On 28/11/16 16:58, David Lechner wrote: > This adds a new driver for the TI ADS7950 family of ADC chips. These > communicate using SPI and come in 8/10/12-bit and 4/8/12/16 channel > varieties. > > Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx> Very nice. Applied to the togreg branch of iio.git - initially pushed out as testing when I next have an internet connection.... thanks, Jonathan > --- > > v4 changes: > * Change spi_async() back to spi_sync(). (I have learned that this is in a > threaded interrupt handler, so sleeping is OK.) > > v3 changes: > > * Use spi_async() instead of spi_sync() in ti_ads7950_trigger_handler() > * Fix scaling in ti_ads7950_read_raw() > > v2 changes: > > * Got rid of XX wildcards - using ADS7950 everywhere > * Fixed some macro parentheses issues > * Added TI_ prefix to macros to match ti_ prefixes used elsewhere > * Added space in rx_buf for holding timestamp > * Use iio_device_claim_direct_mode() and spi_message_init_with_transfers() > helper functions > * Don't use dev_info() at end of probe > * Minor spelling and code style fixes > > drivers/iio/adc/Kconfig | 13 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/ti-ads7950.c | 490 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 504 insertions(+) > create mode 100644 drivers/iio/adc/ti-ads7950.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 6bbee0b..26b32f0 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -527,6 +527,19 @@ config TI_ADS1015 > This driver can also be built as a module. If so, the module will be > called ti-ads1015. > > +config TI_ADS7950 > + tristate "Texas Instruments ADS7950 ADC driver" > + depends on SPI > + select IIO_BUFFER > + select IIO_TRIGGERED_BUFFER > + help > + Say yes here to build support for Texas Instruments ADS7950, ADS7951, > + ADS7952, ADS7953, ADS7954, ADS7955, ADS7956, ADS7957, ADS7958, ADS7959. > + ADS7960, ADS7961. > + > + To compile this driver as a module, choose M here: the > + module will be called ti-ads7950. > + > config TI_ADS8688 > tristate "Texas Instruments ADS8688" > depends on SPI && OF > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 9391217..1966801 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -49,6 +49,7 @@ obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o > obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o > obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o > obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o > +obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o > obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o > obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o > obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o > diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c > new file mode 100644 > index 0000000..0330361 > --- /dev/null > +++ b/drivers/iio/adc/ti-ads7950.c > @@ -0,0 +1,490 @@ > +/* > + * Texas Instruments ADS7950 SPI ADC driver > + * > + * Copyright 2016 David Lechner <david@xxxxxxxxxxxxxx> > + * > + * Based on iio/ad7923.c: > + * Copyright 2011 Analog Devices Inc > + * Copyright 2012 CS Systemes d'Information > + * > + * And also on hwmon/ads79xx.c > + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/ > + * Nishanth Menon > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License as > + * published by the Free Software Foundation version 2. > + * > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <linux/bitops.h> > +#include <linux/device.h> > +#include <linux/err.h> > +#include <linux/interrupt.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/regulator/consumer.h> > +#include <linux/slab.h> > +#include <linux/spi/spi.h> > + > +#include <linux/iio/buffer.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > +#include <linux/iio/trigger_consumer.h> > +#include <linux/iio/triggered_buffer.h> > + > +#define TI_ADS7950_CR_MANUAL BIT(12) > +#define TI_ADS7950_CR_WRITE BIT(11) > +#define TI_ADS7950_CR_CHAN(ch) ((ch) << 7) > +#define TI_ADS7950_CR_RANGE_5V BIT(6) > + > +#define TI_ADS7950_MAX_CHAN 16 > + > +#define TI_ADS7950_TIMESTAMP_SIZE (sizeof(int64_t) / sizeof(__be16)) > + > +/* val = value, dec = left shift, bits = number of bits of the mask */ > +#define TI_ADS7950_EXTRACT(val, dec, bits) \ > + (((val) >> (dec)) & ((1 << (bits)) - 1)) > + > +struct ti_ads7950_state { > + struct spi_device *spi; > + struct spi_transfer ring_xfer[TI_ADS7950_MAX_CHAN + 2]; > + struct spi_transfer scan_single_xfer[3]; > + struct spi_message ring_msg; > + struct spi_message scan_single_msg; > + > + struct regulator *reg; > + > + unsigned int settings; > + > + /* > + * DMA (thus cache coherency maintenance) requires the > + * transfer buffers to live in their own cache lines. > + */ > + __be16 rx_buf[TI_ADS7950_MAX_CHAN + TI_ADS7950_TIMESTAMP_SIZE] > + ____cacheline_aligned; > + __be16 tx_buf[TI_ADS7950_MAX_CHAN]; > +}; > + > +struct ti_ads7950_chip_info { > + const struct iio_chan_spec *channels; > + unsigned int num_channels; > +}; > + > +enum ti_ads7950_id { > + TI_ADS7950, > + TI_ADS7951, > + TI_ADS7952, > + TI_ADS7953, > + TI_ADS7954, > + TI_ADS7955, > + TI_ADS7956, > + TI_ADS7957, > + TI_ADS7958, > + TI_ADS7959, > + TI_ADS7960, > + TI_ADS7961, > +}; > + > +#define TI_ADS7950_V_CHAN(index, bits) \ > +{ \ > + .type = IIO_VOLTAGE, \ > + .indexed = 1, \ > + .channel = index, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > + .address = index, \ > + .datasheet_name = "CH##index", \ > + .scan_index = index, \ > + .scan_type = { \ > + .sign = 'u', \ > + .realbits = bits, \ > + .storagebits = 16, \ > + .shift = 12 - (bits), \ > + .endianness = IIO_BE, \ > + }, \ > +} > + > +#define DECLARE_TI_ADS7950_4_CHANNELS(name, bits) \ > +const struct iio_chan_spec name ## _channels[] = { \ > + TI_ADS7950_V_CHAN(0, bits), \ > + TI_ADS7950_V_CHAN(1, bits), \ > + TI_ADS7950_V_CHAN(2, bits), \ > + TI_ADS7950_V_CHAN(3, bits), \ > + IIO_CHAN_SOFT_TIMESTAMP(4), \ > +} > + > +#define DECLARE_TI_ADS7950_8_CHANNELS(name, bits) \ > +const struct iio_chan_spec name ## _channels[] = { \ > + TI_ADS7950_V_CHAN(0, bits), \ > + TI_ADS7950_V_CHAN(1, bits), \ > + TI_ADS7950_V_CHAN(2, bits), \ > + TI_ADS7950_V_CHAN(3, bits), \ > + TI_ADS7950_V_CHAN(4, bits), \ > + TI_ADS7950_V_CHAN(5, bits), \ > + TI_ADS7950_V_CHAN(6, bits), \ > + TI_ADS7950_V_CHAN(7, bits), \ > + IIO_CHAN_SOFT_TIMESTAMP(8), \ > +} > + > +#define DECLARE_TI_ADS7950_12_CHANNELS(name, bits) \ > +const struct iio_chan_spec name ## _channels[] = { \ > + TI_ADS7950_V_CHAN(0, bits), \ > + TI_ADS7950_V_CHAN(1, bits), \ > + TI_ADS7950_V_CHAN(2, bits), \ > + TI_ADS7950_V_CHAN(3, bits), \ > + TI_ADS7950_V_CHAN(4, bits), \ > + TI_ADS7950_V_CHAN(5, bits), \ > + TI_ADS7950_V_CHAN(6, bits), \ > + TI_ADS7950_V_CHAN(7, bits), \ > + TI_ADS7950_V_CHAN(8, bits), \ > + TI_ADS7950_V_CHAN(9, bits), \ > + TI_ADS7950_V_CHAN(10, bits), \ > + TI_ADS7950_V_CHAN(11, bits), \ > + IIO_CHAN_SOFT_TIMESTAMP(12), \ > +} > + > +#define DECLARE_TI_ADS7950_16_CHANNELS(name, bits) \ > +const struct iio_chan_spec name ## _channels[] = { \ > + TI_ADS7950_V_CHAN(0, bits), \ > + TI_ADS7950_V_CHAN(1, bits), \ > + TI_ADS7950_V_CHAN(2, bits), \ > + TI_ADS7950_V_CHAN(3, bits), \ > + TI_ADS7950_V_CHAN(4, bits), \ > + TI_ADS7950_V_CHAN(5, bits), \ > + TI_ADS7950_V_CHAN(6, bits), \ > + TI_ADS7950_V_CHAN(7, bits), \ > + TI_ADS7950_V_CHAN(8, bits), \ > + TI_ADS7950_V_CHAN(9, bits), \ > + TI_ADS7950_V_CHAN(10, bits), \ > + TI_ADS7950_V_CHAN(11, bits), \ > + TI_ADS7950_V_CHAN(12, bits), \ > + TI_ADS7950_V_CHAN(13, bits), \ > + TI_ADS7950_V_CHAN(14, bits), \ > + TI_ADS7950_V_CHAN(15, bits), \ > + IIO_CHAN_SOFT_TIMESTAMP(16), \ > +} > + > +static DECLARE_TI_ADS7950_4_CHANNELS(ti_ads7950, 12); > +static DECLARE_TI_ADS7950_8_CHANNELS(ti_ads7951, 12); > +static DECLARE_TI_ADS7950_12_CHANNELS(ti_ads7952, 12); > +static DECLARE_TI_ADS7950_16_CHANNELS(ti_ads7953, 12); > +static DECLARE_TI_ADS7950_4_CHANNELS(ti_ads7954, 10); > +static DECLARE_TI_ADS7950_8_CHANNELS(ti_ads7955, 10); > +static DECLARE_TI_ADS7950_12_CHANNELS(ti_ads7956, 10); > +static DECLARE_TI_ADS7950_16_CHANNELS(ti_ads7957, 10); > +static DECLARE_TI_ADS7950_4_CHANNELS(ti_ads7958, 8); > +static DECLARE_TI_ADS7950_8_CHANNELS(ti_ads7959, 8); > +static DECLARE_TI_ADS7950_12_CHANNELS(ti_ads7960, 8); > +static DECLARE_TI_ADS7950_16_CHANNELS(ti_ads7961, 8); > + > +static const struct ti_ads7950_chip_info ti_ads7950_chip_info[] = { > + [TI_ADS7950] = { > + .channels = ti_ads7950_channels, > + .num_channels = ARRAY_SIZE(ti_ads7950_channels), > + }, > + [TI_ADS7951] = { > + .channels = ti_ads7951_channels, > + .num_channels = ARRAY_SIZE(ti_ads7951_channels), > + }, > + [TI_ADS7952] = { > + .channels = ti_ads7952_channels, > + .num_channels = ARRAY_SIZE(ti_ads7952_channels), > + }, > + [TI_ADS7953] = { > + .channels = ti_ads7953_channels, > + .num_channels = ARRAY_SIZE(ti_ads7953_channels), > + }, > + [TI_ADS7954] = { > + .channels = ti_ads7954_channels, > + .num_channels = ARRAY_SIZE(ti_ads7954_channels), > + }, > + [TI_ADS7955] = { > + .channels = ti_ads7955_channels, > + .num_channels = ARRAY_SIZE(ti_ads7955_channels), > + }, > + [TI_ADS7956] = { > + .channels = ti_ads7956_channels, > + .num_channels = ARRAY_SIZE(ti_ads7956_channels), > + }, > + [TI_ADS7957] = { > + .channels = ti_ads7957_channels, > + .num_channels = ARRAY_SIZE(ti_ads7957_channels), > + }, > + [TI_ADS7958] = { > + .channels = ti_ads7958_channels, > + .num_channels = ARRAY_SIZE(ti_ads7958_channels), > + }, > + [TI_ADS7959] = { > + .channels = ti_ads7959_channels, > + .num_channels = ARRAY_SIZE(ti_ads7959_channels), > + }, > + [TI_ADS7960] = { > + .channels = ti_ads7960_channels, > + .num_channels = ARRAY_SIZE(ti_ads7960_channels), > + }, > + [TI_ADS7961] = { > + .channels = ti_ads7961_channels, > + .num_channels = ARRAY_SIZE(ti_ads7961_channels), > + }, > +}; > + > +/* > + * ti_ads7950_update_scan_mode() setup the spi transfer buffer for the new > + * scan mask > + */ > +static int ti_ads7950_update_scan_mode(struct iio_dev *indio_dev, > + const unsigned long *active_scan_mask) > +{ > + struct ti_ads7950_state *st = iio_priv(indio_dev); > + int i, cmd, len; > + > + len = 0; > + for_each_set_bit(i, active_scan_mask, indio_dev->num_channels) { > + cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings; > + st->tx_buf[len++] = cpu_to_be16(cmd); > + } > + > + /* Data for the 1st channel is not returned until the 3rd transfer */ > + len += 2; > + for (i = 0; i < len; i++) { > + if ((i + 2) < len) > + st->ring_xfer[i].tx_buf = &st->tx_buf[i]; > + if (i >= 2) > + st->ring_xfer[i].rx_buf = &st->rx_buf[i - 2]; > + st->ring_xfer[i].len = 2; > + st->ring_xfer[i].cs_change = 1; > + } > + /* make sure last transfer's cs_change is not set */ > + st->ring_xfer[len - 1].cs_change = 0; > + > + spi_message_init_with_transfers(&st->ring_msg, st->ring_xfer, len); > + > + return 0; > +} > + > +static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p) > +{ > + struct iio_poll_func *pf = p; > + struct iio_dev *indio_dev = pf->indio_dev; > + struct ti_ads7950_state *st = iio_priv(indio_dev); > + int ret; > + > + ret = spi_sync(st->spi, &st->ring_msg); > + if (ret < 0) > + goto out; > + > + iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf, > + iio_get_time_ns(indio_dev)); > + > +out: > + iio_trigger_notify_done(indio_dev->trig); > + > + return IRQ_HANDLED; > +} > + > +static int ti_ads7950_scan_direct(struct ti_ads7950_state *st, unsigned int ch) > +{ > + int ret, cmd; > + > + cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings; > + 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 ti_ads7950_get_range(struct ti_ads7950_state *st) > +{ > + int vref; > + > + vref = regulator_get_voltage(st->reg); > + if (vref < 0) > + return vref; > + > + vref /= 1000; > + > + if (st->settings & TI_ADS7950_CR_RANGE_5V) > + vref *= 2; > + > + return vref; > +} > + > +static int ti_ads7950_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long m) > +{ > + struct ti_ads7950_state *st = iio_priv(indio_dev); > + int ret; > + > + switch (m) { > + case IIO_CHAN_INFO_RAW: > + > + ret = iio_device_claim_direct_mode(indio_dev); > + if (ret < 0) > + return ret; > + > + ret = ti_ads7950_scan_direct(st, chan->address); > + iio_device_release_direct_mode(indio_dev); > + if (ret < 0) > + return ret; > + > + if (chan->address != TI_ADS7950_EXTRACT(ret, 12, 4)) > + return -EIO; > + > + *val = TI_ADS7950_EXTRACT(ret, chan->scan_type.shift, > + chan->scan_type.realbits); > + > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + ret = ti_ads7950_get_range(st); > + if (ret < 0) > + return ret; > + > + *val = ret; > + *val2 = (1 << chan->scan_type.realbits) - 1; > + > + return IIO_VAL_FRACTIONAL; > + } > + > + return -EINVAL; > +} > + > +static const struct iio_info ti_ads7950_info = { > + .read_raw = &ti_ads7950_read_raw, > + .update_scan_mode = ti_ads7950_update_scan_mode, > + .driver_module = THIS_MODULE, > +}; > + > +static int ti_ads7950_probe(struct spi_device *spi) > +{ > + struct ti_ads7950_state *st; > + struct iio_dev *indio_dev; > + const struct ti_ads7950_chip_info *info; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); > + if (!indio_dev) > + return -ENOMEM; > + > + st = iio_priv(indio_dev); > + > + spi_set_drvdata(spi, indio_dev); > + > + st->spi = spi; > + st->settings = TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_RANGE_5V; > + > + info = &ti_ads7950_chip_info[spi_get_device_id(spi)->driver_data]; > + > + indio_dev->name = spi_get_device_id(spi)->name; > + indio_dev->dev.parent = &spi->dev; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = info->channels; > + indio_dev->num_channels = info->num_channels; > + indio_dev->info = &ti_ads7950_info; > + > + /* > + * Setup default message. The sample is read at the end of the first > + * transfer, then it takes one full cycle to convert the sample and one > + * more cycle to send the value. The conversion process is driven by > + * the SPI clock, which is why we have 3 transfers. The middle one is > + * just dummy data sent while the chip is converting the sample that > + * was read at the end of the first transfer. > + */ > + > + 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].tx_buf = &st->tx_buf[0]; > + st->scan_single_xfer[1].len = 2; > + st->scan_single_xfer[1].cs_change = 1; > + st->scan_single_xfer[2].rx_buf = &st->rx_buf[0]; > + st->scan_single_xfer[2].len = 2; > + > + spi_message_init_with_transfers(&st->scan_single_msg, > + st->scan_single_xfer, 3); > + > + st->reg = devm_regulator_get(&spi->dev, "refin"); > + if (IS_ERR(st->reg)) { > + dev_err(&spi->dev, "Failed get get regulator \"refin\"\n"); > + return PTR_ERR(st->reg); > + } > + > + ret = regulator_enable(st->reg); > + if (ret) { > + dev_err(&spi->dev, "Failed to enable regulator \"refin\"\n"); > + return ret; > + } > + > + ret = iio_triggered_buffer_setup(indio_dev, NULL, > + &ti_ads7950_trigger_handler, NULL); > + if (ret) { > + dev_err(&spi->dev, "Failed to setup triggered buffer\n"); > + goto error_disable_reg; > + } > + > + ret = iio_device_register(indio_dev); > + if (ret) { > + dev_err(&spi->dev, "Failed to register iio device\n"); > + goto error_cleanup_ring; > + } > + > + return 0; > + > +error_cleanup_ring: > + iio_triggered_buffer_cleanup(indio_dev); > +error_disable_reg: > + regulator_disable(st->reg); > + > + return ret; > +} > + > +static int ti_ads7950_remove(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev = spi_get_drvdata(spi); > + struct ti_ads7950_state *st = iio_priv(indio_dev); > + > + iio_device_unregister(indio_dev); > + iio_triggered_buffer_cleanup(indio_dev); > + regulator_disable(st->reg); > + > + return 0; > +} > + > +static const struct spi_device_id ti_ads7950_id[] = { > + {"ti-ads7950", TI_ADS7950}, > + {"ti-ads7951", TI_ADS7951}, > + {"ti-ads7952", TI_ADS7952}, > + {"ti-ads7953", TI_ADS7953}, > + {"ti-ads7954", TI_ADS7954}, > + {"ti-ads7955", TI_ADS7955}, > + {"ti-ads7956", TI_ADS7956}, > + {"ti-ads7957", TI_ADS7957}, > + {"ti-ads7958", TI_ADS7958}, > + {"ti-ads7959", TI_ADS7959}, > + {"ti-ads7960", TI_ADS7960}, > + {"ti-ads7961", TI_ADS7961}, > + { } > +}; > +MODULE_DEVICE_TABLE(spi, ti_ads7950_id); > + > +static struct spi_driver ti_ads7950_driver = { > + .driver = { > + .name = "ti-ads7950", > + }, > + .probe = ti_ads7950_probe, > + .remove = ti_ads7950_remove, > + .id_table = ti_ads7950_id, > +}; > +module_spi_driver(ti_ads7950_driver); > + > +MODULE_AUTHOR("David Lechner <david@xxxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("TI TI_ADS7950 ADC"); > +MODULE_LICENSE("GPL v2"); > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
