1 files changed, 371 insertions, 58 deletions

diff --git a/drivers/iio/accel/stk8312.c b/drivers/iio/accel/stk8312.c
index d211d9f3975b..c764af284c94 100644
--- a/drivers/iio/accel/stk8312.c
+++ b/drivers/iio/accel/stk8312.c
@@ -11,17 +11,25 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
+#include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/delay.h>
+#include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
 
 #define STK8312_REG_XOUT		0x00
 #define STK8312_REG_YOUT		0x01
 #define STK8312_REG_ZOUT		0x02
+#define STK8312_REG_INTSU		0x06
 #define STK8312_REG_MODE		0x07
+#define STK8312_REG_SR			0x08
 #define STK8312_REG_STH			0x13
 #define STK8312_REG_RESET		0x20
 #define STK8312_REG_AFECTRL		0x24
@@ -29,14 +37,21 @@
 #define STK8312_REG_OTPDATA		0x3E
 #define STK8312_REG_OTPCTRL		0x3F
 
-#define STK8312_MODE_ACTIVE		1
-#define STK8312_MODE_STANDBY		0
-#define STK8312_MODE_MASK		0x01
-#define STK8312_RNG_MASK		0xC0
+#define STK8312_MODE_ACTIVE		BIT(0)
+#define STK8312_MODE_STANDBY		0x00
+#define STK8312_MODE_INT_AH_PP		0xC0	/* active-high, push-pull */
+#define STK8312_DREADY_BIT		BIT(4)
+#define STK8312_RNG_6G			1
 #define STK8312_RNG_SHIFT		6
-#define STK8312_READ_RETRIES		16
+#define STK8312_RNG_MASK		GENMASK(7, 6)
+#define STK8312_SR_MASK			GENMASK(2, 0)
+#define STK8312_SR_400HZ_IDX		0
+#define STK8312_ALL_CHANNEL_MASK	GENMASK(2, 0)
+#define STK8312_ALL_CHANNEL_SIZE	3
 
 #define STK8312_DRIVER_NAME		"stk8312"
+#define STK8312_GPIO			"stk8312_gpio"
+#define STK8312_IRQ_NAME		"stk8312_event"
 
 /*
  * The accelerometer has two measurement ranges:
@@ -53,32 +68,56 @@ static const int stk8312_scale_table[][2] = {
 	{0, 461600}, {1, 231100}
 };
 
-#define STK8312_ACCEL_CHANNEL(reg, axis) {			\
-	.type = IIO_ACCEL,					\
-	.address = reg,						\
-	.modified = 1,						\
-	.channel2 = IIO_MOD_##axis,				\
-	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
-	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+static const struct {
+	int val;
+	int val2;
+} stk8312_samp_freq_table[] = {
+	{400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},
+	{12, 500000}, {6, 250000}, {3, 125000}
+};
+
+#define STK8312_ACCEL_CHANNEL(index, reg, axis) {			\
+	.type = IIO_ACCEL,						\
+	.address = reg,							\
+	.modified = 1,							\
+	.channel2 = IIO_MOD_##axis,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
+				    BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+	.scan_index = index,						\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 8,						\
+		.storagebits = 8,					\
+		.endianness = IIO_CPU,					\
+	},								\
 }
 
 static const struct iio_chan_spec stk8312_channels[] = {
-	STK8312_ACCEL_CHANNEL(STK8312_REG_XOUT, X),
-	STK8312_ACCEL_CHANNEL(STK8312_REG_YOUT, Y),
-	STK8312_ACCEL_CHANNEL(STK8312_REG_ZOUT, Z),
+	STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X),
+	STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y),
+	STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
 };
 
 struct stk8312_data {
 	struct i2c_client *client;
 	struct mutex lock;
-	int range;
+	u8 range;
+	u8 sample_rate_idx;
 	u8 mode;
+	struct iio_trigger *dready_trig;
+	bool dready_trigger_on;
+	s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */
 };
 
 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
 
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
+
 static struct attribute *stk8312_attributes[] = {
 	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
 	NULL,
 };
 
@@ -105,22 +144,25 @@ static int stk8312_otp_init(struct stk8312_data *data)
 		if (ret < 0)
 			goto exit_err;
 		count--;
-	} while (!(ret & 0x80) && count > 0);
+	} while (!(ret & BIT(7)) && count > 0);
 
-	if (count == 0)
+	if (count == 0) {
+		ret = -ETIMEDOUT;
 		goto exit_err;
+	}
 
 	ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
+	if (ret == 0)
+		ret = -EINVAL;
 	if (ret < 0)
 		goto exit_err;
 
-	ret = i2c_smbus_write_byte_data(data->client,
-			STK8312_REG_AFECTRL, ret);
+	ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret);
 	if (ret < 0)
 		goto exit_err;
 	msleep(150);
 
-	return ret;
+	return 0;
 
 exit_err:
 	dev_err(&client->dev, "failed to initialize sensor\n");
@@ -130,31 +172,19 @@ exit_err:
 static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
 {
 	int ret;
-	u8 masked_reg;
 	struct i2c_client *client = data->client;
 
-	if (mode > 1)
-		return -EINVAL;
-	else if (mode == data->mode)
+	if (mode == data->mode)
 		return 0;
 
-	ret = i2c_smbus_read_byte_data(client, STK8312_REG_MODE);
-	if (ret < 0) {
-		dev_err(&client->dev, "failed to change sensor mode\n");
-		return ret;
-	}
-	masked_reg = ret & (~STK8312_MODE_MASK);
-	masked_reg |= mode;
-
-	ret = i2c_smbus_write_byte_data(client,
-			STK8312_REG_MODE, masked_reg);
+	ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed to change sensor mode\n");
 		return ret;
 	}
 
 	data->mode = mode;
-	if (mode == STK8312_MODE_ACTIVE) {
+	if (mode & STK8312_MODE_ACTIVE) {
 		/* Need to run OTP sequence before entering active mode */
 		usleep_range(1000, 5000);
 		ret = stk8312_otp_init(data);
@@ -163,6 +193,92 @@ static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
 	return ret;
 }
 
+static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
+{
+	int ret;
+	u8 mode;
+	struct i2c_client *client = data->client;
+
+	mode = data->mode;
+	/* We need to go in standby mode to modify registers */
+	ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to set interrupts\n");
+		stk8312_set_mode(data, mode);
+		return ret;
+	}
+
+	return stk8312_set_mode(data, mode);
+}
+
+static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
+					      bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct stk8312_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (state)
+		ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
+	else
+		ret = stk8312_set_interrupts(data, 0x00);
+
+	if (ret < 0) {
+		dev_err(&data->client->dev, "failed to set trigger state\n");
+		return ret;
+	}
+
+	data->dready_trigger_on = state;
+
+	return 0;
+}
+
+static const struct iio_trigger_ops stk8312_trigger_ops = {
+	.set_trigger_state = stk8312_data_rdy_trigger_set_state,
+	.owner = THIS_MODULE,
+};
+
+static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate)
+{
+	int ret;
+	u8 masked_reg;
+	u8 mode;
+	struct i2c_client *client = data->client;
+
+	if (rate == data->sample_rate_idx)
+		return 0;
+
+	mode = data->mode;
+	/* We need to go in standby mode to modify registers */
+	ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);
+	if (ret < 0)
+		goto err_activate;
+
+	masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
+
+	ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
+	if (ret < 0)
+		goto err_activate;
+
+	data->sample_rate_idx = rate;
+
+	return stk8312_set_mode(data, mode);
+
+err_activate:
+	dev_err(&client->dev, "failed to set sampling rate\n");
+	stk8312_set_mode(data, mode);
+
+	return ret;
+}
+
 static int stk8312_set_range(struct stk8312_data *data, u8 range)
 {
 	int ret;
@@ -182,21 +298,25 @@ static int stk8312_set_range(struct stk8312_data *data, u8 range)
 		return ret;
 
 	ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
-	if (ret < 0) {
-		dev_err(&client->dev, "failed to change sensor range\n");
-		return ret;
-	}
+	if (ret < 0)
+		goto err_activate;
 
 	masked_reg = ret & (~STK8312_RNG_MASK);
 	masked_reg |= range << STK8312_RNG_SHIFT;
 
 	ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
 	if (ret < 0)
-		dev_err(&client->dev, "failed to change sensor range\n");
-	else
-		data->range = range;
+		goto err_activate;
+
+	data->range = range;
 
 	return stk8312_set_mode(data, mode);
+
+err_activate:
+	dev_err(&client->dev, "failed to change sensor range\n");
+	stk8312_set_mode(data, mode);
+
+	return ret;
 }
 
 static int stk8312_read_accel(struct stk8312_data *data, u8 address)
@@ -208,12 +328,10 @@ static int stk8312_read_accel(struct stk8312_data *data, u8 address)
 		return -EINVAL;
 
 	ret = i2c_smbus_read_byte_data(client, address);
-	if (ret < 0) {
+	if (ret < 0)
 		dev_err(&client->dev, "register read failed\n");
-		return ret;
-	}
 
-	return sign_extend32(ret, 7);
+	return ret;
 }
 
 static int stk8312_read_raw(struct iio_dev *indio_dev,
@@ -221,20 +339,40 @@ static int stk8312_read_raw(struct iio_dev *indio_dev,
 			    int *val, int *val2, long mask)
 {
 	struct stk8312_data *data = iio_priv(indio_dev);
-
-	if (chan->type != IIO_ACCEL)
-		return -EINVAL;
+	int ret;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
+		if (iio_buffer_enabled(indio_dev))
+			return -EBUSY;
 		mutex_lock(&data->lock);
-		*val = stk8312_read_accel(data, chan->address);
+		ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
+		if (ret < 0) {
+			mutex_unlock(&data->lock);
+			return ret;
+		}
+		ret = stk8312_read_accel(data, chan->address);
+		if (ret < 0) {
+			stk8312_set_mode(data,
+					 data->mode & (~STK8312_MODE_ACTIVE));
+			mutex_unlock(&data->lock);
+			return ret;
+		}
+		*val = sign_extend32(ret, 7);
+		ret = stk8312_set_mode(data,
+				       data->mode & (~STK8312_MODE_ACTIVE));
 		mutex_unlock(&data->lock);
+		if (ret < 0)
+			return ret;
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		*val = stk8312_scale_table[data->range - 1][0];
 		*val2 = stk8312_scale_table[data->range - 1][1];
 		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = stk8312_samp_freq_table[data->sample_rate_idx].val;
+		*val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
+		return IIO_VAL_INT_PLUS_MICRO;
 	}
 
 	return -EINVAL;
@@ -265,6 +403,20 @@ static int stk8312_write_raw(struct iio_dev *indio_dev,
 		mutex_unlock(&data->lock);
 
 		return ret;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
+			if (val == stk8312_samp_freq_table[i].val &&
+			    val2 == stk8312_samp_freq_table[i].val2) {
+				index = i;
+				break;
+			}
+		if (index < 0)
+			return -EINVAL;
+		mutex_lock(&data->lock);
+		ret = stk8312_set_sample_rate(data, index);
+		mutex_unlock(&data->lock);
+
+		return ret;
 	}
 
 	return -EINVAL;
@@ -277,6 +429,105 @@ static const struct iio_info stk8312_info = {
 	.attrs			= &stk8312_attribute_group,
 };
 
+static irqreturn_t stk8312_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct stk8312_data *data = iio_priv(indio_dev);
+	int bit, ret, i = 0;
+
+	mutex_lock(&data->lock);
+	/*
+	 * Do a bulk read if all channels are requested,
+	 * from 0x00 (XOUT) to 0x02 (ZOUT)
+	 */
+	if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
+		ret = i2c_smbus_read_i2c_block_data(data->client,
+						    STK8312_REG_XOUT,
+						    STK8312_ALL_CHANNEL_SIZE,
+						    data->buffer);
+		if (ret < STK8312_ALL_CHANNEL_SIZE) {
+			dev_err(&data->client->dev, "register read failed\n");
+			mutex_unlock(&data->lock);
+			goto err;
+		}
+	} else {
+		for_each_set_bit(bit, indio_dev->active_scan_mask,
+				 indio_dev->masklength) {
+			ret = stk8312_read_accel(data, bit);
+			if (ret < 0) {
+				mutex_unlock(&data->lock);
+				goto err;
+			}
+			data->buffer[i++] = ret;
+		}
+	}
+	mutex_unlock(&data->lock);
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+					   pf->timestamp);
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct stk8312_data *data = iio_priv(indio_dev);
+
+	if (data->dready_trigger_on)
+		iio_trigger_poll(data->dready_trig);
+
+	return IRQ_HANDLED;
+}
+
+static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct stk8312_data *data = iio_priv(indio_dev);
+
+	return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
+}
+
+static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct stk8312_data *data = iio_priv(indio_dev);
+
+	return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
+}
+
+static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
+	.preenable   = stk8312_buffer_preenable,
+	.postenable  = iio_triggered_buffer_postenable,
+	.predisable  = iio_triggered_buffer_predisable,
+	.postdisable = stk8312_buffer_postdisable,
+};
+
+static int stk8312_gpio_probe(struct i2c_client *client)
+{
+	struct device *dev;
+	struct gpio_desc *gpio;
+	int ret;
+
+	if (!client)
+		return -EINVAL;
+
+	dev = &client->dev;
+
+	/* data ready gpio interrupt pin */
+	gpio = devm_gpiod_get_index(dev, STK8312_GPIO, 0, GPIOD_IN);
+	if (IS_ERR(gpio)) {
+		dev_err(dev, "acpi gpio get index failed\n");
+		return PTR_ERR(gpio);
+	}
+
+	ret = gpiod_to_irq(gpio);
+	dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
+
+	return ret;
+}
+
 static int stk8312_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
@@ -308,30 +559,91 @@ static int stk8312_probe(struct i2c_client *client,
 		dev_err(&client->dev, "failed to reset sensor\n");
 		return ret;
 	}
-	ret = stk8312_set_range(data, 1);
+	data->sample_rate_idx = STK8312_SR_400HZ_IDX;
+	ret = stk8312_set_range(data, STK8312_RNG_6G);
 	if (ret < 0)
 		return ret;
 
-	ret = stk8312_set_mode(data, STK8312_MODE_ACTIVE);
+	ret = stk8312_set_mode(data,
+			       STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE);
 	if (ret < 0)
 		return ret;
 
+	if (client->irq < 0)
+		client->irq = stk8312_gpio_probe(client);
+
+	if (client->irq >= 0) {
+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+						stk8312_data_rdy_trig_poll,
+						NULL,
+						IRQF_TRIGGER_RISING |
+						IRQF_ONESHOT,
+						STK8312_IRQ_NAME,
+						indio_dev);
+		if (ret < 0) {
+			dev_err(&client->dev, "request irq %d failed\n",
+				client->irq);
+			goto err_power_off;
+		}
+
+		data->dready_trig = devm_iio_trigger_alloc(&client->dev,
+							   "%s-dev%d",
+							   indio_dev->name,
+							   indio_dev->id);
+		if (!data->dready_trig) {
+			ret = -ENOMEM;
+			goto err_power_off;
+		}
+
+		data->dready_trig->dev.parent = &client->dev;
+		data->dready_trig->ops = &stk8312_trigger_ops;
+		iio_trigger_set_drvdata(data->dready_trig, indio_dev);
+		ret = iio_trigger_register(data->dready_trig);
+		if (ret) {
+			dev_err(&client->dev, "iio trigger register failed\n");
+			goto err_power_off;
+		}
+	}
+
+	ret = iio_triggered_buffer_setup(indio_dev,
+					 iio_pollfunc_store_time,
+					 stk8312_trigger_handler,
+					 &stk8312_buffer_setup_ops);
+	if (ret < 0) {
+		dev_err(&client->dev, "iio triggered buffer setup failed\n");
+		goto err_trigger_unregister;
+	}
+
 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
 		dev_err(&client->dev, "device_register failed\n");
-		stk8312_set_mode(data, STK8312_MODE_STANDBY);
+		goto err_buffer_cleanup;
 	}
 
+	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+	if (data->dready_trig)
+		iio_trigger_unregister(data->dready_trig);
+err_power_off:
+	stk8312_set_mode(data, STK8312_MODE_STANDBY);
 	return ret;
 }
 
 static int stk8312_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct stk8312_data *data = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+
+	if (data->dready_trig)
+		iio_trigger_unregister(data->dready_trig);
 
-	return stk8312_set_mode(iio_priv(indio_dev), STK8312_MODE_STANDBY);
+	return stk8312_set_mode(data, STK8312_MODE_STANDBY);
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -341,7 +653,7 @@ static int stk8312_suspend(struct device *dev)
 
 	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 
-	return stk8312_set_mode(data, STK8312_MODE_STANDBY);
+	return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
 }
 
 static int stk8312_resume(struct device *dev)
@@ -350,7 +662,7 @@ static int stk8312_resume(struct device *dev)
 
 	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 
-	return stk8312_set_mode(data, STK8312_MODE_ACTIVE);
+	return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
 }
 
 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
@@ -364,6 +676,7 @@ static const struct i2c_device_id stk8312_i2c_id[] = {
 	{"STK8312", 0},
 	{}
 };
+MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
 
 static const struct acpi_device_id stk8312_acpi_id[] = {
 	{"STK8312", 0},
@@ -374,7 +687,7 @@ MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
 
 static struct i2c_driver stk8312_driver = {
 	.driver = {
-		.name = "stk8312",
+		.name = STK8312_DRIVER_NAME,
 		.pm = STK8312_PM_OPS,
 		.acpi_match_table = ACPI_PTR(stk8312_acpi_id),
 	},