Re: [PATCH 5/5] iio: light: us5182d: Add interrupt support and events

Jonathan Cameron
2015-11-29T14:59:55Z

On 24/11/15 10:59, Adriana Reus wrote:
> Add interrupt support and events for proximity.
> Add two threshold events to signal rising and falling directions.
>
> Signed-off-by: Adriana Reus <adriana.reus@intel.com>
A few bits and bobs inline...
> ---
> drivers/iio/light/us5182d.c | 272 +++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 271 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iio/light/us5182d.c b/drivers/iio/light/us5182d.c
> index 60cab4a..4d1f80d 100644
> --- a/drivers/iio/light/us5182d.c
> +++ b/drivers/iio/light/us5182d.c
> @@ -20,7 +20,10 @@
> #include <linux/acpi.h>
> #include <linux/delay.h>
> #include <linux/i2c.h>
> +#include <linux/iio/events.h>
> #include <linux/iio/iio.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> #include <linux/iio/sysfs.h>
> #include <linux/mutex.h>
> #include <linux/pm.h>
> @@ -30,6 +33,8 @@
> #define US5182D_CFG0_ONESHOT_EN BIT(6)
> #define US5182D_CFG0_SHUTDOWN_EN BIT(7)
> #define US5182D_CFG0_WORD_ENABLE BIT(0)
> +#define US5182D_CFG0_PROX BIT(3)
> +#define US5182D_CFG0_PX_IRQ BIT(2)
>
> #define US5182D_REG_CFG1 0x01
> #define US5182D_CFG1_ALS_RES16 BIT(4)
> @@ -41,6 +46,7 @@
>
> #define US5182D_REG_CFG3 0x03
> #define US5182D_CFG3_LED_CURRENT100 (BIT(4) | BIT(5))
> +#define US5182D_CFG3_INT_SOURCE_PX BIT(3)
>
> #define US5182D_REG_CFG4 0x10
>
> @@ -55,6 +61,13 @@
> #define US5182D_REG_AUTO_LDARK_GAIN 0x29
> #define US5182D_REG_AUTO_HDARK_GAIN 0x2a
>
> +/* Thresholds for events: px low (0x08-l, 0x09-h), px high (0x0a-l 0x0b-h) */
> +#define US5182D_REG_PXL_TH 0x08
> +#define US5182D_REG_PXH_TH 0x0a
> +
> +#define US5182D_REG_PXL_TH_DEFAULT 1000
> +#define US5182D_REG_PXH_TH_DEFAULT 30000
> +
> #define US5182D_OPMODE_ALS 0x01
> #define US5182D_OPMODE_PX 0x02
> #define US5182D_OPMODE_SHIFT 4
> @@ -84,6 +97,8 @@
> #define US5182D_READ_WORD 2
> #define US5182D_OPSTORE_SLEEP_TIME 20 /* ms */
> #define US5182D_SLEEP_MS 3000 /* ms */
> +#define US5182D_PXH_TH_DISABLE 0xffff
> +#define US5182D_PXL_TH_DISABLE 0x0000
>
> /* Available ranges: [12354, 7065, 3998, 2202, 1285, 498, 256, 138] lux */
> static const int us5182d_scales[] = {188500, 107800, 61000, 33600, 19600, 7600,
> @@ -119,6 +134,12 @@ struct us5182d_data {
> u8 upper_dark_gain;
> u16 *us5182d_dark_ths;
>
> + u16 px_low_th;
> + u16 px_high_th;
> +
> + int rising_en;
> + int falling_en;
> +
> u8 opmode;
> u8 power_mode;
>
> @@ -148,10 +169,26 @@ static const struct {
> {US5182D_REG_CFG1, US5182D_CFG1_ALS_RES16},
> {US5182D_REG_CFG2, (US5182D_CFG2_PX_RES16 |
> US5182D_CFG2_PXGAIN_DEFAULT)},
> - {US5182D_REG_CFG3, US5182D_CFG3_LED_CURRENT100},
> + {US5182D_REG_CFG3, US5182D_CFG3_LED_CURRENT100 |
> + US5182D_CFG3_INT_SOURCE_PX},
> {US5182D_REG_CFG4, 0x00},
> };
>
> +static const struct iio_event_spec us5182d_events[] = {
> + {
> + .type = IIO_EV_TYPE_THRESH,
> + .dir = IIO_EV_DIR_RISING,
> + .mask_separate = BIT(IIO_EV_INFO_VALUE) |
> + BIT(IIO_EV_INFO_ENABLE),
> + },
> + {
> + .type = IIO_EV_TYPE_THRESH,
> + .dir = IIO_EV_DIR_FALLING,
> + .mask_separate = BIT(IIO_EV_INFO_VALUE) |
> + BIT(IIO_EV_INFO_ENABLE),
> + },
> +};
> +
> static const struct iio_chan_spec us5182d_channels[] = {
> {
> .type = IIO_LIGHT,
> @@ -161,6 +198,8 @@ static const struct iio_chan_spec us5182d_channels[] = {
> {
> .type = IIO_PROXIMITY,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + .event_spec = us5182d_events,
> + .num_event_specs = ARRAY_SIZE(us5182d_events),
> }
> };
>
> @@ -477,11 +516,199 @@ static int us5182d_write_raw(struct iio_dev *indio_dev,
> return -EINVAL;
> }
>
> +static int us5182d_setup_prox(struct iio_dev *indio_dev,
> + enum iio_event_direction dir, u16 val)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> + int ret = 0;
> +
> + if (dir == IIO_EV_DIR_FALLING)
> + ret = i2c_smbus_write_word_data(data->client,
> + US5182D_REG_PXL_TH, val);
> +
> + if (dir == IIO_EV_DIR_RISING)
> + ret = i2c_smbus_write_word_data(data->client,
> + US5182D_REG_PXH_TH, val);
> +
> + return ret;
return directly above, no need for the local ret variable and return
0 here.
> +}
> +
> +static int us5182d_read_thresh(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan, enum iio_event_type type,
> + enum iio_event_direction dir, enum iio_event_info info, int *val,
> + int *val2)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> +
> + switch (dir) {
> + case IIO_EV_DIR_RISING:
> + mutex_lock(&data->lock);
> + *val = data->px_high_th;
> + mutex_unlock(&data->lock);
> + break;
> + case IIO_EV_DIR_FALLING:
> + mutex_lock(&data->lock);
> + *val = data->px_low_th;
> + mutex_unlock(&data->lock);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return IIO_VAL_INT;
> +}
> +
> +static int us5182d_write_thresh(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan, enum iio_event_type type,
> + enum iio_event_direction dir, enum iio_event_info info, int val,
> + int val2)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> + int ret = 0;
There is no path in which ret is used and not overriden that I can see
so drop the initialize.

> +
> + if (val < 0 || val > USHRT_MAX || val2 != 0)
> + return -EINVAL;
> +
> + switch (dir) {
> + case IIO_EV_DIR_RISING:
> + mutex_lock(&data->lock);
> + if (data->rising_en) {
> + ret = us5182d_setup_prox(indio_dev, dir, val);
> + if (ret < 0)
> + goto err;
> + }
> + data->px_high_th = val;
> + mutex_unlock(&data->lock);
> + break;
> + case IIO_EV_DIR_FALLING:
> + mutex_lock(&data->lock);
> + if (data->falling_en) {
> + ret = us5182d_setup_prox(indio_dev, dir, val);
> + if (ret < 0)
> + goto err;
> + }
> + data->px_low_th = val;
> + mutex_unlock(&data->lock);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return 0;
> +err:
> + mutex_unlock(&data->lock);
> + return ret;
> +}
> +
> +static int us5182d_read_event_config(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan, enum iio_event_type type,
> + enum iio_event_direction dir)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + switch (dir) {
> + case IIO_EV_DIR_RISING:
> + mutex_lock(&data->lock);
> + ret = data->rising_en;
> + mutex_unlock(&data->lock);

> + break;
> + case IIO_EV_DIR_FALLING:
> + mutex_lock(&data->lock);
> + ret = data->falling_en;
> + mutex_unlock(&data->lock);
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + return ret;
> +}
> +
> +static int us5182d_write_event_config(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan, enum iio_event_type type,
> + enum iio_event_direction dir, int state)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> + int ret;
> + u16 new_th;
> +
> + mutex_lock(&data->lock);
> +
> + switch (dir) {
> + case IIO_EV_DIR_RISING:
> + if (data->rising_en == state)
> + goto out;
> + new_th = US5182D_PXH_TH_DISABLE;
> + if (state) {
> + data->power_mode = US5182D_CONTINUOUS;
> + ret = us5182d_set_power_state(data, true);
> + if (ret < 0)
> + goto err;
> + ret = us5182d_px_enable(data);
> + if (ret < 0)
> + goto err_poweroff;
> + new_th = data->px_high_th;
> + }
> + ret = us5182d_setup_prox(indio_dev, dir, new_th);
> + if (ret < 0)
> + goto err_poweroff;
> + data->rising_en = state;
> + break;
> + case IIO_EV_DIR_FALLING:
> + if (data->falling_en == state)
> + goto out;
> + new_th = US5182D_PXL_TH_DISABLE;
> + if (state) {
> + data->power_mode = US5182D_CONTINUOUS;
> + ret = us5182d_set_power_state(data, true);
> + if (ret < 0)
> + goto err;
> + ret = us5182d_px_enable(data);
> + if (ret < 0)
> + goto err_poweroff;
> + new_th = data->px_low_th;
> + }
> + ret = us5182d_setup_prox(indio_dev, dir, new_th);
> + if (ret < 0)
> + goto err_poweroff;
> + data->falling_en = state;
> + break;
> + default:
> + ret = -EINVAL;
> + goto err;
> + }
> +
> + if (!state) {
> + ret = us5182d_set_power_state(data, false);
> + if (ret < 0)
> + goto err;
> + }
> +
> + if (!data->falling_en && !data->rising_en && !data->default_continuous)
> + data->power_mode = US5182D_ONESHOT;
> +
> +out:
> + mutex_unlock(&data->lock);
> + return 0;
I'm not terribly keen on these multiple exit routes reached by gotos but
can't see a trivial way to clean this up other than simply having
mutex unlock and return inline where you use the above goto. Might
be easier to follow.

> +err_poweroff:
> + if (state)
> + us5182d_set_power_state(data, false);
> +err:
> + mutex_unlock(&data->lock);
> + return ret;
> +}
> +
> static const struct iio_info us5182d_info = {
> .driver_module = THIS_MODULE,
> .read_raw = us5182d_read_raw,
> .write_raw = us5182d_write_raw,
> .attrs = &us5182d_attr_group,
> + .read_event_value = &us5182d_read_thresh,
> + .write_event_value = &us5182d_write_thresh,
> + .read_event_config = &us5182d_read_event_config,
> + .write_event_config = &us5182d_write_event_config,
> };
>
> static int us5182d_reset(struct iio_dev *indio_dev)
> @@ -503,6 +730,9 @@ static int us5182d_init(struct iio_dev *indio_dev)
>
> data->opmode = 0;
> data->power_mode = US5182D_CONTINUOUS;
> + data->px_low_th = US5182D_REG_PXL_TH_DEFAULT;
> + data->px_high_th = US5182D_REG_PXH_TH_DEFAULT;
> +
> for (i = 0; i < ARRAY_SIZE(us5182d_regvals); i++) {
> ret = i2c_smbus_write_byte_data(data->client,
> us5182d_regvals[i].reg,
> @@ -573,6 +803,36 @@ static int us5182d_dark_gain_config(struct iio_dev *indio_dev)
> US5182D_REG_DARK_AUTO_EN_DEFAULT);
> }
>
> +static irqreturn_t us5182d_irq_thread_handler(int irq, void *private)
> +{
> + struct iio_dev *indio_dev = private;
> + struct us5182d_data *data = iio_priv(indio_dev);
> + enum iio_event_direction dir;
> + int ret;
> + int approach;
> + u64 ev;
> +
> + ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG0);
> + if (ret < 0) {
> + dev_err(&data->client->dev, "i2c transfer error in irq\n");
> + return IRQ_HANDLED;
> + }
> +
> + approach = ret & US5182D_CFG0_PROX;
> + dir = approach ? IIO_EV_DIR_RISING : IIO_EV_DIR_FALLING;
> + ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 1, IIO_EV_TYPE_THRESH, dir);
> +
> + iio_push_event(indio_dev, ev, iio_get_time_ns());
I might argue slightly in favour of doing the timestamp acquire in the
top half, but I doubt anyone is ever that bothered by precise timing
of such an event so lets leave it as is for now.

> +
> + ret = ret & ~US5182D_CFG0_PX_IRQ;
> +
>From a reability point of view, I'd have been tempted to do this manipulation
directly in the next call - out here you almost look ato be manipulating
return values rather than working out the value to write.

> + ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG0, ret);

> + if (ret < 0)
> + dev_err(&data->client->dev, "i2c transfer error in irq\n");
> +
> + return IRQ_HANDLED;
> +}
> +
> static int us5182d_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> @@ -604,6 +864,16 @@ static int us5182d_probe(struct i2c_client *client,
> return (ret < 0) ? ret : -ENODEV;
> }
>
> + if (client->irq > 0) {
> + ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> + us5182d_irq_thread_handler,
> + IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> + "us5182d-irq", indio_dev);
> + if (ret < 0)
> + return ret;
> + } else
> + dev_warn(&client->dev, "no valid irq found\n");
> +
> us5182d_get_platform_data(indio_dev);
> ret = us5182d_init(indio_dev);
> if (ret < 0)
>