diff options
Diffstat (limited to 'drivers/iio/magnetometer/ak8975.c')
| -rw-r--r-- | drivers/iio/magnetometer/ak8975.c | 154 |
1 files changed, 122 insertions, 32 deletions
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c index 609a2c401b5d..af8606cc7812 100644 --- a/drivers/iio/magnetometer/ak8975.c +++ b/drivers/iio/magnetometer/ak8975.c @@ -33,6 +33,7 @@ #include <linux/of_gpio.h> #include <linux/acpi.h> #include <linux/regulator/consumer.h> +#include <linux/pm_runtime.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> @@ -379,37 +380,40 @@ struct ak8975_data { u8 cntl_cache; struct iio_mount_matrix orientation; struct regulator *vdd; + struct regulator *vid; }; /* Enable attached power regulator if any. */ -static int ak8975_power_on(struct i2c_client *client) +static int ak8975_power_on(const struct ak8975_data *data) { - const struct iio_dev *indio_dev = i2c_get_clientdata(client); - struct ak8975_data *data = iio_priv(indio_dev); int ret; - data->vdd = devm_regulator_get(&client->dev, "vdd"); - if (IS_ERR_OR_NULL(data->vdd)) { - ret = PTR_ERR(data->vdd); - if (ret == -ENODEV) - ret = 0; - } else { - ret = regulator_enable(data->vdd); + ret = regulator_enable(data->vdd); + if (ret) { + dev_warn(&data->client->dev, + "Failed to enable specified Vdd supply\n"); + return ret; } - - if (ret) - dev_err(&client->dev, "failed to enable Vdd supply: %d\n", ret); - return ret; + ret = regulator_enable(data->vid); + if (ret) { + dev_warn(&data->client->dev, + "Failed to enable specified Vid supply\n"); + return ret; + } + /* + * According to the datasheet the power supply rise time i 200us + * and the minimum wait time before mode setting is 100us, in + * total 300 us. Add some margin and say minimum 500us here. + */ + usleep_range(500, 1000); + return 0; } /* Disable attached power regulator if any. */ -static void ak8975_power_off(const struct i2c_client *client) +static void ak8975_power_off(const struct ak8975_data *data) { - const struct iio_dev *indio_dev = i2c_get_clientdata(client); - const struct ak8975_data *data = iio_priv(indio_dev); - - if (!IS_ERR_OR_NULL(data->vdd)) - regulator_disable(data->vdd); + regulator_disable(data->vid); + regulator_disable(data->vdd); } /* @@ -430,8 +434,8 @@ static int ak8975_who_i_am(struct i2c_client *client, * AK8975 | DEVICE_ID | NA * AK8963 | DEVICE_ID | NA */ - ret = i2c_smbus_read_i2c_block_data(client, AK09912_REG_WIA1, - 2, wia_val); + ret = i2c_smbus_read_i2c_block_data_or_emulated( + client, AK09912_REG_WIA1, 2, wia_val); if (ret < 0) { dev_err(&client->dev, "Error reading WIA\n"); return ret; @@ -543,9 +547,9 @@ static int ak8975_setup(struct i2c_client *client) } /* Get asa data and store in the device data. */ - ret = i2c_smbus_read_i2c_block_data(client, - data->def->ctrl_regs[ASA_BASE], - 3, data->asa); + ret = i2c_smbus_read_i2c_block_data_or_emulated( + client, data->def->ctrl_regs[ASA_BASE], + 3, data->asa); if (ret < 0) { dev_err(&client->dev, "Not able to read asa data\n"); return ret; @@ -686,22 +690,31 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) struct ak8975_data *data = iio_priv(indio_dev); const struct i2c_client *client = data->client; const struct ak_def *def = data->def; + u16 buff; int ret; + pm_runtime_get_sync(&data->client->dev); + mutex_lock(&data->lock); ret = ak8975_start_read_axis(data, client); if (ret) goto exit; - ret = i2c_smbus_read_word_data(client, def->data_regs[index]); + ret = i2c_smbus_read_i2c_block_data_or_emulated( + client, def->data_regs[index], + sizeof(buff), (u8*)&buff); if (ret < 0) goto exit; mutex_unlock(&data->lock); - /* Clamp to valid range. */ - *val = clamp_t(s16, ret, -def->range, def->range); + pm_runtime_mark_last_busy(&data->client->dev); + pm_runtime_put_autosuspend(&data->client->dev); + + /* Swap bytes and convert to valid range. */ + buff = le16_to_cpu(buff); + *val = clamp_t(s16, buff, -def->range, def->range); return IIO_VAL_INT; exit: @@ -825,7 +838,8 @@ static void ak8975_fill_buffer(struct iio_dev *indio_dev) buff[1] = clamp_t(s16, le16_to_cpu(buff[1]), -def->range, def->range); buff[2] = clamp_t(s16, le16_to_cpu(buff[2]), -def->range, def->range); - iio_push_to_buffers_with_timestamp(indio_dev, buff, iio_get_time_ns()); + iio_push_to_buffers_with_timestamp(indio_dev, buff, + iio_get_time_ns(indio_dev)); return; unlock: @@ -919,7 +933,15 @@ static int ak8975_probe(struct i2c_client *client, data->def = &ak_def_array[chipset]; - err = ak8975_power_on(client); + /* Fetch the regulators */ + data->vdd = devm_regulator_get(&client->dev, "vdd"); + if (IS_ERR(data->vdd)) + return PTR_ERR(data->vdd); + data->vid = devm_regulator_get(&client->dev, "vid"); + if (IS_ERR(data->vid)) + return PTR_ERR(data->vid); + + err = ak8975_power_on(data); if (err) return err; @@ -959,26 +981,93 @@ static int ak8975_probe(struct i2c_client *client, goto cleanup_buffer; } + /* Enable runtime PM */ + pm_runtime_get_noresume(&client->dev); + pm_runtime_set_active(&client->dev); + pm_runtime_enable(&client->dev); + /* + * The device comes online in 500us, so add two orders of magnitude + * of delay before autosuspending: 50 ms. + */ + pm_runtime_set_autosuspend_delay(&client->dev, 50); + pm_runtime_use_autosuspend(&client->dev); + pm_runtime_put(&client->dev); + return 0; cleanup_buffer: iio_triggered_buffer_cleanup(indio_dev); power_off: - ak8975_power_off(client); + ak8975_power_off(data); return err; } static int ak8975_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ak8975_data *data = iio_priv(indio_dev); + pm_runtime_get_sync(&client->dev); + pm_runtime_put_noidle(&client->dev); + pm_runtime_disable(&client->dev); iio_device_unregister(indio_dev); iio_triggered_buffer_cleanup(indio_dev); - ak8975_power_off(client); + ak8975_set_mode(data, POWER_DOWN); + ak8975_power_off(data); return 0; } +#ifdef CONFIG_PM +static int ak8975_runtime_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ak8975_data *data = iio_priv(indio_dev); + int ret; + + /* Set the device in power down if it wasn't already */ + ret = ak8975_set_mode(data, POWER_DOWN); + if (ret < 0) { + dev_err(&client->dev, "Error in setting power-down mode\n"); + return ret; + } + /* Next cut the regulators */ + ak8975_power_off(data); + + return 0; +} + +static int ak8975_runtime_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ak8975_data *data = iio_priv(indio_dev); + int ret; + + /* Take up the regulators */ + ak8975_power_on(data); + /* + * We come up in powered down mode, the reading routines will + * put us in the mode to read values later. + */ + ret = ak8975_set_mode(data, POWER_DOWN); + if (ret < 0) { + dev_err(&client->dev, "Error in setting power-down mode\n"); + return ret; + } + + return 0; +} +#endif /* CONFIG_PM */ + +static const struct dev_pm_ops ak8975_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(ak8975_runtime_suspend, + ak8975_runtime_resume, NULL) +}; + static const struct i2c_device_id ak8975_id[] = { {"ak8975", AK8975}, {"ak8963", AK8963}, @@ -1006,6 +1095,7 @@ MODULE_DEVICE_TABLE(of, ak8975_of_match); static struct i2c_driver ak8975_driver = { .driver = { .name = "ak8975", + .pm = &ak8975_dev_pm_ops, .of_match_table = of_match_ptr(ak8975_of_match), .acpi_match_table = ACPI_PTR(ak_acpi_match), }, |