This patch adds support for Analog Devices AD7923 ADC in the IIO Subsystem.
Signed-off-by: Patrick Vasseur <[email protected]> Signed-off-by: Christophe Leroy <[email protected]> diff -uN linux-3.7.1/drivers/staging/iio/adc/Kconfig linux/drivers/staging/iio/adc/Kconfig --- linux-3.7.1/drivers/staging/iio/adc/Kconfig 2012-12-17 20:14:54.000000000 +0100 +++ linux/drivers/staging/iio/adc/Kconfig 2012-12-13 19:52:10.000000000 +0100 @@ -21,6 +21,17 @@ To compile this driver as a module, choose M here: the module will be called ad7298. +config AD7923 + tristate "Analog Devices AD7923 ADC driver" + depends on SPI + select IIO_TRIGGERED_BUFFER if IIO_BUFFER + help + Say yes here to build support for Analog Devices AD7923 + 4 Channel ADC. + + To compile this driver as a module, choose M here: the + module will be called ad7923. + config AD7606 tristate "Analog Devices AD7606 ADC driver" depends on GPIOLIB diff -uN linux-3.7.1/drivers/staging/iio/adc/Makefile linux/drivers/staging/iio/adc/Makefile --- linux-3.7.1/drivers/staging/iio/adc/Makefile 2012-12-17 20:14:54.000000000 +0100 +++ linux/drivers/staging/iio/adc/Makefile 2012-12-13 19:52:10.000000000 +0100 @@ -25,6 +25,10 @@ ad7298-$(CONFIG_IIO_BUFFER) += ad7298_ring.o obj-$(CONFIG_AD7298) += ad7298.o +ad7923-y := ad7923_core.o +ad7923-$(CONFIG_IIO_BUFFER) += ad7923_ring.o +obj-$(CONFIG_AD7923) += ad7923.o + obj-$(CONFIG_AD7291) += ad7291.o obj-$(CONFIG_AD7780) += ad7780.o obj-$(CONFIG_AD7793) += ad7793.o diff -uN linux-3.7.1/drivers/staging/iio/adc/ad7923.h linux/drivers/staging/iio/adc/ad7923.h --- linux-3.7.1/drivers/staging/iio/adc/ad7923.h 1970-01-01 01:00:00.000000000 +0100 +++ linux/drivers/staging/iio/adc/ad7923.h 2013-01-05 17:53:53.000000000 +0100 @@ -0,0 +1,72 @@ +/* + * AD7923 SPI ADC driver + * + * Copyright 2011 Analog Devices Inc (from AD7298 Driver) + * Copyright 2012 CS Systemes d'Information + * + * Licensed under the GPL-2 or later. + */ +#ifndef IIO_ADC_AD7923_H_ +#define IIO_ADC_AD7923_H_ + +#define AD7923_WRITE_CR (1 << 11) /* write control register */ +#define AD7923_RANGE (1 << 1) /* range to REFin */ +#define AD7923_CODING (1 << 0) /* coding is straight binary */ +#define AD7923_PM_MODE_AS (1) /* auto shutdown */ +#define AD7923_PM_MODE_FS (2) /* full shutdown */ +#define AD7923_PM_MODE_OPS (3) /* normal operation */ +#define AD7923_CHANNEL_0 (0) /* analog input 0 */ +#define AD7923_CHANNEL_1 (1) /* analog input 1 */ +#define AD7923_CHANNEL_2 (2) /* analog input 2 */ +#define AD7923_CHANNEL_3 (3) /* analog input 3 */ +#define AD7923_SEQUENCE_OFF (0) /* no sequence fonction */ +#define AD7923_SEQUENCE_PROTECT (2) /* no interrupt write cycle */ +#define AD7923_SEQUENCE_ON (3) /* continuous sequence */ + +#define AD7923_MAX_CHAN 4 + +#define AD7923_PM_MODE_WRITE(mode) (mode << 4) /* write mode */ +#define AD7923_CHANNEL_WRITE(channel) (channel << 6) /* write channel */ +#define AD7923_SEQUENCE_WRITE(sequence) (((sequence & 1) << 3) \ + + ((sequence & 2) << 9)) + /* write sequence fonction */ +/* left shift for CR : bit 11 transmit in first */ +#define AD7923_SHIFT_REGISTER 4 + +/* val = value, dec = left shift, bits = number of bits of the mask */ +#define EXTRACT(val, dec, bits) ((val >> dec) & ((1 << bits) - 1)) +/* val = value, bits = number of bits of the original value */ +#define EXTRACT_PERCENT(val, bits) (((val + 1) * 100) >> bits) + +struct ad7923_state { + struct spi_device *spi; + struct regulator *reg; + struct spi_transfer ring_xfer[6]; + struct spi_transfer scan_single_xfer[2]; + 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[4] ____cacheline_aligned; + unsigned short tx_buf[2]; +}; + +#ifdef CONFIG_IIO_BUFFER +int ad7923_register_ring_funcs_and_init(struct iio_dev *indio_dev); +void ad7923_ring_cleanup(struct iio_dev *indio_dev); +int ad7923_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *active_scan_mask); +#else /* CONFIG_IIO_BUFFER */ +static inline int +ad7923_register_ring_funcs_and_init(struct iio_dev *indio_dev) +{ + return 0; +} +static inline void ad7923_ring_cleanup(struct iio_dev *indio_dev) +{ +} +#define ad7923_update_scan_mode NULL +#endif /* CONFIG_IIO_BUFFER */ +#endif /* IIO_ADC_AD7923_H_ */ diff -uN linux-3.7.1/drivers/staging/iio/adc/ad7923_core.c linux/drivers/staging/iio/adc/ad7923_core.c --- linux-3.7.1/drivers/staging/iio/adc/ad7923_core.c 1970-01-01 01:00:00.000000000 +0100 +++ linux/drivers/staging/iio/adc/ad7923_core.c 2013-01-05 17:54:11.000000000 +0100 @@ -0,0 +1,202 @@ +/* + * AD7923 SPI ADC driver + * + * Copyright 2011 Analog Devices Inc (from AD7298 Driver) + * Copyright 2012 CS Systemes d'Information + * + * Licensed under the GPL-2. + */ + +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/spi/spi.h> +#include <linux/regulator/consumer.h> +#include <linux/err.h> +#include <linux/module.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/buffer.h> + +#include "ad7923.h" + +#define AD7923_V_CHAN(index) \ + { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = index, \ + .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ + IIO_CHAN_INFO_SCALE_SHARED_BIT, \ + .address = index, \ + .scan_index = index, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 12, \ + .storagebits = 16, \ + }, \ + } + +static struct iio_chan_spec ad7923_channels[] = { + AD7923_V_CHAN(0), + AD7923_V_CHAN(1), + AD7923_V_CHAN(2), + AD7923_V_CHAN(3), + IIO_CHAN_SOFT_TIMESTAMP(4), +}; + +static int ad7923_scan_direct(struct ad7923_state *st, unsigned ch) +{ + int ret, cmd; + + cmd = AD7923_WRITE_CR | AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS) | + AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) | AD7923_CODING | + AD7923_CHANNEL_WRITE(ch) | AD7923_RANGE; + cmd <<= AD7923_SHIFT_REGISTER; + st->tx_buf[0] = cpu_to_be16(cmd); + + ret = spi_sync(st->spi, &st->scan_single_msg); + if (ret) + return ret; + + return be16_to_cpu(st->rx_buf[0]); +} + +static int ad7923_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long m) +{ + int ret; + struct ad7923_state *st = iio_priv(indio_dev); + + switch (m) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&indio_dev->mlock); + if (iio_buffer_enabled(indio_dev)) + ret = -EBUSY; + else + ret = ad7923_scan_direct(st, chan->address); + mutex_unlock(&indio_dev->mlock); + + if (ret < 0) + return ret; + if (chan->address == EXTRACT(ret, 12, 4)) { + *val = EXTRACT(ret, 0, 12); + *val2 = EXTRACT_PERCENT(*val, 12); + } + return IIO_VAL_INT; + } + return -EINVAL; +} + +static const struct iio_info ad7923_info = { + .read_raw = &ad7923_read_raw, + .update_scan_mode = ad7923_update_scan_mode, + .driver_module = THIS_MODULE, +}; + +static int __devinit ad7923_probe(struct spi_device *spi) +{ + struct ad7923_state *st; + struct device *dev = &spi->dev; + int ret; + struct iio_dev *indio_dev = iio_device_alloc(sizeof(*st)); + + if (indio_dev == NULL) + return -ENOMEM; + + st = iio_priv(indio_dev); + + st->reg = regulator_get(&spi->dev, "vcc"); + if (!IS_ERR(st->reg)) { + ret = regulator_enable(st->reg); + if (ret) + goto error_put_reg; + } + + spi_set_drvdata(spi, indio_dev); + + st->spi = spi; + + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->dev.parent = &spi->dev; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = ad7923_channels; + indio_dev->num_channels = ARRAY_SIZE(ad7923_channels); + indio_dev->info = &ad7923_info; + + /* Setup default message */ + st->scan_single_xfer[0].tx_buf = &st->tx_buf[0]; + st->scan_single_xfer[0].len = 2; + st->scan_single_xfer[0].cs_change = 1; + st->scan_single_xfer[1].rx_buf = &st->rx_buf[0]; + st->scan_single_xfer[1].len = 2; + + spi_message_init(&st->scan_single_msg); + spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg); + spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg); + + ret = ad7923_register_ring_funcs_and_init(indio_dev); + if (ret) + goto error_disable_reg; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_cleanup_ring; + + dev_info(dev, "Driver AD7923 is added.\n"); + + return 0; + +error_cleanup_ring: + ad7923_ring_cleanup(indio_dev); +error_disable_reg: + if (!IS_ERR(st->reg)) + regulator_disable(st->reg); +error_put_reg: + if (!IS_ERR(st->reg)) + regulator_put(st->reg); + iio_device_free(indio_dev); + + return ret; +} + +static int __devexit ad7923_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct ad7923_state *st = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + ad7923_ring_cleanup(indio_dev); + if (!IS_ERR(st->reg)) { + regulator_disable(st->reg); + regulator_put(st->reg); + } + iio_device_free(indio_dev); + + return 0; +} + +static const struct spi_device_id ad7923_id[] = { + {"ad7923", 0}, + {} +}; +MODULE_DEVICE_TABLE(spi, ad7923_id); + +static struct spi_driver ad7923_driver = { + .driver = { + .name = "ad7923", + .owner = THIS_MODULE, + }, + .probe = ad7923_probe, + .remove = __devexit_p(ad7923_remove), + .id_table = ad7923_id, +}; +module_spi_driver(ad7923_driver); + +MODULE_AUTHOR("Patrick Vasseur <[email protected]>"); +MODULE_DESCRIPTION("Analog Devices AD7923 ADC"); +MODULE_LICENSE("GPL v2"); diff -uN linux-3.7.1/drivers/staging/iio/adc/ad7923_ring.c linux/drivers/staging/iio/adc/ad7923_ring.c --- linux-3.7.1/drivers/staging/iio/adc/ad7923_ring.c 1970-01-01 01:00:00.000000000 +0100 +++ linux/drivers/staging/iio/adc/ad7923_ring.c 2013-01-05 17:51:47.000000000 +0100 @@ -0,0 +1,113 @@ +/* + * AD7923 SPI ADC driver + * + * Copyright 2011 Analog Devices Inc (from AD7298 Driver) + * Copyright 2012 CS Systemes d'Information + * + * Licensed under the GPL-2. + */ + +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> + +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +#include "ad7923.h" + +/** + * ad7923_update_scan_mode() setup the spi transfer buffer for the new scan mask + **/ +int ad7923_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *active_scan_mask) +{ + struct ad7923_state *st = iio_priv(indio_dev); + int i, cmd, channel; + int scan_count; + + /* Now compute overall size */ + for (i = 0, channel = 0; i < AD7923_MAX_CHAN; i++) + if (test_bit(i, active_scan_mask)) + channel = i; + + cmd = AD7923_WRITE_CR | AD7923_CODING | AD7923_RANGE | + AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS) | + AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_ON) | + AD7923_CHANNEL_WRITE(channel); + cmd <<= AD7923_SHIFT_REGISTER; + st->tx_buf[0] = cpu_to_be16(cmd); + + /* 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; + + spi_message_init(&st->ring_msg); + spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg); + + for (i = 0; i < (channel + 1); i++) { + st->ring_xfer[i + 1].rx_buf = &st->rx_buf[i]; + st->ring_xfer[i + 1].len = 2; + st->ring_xfer[i + 1].cs_change = 1; + spi_message_add_tail(&st->ring_xfer[i + 1], &st->ring_msg); + } + /* make sure last transfer cs_change is not set */ + st->ring_xfer[i + 1].cs_change = 0; + + return 0; +} + +/** + * ad7923_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 ad7923_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct ad7923_state *st = iio_priv(indio_dev); + s64 time_ns = 0; + __u16 buf[16]; + int b_sent, i, channel; + + 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 *)buf + indio_dev->scan_bytes - sizeof(s64), + &time_ns, sizeof(time_ns)); + } + + for (i = 0, channel = 0; i < AD7923_MAX_CHAN; i++) + if (test_bit(i, indio_dev->active_scan_mask)) + channel = i; + + for (i = 0; i < (channel + 1); i++) + buf[i] = be16_to_cpu(st->rx_buf[i]); + + iio_push_to_buffer(indio_dev->buffer, (u8 *)buf); + +done: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +int ad7923_register_ring_funcs_and_init(struct iio_dev *indio_dev) +{ + return iio_triggered_buffer_setup(indio_dev, NULL, + &ad7923_trigger_handler, NULL); +} + +void ad7923_ring_cleanup(struct iio_dev *indio_dev) +{ + iio_triggered_buffer_cleanup(indio_dev); +} -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
