile uint32_t oe;
volatile uint32_t datain;
volatile uint32_t dataout;
uint32_t pad_140[20];
volatile uint32_t cleardataout;
volatile uint32_t setdataout;
};
static struct gpio_regs *digital_regs[] = {
(void*)0x44e07000, (void*)0x4804c000, (void*)0x481ac000, (void*)0x481ae000
};
#define MUXPORT(offset) (((offset)-0x800) / 4)
static uint8_t gpio_mux_offset[32 * ARRAY_SIZE(digital_regs)] = {
// gpio 0
0xff , 0xff , MUXPORT(0x950), MUXPORT(0x954),
MUXPORT(0x958), MUXPORT(0x95c), 0xff , MUXPORT(0x964),
MUXPORT(0x8d0), MUXPORT(0x8d4), MUXPORT(0x8d8), MUXPORT(0x8dc),
MUXPORT(0x978), MUXPORT(0x97c), MUXPORT(0x980), MUXPORT(0x984),
0xff , 0xff , 0xff , 0xff ,
MUXPORT(0x9b4), 0xff , MUXPORT(0x820), MUXPORT(0x824),
0xff , 0xff , MUXPORT(0x828), MUXPORT(0x82c),
0xff , 0xff , MUXPORT(0x870), MUXPORT(0x874),
// gpio 1
MUXPORT(0x800), MUXPORT(0x804), MUXPORT(0x808), MUXPORT(0x80c),
MUXPORT(0x810), MUXPORT(0x814), MUXPORT(0x818), MUXPORT(0x81c),
0xff , 0xff , 0xff , 0xff ,
MUXPORT(0x830), MUXPORT(0x834), MUXPORT(0x838), MUXPORT(0x83c),
MUXPORT(0x840), MUXPORT(0x844), MUXPORT(0x848), MUXPORT(0x84c),
0xff , 0xff , 0xff , 0xff ,
0xff , 0xff , 0xff , 0xff ,
MUXPORT(0x878), MUXPORT(0x87c), MUXPORT(0x880), MUXPORT(0x884),
// gpio 2
0xff , MUXPORT(0x88c), MUXPORT(0x890), MUXPORT(0x894),
MUXPORT(0x898), MUXPORT(0x89c), MUXPORT(0x8a0), MUXPORT(0x8a4),
MUXPORT(0x8a8), MUXPORT(0x8ac), MUXPORT(0x8b0), MUXPORT(0x8b4),
MUXPORT(0x8b8), MUXPORT(0x8bc), MUXPORT(0x8c0), MUXPORT(0x8c4),
MUXPORT(0x8c8), MUXPORT(0x8cc), 0xff , 0xff ,
0xff , 0xff , MUXPORT(0x8e0), MUXPORT(0x8e4),
MUXPORT(0x8e8), MUXPORT(0x8ec), 0xff , 0xff ,
0xff , 0xff , 0xff , 0xff ,
// gpio 3
0xff , 0xff , 0xff , 0xff ,
0xff , 0xff , 0xff , 0xff ,
0xff , 0xff , 0xff , 0xff ,
0xff , 0xff , MUXPORT(0x990), MUXPORT(0x994),
MUXPORT(0x998), MUXPORT(0x99c), MUXPORT(0x9a0), MUXPORT(0x9a4),
MUXPORT(0x9a8), MUXPORT(0x9ac), 0xff , 0xff ,
0xff , 0xff , 0xff , 0xff ,
0xff , 0xff , 0xff , 0xff ,
};
#define MUXREG(mux_offset) ((volatile uint32_t *)0x44e10800 + mux_offset)
/****************************************************************
* 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;
uint8_t mux_offset = gpio_mux_offset[pin];
if (mux_offset == 0xff)
goto fail;
struct gpio_regs *regs = digital_regs[GPIO2PORT(pin)];
uint32_t bit = GPIO2BIT(pin);
struct gpio_out rv = (struct gpio_out){ .reg=®s->cleardataout, .bit=bit };
gpio_out_write(rv, val);
regs->oe &= ~bit;
*MUXREG(mux_offset) = 0x0f;
return rv;
fail:
shutdown("Not an output pin");
}
void
gpio_out_toggle(struct gpio_out g)
{
gpio_out_write(g, !(*g.reg & g.bit));
}
void
gpio_out_write(struct gpio_out g, uint8_t val)
{
volatile uint32_t *reg = g.reg;
if (val)
reg++;
*reg = g.bit;
}
struct gpio_in
gpio_in_setup(uint8_t pin, int8_t pull_up)
{
if (GPIO2PORT(pin) >= ARRAY_SIZE(digital_regs))
goto fail;
uint8_t mux_offset = gpio_mux_offset[pin];
if (mux_offset == 0xff)
goto fail;
struct gpio_regs *regs = digital_regs[GPIO2PORT(pin)];
uint32_t bit = GPIO2BIT(pin);
regs->oe |= bit;
*MUXREG(mux_offset) = pull_up > 0 ? 0x37 : (pull_up < 0 ? 0x27 : 0x2f);
return (struct gpio_in){ .reg=®s->datain, .bit=bit };
fail:
shutdown("Not an input pin");
}
uint8_t
gpio_in_read(struct gpio_in g)
{
return !!(*g.reg & g.bit);
}
/****************************************************************
* Analog to Digital Converter (ADC) pins
****************************************************************/
DECL_CONSTANT(ADC_MAX, 4095);
struct gpio_adc
gpio_adc_setup(uint8_t pin)
{
uint8_t chan = pin - ARRAY_SIZE(digital_regs) * 32;
if (chan >= 8)
shutdown("Not an adc channel");
if (!readl(&ADC->ctrl))
shutdown("ADC module not enabled");
return (struct gpio_adc){ .chan = chan };
}
enum { ADC_DUMMY=0xff };
static uint8_t last_analog_read = ADC_DUMMY;
static uint16_t last_analog_sample;
// Try to sample a value. Returns zero if sample ready, otherwise
// returns the number of clock ticks the caller should wait before
// retrying this function.
uint32_t
gpio_adc_sample(struct gpio_adc g)
{
uint8_t last = last_analog_read;
if (last == ADC_DUMMY) {
// Start sample
last_analog_read = g.chan;
writel(&ADC->stepenable, 1 << (g.chan + 1));
goto need_delay;
}
if (last == g.chan) {
// Check if sample ready
while (readl(&ADC->fifo0count)) {
uint32_t sample = readl(&ADC->fifo0data);
if (sample >> 16 == g.chan) {
last_analog_read = ADC_DUMMY;
last_analog_sample = sample;
return 0;
}
}
}
need_delay:
return 160;
}
// Read a value; use only after gpio_adc_sample() returns zero
uint16_t
gpio_adc_read(struct gpio_adc g)
{
return last_analog_sample;
}
// Cancel a sample that may have been started with gpio_adc_sample()
void
gpio_adc_cancel_sample(struct gpio_adc g)
{
if (last_analog_read == g.chan)
last_analog_read = ADC_DUMMY;
}
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