From 6da93a6710a3b1eb3d15b88bf96efaac322c893f Mon Sep 17 00:00:00 2001 From: Irina Tirdea Date: Sun, 11 Jan 2015 21:10:14 +0200 Subject: [PATCH] iio: accel: mma9551: Add runtime pm support Add support for runtime pm to reduce the power consumed by the device when not used. If CONFIG_PM is not enabled, the device will be powered on at init and only powered off on system suspend. If CONFIG_PM is enabled, runtime pm autosuspend is used: - for raw reads will keep the device on for a specified time - for events it will keep the device on as long as we have at least one event active Signed-off-by: Irina Tirdea Reviewed-by: Vlad Dogaru Signed-off-by: Jonathan Cameron --- drivers/iio/accel/mma9551.c | 162 +++++++++++++++++++++++++++++++++++++------- 1 file changed, 139 insertions(+), 23 deletions(-) diff --git a/drivers/iio/accel/mma9551.c b/drivers/iio/accel/mma9551.c index 6563e26..f1a5a06 100644 --- a/drivers/iio/accel/mma9551.c +++ b/drivers/iio/accel/mma9551.c @@ -22,6 +22,7 @@ #include #include #include +#include #define MMA9551_DRV_NAME "mma9551" #define MMA9551_IRQ_NAME "mma9551_event" @@ -71,6 +72,7 @@ enum mma9551_gpio_pin { /* Sleep/Wake application */ #define MMA9551_SLEEP_CFG 0x06 #define MMA9551_SLEEP_CFG_SNCEN BIT(0) +#define MMA9551_SLEEP_CFG_FLEEN BIT(1) #define MMA9551_SLEEP_CFG_SCHEN BIT(2) /* AFE application */ @@ -114,6 +116,9 @@ enum mma9551_tilt_axis { #define MMA9551_I2C_READ_RETRIES 5 #define MMA9551_I2C_READ_DELAY 50 /* us */ +#define MMA9551_DEFAULT_SAMPLE_RATE 122 /* Hz */ +#define MMA9551_AUTO_SUSPEND_DELAY_MS 2000 + struct mma9551_mbox_request { u8 start_mbox; /* Always 0. */ u8 app_id; @@ -387,16 +392,55 @@ static int mma9551_read_version(struct i2c_client *client) } /* + * Power on chip and enable doze mode. * Use 'false' as the second parameter to cause the device to enter * sleep. */ -static int mma9551_set_device_state(struct i2c_client *client, - bool enable) +static int mma9551_set_device_state(struct i2c_client *client, bool enable) { return mma9551_update_config_bits(client, MMA9551_APPID_SLEEP_WAKE, MMA9551_SLEEP_CFG, - MMA9551_SLEEP_CFG_SNCEN, - enable ? 0 : MMA9551_SLEEP_CFG_SNCEN); + MMA9551_SLEEP_CFG_SNCEN | + MMA9551_SLEEP_CFG_FLEEN | + MMA9551_SLEEP_CFG_SCHEN, + enable ? MMA9551_SLEEP_CFG_SCHEN | + MMA9551_SLEEP_CFG_FLEEN : + MMA9551_SLEEP_CFG_SNCEN); +} + +static int mma9551_set_power_state(struct i2c_client *client, bool on) +{ +#ifdef CONFIG_PM + int ret; + + if (on) + ret = pm_runtime_get_sync(&client->dev); + else { + pm_runtime_mark_last_busy(&client->dev); + ret = pm_runtime_put_autosuspend(&client->dev); + } + + if (ret < 0) { + dev_err(&client->dev, + "failed to change power state to %d\n", on); + if (on) + pm_runtime_put_noidle(&client->dev); + + return ret; + } +#endif + + return 0; +} + +static void mma9551_sleep(int freq) +{ + int sleep_val = 1000 / freq; + + if (sleep_val < 20) + usleep_range(sleep_val * 1000, 20000); + else + msleep_interruptible(sleep_val); } static int mma9551_read_incli_chan(struct i2c_client *client, @@ -424,15 +468,19 @@ static int mma9551_read_incli_chan(struct i2c_client *client, return -EINVAL; } + ret = mma9551_set_power_state(client, true); + if (ret < 0) + return ret; + ret = mma9551_read_status_byte(client, MMA9551_APPID_TILT, reg_addr, &angle); if (ret < 0) - return ret; + goto out_poweroff; ret = mma9551_read_status_byte(client, MMA9551_APPID_TILT, MMA9551_TILT_QUAD_REG, &quadrant); if (ret < 0) - return ret; + goto out_poweroff; angle &= ~MMA9551_TILT_ANGFLG; quadrant = (quadrant >> quad_shift) & 0x03; @@ -442,7 +490,11 @@ static int mma9551_read_incli_chan(struct i2c_client *client, else *val = angle + 90 * quadrant; - return IIO_VAL_INT; + ret = IIO_VAL_INT; + +out_poweroff: + mma9551_set_power_state(client, false); + return ret; } static int mma9551_read_accel_chan(struct i2c_client *client, @@ -467,14 +519,22 @@ static int mma9551_read_accel_chan(struct i2c_client *client, return -EINVAL; } + ret = mma9551_set_power_state(client, true); + if (ret < 0) + return ret; + ret = mma9551_read_status_word(client, MMA9551_APPID_AFE, reg_addr, &raw_accel); if (ret < 0) - return ret; + goto out_poweroff; *val = raw_accel; - return IIO_VAL_INT; + ret = IIO_VAL_INT; + +out_poweroff: + mma9551_set_power_state(client, false); + return ret; } static int mma9551_read_raw(struct iio_dev *indio_dev, @@ -556,6 +616,10 @@ static int mma9551_config_incli_event(struct iio_dev *indio_dev, MMA9551_APPID_NONE, 0, 0); if (ret < 0) return ret; + + ret = mma9551_set_power_state(data->client, false); + if (ret < 0) + return ret; } else { int bitnum; @@ -574,11 +638,18 @@ static int mma9551_config_incli_event(struct iio_dev *indio_dev, return -EINVAL; } + + ret = mma9551_set_power_state(data->client, true); + if (ret < 0) + return ret; + ret = mma9551_gpio_config(data->client, (enum mma9551_gpio_pin)mma_axis, MMA9551_APPID_TILT, bitnum, 0); - if (ret < 0) + if (ret < 0) { + mma9551_set_power_state(data->client, false); return ret; + } } data->event_enabled[mma_axis] = state; @@ -771,12 +842,7 @@ static int mma9551_init(struct mma9551_data *data) if (ret) return ret; - /* Power on chip and enable doze mode. */ - return mma9551_update_config_bits(data->client, - MMA9551_APPID_SLEEP_WAKE, - MMA9551_SLEEP_CFG, - MMA9551_SLEEP_CFG_SCHEN | MMA9551_SLEEP_CFG_SNCEN, - MMA9551_SLEEP_CFG_SCHEN); + return mma9551_set_device_state(data->client, true); } static int mma9551_gpio_probe(struct iio_dev *indio_dev) @@ -869,8 +935,19 @@ static int mma9551_probe(struct i2c_client *client, goto out_poweroff; } + ret = pm_runtime_set_active(&client->dev); + if (ret < 0) + goto out_iio_unregister; + + pm_runtime_enable(&client->dev); + pm_runtime_set_autosuspend_delay(&client->dev, + MMA9551_AUTO_SUSPEND_DELAY_MS); + pm_runtime_use_autosuspend(&client->dev); + return 0; +out_iio_unregister: + iio_device_unregister(indio_dev); out_poweroff: mma9551_set_device_state(client, false); @@ -882,6 +959,10 @@ static int mma9551_remove(struct i2c_client *client) struct iio_dev *indio_dev = i2c_get_clientdata(client); struct mma9551_data *data = iio_priv(indio_dev); + pm_runtime_disable(&client->dev); + pm_runtime_set_suspended(&client->dev); + pm_runtime_put_noidle(&client->dev); + iio_device_unregister(indio_dev); mutex_lock(&data->mutex); mma9551_set_device_state(data->client, false); @@ -890,37 +971,72 @@ static int mma9551_remove(struct i2c_client *client) return 0; } +#ifdef CONFIG_PM +static int mma9551_runtime_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); + struct mma9551_data *data = iio_priv(indio_dev); + int ret; + + mutex_lock(&data->mutex); + ret = mma9551_set_device_state(data->client, false); + mutex_unlock(&data->mutex); + if (ret < 0) { + dev_err(&data->client->dev, "powering off device failed\n"); + return -EAGAIN; + } + + return 0; +} + +static int mma9551_runtime_resume(struct device *dev) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); + struct mma9551_data *data = iio_priv(indio_dev); + int ret; + + ret = mma9551_set_device_state(data->client, true); + if (ret < 0) + return ret; + + mma9551_sleep(MMA9551_DEFAULT_SAMPLE_RATE); + + return 0; +} +#endif + #ifdef CONFIG_PM_SLEEP static int mma9551_suspend(struct device *dev) { struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); struct mma9551_data *data = iio_priv(indio_dev); + int ret; mutex_lock(&data->mutex); - mma9551_set_device_state(data->client, false); + ret = mma9551_set_device_state(data->client, false); mutex_unlock(&data->mutex); - return 0; + return ret; } static int mma9551_resume(struct device *dev) { struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); struct mma9551_data *data = iio_priv(indio_dev); + int ret; mutex_lock(&data->mutex); - mma9551_set_device_state(data->client, true); + ret = mma9551_set_device_state(data->client, true); mutex_unlock(&data->mutex); - return 0; + return ret; } -#else -#define mma9551_suspend NULL -#define mma9551_resume NULL #endif static const struct dev_pm_ops mma9551_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(mma9551_suspend, mma9551_resume) + SET_RUNTIME_PM_OPS(mma9551_runtime_suspend, + mma9551_runtime_resume, NULL) }; static const struct acpi_device_id mma9551_acpi_match[] = { -- 2.7.4