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freebsd-skq/sys/dev/iicbus/gpio/tca6416.c
Marcin Wojtas 7187ccccdc Add TCA6416 GPIO expander support. 
Add basic TCA6416 GPIO expander support over I2C bus. The driver handles
enabling and disabling pins, setting pin mode to IN and OUT and
toggling the pins. External interrupts are not supported.

Submitted by: Dawid Gorecki <dgr@semihalf.com>
Reviewed by: manu, mmel
Obtained from: Semihalf
Sponsored by: Alstom Group
Differential Revision: https://reviews.freebsd.org/D24363
2020-05-25 15:31:43 +00:00

535 lines
13 KiB
C
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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Alstom Group.
* Copyright (c) 2020 Semihalf.
*
* 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 AUTHOR 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 AUTHOR 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.
*/
/*
* Driver for TI TCA6416 I2C GPIO expander module.
*
* This driver only supports basic functionality
* (interrupt handling and polarity inversion were omitted).
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/gpio.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/gpio/gpiobusvar.h>
#include "gpio_if.h"
/* Base addresses of registers. LSB omitted. */
#define IN_PORT_REG 0x00
#define OUT_PORT_REG 0x02
#define POLARITY_INV_REG 0x04
#define CONF_REG 0x06
#define NUM_PINS 16
#define PINS_PER_REG 8
#define PIN_CAPS \
(GPIO_PIN_OUTPUT | GPIO_PIN_INPUT \
| GPIO_PIN_PUSHPULL | GPIO_PIN_INVIN)
#ifdef DEBUG
#define dbg_dev_printf(dev, fmt, args...) \
device_printf(dev, fmt, ##args)
#else
#define dbg_dev_printf(dev, fmt, args...)
#endif
#define TCA6416_BIT_FROM_PIN(pin) (pin % PINS_PER_REG)
#define TCA6416_REG_ADDR(pin, baseaddr) (baseaddr | (pin / PINS_PER_REG))
struct tca6416_softc {
device_t dev;
device_t busdev;
struct mtx mtx;
uint32_t addr;
};
static int tca6416_read(device_t, uint8_t, uint8_t*);
static int tca6416_write(device_t, uint8_t, uint8_t);
static int tca6416_probe(device_t);
static int tca6416_attach(device_t);
static int tca6416_detach(device_t);
static device_t tca6416_get_bus(device_t);
static int tca6416_pin_max(device_t, int*);
static int tca6416_pin_getcaps(device_t, uint32_t, uint32_t*);
static int tca6416_pin_getflags(device_t, uint32_t, uint32_t*);
static int tca6416_pin_setflags(device_t, uint32_t, uint32_t);
static int tca6416_pin_getname(device_t, uint32_t, char*);
static int tca6416_pin_get(device_t, uint32_t, unsigned int*);
static int tca6416_pin_set(device_t, uint32_t, unsigned int);
static int tca6416_pin_toggle(device_t, uint32_t);
#ifdef DEBUG
static void tca6416_regdump_setup(device_t dev);
static int tca6416_regdump_sysctl(SYSCTL_HANDLER_ARGS);
#endif
static device_method_t tca6416_methods[] = {
DEVMETHOD(device_probe, tca6416_probe),
DEVMETHOD(device_attach, tca6416_attach),
DEVMETHOD(device_detach, tca6416_detach),
/* GPIO methods */
DEVMETHOD(gpio_get_bus, tca6416_get_bus),
DEVMETHOD(gpio_pin_max, tca6416_pin_max),
DEVMETHOD(gpio_pin_getcaps, tca6416_pin_getcaps),
DEVMETHOD(gpio_pin_getflags, tca6416_pin_getflags),
DEVMETHOD(gpio_pin_setflags, tca6416_pin_setflags),
DEVMETHOD(gpio_pin_getname, tca6416_pin_getname),
DEVMETHOD(gpio_pin_get, tca6416_pin_get),
DEVMETHOD(gpio_pin_set, tca6416_pin_set),
DEVMETHOD(gpio_pin_toggle, tca6416_pin_toggle),
DEVMETHOD_END
};
static driver_t tca6416_driver = {
"gpio",
tca6416_methods,
sizeof(struct tca6416_softc)
};
static devclass_t tca6416_devclass;
DRIVER_MODULE(tca6416, iicbus, tca6416_driver, tca6416_devclass, 0, 0);
MODULE_VERSION(tca6416, 1);
static struct ofw_compat_data compat_data[] = {
{"ti,tca6416", 1},
{0,0}
};
static int
tca6416_read(device_t dev, uint8_t reg, uint8_t *data)
{
struct iic_msg msgs[2];
struct tca6416_softc *sc;
int error;
sc = device_get_softc(dev);
if (data == NULL)
return (EINVAL);
msgs[0].slave = sc->addr;
msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP;
msgs[0].len = 1;
msgs[0].buf = &reg;
msgs[1].slave = sc->addr;
msgs[1].flags = IIC_M_RD;
msgs[1].len = 1;
msgs[1].buf = data;
error = iicbus_transfer_excl(dev, msgs, 2, IIC_WAIT);
return (iic2errno(error));
}
static int
tca6416_write(device_t dev, uint8_t reg, uint8_t val)
{
struct iic_msg msg;
struct tca6416_softc *sc;
int error;
uint8_t buffer[2] = {reg, val};
sc = device_get_softc(dev);
msg.slave = sc->addr;
msg.flags = IIC_M_WR;
msg.len = 2;
msg.buf = buffer;
error = iicbus_transfer_excl(dev, &msg, 1, IIC_WAIT);
return (iic2errno(error));
}
static int
tca6416_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
return (ENXIO);
device_set_desc(dev, "TCA6416 I/O expander");
return (BUS_PROBE_DEFAULT);
}
static int
tca6416_attach(device_t dev)
{
struct tca6416_softc *sc;
sc = device_get_softc(dev);
sc->dev = dev;
sc->addr = iicbus_get_addr(dev);
mtx_init(&sc->mtx, "tca6416 gpio", "gpio", MTX_DEF);
sc->busdev = gpiobus_attach_bus(dev);
if (sc->busdev == NULL) {
device_printf(dev, "Could not create busdev child\n");
return (ENXIO);
}
#ifdef DEBUG
tca6416_regdump_setup(dev);
#endif
return (0);
}
static int
tca6416_detach(device_t dev)
{
struct tca6416_softc *sc;
sc = device_get_softc(dev);
if (sc->busdev != NULL)
gpiobus_detach_bus(sc->busdev);
mtx_destroy(&sc->mtx);
return (0);
}
static device_t
tca6416_get_bus(device_t dev)
{
struct tca6416_softc *sc;
sc = device_get_softc(dev);
return (sc->busdev);
}
static int
tca6416_pin_max(device_t dev __unused, int *maxpin)
{
if (maxpin == NULL)
return (EINVAL);
*maxpin = NUM_PINS - 1;
return (0);
}
static int
tca6416_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
{
if (pin >= NUM_PINS || caps == NULL)
return (EINVAL);
*caps = PIN_CAPS;
return (0);
}
static int
tca6416_pin_getflags(device_t dev, uint32_t pin, uint32_t *pflags)
{
struct tca6416_softc *sc;
int error;
uint8_t reg_addr, reg_bit, val;
sc = device_get_softc(dev);
if (pin >= NUM_PINS || pflags == NULL)
return (EINVAL);
reg_addr = TCA6416_REG_ADDR(pin, CONF_REG);
reg_bit = TCA6416_BIT_FROM_PIN(pin);
error = tca6416_read(dev, reg_addr, &val);
if (error != 0)
return (error);
*pflags = (val & (1 << reg_bit))
? GPIO_PIN_INPUT : GPIO_PIN_OUTPUT;
reg_addr = TCA6416_REG_ADDR(pin, POLARITY_INV_REG);
error = tca6416_read(dev, reg_addr, &val);
if (error != 0)
return (error);
if (val & (1 << reg_bit))
*pflags |= GPIO_PIN_INVIN;
return (0);
}
static int
tca6416_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
{
uint8_t reg_addr, inv_reg_addr, reg_bit, val, inv_val;
struct tca6416_softc *sc;
int error;
sc = device_get_softc(dev);
if (pin >= NUM_PINS)
return (EINVAL);
reg_addr = TCA6416_REG_ADDR(pin, CONF_REG);
inv_reg_addr = TCA6416_REG_ADDR(pin, POLARITY_INV_REG);
reg_bit = TCA6416_BIT_FROM_PIN(pin);
mtx_lock(&sc->mtx);
error = tca6416_read(dev, reg_addr, &val);
if (error != 0)
goto fail;
error = tca6416_read(dev, inv_reg_addr, &inv_val);
if (error != 0)
goto fail;
if (flags & GPIO_PIN_INPUT)
val |= (1 << reg_bit);
else if (flags & GPIO_PIN_OUTPUT)
val &= ~(1 << reg_bit);
if (flags & GPIO_PIN_INVIN)
inv_val |= (1 << reg_bit);
else
inv_val &= ~(1 << reg_bit);
error = tca6416_write(dev, reg_addr, val);
if (error != 0)
goto fail;
error = tca6416_write(dev, inv_reg_addr, val);
fail:
mtx_unlock(&sc->mtx);
return (error);
}
static int
tca6416_pin_getname(device_t dev, uint32_t pin, char *name)
{
if (pin >= NUM_PINS || name == NULL)
return (EINVAL);
snprintf(name, GPIOMAXNAME, "gpio_P%d%d", pin / PINS_PER_REG,
pin % PINS_PER_REG);
return (0);
}
static int
tca6416_pin_get(device_t dev, uint32_t pin, unsigned int *pval)
{
struct tca6416_softc *sc;
uint8_t reg_bit, reg_addr, reg_pvalue;
int error;
sc = device_get_softc(dev);
if (pin >= NUM_PINS || pval == NULL)
return (EINVAL);
reg_bit = TCA6416_BIT_FROM_PIN(pin);
reg_addr = TCA6416_REG_ADDR(pin, IN_PORT_REG);
dbg_dev_printf(dev, "Reading pin %u pvalue.", pin);
error = tca6416_read(dev, reg_addr, &reg_pvalue);
if (error != 0)
return (error);
*pval = reg_pvalue & (1 << reg_bit) ? 1 : 0;
return (0);
}
static int
tca6416_pin_set(device_t dev, uint32_t pin, unsigned int val)
{
struct tca6416_softc *sc;
uint8_t reg_addr, reg_bit, reg_value;
int error;
sc = device_get_softc(dev);
if (pin >= NUM_PINS)
return (EINVAL);
reg_addr = TCA6416_REG_ADDR(pin , OUT_PORT_REG);
reg_bit = TCA6416_BIT_FROM_PIN(pin);
dbg_dev_printf(dev, "Setting pin: %u to %u\n", pin, val);
mtx_lock(&sc->mtx);
error = tca6416_read(dev, reg_addr, &reg_value);
if (error != 0) {
dbg_dev_printf(dev, "Failed to read from register.\n");
mtx_unlock(&sc->mtx);
return (error);
}
if (val != 0)
reg_value |= (1 << reg_bit);
else
reg_value &= ~(1 << reg_bit);
error = tca6416_write(dev, reg_addr, reg_value);
if (error != 0) {
dbg_dev_printf(dev, "Could not write to register.\n");
mtx_unlock(&sc->mtx);
return (error);
}
mtx_unlock(&sc->mtx);
return (0);
}
static int
tca6416_pin_toggle(device_t dev, uint32_t pin)
{
struct tca6416_softc *sc;
int error;
uint8_t reg_addr, reg_bit, reg_value;
sc = device_get_softc(dev);
if (pin >= NUM_PINS)
return (EINVAL);
reg_addr = TCA6416_REG_ADDR(pin, OUT_PORT_REG);
reg_bit = TCA6416_BIT_FROM_PIN(pin);
dbg_dev_printf(dev, "Toggling pin: %d\n", pin);
mtx_lock(&sc->mtx);
error = tca6416_read(dev, reg_addr, &reg_value);
if (error != 0) {
mtx_unlock(&sc->mtx);
dbg_dev_printf(dev, "Cannot read from register.\n");
return (error);
}
reg_value ^= (1 << reg_bit);
error = tca6416_write(dev, reg_addr, reg_value);
if (error != 0)
dbg_dev_printf(dev, "Cannot write to register.\n");
mtx_unlock(&sc->mtx);
return (error);
}
#ifdef DEBUG
static void
tca6416_regdump_setup(device_t dev)
{
struct sysctl_ctx_list *ctx;
struct sysctl_oid *node;
ctx = device_get_sysctl_ctx(dev);
node = device_get_sysctl_tree(dev);
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(node), OID_AUTO, "in_reg_1",
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, IN_PORT_REG,
tca6416_regdump_sysctl, "A", "Input port 1");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(node), OID_AUTO, "in_reg_2",
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev,
IN_PORT_REG | 1, tca6416_regdump_sysctl, "A", "Input port 2");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(node), OID_AUTO, "out_reg_1",
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, OUT_PORT_REG,
tca6416_regdump_sysctl, "A", "Output port 1");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(node), OID_AUTO, "out_reg_2",
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev, OUT_PORT_REG
| 1, tca6416_regdump_sysctl, "A", "Output port 2");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(node), OID_AUTO, "pol_inv_1",
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev,
POLARITY_INV_REG, tca6416_regdump_sysctl, "A", "Polarity inv 1");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(node), OID_AUTO, "pol_inv_2",
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev,
POLARITY_INV_REG | 1, tca6416_regdump_sysctl, "A",
"Polarity inv 2");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(node), OID_AUTO, "conf_reg_1",
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev,
CONF_REG, tca6416_regdump_sysctl, "A", "Configuration 1");
SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(node), OID_AUTO, "conf_reg_2",
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, dev,
CONF_REG | 1, tca6416_regdump_sysctl, "A", "Configuration 2");
}
static int
tca6416_regdump_sysctl(SYSCTL_HANDLER_ARGS)
{
device_t dev;
char buf[5];
struct tca6416_softc *sc;
int len, error;
uint8_t reg, regval;
dev = (device_t)arg1;
reg = (uint8_t)arg2;
sc = device_get_softc(dev);
error = tca6416_read(dev, reg, &regval);
if (error != 0) {
return (error);
}
len = snprintf(buf, 5, "0x%02x", regval);
error = sysctl_handle_string(oidp, buf, len, req);
return (error);
}
#endif
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