static int inv_mpu6050_select_bypass(struct i2c_mux_core *muxc, u32 chan_id)
{
struct iio_dev *indio_dev = i2c_mux_priv(muxc);
struct inv_mpu6050_state *st = iio_priv(indio_dev);
int ret = 0;
/* Use the same mutex which was used everywhere to protect power-op */
mutex_lock(&indio_dev->mlock);
if (!st->powerup_count) {
ret = regmap_write(st->map, st->reg->pwr_mgmt_1, 0);
if (ret)
goto write_error;
usleep_range(INV_MPU6050_REG_UP_TIME_MIN,
INV_MPU6050_REG_UP_TIME_MAX);
}
if (!ret) {
st->powerup_count++;
ret = regmap_write(st->map, st->reg->int_pin_cfg,
INV_MPU6050_INT_PIN_CFG |
INV_MPU6050_BIT_BYPASS_EN);
}
write_error:
mutex_unlock(&indio_dev->mlock);
return ret;
}
static int i2c_mux_gpio_deselect(struct i2c_mux_core *muxc, u32 chan)
{
struct gpiomux *mux = i2c_mux_priv(muxc);
i2c_mux_gpio_set(mux, mux->data.idle);
return 0;
}
static int mpu3050_i2c_bypass_deselect(struct i2c_mux_core *mux, u32 chan_id)
{
struct mpu3050 *mpu3050 = i2c_mux_priv(mux);
pm_runtime_mark_last_busy(mpu3050->dev);
pm_runtime_put_autosuspend(mpu3050->dev);
return 0;
}
static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan)
{
struct gpiomux *mux = i2c_mux_priv(muxc);
i2c_mux_gpio_set(mux, chan);
return 0;
}
static int mpu3050_i2c_bypass_select(struct i2c_mux_core *mux, u32 chan_id)
{
struct mpu3050 *mpu3050 = i2c_mux_priv(mux);
/* Just power up the device, that is all that is needed */
pm_runtime_get_sync(mpu3050->dev);
return 0;
}
static int i2c_mux_reg_deselect(struct i2c_mux_core *muxc, u32 chan)
{
struct regmux *mux = i2c_mux_priv(muxc);
if (mux->data.idle_in_use)
return i2c_mux_reg_set(mux, mux->data.idle);
return 0;
}
/**
* i2c_arbitrator_deselect - release the I2C bus
*
* Release the I2C bus using the GPIO-based signalling protocol.
*/
static int i2c_arbitrator_deselect(struct i2c_mux_core *muxc, u32 chan)
{
const struct i2c_arbitrator_data *arb = i2c_mux_priv(muxc);
/* Release the bus and wait for the other master to notice */
gpio_set_value(arb->our_gpio, arb->our_gpio_release);
udelay(arb->slew_delay_us);
return 0;
}
static int mlxcpld_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
{
struct mlxcpld_mux *data = i2c_mux_priv(muxc);
struct i2c_client *client = data->client;
/* Deselect active channel */
data->last_chan = 0;
return mlxcpld_mux_reg_write(muxc->parent, client, data->last_chan);
}
static int mlxcpld_mux_select_chan(struct i2c_mux_core *muxc, u32 chan)
{
struct mlxcpld_mux *data = i2c_mux_priv(muxc);
struct i2c_client *client = data->client;
u8 regval = chan + 1;
int err = 0;
/* Only select the channel if its different from the last channel */
if (data->last_chan != regval) {
err = mlxcpld_mux_reg_write(muxc->parent, client, regval);
data->last_chan = err < 0 ? 0 : regval;
}
return err;
}
static int inv_mpu6050_deselect_bypass(struct i2c_mux_core *muxc, u32 chan_id)
{
struct iio_dev *indio_dev = i2c_mux_priv(muxc);
struct inv_mpu6050_state *st = iio_priv(indio_dev);
mutex_lock(&indio_dev->mlock);
/* It doesn't really mattter, if any of the calls fails */
regmap_write(st->map, st->reg->int_pin_cfg, INV_MPU6050_INT_PIN_CFG);
st->powerup_count--;
if (!st->powerup_count)
regmap_write(st->map, st->reg->pwr_mgmt_1,
INV_MPU6050_BIT_SLEEP);
mutex_unlock(&indio_dev->mlock);
return 0;
}
/* Probe/reomove functions */
static int mlxcpld_mux_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
struct mlxcpld_mux_plat_data *pdata = dev_get_platdata(&client->dev);
struct i2c_mux_core *muxc;
int num, force;
struct mlxcpld_mux *data;
int err;
if (!pdata)
return -EINVAL;
if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
return -ENODEV;
muxc = i2c_mux_alloc(adap, &client->dev, CPLD_MUX_MAX_NCHANS,
sizeof(*data), 0, mlxcpld_mux_select_chan,
mlxcpld_mux_deselect);
if (!muxc)
return -ENOMEM;
data = i2c_mux_priv(muxc);
i2c_set_clientdata(client, muxc);
data->client = client;
data->last_chan = 0; /* force the first selection */
/* Create an adapter for each channel. */
for (num = 0; num < CPLD_MUX_MAX_NCHANS; num++) {
if (num >= pdata->num_adaps)
/* discard unconfigured channels */
break;
force = pdata->adap_ids[num];
err = i2c_mux_add_adapter(muxc, force, num, 0);
if (err)
goto virt_reg_failed;
}
return 0;
virt_reg_failed:
i2c_mux_del_adapters(muxc);
return err;
}
/**
* i2c_arbitrator_select - claim the I2C bus
*
* Use the GPIO-based signalling protocol; return -EBUSY if we fail.
*/
static int i2c_arbitrator_select(struct i2c_mux_core *muxc, u32 chan)
{
const struct i2c_arbitrator_data *arb = i2c_mux_priv(muxc);
unsigned long stop_retry, stop_time;
/* Start a round of trying to claim the bus */
stop_time = jiffies + usecs_to_jiffies(arb->wait_free_us) + 1;
do {
/* Indicate that we want to claim the bus */
gpio_set_value(arb->our_gpio, !arb->our_gpio_release);
udelay(arb->slew_delay_us);
/* Wait for the other master to release it */
stop_retry = jiffies + usecs_to_jiffies(arb->wait_retry_us) + 1;
while (time_before(jiffies, stop_retry)) {
int gpio_val = !!gpio_get_value(arb->their_gpio);
if (gpio_val == arb->their_gpio_release) {
/* We got it, so return */
return 0;
}
usleep_range(50, 200);
}
/* It didn't release, so give up, wait, and try again */
gpio_set_value(arb->our_gpio, arb->our_gpio_release);
usleep_range(arb->wait_retry_us, arb->wait_retry_us * 2);
} while (time_before(jiffies, stop_time));
/* Give up, release our claim */
gpio_set_value(arb->our_gpio, arb->our_gpio_release);
udelay(arb->slew_delay_us);
dev_err(muxc->dev, "Could not claim bus, timeout\n");
return -EBUSY;
}
static int i2c_mux_reg_select(struct i2c_mux_core *muxc, u32 chan)
{
struct regmux *mux = i2c_mux_priv(muxc);
return i2c_mux_reg_set(mux, chan);
}
static int i2c_arbitrator_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct device_node *parent_np;
struct i2c_mux_core *muxc;
struct i2c_arbitrator_data *arb;
enum of_gpio_flags gpio_flags;
unsigned long out_init;
int ret;
/* We only support probing from device tree; no platform_data */
if (!np) {
dev_err(dev, "Cannot find device tree node\n");
return -ENODEV;
}
if (dev_get_platdata(dev)) {
dev_err(dev, "Platform data is not supported\n");
return -EINVAL;
}
muxc = i2c_mux_alloc(NULL, dev, 1, sizeof(*arb), I2C_MUX_ARBITRATOR,
i2c_arbitrator_select, i2c_arbitrator_deselect);
if (!muxc)
return -ENOMEM;
arb = i2c_mux_priv(muxc);
platform_set_drvdata(pdev, muxc);
/* Request GPIOs */
ret = of_get_named_gpio_flags(np, "our-claim-gpio", 0, &gpio_flags);
if (!gpio_is_valid(ret)) {
if (ret != -EPROBE_DEFER)
dev_err(dev, "Error getting our-claim-gpio\n");
return ret;
}
arb->our_gpio = ret;
arb->our_gpio_release = !!(gpio_flags & OF_GPIO_ACTIVE_LOW);
out_init = (gpio_flags & OF_GPIO_ACTIVE_LOW) ?
GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
ret = devm_gpio_request_one(dev, arb->our_gpio, out_init,
"our-claim-gpio");
if (ret) {
if (ret != -EPROBE_DEFER)
dev_err(dev, "Error requesting our-claim-gpio\n");
return ret;
}
ret = of_get_named_gpio_flags(np, "their-claim-gpios", 0, &gpio_flags);
if (!gpio_is_valid(ret)) {
if (ret != -EPROBE_DEFER)
dev_err(dev, "Error getting their-claim-gpio\n");
return ret;
}
arb->their_gpio = ret;
arb->their_gpio_release = !!(gpio_flags & OF_GPIO_ACTIVE_LOW);
ret = devm_gpio_request_one(dev, arb->their_gpio, GPIOF_IN,
"their-claim-gpio");
if (ret) {
if (ret != -EPROBE_DEFER)
dev_err(dev, "Error requesting their-claim-gpio\n");
return ret;
}
/* At the moment we only support a single two master (us + 1 other) */
if (gpio_is_valid(of_get_named_gpio(np, "their-claim-gpios", 1))) {
dev_err(dev, "Only one other master is supported\n");
return -EINVAL;
}
/* Arbitration parameters */
if (of_property_read_u32(np, "slew-delay-us", &arb->slew_delay_us))
arb->slew_delay_us = 10;
if (of_property_read_u32(np, "wait-retry-us", &arb->wait_retry_us))
arb->wait_retry_us = 3000;
if (of_property_read_u32(np, "wait-free-us", &arb->wait_free_us))
arb->wait_free_us = 50000;
/* Find our parent */
parent_np = of_parse_phandle(np, "i2c-parent", 0);
if (!parent_np) {
dev_err(dev, "Cannot parse i2c-parent\n");
return -EINVAL;
}
muxc->parent = of_get_i2c_adapter_by_node(parent_np);
of_node_put(parent_np);
if (!muxc->parent) {
dev_err(dev, "Cannot find parent bus\n");
return -EPROBE_DEFER;
}
/* Actually add the mux adapter */
ret = i2c_mux_add_adapter(muxc, 0, 0, 0);
if (ret) {
dev_err(dev, "Failed to add adapter\n");
i2c_put_adapter(muxc->parent);
}
return ret;
}
