NetBSD/sys/dev/i2c/tcagpio.c

277 lines
6.8 KiB
C

/* $NetBSD: tcagpio.c,v 1.5 2019/12/23 19:38:58 thorpej Exp $ */
/*-
* Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tcagpio.c,v 1.5 2019/12/23 19:38:58 thorpej Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/kmem.h>
#include <sys/gpio.h>
#include <dev/i2c/i2cvar.h>
#include <dev/fdt/fdtvar.h>
#define PORT_BANK(pin) (pin / 8)
#define PORT_BIT(pin) __BIT(pin % 8)
#define PORT_IN(pin) (0x00 + PORT_BANK(pin))
#define PORT_OUT(pin) (0x02 + PORT_BANK(pin))
#define PORT_POLARITY(pin) (0x04 + PORT_BANK(pin))
#define PORT_CFG(pin) (0x06 + PORT_BANK(pin))
#define TCA_PIN_COUNT 16
struct tcagpio_softc {
device_t sc_dev;
i2c_tag_t sc_i2c;
i2c_addr_t sc_addr;
int sc_phandle;
int sc_npins;
};
struct tcagpio_pin {
struct tcagpio_softc *pin_sc;
int pin_num;
int pin_flags;
bool pin_actlo;
};
static const struct device_compatible_entry compat_data[] = {
{ "ti,tca9539", 0 },
{ NULL, 0 }
};
static uint8_t
tcagpio_read(struct tcagpio_softc *sc, uint8_t reg, int flags)
{
uint8_t val = 0;
int error;
error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP, sc->sc_addr,
&reg, 1, &val, 1, flags);
if (error != 0)
aprint_error_dev(sc->sc_dev, "error reading reg %#x: %d\n", reg, error);
return val;
}
static void
tcagpio_write(struct tcagpio_softc *sc, uint8_t reg, uint8_t val, int flags)
{
uint8_t buf[2];
int error;
buf[0] = reg;
buf[1] = val;
error = iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP, sc->sc_addr,
NULL, 0, buf, 2, flags);
if (error != 0)
aprint_error_dev(sc->sc_dev, "error writing reg %#x: %d\n", reg, error);
}
#define I2C_READ(sc, reg) tcagpio_read((sc), (reg), 0)
#define I2C_WRITE(sc, reg, val) tcagpio_write((sc), (reg), (val), 0)
#define I2C_LOCK(sc) iic_acquire_bus((sc)->sc_i2c, 0)
#define I2C_UNLOCK(sc) iic_release_bus((sc)->sc_i2c, 0)
static int
tcagpio_gpio_config(struct tcagpio_softc *sc, int pin, int flags)
{
uint16_t gpio;
KASSERT(pin >= 0 && pin < sc->sc_npins);
gpio = I2C_READ(sc, PORT_CFG(pin));
switch (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
case GPIO_PIN_INPUT:
gpio |= PORT_BIT(pin);
break;
case GPIO_PIN_OUTPUT:
gpio &= ~PORT_BIT(pin);
break;
default:
return EINVAL;
}
I2C_WRITE(sc, PORT_CFG(pin), gpio);
return 0;
}
static void *
tcagpio_gpio_acquire(device_t dev, const void *data, size_t len, int flags)
{
struct tcagpio_softc * const sc = device_private(dev);
struct tcagpio_pin *gpin;
const u_int *gpio = data;
int error;
if (len != 12)
return NULL;
const uint8_t pin = be32toh(gpio[1]) & 0xff;
const bool actlo = (be32toh(gpio[2]) & __BIT(0)) != 0;
if (pin >= sc->sc_npins)
return NULL;
I2C_LOCK(sc);
error = tcagpio_gpio_config(sc, pin, flags);
I2C_UNLOCK(sc);
if (error != 0) {
device_printf(dev, "bad pin %d config %#x\n", pin, flags);
return NULL;
}
gpin = kmem_zalloc(sizeof(*gpin), KM_SLEEP);
gpin->pin_sc = sc;
gpin->pin_num = pin;
gpin->pin_flags = flags;
gpin->pin_actlo = actlo;
return gpin;
}
static void
tcagpio_gpio_release(device_t dev, void *priv)
{
struct tcagpio_softc * const sc = device_private(dev);
struct tcagpio_pin *gpin = priv;
I2C_LOCK(sc);
tcagpio_gpio_config(sc, gpin->pin_num, GPIO_PIN_INPUT);
I2C_UNLOCK(sc);
kmem_free(gpin, sizeof(*gpin));
}
static int
tcagpio_gpio_read(device_t dev, void *priv, bool raw)
{
struct tcagpio_softc * const sc = device_private(dev);
struct tcagpio_pin *gpin = priv;
uint8_t gpio;
int val;
I2C_LOCK(sc);
gpio = I2C_READ(sc, PORT_IN(gpin->pin_num));
I2C_UNLOCK(sc);
val = __SHIFTOUT(gpio, PORT_BIT(gpin->pin_num));
if (!raw && gpin->pin_actlo)
val = !val;
#ifdef TCAGPIO_DEBUG
device_printf(sc->sc_dev, "GPIO%d rd %02x (%d %d)\n",
gpin->pin_num, gpio,
(int)__SHIFTOUT(gpio, PORT_BIT(gpin->pin_num)), val);
#endif
return val;
}
static void
tcagpio_gpio_write(device_t dev, void *priv, int val, bool raw)
{
struct tcagpio_softc * const sc = device_private(dev);
struct tcagpio_pin *gpin = priv;
uint8_t gpio;
if (!raw && gpin->pin_actlo)
val = !val;
I2C_LOCK(sc);
gpio = I2C_READ(sc, PORT_OUT(gpin->pin_num));
gpio &= ~PORT_BIT(gpin->pin_num);
gpio |= __SHIFTIN(val, PORT_BIT(gpin->pin_num));
#ifdef TCAGPIO_DEBUG
device_printf(sc->sc_dev, "GPIO%d wr %02x -> %02x\n",
gpin->pin_num,
I2C_READ(sc, PORT_OUT(gpin->pin_num)), gpio);
#endif
I2C_WRITE(sc, PORT_OUT(gpin->pin_num), gpio);
I2C_UNLOCK(sc);
}
static struct fdtbus_gpio_controller_func tcagpio_gpio_funcs = {
.acquire = tcagpio_gpio_acquire,
.release = tcagpio_gpio_release,
.read = tcagpio_gpio_read,
.write = tcagpio_gpio_write,
};
static void
tcagpio_gpio_attach(struct tcagpio_softc *sc)
{
fdtbus_register_gpio_controller(sc->sc_dev, sc->sc_phandle,
&tcagpio_gpio_funcs);
}
static int
tcagpio_match(device_t parent, cfdata_t match, void *aux)
{
struct i2c_attach_args *ia = aux;
int match_result;
if (iic_use_direct_match(ia, match, compat_data, &match_result))
return match_result;
return 0;
}
static void
tcagpio_attach(device_t parent, device_t self, void *aux)
{
struct tcagpio_softc * const sc = device_private(self);
struct i2c_attach_args *ia = aux;
sc->sc_dev = self;
sc->sc_i2c = ia->ia_tag;
sc->sc_addr = ia->ia_addr;
sc->sc_phandle = ia->ia_cookie;
sc->sc_npins = TCA_PIN_COUNT;
aprint_naive("\n");
aprint_normal(": I2C/SMBus I/O Expander\n");
tcagpio_gpio_attach(sc);
}
CFATTACH_DECL_NEW(tcagpio, sizeof(struct tcagpio_softc),
tcagpio_match, tcagpio_attach, NULL, NULL);