[PATCH 6/6] iio: light: Updated Vishay Capella cm32181 ambient light sensor driver.

From: Kevin Tsai
Date: Fri May 22 2015 - 00:27:59 EST


- Added Interrupt support.

Signed-off-by: Kevin Tsai <ktsai@xxxxxxxxxxxxxxxx>
---
drivers/iio/light/cm32181.c | 156 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 153 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
index b7abd46..1ae32a0 100644
--- a/drivers/iio/light/cm32181.c
+++ b/drivers/iio/light/cm32181.c
@@ -47,6 +47,10 @@
/* ALS_WL register */
#define CM32181_ALS_WL_DEFAULT 0x0000

+/* STATUS register */
+#define CM32181_STATUS_ALS_IF_L BIT(15)
+#define CM32181_STATUS_ALS_IF_H BIT(14)
+
/* Software parameters */
#define CM32181_HW_ID 0x81
#define CM32181_MLUX_PER_BIT 5 /* ALS_SM=01 IT=800ms */
@@ -122,7 +126,8 @@ void cm32181_parse_dt(struct cm32181_chip *chip)
if (!of_property_read_u32(dn, "capella,mlux_per_bit", &temp_val))
als_info->mlux_per_bit = (int)temp_val;
if (!of_property_read_u32(dn, "capella,thd_percent", &temp_val))
- als_info->thd_percent = (int)temp_val;
+ if (((int)temp_val >= 0) && ((int)temp_val < 100))
+ als_info->thd_percent = (int)temp_val;
}
#endif

@@ -173,6 +178,63 @@ static int cm32181_reg_init(struct cm32181_chip *chip)
}

/**
+ * cm32181_interrupt() - enable/disable interrupt
+ * @chip: pointer of struct cm32181_chip
+ * @ int_en: truen for enable; false for disable
+ *
+ * Enable/disable interrupt mode
+ *
+ * Return: 0 for success; otherwise for error code.
+ */
+static int cm32181_interrupt(struct cm32181_chip *cm32181, bool int_en)
+{
+ int ret;
+
+ mutex_lock(&cm32181->lock);
+ if (int_en)
+ cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
+ CM32181_CMD_ALS_INT_EN;
+ else
+ cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
+ ~CM32181_CMD_ALS_INT_EN;
+
+ ret = i2c_smbus_write_word_data(cm32181->client,
+ CM32181_REG_ADDR_CMD,
+ cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
+ mutex_unlock(&cm32181->lock);
+ return ret;
+}
+
+static irqreturn_t cm32181_irq_handler(int irq, void *data)
+{
+ struct iio_dev *indio_dev = data;
+ struct cm32181_chip *cm32181 = iio_priv(indio_dev);
+ struct i2c_client *client = cm32181->client;
+ int ret;
+ u64 ev_code;
+
+ ret = i2c_smbus_read_word_data(cm32181->client,
+ CM32181_REG_ADDR_STATUS);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "%s: Data read failed: %d\n", __func__, ret);
+ return IRQ_NONE;
+ }
+
+ if (!(ret & (CM32181_STATUS_ALS_IF_H | CM32181_STATUS_ALS_IF_L)))
+ return IRQ_NONE;
+
+ ev_code = IIO_UNMOD_EVENT_CODE(IIO_LIGHT,
+ 0,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_EITHER);
+
+ iio_push_event(indio_dev, ev_code, iio_get_time_ns());
+
+ return IRQ_HANDLED;
+}
+
+/**
* cm32181_read_als_it() - Get sensor integration time
* @chip: pointer of struct cm32181_chip
* @val: pointer of int to load the integration (sec)
@@ -242,6 +304,51 @@ static int cm32181_write_als_it(struct cm32181_chip *chip, int val, int val2)
}

/**
+ * cm32181_ials_read() - read ALS raw data
+ * @chip: pointer of struct cm32181_chip
+ *
+ * Read the ALS raw data and update the interrupt threshold windows.
+ *
+ * Return: Positive value is ALS raw data, otherwise is error code.
+ */
+static int cm32181_als_read(struct cm32181_chip *chip)
+{
+ struct i2c_client *client = chip->client;
+ struct cm32181_als_info *als_info = chip->als_info;
+ u16 als, wh, wl, delta;
+ int ret;
+
+ ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
+ if (ret < 0)
+ return ret;
+
+ als = (u16)ret;
+
+ if (als_info->thd_percent) {
+ delta = als * als_info->thd_percent / 100;
+ if (delta < 3)
+ delta = 3;
+ wh = (als + delta > 0xFFFF) ? 0xFFFF : (als + delta);
+ wl = (als < delta) ? 0 : (als - delta);
+
+ ret = i2c_smbus_write_word_data(client,
+ CM32181_REG_ADDR_ALS_WH, wh);
+ if (ret < 0)
+ return ret;
+ chip->conf_regs[CM32181_REG_ADDR_ALS_WH] = wh;
+
+ ret = i2c_smbus_write_word_data(client,
+ CM32181_REG_ADDR_ALS_WL, wl);
+ if (ret < 0)
+ return ret;
+ chip->conf_regs[CM32181_REG_ADDR_ALS_WL] = wl;
+ ret = als;
+ }
+
+ return ret;
+}
+
+/**
* cm32181_get_lux() - report current lux value
* @chip: pointer of struct cm32181_chip
*
@@ -252,7 +359,6 @@ static int cm32181_write_als_it(struct cm32181_chip *chip, int val, int val2)
*/
static int cm32181_get_lux(struct cm32181_chip *chip)
{
- struct i2c_client *client = chip->client;
struct cm32181_als_info *als_info = chip->als_info;
int ret;
int val, val2;
@@ -268,7 +374,7 @@ static int cm32181_get_lux(struct cm32181_chip *chip)
lux *= als_info->mlux_per_bit_base_it;
lux = div_u64(lux, als_it);

- ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
+ ret = cm32181_als_read(chip);
if (ret < 0)
return ret;

@@ -350,6 +456,15 @@ static ssize_t cm32181_get_it_available(struct device *dev,
return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");
}

+static const struct iio_event_spec cm32181_event_spec[] = {
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_EITHER,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+ BIT(IIO_EV_INFO_ENABLE),
+ }
+};
+
static const struct iio_chan_spec cm32181_channels[] = {
{
.type = IIO_LIGHT,
@@ -357,6 +472,8 @@ static const struct iio_chan_spec cm32181_channels[] = {
BIT(IIO_CHAN_INFO_PROCESSED) |
BIT(IIO_CHAN_INFO_CALIBSCALE) |
BIT(IIO_CHAN_INFO_INT_TIME),
+ .event_spec = cm32181_event_spec,
+ .num_event_specs = ARRAY_SIZE(cm32181_event_spec),
}
};

@@ -383,6 +500,7 @@ static int cm32181_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct cm32181_chip *chip;
+ struct cm32181_als_info *als_info;
struct iio_dev *indio_dev;
int ret;

@@ -412,11 +530,35 @@ static int cm32181_probe(struct i2c_client *client,
return ret;
}

+ als_info = chip->als_info;
+ if (als_info->thd_percent && client->irq) {
+ ret = request_threaded_irq(client->irq, NULL,
+ cm32181_irq_handler,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ indio_dev->name, indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "%s: request irq failed\n",
+ __func__);
+ return ret;
+ }
+
+ ret = cm32181_interrupt(chip, true);
+ if (ret) {
+ als_info->thd_percent = 0;
+ dev_err(&client->dev,
+ "%s: failed to enable interrupt\n", __func__);
+ }
+ } else {
+ als_info->thd_percent = 0; /* Polling Mode */
+ }
+
ret = devm_iio_device_register(&client->dev, indio_dev);
if (ret) {
dev_err(&client->dev,
"%s: regist device failed\n",
__func__);
+ if (als_info->thd_percent)
+ free_irq(client->irq, indio_dev);
return ret;
}

@@ -425,9 +567,17 @@ static int cm32181_probe(struct i2c_client *client,

static int cm32181_remove(struct i2c_client *client)
{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct cm32181_chip *chip = iio_priv(indio_dev);
+ struct cm32181_als_info *als_info = chip->als_info;
+
+ cm32181_interrupt(chip, false);
i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
CM32181_CMD_ALS_DISABLE);

+ if (als_info->thd_percent)
+ free_irq(client->irq, indio_dev);
+
return 0;
}

--
1.8.3.1

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