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Add bus recovery handling to the imx5/imx6 i2c driver.

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This commit is contained in:
Ian Lepore 2017-06-29 01:59:39 +00:00
parent 930b312319
commit 8928c2e4f5
1 changed files with 148 additions and 2 deletions
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150
sys/arm/freescale/imx/imx_i2c.c
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@ -48,6 +48,7 @@ __FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/gpio.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/module.h>
@ -61,12 +62,16 @@ __FBSDID("$FreeBSD$");
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iic_recover_bus.h>
#include "iicbus_if.h"
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/fdt/fdt_pinctrl.h>
#include <dev/gpio/gpiobusvar.h>
#define I2C_ADDR_REG 0x00 /* I2C slave address register */
#define I2C_FDR_REG 0x04 /* I2C frequency divider register */
#define I2C_CONTROL_REG 0x08 /* I2C control register */
@ -130,6 +135,9 @@ struct i2c_softc {
struct resource *res;
int rid;
sbintime_t byte_time_sbt;
int rb_pinctl_idx;
gpio_pin_t rb_sclpin;
gpio_pin_t rb_sdapin;
};
static phandle_t i2c_get_node(device_t, device_t);
@ -273,6 +281,68 @@ i2c_error_handler(struct i2c_softc *sc, int error)
return (error);
}
static int
i2c_recover_getsda(void *ctx)
{
bool active;
gpio_pin_is_active(((struct i2c_softc *)ctx)->rb_sdapin, &active);
return (active);
}
static void
i2c_recover_setsda(void *ctx, int value)
{
gpio_pin_set_active(((struct i2c_softc *)ctx)->rb_sdapin, value);
}
static int
i2c_recover_getscl(void *ctx)
{
bool active;
gpio_pin_is_active(((struct i2c_softc *)ctx)->rb_sclpin, &active);
return (active);
}
static void
i2c_recover_setscl(void *ctx, int value)
{
gpio_pin_set_active(((struct i2c_softc *)ctx)->rb_sclpin, value);
}
static int
i2c_recover_bus(struct i2c_softc *sc)
{
struct iicrb_pin_access pins;
int err;
/*
* If we have gpio pinmux config, reconfigure the pins to gpio mode,
* invoke iic_recover_bus which checks for a hung bus and bitbangs a
* recovery sequence if necessary, then configure the pins back to i2c
* mode (idx 0).
*/
if (sc->rb_pinctl_idx == 0)
return (0);
fdt_pinctrl_configure(sc->dev, sc->rb_pinctl_idx);
pins.ctx = sc;
pins.getsda = i2c_recover_getsda;
pins.setsda = i2c_recover_setsda;
pins.getscl = i2c_recover_getscl;
pins.setscl = i2c_recover_setscl;
err = iic_recover_bus(&pins);
fdt_pinctrl_configure(sc->dev, 0);
return (err);
}
static int
i2c_probe(device_t dev)
{
@ -291,7 +361,10 @@ i2c_probe(device_t dev)
static int
i2c_attach(device_t dev)
{
char wrkstr[16];
struct i2c_softc *sc;
phandle_t node;
int err, cfgidx;
sc = device_get_softc(dev);
sc->dev = dev;
@ -310,6 +383,49 @@ i2c_attach(device_t dev)
return (ENXIO);
}
/*
* Set up for bus recovery using gpio pins, if the pinctrl and gpio
* properties are present. This is optional. If all the config data is
* not in place, we just don't do gpio bitbang bus recovery.
*/
node = ofw_bus_get_node(sc->dev);
err = gpio_pin_get_by_ofw_property(dev, node, "scl-gpios",
&sc->rb_sclpin);
if (err != 0)
goto no_recovery;
err = gpio_pin_get_by_ofw_property(dev, node, "sda-gpios",
&sc->rb_sdapin);
if (err != 0)
goto no_recovery;
/*
* Preset the gpio pins to output high (idle bus state). The signal
* won't actually appear on the pins until the bus recovery code changes
* the pinmux config from i2c to gpio.
*/
gpio_pin_setflags(sc->rb_sclpin, GPIO_PIN_OUTPUT);
gpio_pin_setflags(sc->rb_sdapin, GPIO_PIN_OUTPUT);
gpio_pin_set_active(sc->rb_sclpin, true);
gpio_pin_set_active(sc->rb_sdapin, true);
/*
* Obtain the index of pinctrl node for bus recovery using gpio pins,
* then confirm that pinctrl properties exist for that index and for the
* default pinctrl-0. If sc->rb_pinctl_idx is non-zero, the reset code
* will also do a bus recovery, so setting this value must be last.
*/
err = ofw_bus_find_string_index(node, "pinctrl-names", "gpio", &cfgidx);
if (err == 0) {
snprintf(wrkstr, sizeof(wrkstr), "pinctrl-%d", cfgidx);
if (OF_hasprop(node, "pinctrl-0") && OF_hasprop(node, wrkstr))
sc->rb_pinctl_idx = cfgidx;
}
no_recovery:
/* We don't do a hardware reset here because iicbus_attach() does it. */
bus_generic_attach(dev);
return (0);
}
@ -339,7 +455,7 @@ i2c_repeated_start(device_t dev, u_char slave, int timeout)
}
static int
i2c_start(device_t dev, u_char slave, int timeout)
i2c_start_ll(device_t dev, u_char slave, int timeout)
{
struct i2c_softc *sc;
int error;
@ -360,6 +476,31 @@ i2c_start(device_t dev, u_char slave, int timeout)
return (i2c_error_handler(sc, error));
}
static int
i2c_start(device_t dev, u_char slave, int timeout)
{
struct i2c_softc *sc;
int error;
sc = device_get_softc(dev);
/*
* Invoke the low-level code to put the bus into master mode and address
* the given slave. If that fails, idle the controller and attempt a
* bus recovery, and then try again one time. Signaling a start and
* addressing the slave is the only operation that a low-level driver
* can safely retry without any help from the upper layers that know
* more about the slave device.
*/
if ((error = i2c_start_ll(dev, slave, timeout)) != 0) {
i2c_write_reg(sc, I2C_CONTROL_REG, 0x0);
if ((error = i2c_recover_bus(sc)) != 0)
return (error);
error = i2c_start_ll(dev, slave, timeout);
}
return (error);
}
static int
i2c_stop(device_t dev)
{
@ -409,7 +550,12 @@ i2c_reset(device_t dev, u_char speed, u_char addr, u_char *oldadr)
i2c_write_reg(sc, I2C_STATUS_REG, 0x0);
i2c_write_reg(sc, I2C_CONTROL_REG, 0x0);
i2c_write_reg(sc, I2C_FDR_REG, (uint8_t)clkdiv_table[i].regcode);
return (IIC_NOERR);
/*
* Now that the controller is idle, perform bus recovery. If the bus
* isn't hung, this a fairly fast no-op.
*/
return (i2c_recover_bus(sc));
}
static int