diff options
Diffstat (limited to 'drivers/iio/adc/ad7606_spi.c')
| -rw-r--r-- | drivers/iio/adc/ad7606_spi.c | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c new file mode 100644 index 000000000000..f28e4ca37707 --- /dev/null +++ b/drivers/iio/adc/ad7606_spi.c @@ -0,0 +1,512 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * AD7606 SPI ADC driver + * + * Copyright 2011 Analog Devices Inc. + */ + +#include <linux/bitmap.h> +#include <linux/err.h> +#include <linux/math.h> +#include <linux/module.h> +#include <linux/pwm.h> +#include <linux/spi/offload/consumer.h> +#include <linux/spi/offload/provider.h> +#include <linux/spi/spi.h> +#include <linux/types.h> +#include <linux/units.h> + +#include <linux/iio/buffer-dmaengine.h> +#include <linux/iio/iio.h> + +#include <dt-bindings/iio/adc/adi,ad7606.h> + +#include "ad7606.h" + +#define MAX_SPI_FREQ_HZ 23500000 /* VDRIVE above 4.75 V */ + +struct spi_bus_data { + struct spi_offload *offload; + struct spi_offload_trigger *offload_trigger; + struct spi_transfer offload_xfer; + struct spi_message offload_msg; +}; + +static u16 ad7616_spi_rd_wr_cmd(int addr, char is_write_op) +{ + /* + * The address of register consist of one w/r bit + * 6 bits of address followed by one reserved bit. + */ + return ((addr & 0x7F) << 1) | ((is_write_op & 0x1) << 7); +} + +static u16 ad7606b_spi_rd_wr_cmd(int addr, char is_write_op) +{ + /* + * The address of register consists of one bit which + * specifies a read command placed in bit 6, followed by + * 6 bits of address. + */ + return (addr & 0x3F) | (((~is_write_op) & 0x1) << 6); +} + +static int ad7606_spi_read_block(struct device *dev, + int count, void *buf) +{ + struct spi_device *spi = to_spi_device(dev); + int i, ret; + unsigned short *data = buf; + __be16 *bdata = buf; + + ret = spi_read(spi, buf, count * 2); + if (ret < 0) { + dev_err(&spi->dev, "SPI read error\n"); + return ret; + } + + for (i = 0; i < count; i++) + data[i] = be16_to_cpu(bdata[i]); + + return 0; +} + +static int ad7606_spi_read_block14to16(struct device *dev, + int count, void *buf) +{ + struct spi_device *spi = to_spi_device(dev); + struct spi_transfer xfer = { + .bits_per_word = 14, + .len = count * sizeof(u16), + .rx_buf = buf, + }; + + return spi_sync_transfer(spi, &xfer, 1); +} + +static int ad7606_spi_read_block18to32(struct device *dev, + int count, void *buf) +{ + struct spi_device *spi = to_spi_device(dev); + struct spi_transfer xfer = { + .bits_per_word = 18, + .len = count * sizeof(u32), + .rx_buf = buf, + }; + + return spi_sync_transfer(spi, &xfer, 1); +} + +static int ad7606_spi_reg_read(struct ad7606_state *st, unsigned int addr) +{ + struct spi_device *spi = to_spi_device(st->dev); + struct spi_transfer t[] = { + { + .tx_buf = &st->d16[0], + .len = 2, + .cs_change = 1, + }, { + .rx_buf = &st->d16[1], + .len = 2, + }, + }; + int ret; + + st->d16[0] = cpu_to_be16(st->bops->rd_wr_cmd(addr, 0) << 8); + + ret = spi_sync_transfer(spi, t, ARRAY_SIZE(t)); + if (ret < 0) + return ret; + + return be16_to_cpu(st->d16[1]); +} + +static int ad7606_spi_reg_write(struct ad7606_state *st, + unsigned int addr, + unsigned int val) +{ + struct spi_device *spi = to_spi_device(st->dev); + + st->d16[0] = cpu_to_be16((st->bops->rd_wr_cmd(addr, 1) << 8) | + (val & 0xFF)); + + return spi_write(spi, &st->d16[0], sizeof(st->d16[0])); +} + +static int ad7606b_sw_mode_config(struct iio_dev *indio_dev) +{ + struct ad7606_state *st = iio_priv(indio_dev); + + /* Configure device spi to output on a single channel */ + return st->bops->reg_write(st, AD7606_CONFIGURATION_REGISTER, + AD7606_SINGLE_DOUT); +} + +static const struct spi_offload_config ad7606_spi_offload_config = { + .capability_flags = SPI_OFFLOAD_CAP_TRIGGER | + SPI_OFFLOAD_CAP_RX_STREAM_DMA, +}; + +static int ad7606_spi_offload_buffer_postenable(struct iio_dev *indio_dev) +{ + const struct iio_scan_type *scan_type; + struct ad7606_state *st = iio_priv(indio_dev); + struct spi_bus_data *bus_data = st->bus_data; + struct spi_transfer *xfer = &bus_data->offload_xfer; + struct spi_device *spi = to_spi_device(st->dev); + struct spi_offload_trigger_config config = { + .type = SPI_OFFLOAD_TRIGGER_DATA_READY, + }; + int ret; + + scan_type = &indio_dev->channels[0].scan_type; + + xfer->bits_per_word = scan_type->realbits; + xfer->offload_flags = SPI_OFFLOAD_XFER_RX_STREAM; + /* + * Using SPI offload, storagebits are related to the spi-engine + * hw implementation, can be 16 or 32, so can't be used to compute + * struct spi_transfer.len. Using realbits instead. + */ + xfer->len = (scan_type->realbits > 16 ? 4 : 2) * + st->chip_info->num_adc_channels; + + spi_message_init_with_transfers(&bus_data->offload_msg, xfer, 1); + bus_data->offload_msg.offload = bus_data->offload; + + ret = spi_optimize_message(spi, &bus_data->offload_msg); + if (ret) { + dev_err(st->dev, "failed to prepare offload, err: %d\n", ret); + return ret; + } + + ret = spi_offload_trigger_enable(bus_data->offload, + bus_data->offload_trigger, + &config); + if (ret) + goto err_unoptimize_message; + + ret = ad7606_pwm_set_swing(st); + if (ret) + goto err_offload_exit_conversion_mode; + + return 0; + +err_offload_exit_conversion_mode: + spi_offload_trigger_disable(bus_data->offload, + bus_data->offload_trigger); + +err_unoptimize_message: + spi_unoptimize_message(&bus_data->offload_msg); + + return ret; +} + +static int ad7606_spi_offload_buffer_predisable(struct iio_dev *indio_dev) +{ + struct ad7606_state *st = iio_priv(indio_dev); + struct spi_bus_data *bus_data = st->bus_data; + int ret; + + ret = ad7606_pwm_set_low(st); + if (ret) + return ret; + + spi_offload_trigger_disable(bus_data->offload, + bus_data->offload_trigger); + spi_unoptimize_message(&bus_data->offload_msg); + + return 0; +} + +static const struct iio_buffer_setup_ops ad7606_offload_buffer_setup_ops = { + .postenable = ad7606_spi_offload_buffer_postenable, + .predisable = ad7606_spi_offload_buffer_predisable, +}; + +static bool ad7606_spi_offload_trigger_match( + struct spi_offload_trigger *trigger, + enum spi_offload_trigger_type type, + u64 *args, u32 nargs) +{ + if (type != SPI_OFFLOAD_TRIGGER_DATA_READY) + return false; + + /* + * Requires 1 arg: + * args[0] is the trigger event. + */ + if (nargs != 1 || args[0] != AD7606_TRIGGER_EVENT_BUSY) + return false; + + return true; +} + +static int ad7606_spi_offload_trigger_request( + struct spi_offload_trigger *trigger, + enum spi_offload_trigger_type type, + u64 *args, u32 nargs) +{ + /* Should already be validated by match, but just in case. */ + if (nargs != 1) + return -EINVAL; + + return 0; +} + +static int ad7606_spi_offload_trigger_validate( + struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config) +{ + if (config->type != SPI_OFFLOAD_TRIGGER_DATA_READY) + return -EINVAL; + + return 0; +} + +static const struct spi_offload_trigger_ops ad7606_offload_trigger_ops = { + .match = ad7606_spi_offload_trigger_match, + .request = ad7606_spi_offload_trigger_request, + .validate = ad7606_spi_offload_trigger_validate, +}; + +static int ad7606_spi_offload_probe(struct device *dev, + struct iio_dev *indio_dev) +{ + struct ad7606_state *st = iio_priv(indio_dev); + struct spi_device *spi = to_spi_device(dev); + struct spi_bus_data *bus_data; + struct dma_chan *rx_dma; + struct spi_offload_trigger_info trigger_info = { + .fwnode = dev_fwnode(dev), + .ops = &ad7606_offload_trigger_ops, + .priv = st, + }; + int ret; + + bus_data = devm_kzalloc(dev, sizeof(*bus_data), GFP_KERNEL); + if (!bus_data) + return -ENOMEM; + st->bus_data = bus_data; + + bus_data->offload = devm_spi_offload_get(dev, spi, + &ad7606_spi_offload_config); + ret = PTR_ERR_OR_ZERO(bus_data->offload); + if (ret && ret != -ENODEV) + return dev_err_probe(dev, ret, "failed to get SPI offload\n"); + /* Allow main ad7606_probe function to continue. */ + if (ret == -ENODEV) + return 0; + + ret = devm_spi_offload_trigger_register(dev, &trigger_info); + if (ret) + return dev_err_probe(dev, ret, + "failed to register offload trigger\n"); + + bus_data->offload_trigger = devm_spi_offload_trigger_get(dev, + bus_data->offload, SPI_OFFLOAD_TRIGGER_DATA_READY); + if (IS_ERR(bus_data->offload_trigger)) + return dev_err_probe(dev, PTR_ERR(bus_data->offload_trigger), + "failed to get offload trigger\n"); + + /* TODO: PWM setup should be ok, done for the backend. PWM mutex ? */ + rx_dma = devm_spi_offload_rx_stream_request_dma_chan(dev, + bus_data->offload); + if (IS_ERR(rx_dma)) + return dev_err_probe(dev, PTR_ERR(rx_dma), + "failed to get offload RX DMA\n"); + + ret = devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev, + rx_dma, IIO_BUFFER_DIRECTION_IN); + if (ret) + return dev_err_probe(dev, ret, + "failed to setup offload RX DMA\n"); + + /* Use offload ops. */ + indio_dev->setup_ops = &ad7606_offload_buffer_setup_ops; + + st->offload_en = true; + + return 0; +} + +static int ad7606_spi_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *scan_mask) +{ + struct ad7606_state *st = iio_priv(indio_dev); + + if (st->offload_en) { + unsigned int num_adc_ch = st->chip_info->num_adc_channels; + + /* + * SPI offload requires that all channels are enabled since + * there isn't a way to selectively disable channels that get + * read (this is simultaneous sampling ADC) and the DMA buffer + * has no way of demuxing the data to filter out unwanted + * channels. + */ + if (bitmap_weight(scan_mask, num_adc_ch) != num_adc_ch) + return -EINVAL; + } + + return 0; +} + +static const struct ad7606_bus_ops ad7606_spi_bops = { + .offload_config = ad7606_spi_offload_probe, + .read_block = ad7606_spi_read_block, + .update_scan_mode = ad7606_spi_update_scan_mode, +}; + +static const struct ad7606_bus_ops ad7607_spi_bops = { + .offload_config = ad7606_spi_offload_probe, + .read_block = ad7606_spi_read_block14to16, + .update_scan_mode = ad7606_spi_update_scan_mode, +}; + +static const struct ad7606_bus_ops ad7608_spi_bops = { + .offload_config = ad7606_spi_offload_probe, + .read_block = ad7606_spi_read_block18to32, + .update_scan_mode = ad7606_spi_update_scan_mode, +}; + +static const struct ad7606_bus_ops ad7616_spi_bops = { + .offload_config = ad7606_spi_offload_probe, + .read_block = ad7606_spi_read_block, + .reg_read = ad7606_spi_reg_read, + .reg_write = ad7606_spi_reg_write, + .rd_wr_cmd = ad7616_spi_rd_wr_cmd, + .update_scan_mode = ad7606_spi_update_scan_mode, +}; + +static const struct ad7606_bus_ops ad7606b_spi_bops = { + .offload_config = ad7606_spi_offload_probe, + .read_block = ad7606_spi_read_block, + .reg_read = ad7606_spi_reg_read, + .reg_write = ad7606_spi_reg_write, + .rd_wr_cmd = ad7606b_spi_rd_wr_cmd, + .sw_mode_config = ad7606b_sw_mode_config, + .update_scan_mode = ad7606_spi_update_scan_mode, +}; + +static const struct ad7606_bus_ops ad7606c_18_spi_bops = { + .offload_config = ad7606_spi_offload_probe, + .read_block = ad7606_spi_read_block18to32, + .reg_read = ad7606_spi_reg_read, + .reg_write = ad7606_spi_reg_write, + .rd_wr_cmd = ad7606b_spi_rd_wr_cmd, + .sw_mode_config = ad7606b_sw_mode_config, + .update_scan_mode = ad7606_spi_update_scan_mode, +}; + +static const struct ad7606_bus_info ad7605_4_bus_info = { + .chip_info = &ad7605_4_info, + .bops = &ad7606_spi_bops, +}; + +static const struct ad7606_bus_info ad7606_8_bus_info = { + .chip_info = &ad7606_8_info, + .bops = &ad7606_spi_bops, +}; + +static const struct ad7606_bus_info ad7606_6_bus_info = { + .chip_info = &ad7606_6_info, + .bops = &ad7606_spi_bops, +}; + +static const struct ad7606_bus_info ad7606_4_bus_info = { + .chip_info = &ad7606_4_info, + .bops = &ad7606_spi_bops, +}; + +static const struct ad7606_bus_info ad7606b_bus_info = { + .chip_info = &ad7606b_info, + .bops = &ad7606b_spi_bops, +}; + +static const struct ad7606_bus_info ad7606c_16_bus_info = { + .chip_info = &ad7606c_16_info, + .bops = &ad7606b_spi_bops, +}; + +static const struct ad7606_bus_info ad7606c_18_bus_info = { + .chip_info = &ad7606c_18_info, + .bops = &ad7606c_18_spi_bops, +}; + +static const struct ad7606_bus_info ad7607_bus_info = { + .chip_info = &ad7607_info, + .bops = &ad7607_spi_bops, +}; + +static const struct ad7606_bus_info ad7608_bus_info = { + .chip_info = &ad7608_info, + .bops = &ad7608_spi_bops, +}; + +static const struct ad7606_bus_info ad7609_bus_info = { + .chip_info = &ad7609_info, + .bops = &ad7608_spi_bops, +}; + +static const struct ad7606_bus_info ad7616_bus_info = { + .chip_info = &ad7616_info, + .bops = &ad7616_spi_bops, +}; + +static int ad7606_spi_probe(struct spi_device *spi) +{ + const struct ad7606_bus_info *bus_info = spi_get_device_match_data(spi); + + return ad7606_probe(&spi->dev, spi->irq, NULL, + bus_info->chip_info, bus_info->bops); +} + +static const struct spi_device_id ad7606_id_table[] = { + { "ad7605-4", (kernel_ulong_t)&ad7605_4_bus_info }, + { "ad7606-4", (kernel_ulong_t)&ad7606_4_bus_info }, + { "ad7606-6", (kernel_ulong_t)&ad7606_6_bus_info }, + { "ad7606-8", (kernel_ulong_t)&ad7606_8_bus_info }, + { "ad7606b", (kernel_ulong_t)&ad7606b_bus_info }, + { "ad7606c-16", (kernel_ulong_t)&ad7606c_16_bus_info }, + { "ad7606c-18", (kernel_ulong_t)&ad7606c_18_bus_info }, + { "ad7607", (kernel_ulong_t)&ad7607_bus_info }, + { "ad7608", (kernel_ulong_t)&ad7608_bus_info }, + { "ad7609", (kernel_ulong_t)&ad7609_bus_info }, + { "ad7616", (kernel_ulong_t)&ad7616_bus_info }, + { } +}; +MODULE_DEVICE_TABLE(spi, ad7606_id_table); + +static const struct of_device_id ad7606_of_match[] = { + { .compatible = "adi,ad7605-4", .data = &ad7605_4_bus_info }, + { .compatible = "adi,ad7606-4", .data = &ad7606_4_bus_info }, + { .compatible = "adi,ad7606-6", .data = &ad7606_6_bus_info }, + { .compatible = "adi,ad7606-8", .data = &ad7606_8_bus_info }, + { .compatible = "adi,ad7606b", .data = &ad7606b_bus_info }, + { .compatible = "adi,ad7606c-16", .data = &ad7606c_16_bus_info }, + { .compatible = "adi,ad7606c-18", .data = &ad7606c_18_bus_info }, + { .compatible = "adi,ad7607", .data = &ad7607_bus_info }, + { .compatible = "adi,ad7608", .data = &ad7608_bus_info }, + { .compatible = "adi,ad7609", .data = &ad7609_bus_info }, + { .compatible = "adi,ad7616", .data = &ad7616_bus_info }, + { } +}; +MODULE_DEVICE_TABLE(of, ad7606_of_match); + +static struct spi_driver ad7606_driver = { + .driver = { + .name = "ad7606", + .of_match_table = ad7606_of_match, + .pm = AD7606_PM_OPS, + }, + .probe = ad7606_spi_probe, + .id_table = ad7606_id_table, +}; +module_spi_driver(ad7606_driver); + +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>"); +MODULE_DESCRIPTION("Analog Devices AD7606 ADC"); +MODULE_LICENSE("GPL v2"); +MODULE_IMPORT_NS("IIO_AD7606"); +MODULE_IMPORT_NS("IIO_DMAENGINE_BUFFER"); |