staging:iio:ad7298: Squash everything into one file

The recent cleanups have decimated the drivers code size by quite a bit. It is
only a few hundred lines in total now. Putting everything into one file also
allows to reduce the code size a bit more by removing a few lines of boilerplate
code. The only functional change made by this patch is that we now always
include buffer support, instead of making it optional. This is more consistent
with what we do for other drivers.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/adc/Kconfig

@@ -13,7 +13,8 @@ config AD7291
 config AD7298
 	tristate "Analog Devices AD7298 ADC driver"
 	depends on SPI
-	select IIO_TRIGGERED_BUFFER if IIO_BUFFER
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 	help
 	  Say yes here to build support for Analog Devices AD7298
 	  8 Channel ADC with temperature sensor.

drivers/staging/iio/adc/Makefile

@@ -12,8 +12,6 @@ ad799x-y := ad799x_core.o
 ad799x-$(CONFIG_AD799X_RING_BUFFER) += ad799x_ring.o
 obj-$(CONFIG_AD799X) += ad799x.o
 
-ad7298-y := ad7298_core.o
-ad7298-$(CONFIG_IIO_BUFFER) += ad7298_ring.o
 obj-$(CONFIG_AD7298) += ad7298.o
 
 obj-$(CONFIG_AD7291) += ad7291.o

drivers/staging/iio/adc/ad7298_core.c → drivers/staging/iio/adc/ad7298.c

@@ -15,13 +15,49 @@
 #include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/module.h>
+#include <linux/interrupt.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 
 #include "ad7298.h"
 
+#define AD7298_WRITE	(1 << 15) /* write to the control register */
+#define AD7298_REPEAT	(1 << 14) /* repeated conversion enable */
+#define AD7298_CH(x)	(1 << (13 - (x))) /* channel select */
+#define AD7298_TSENSE	(1 << 5) /* temperature conversion enable */
+#define AD7298_EXTREF	(1 << 2) /* external reference enable */
+#define AD7298_TAVG	(1 << 1) /* temperature sensor averaging enable */
+#define AD7298_PDD	(1 << 0) /* partial power down enable */
+
+#define AD7298_MAX_CHAN		8
+#define AD7298_BITS		12
+#define AD7298_STORAGE_BITS	16
+#define AD7298_INTREF_mV	2500
+
+#define AD7298_CH_TEMP		9
+
+#define RES_MASK(bits)	((1 << (bits)) - 1)
+
+struct ad7298_state {
+	struct spi_device		*spi;
+	struct regulator		*reg;
+	unsigned			ext_ref;
+	struct spi_transfer		ring_xfer[10];
+	struct spi_transfer		scan_single_xfer[3];
+	struct spi_message		ring_msg;
+	struct spi_message		scan_single_msg;
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	unsigned short			rx_buf[12] ____cacheline_aligned;
+	unsigned short			tx_buf[2];
+};
+
 #define AD7298_V_CHAN(index)						\
 	{								\
 		.type = IIO_VOLTAGE,					\
@@ -66,6 +102,84 @@ static const struct iio_chan_spec ad7298_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(8),
 };
 
+/**
+ * ad7298_update_scan_mode() setup the spi transfer buffer for the new scan mask
+ **/
+static int ad7298_update_scan_mode(struct iio_dev *indio_dev,
+	const unsigned long *active_scan_mask)
+{
+	struct ad7298_state *st = iio_priv(indio_dev);
+	int i, m;
+	unsigned short command;
+	int scan_count;
+
+	/* Now compute overall size */
+	scan_count = bitmap_weight(active_scan_mask, indio_dev->masklength);
+
+	command = AD7298_WRITE | st->ext_ref;
+
+	for (i = 0, m = AD7298_CH(0); i < AD7298_MAX_CHAN; i++, m >>= 1)
+		if (test_bit(i, active_scan_mask))
+			command |= m;
+
+	st->tx_buf[0] = cpu_to_be16(command);
+
+	/* build spi ring message */
+	st->ring_xfer[0].tx_buf = &st->tx_buf[0];
+	st->ring_xfer[0].len = 2;
+	st->ring_xfer[0].cs_change = 1;
+	st->ring_xfer[1].tx_buf = &st->tx_buf[1];
+	st->ring_xfer[1].len = 2;
+	st->ring_xfer[1].cs_change = 1;
+
+	spi_message_init(&st->ring_msg);
+	spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
+	spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
+
+	for (i = 0; i < scan_count; i++) {
+		st->ring_xfer[i + 2].rx_buf = &st->rx_buf[i];
+		st->ring_xfer[i + 2].len = 2;
+		st->ring_xfer[i + 2].cs_change = 1;
+		spi_message_add_tail(&st->ring_xfer[i + 2], &st->ring_msg);
+	}
+	/* make sure last transfer cs_change is not set */
+	st->ring_xfer[i + 1].cs_change = 0;
+
+	return 0;
+}
+
+/**
+ * ad7298_trigger_handler() bh of trigger launched polling to ring buffer
+ *
+ * Currently there is no option in this driver to disable the saving of
+ * timestamps within the ring.
+ **/
+static irqreturn_t ad7298_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad7298_state *st = iio_priv(indio_dev);
+	s64 time_ns = 0;
+	int b_sent;
+
+	b_sent = spi_sync(st->spi, &st->ring_msg);
+	if (b_sent)
+		goto done;
+
+	if (indio_dev->scan_timestamp) {
+		time_ns = iio_get_time_ns();
+		memcpy((u8 *)st->rx_buf + indio_dev->scan_bytes - sizeof(s64),
+			&time_ns, sizeof(time_ns));
+	}
+
+	iio_push_to_buffers(indio_dev, (u8 *)st->rx_buf);
+
+done:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
 static int ad7298_scan_direct(struct ad7298_state *st, unsigned ch)
 {
 	int ret;
@@ -231,7 +345,8 @@ static int __devinit ad7298_probe(struct spi_device *spi)
 	spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
 	spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg);
 
-	ret = ad7298_register_ring_funcs_and_init(indio_dev);
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+			&ad7298_trigger_handler, NULL);
 	if (ret)
 		goto error_disable_reg;
 
@@ -242,7 +357,7 @@ static int __devinit ad7298_probe(struct spi_device *spi)
 	return 0;
 
 error_cleanup_ring:
-	ad7298_ring_cleanup(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
 error_disable_reg:
 	if (st->ext_ref)
 		regulator_disable(st->reg);
@@ -261,7 +376,7 @@ static int __devexit ad7298_remove(struct spi_device *spi)
 	struct ad7298_state *st = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
-	ad7298_ring_cleanup(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
 	if (st->ext_ref) {
 		regulator_disable(st->reg);
 		regulator_put(st->reg);

drivers/staging/iio/adc/ad7298.h

@@ -9,23 +9,6 @@
 #ifndef IIO_ADC_AD7298_H_
 #define IIO_ADC_AD7298_H_
 
-#define AD7298_WRITE	(1 << 15) /* write to the control register */
-#define AD7298_REPEAT	(1 << 14) /* repeated conversion enable */
-#define AD7298_CH(x)	(1 << (13 - (x))) /* channel select */
-#define AD7298_TSENSE	(1 << 5) /* temperature conversion enable */
-#define AD7298_EXTREF	(1 << 2) /* external reference enable */
-#define AD7298_TAVG	(1 << 1) /* temperature sensor averaging enable */
-#define AD7298_PDD	(1 << 0) /* partial power down enable */
-
-#define AD7298_MAX_CHAN		8
-#define AD7298_BITS		12
-#define AD7298_STORAGE_BITS	16
-#define AD7298_INTREF_mV	2500
-
-#define AD7298_CH_TEMP		9
-
-#define RES_MASK(bits)	((1 << (bits)) - 1)
-
 /**
  * struct ad7298_platform_data - Platform data for the ad7298 ADC driver
  * @ext_ref: Whether to use an external reference voltage.
@@ -34,40 +17,4 @@ struct ad7298_platform_data {
 	bool ext_ref;
 };
 
-struct ad7298_state {
-	struct spi_device		*spi;
-	struct regulator		*reg;
-	unsigned			ext_ref;
-	struct spi_transfer		ring_xfer[10];
-	struct spi_transfer		scan_single_xfer[3];
-	struct spi_message		ring_msg;
-	struct spi_message		scan_single_msg;
-	/*
-	 * DMA (thus cache coherency maintenance) requires the
-	 * transfer buffers to live in their own cache lines.
-	 */
-	unsigned short			rx_buf[12] ____cacheline_aligned;
-	unsigned short			tx_buf[2];
-};
-
-#ifdef CONFIG_IIO_BUFFER
-int ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev);
-void ad7298_ring_cleanup(struct iio_dev *indio_dev);
-int ad7298_update_scan_mode(struct iio_dev *indio_dev,
-	const unsigned long *active_scan_mask);
-#else /* CONFIG_IIO_BUFFER */
-
-static inline int
-ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev)
-{
-	return 0;
-}
-
-static inline void ad7298_ring_cleanup(struct iio_dev *indio_dev)
-{
-}
-
-#define ad7298_update_scan_mode NULL
-
-#endif /* CONFIG_IIO_BUFFER */
 #endif /* IIO_ADC_AD7298_H_ */