// SPDX-License-Identifier: GPL-2.0-only /* * iio/adc/max1027.c * Copyright (C) 2014 Philippe Reynes * * based on linux/drivers/iio/ad7923.c * Copyright 2011 Analog Devices Inc (from AD7923 Driver) * Copyright 2012 CS Systemes d'Information * * max1027.c * * Partial support for max1027 and similar chips. */ #include #include #include #include #include #include #include #include #include #include #define MAX1027_CONV_REG BIT(7) #define MAX1027_SETUP_REG BIT(6) #define MAX1027_AVG_REG BIT(5) #define MAX1027_RST_REG BIT(4) /* conversion register */ #define MAX1027_TEMP BIT(0) #define MAX1027_SCAN_0_N (0x00 << 1) #define MAX1027_SCAN_N_M (0x01 << 1) #define MAX1027_SCAN_N (0x02 << 1) #define MAX1027_NOSCAN (0x03 << 1) #define MAX1027_CHAN(n) ((n) << 3) /* setup register */ #define MAX1027_UNIPOLAR 0x02 #define MAX1027_BIPOLAR 0x03 #define MAX1027_REF_MODE0 (0x00 << 2) #define MAX1027_REF_MODE1 (0x01 << 2) #define MAX1027_REF_MODE2 (0x02 << 2) #define MAX1027_REF_MODE3 (0x03 << 2) #define MAX1027_CKS_MODE0 (0x00 << 4) #define MAX1027_CKS_MODE1 (0x01 << 4) #define MAX1027_CKS_MODE2 (0x02 << 4) #define MAX1027_CKS_MODE3 (0x03 << 4) /* averaging register */ #define MAX1027_NSCAN_4 0x00 #define MAX1027_NSCAN_8 0x01 #define MAX1027_NSCAN_12 0x02 #define MAX1027_NSCAN_16 0x03 #define MAX1027_NAVG_4 (0x00 << 2) #define MAX1027_NAVG_8 (0x01 << 2) #define MAX1027_NAVG_16 (0x02 << 2) #define MAX1027_NAVG_32 (0x03 << 2) #define MAX1027_AVG_EN BIT(4) /* Device can achieve 300ksps so we assume a 3.33us conversion delay */ #define MAX1027_CONVERSION_UDELAY 4 enum max1027_id { max1027, max1029, max1031, max1227, max1229, max1231, }; static const struct spi_device_id max1027_id[] = { {"max1027", max1027}, {"max1029", max1029}, {"max1031", max1031}, {"max1227", max1227}, {"max1229", max1229}, {"max1231", max1231}, {} }; MODULE_DEVICE_TABLE(spi, max1027_id); static const struct of_device_id max1027_adc_dt_ids[] = { { .compatible = "maxim,max1027" }, { .compatible = "maxim,max1029" }, { .compatible = "maxim,max1031" }, { .compatible = "maxim,max1227" }, { .compatible = "maxim,max1229" }, { .compatible = "maxim,max1231" }, {}, }; MODULE_DEVICE_TABLE(of, max1027_adc_dt_ids); #define MAX1027_V_CHAN(index, depth) \ { \ .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), \ .scan_index = index + 1, \ .scan_type = { \ .sign = 'u', \ .realbits = depth, \ .storagebits = 16, \ .shift = (depth == 10) ? 2 : 0, \ .endianness = IIO_BE, \ }, \ } #define MAX1027_T_CHAN \ { \ .type = IIO_TEMP, \ .channel = 0, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ .scan_index = 0, \ .scan_type = { \ .sign = 'u', \ .realbits = 12, \ .storagebits = 16, \ .endianness = IIO_BE, \ }, \ } #define MAX1X27_CHANNELS(depth) \ MAX1027_T_CHAN, \ MAX1027_V_CHAN(0, depth), \ MAX1027_V_CHAN(1, depth), \ MAX1027_V_CHAN(2, depth), \ MAX1027_V_CHAN(3, depth), \ MAX1027_V_CHAN(4, depth), \ MAX1027_V_CHAN(5, depth), \ MAX1027_V_CHAN(6, depth), \ MAX1027_V_CHAN(7, depth) #define MAX1X29_CHANNELS(depth) \ MAX1X27_CHANNELS(depth), \ MAX1027_V_CHAN(8, depth), \ MAX1027_V_CHAN(9, depth), \ MAX1027_V_CHAN(10, depth), \ MAX1027_V_CHAN(11, depth) #define MAX1X31_CHANNELS(depth) \ MAX1X29_CHANNELS(depth), \ MAX1027_V_CHAN(12, depth), \ MAX1027_V_CHAN(13, depth), \ MAX1027_V_CHAN(14, depth), \ MAX1027_V_CHAN(15, depth) static const struct iio_chan_spec max1027_channels[] = { MAX1X27_CHANNELS(10), }; static const struct iio_chan_spec max1029_channels[] = { MAX1X29_CHANNELS(10), }; static const struct iio_chan_spec max1031_channels[] = { MAX1X31_CHANNELS(10), }; static const struct iio_chan_spec max1227_channels[] = { MAX1X27_CHANNELS(12), }; static const struct iio_chan_spec max1229_channels[] = { MAX1X29_CHANNELS(12), }; static const struct iio_chan_spec max1231_channels[] = { MAX1X31_CHANNELS(12), }; /* * These devices are able to scan from 0 to N, N being the highest voltage * channel requested by the user. The temperature can be included or not, * but cannot be retrieved alone. Based on the below * ->available_scan_masks, the core will select the most appropriate * ->active_scan_mask and the "minimum" number of channels will be * scanned and pushed to the buffers. * * For example, if the user wants channels 1, 4 and 5, all channels from * 0 to 5 will be scanned and pushed to the IIO buffers. The core will then * filter out the unneeded samples based on the ->active_scan_mask that has * been selected and only channels 1, 4 and 5 will be available to the user * in the shared buffer. */ #define MAX1X27_SCAN_MASK_TEMP BIT(0) #define MAX1X27_SCAN_MASKS(temp) \ GENMASK(1, 1 - (temp)), GENMASK(2, 1 - (temp)), \ GENMASK(3, 1 - (temp)), GENMASK(4, 1 - (temp)), \ GENMASK(5, 1 - (temp)), GENMASK(6, 1 - (temp)), \ GENMASK(7, 1 - (temp)), GENMASK(8, 1 - (temp)) #define MAX1X29_SCAN_MASKS(temp) \ MAX1X27_SCAN_MASKS(temp), \ GENMASK(9, 1 - (temp)), GENMASK(10, 1 - (temp)), \ GENMASK(11, 1 - (temp)), GENMASK(12, 1 - (temp)) #define MAX1X31_SCAN_MASKS(temp) \ MAX1X29_SCAN_MASKS(temp), \ GENMASK(13, 1 - (temp)), GENMASK(14, 1 - (temp)), \ GENMASK(15, 1 - (temp)), GENMASK(16, 1 - (temp)) static const unsigned long max1027_available_scan_masks[] = { MAX1X27_SCAN_MASKS(0), MAX1X27_SCAN_MASKS(1), 0x00000000, }; static const unsigned long max1029_available_scan_masks[] = { MAX1X29_SCAN_MASKS(0), MAX1X29_SCAN_MASKS(1), 0x00000000, }; static const unsigned long max1031_available_scan_masks[] = { MAX1X31_SCAN_MASKS(0), MAX1X31_SCAN_MASKS(1), 0x00000000, }; struct max1027_chip_info { const struct iio_chan_spec *channels; unsigned int num_channels; const unsigned long *available_scan_masks; }; static const struct max1027_chip_info max1027_chip_info_tbl[] = { [max1027] = { .channels = max1027_channels, .num_channels = ARRAY_SIZE(max1027_channels), .available_scan_masks = max1027_available_scan_masks, }, [max1029] = { .channels = max1029_channels, .num_channels = ARRAY_SIZE(max1029_channels), .available_scan_masks = max1029_available_scan_masks, }, [max1031] = { .channels = max1031_channels, .num_channels = ARRAY_SIZE(max1031_channels), .available_scan_masks = max1031_available_scan_masks, }, [max1227] = { .channels = max1227_channels, .num_channels = ARRAY_SIZE(max1227_channels), .available_scan_masks = max1027_available_scan_masks, }, [max1229] = { .channels = max1229_channels, .num_channels = ARRAY_SIZE(max1229_channels), .available_scan_masks = max1029_available_scan_masks, }, [max1231] = { .channels = max1231_channels, .num_channels = ARRAY_SIZE(max1231_channels), .available_scan_masks = max1031_available_scan_masks, }, }; struct max1027_state { const struct max1027_chip_info *info; struct spi_device *spi; struct iio_trigger *trig; __be16 *buffer; struct mutex lock; struct completion complete; u8 reg __aligned(IIO_DMA_MINALIGN); }; static int max1027_wait_eoc(struct iio_dev *indio_dev) { struct max1027_state *st = iio_priv(indio_dev); unsigned int conversion_time = MAX1027_CONVERSION_UDELAY; int ret; if (st->spi->irq) { ret = wait_for_completion_timeout(&st->complete, msecs_to_jiffies(1000)); reinit_completion(&st->complete); if (!ret) return -ETIMEDOUT; } else { if (indio_dev->active_scan_mask) conversion_time *= hweight32(*indio_dev->active_scan_mask); usleep_range(conversion_time, conversion_time * 2); } return 0; } /* Scan from chan 0 to the highest requested channel. Include temperature on demand. */ static int max1027_configure_chans_and_start(struct iio_dev *indio_dev) { struct max1027_state *st = iio_priv(indio_dev); st->reg = MAX1027_CONV_REG | MAX1027_SCAN_0_N; st->reg |= MAX1027_CHAN(fls(*indio_dev->active_scan_mask) - 2); if (*indio_dev->active_scan_mask & MAX1X27_SCAN_MASK_TEMP) st->reg |= MAX1027_TEMP; return spi_write(st->spi, &st->reg, 1); } static int max1027_enable_trigger(struct iio_dev *indio_dev, bool enable) { struct max1027_state *st = iio_priv(indio_dev); st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2; /* * Start acquisition on: * MODE0: external hardware trigger wired to the cnvst input pin * MODE2: conversion register write */ if (enable) st->reg |= MAX1027_CKS_MODE0; else st->reg |= MAX1027_CKS_MODE2; return spi_write(st->spi, &st->reg, 1); } static int max1027_read_single_value(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val) { int ret; struct max1027_state *st = iio_priv(indio_dev); ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; /* Configure conversion register with the requested chan */ st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) | MAX1027_NOSCAN; if (chan->type == IIO_TEMP) st->reg |= MAX1027_TEMP; ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to configure conversion register\n"); goto release; } /* * For an unknown reason, when we use the mode "10" (write * conversion register), the interrupt doesn't occur every time. * So we just wait the maximum conversion time and deliver the value. */ ret = max1027_wait_eoc(indio_dev); if (ret) goto release; /* Read result */ ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2); release: iio_device_release_direct_mode(indio_dev); if (ret < 0) return ret; *val = be16_to_cpu(st->buffer[0]); return IIO_VAL_INT; } static int max1027_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { int ret = 0; struct max1027_state *st = iio_priv(indio_dev); mutex_lock(&st->lock); switch (mask) { case IIO_CHAN_INFO_RAW: ret = max1027_read_single_value(indio_dev, chan, val); break; case IIO_CHAN_INFO_SCALE: switch (chan->type) { case IIO_TEMP: *val = 1; *val2 = 8; ret = IIO_VAL_FRACTIONAL; break; case IIO_VOLTAGE: *val = 2500; *val2 = chan->scan_type.realbits; ret = IIO_VAL_FRACTIONAL_LOG2; break; default: ret = -EINVAL; break; } break; default: ret = -EINVAL; break; } mutex_unlock(&st->lock); return ret; } static int max1027_debugfs_reg_access(struct iio_dev *indio_dev, unsigned int reg, unsigned int writeval, unsigned int *readval) { struct max1027_state *st = iio_priv(indio_dev); u8 *val = (u8 *)st->buffer; if (readval) { int ret = spi_read(st->spi, val, 2); *readval = be16_to_cpu(st->buffer[0]); return ret; } *val = (u8)writeval; return spi_write(st->spi, val, 1); } static int max1027_set_cnvst_trigger_state(struct iio_trigger *trig, bool state) { struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); int ret; /* * In order to disable the convst trigger, start acquisition on * conversion register write, which basically disables triggering * conversions upon cnvst changes and thus has the effect of disabling * the external hardware trigger. */ ret = max1027_enable_trigger(indio_dev, state); if (ret) return ret; if (state) { ret = max1027_configure_chans_and_start(indio_dev); if (ret) return ret; } return 0; } static int max1027_read_scan(struct iio_dev *indio_dev) { struct max1027_state *st = iio_priv(indio_dev); unsigned int scanned_chans; int ret; scanned_chans = fls(*indio_dev->active_scan_mask) - 1; if (*indio_dev->active_scan_mask & MAX1X27_SCAN_MASK_TEMP) scanned_chans++; /* fill buffer with all channel */ ret = spi_read(st->spi, st->buffer, scanned_chans * 2); if (ret < 0) return ret; iio_push_to_buffers(indio_dev, st->buffer); return 0; } static irqreturn_t max1027_handler(int irq, void *private) { struct iio_dev *indio_dev = private; struct max1027_state *st = iio_priv(indio_dev); /* * If buffers are disabled (raw read) or when using external triggers, * we just need to unlock the waiters which will then handle the data. * * When using the internal trigger, we must hand-off the choice of the * handler to the core which will then lookup through the interrupt tree * for the right handler registered with iio_triggered_buffer_setup() * to execute, as this trigger might very well be used in conjunction * with another device. The core will then call the relevant handler to * perform the data processing step. */ if (!iio_buffer_enabled(indio_dev)) complete(&st->complete); else iio_trigger_poll(indio_dev->trig); return IRQ_HANDLED; } static irqreturn_t max1027_trigger_handler(int irq, void *private) { struct iio_poll_func *pf = private; struct iio_dev *indio_dev = pf->indio_dev; int ret; if (!iio_trigger_using_own(indio_dev)) { ret = max1027_configure_chans_and_start(indio_dev); if (ret) goto out; /* This is a threaded handler, it is fine to wait for an IRQ */ ret = max1027_wait_eoc(indio_dev); if (ret) goto out; } ret = max1027_read_scan(indio_dev); out: if (ret) dev_err(&indio_dev->dev, "Cannot read scanned values (%d)\n", ret); iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static const struct iio_trigger_ops max1027_trigger_ops = { .validate_device = &iio_trigger_validate_own_device, .set_trigger_state = &max1027_set_cnvst_trigger_state, }; static const struct iio_info max1027_info = { .read_raw = &max1027_read_raw, .debugfs_reg_access = &max1027_debugfs_reg_access, }; static int max1027_probe(struct spi_device *spi) { int ret; struct iio_dev *indio_dev; struct max1027_state *st; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!indio_dev) { pr_err("Can't allocate iio device\n"); return -ENOMEM; } st = iio_priv(indio_dev); st->spi = spi; st->info = &max1027_chip_info_tbl[spi_get_device_id(spi)->driver_data]; mutex_init(&st->lock); init_completion(&st->complete); indio_dev->name = spi_get_device_id(spi)->name; indio_dev->info = &max1027_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = st->info->channels; indio_dev->num_channels = st->info->num_channels; indio_dev->available_scan_masks = st->info->available_scan_masks; st->buffer = devm_kmalloc_array(&indio_dev->dev, indio_dev->num_channels, 2, GFP_KERNEL); if (!st->buffer) return -ENOMEM; /* Enable triggered buffers */ ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, &iio_pollfunc_store_time, &max1027_trigger_handler, NULL); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to setup buffer\n"); return ret; } /* If there is an EOC interrupt, register the cnvst hardware trigger */ if (spi->irq) { st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger", indio_dev->name); if (!st->trig) { ret = -ENOMEM; dev_err(&indio_dev->dev, "Failed to allocate iio trigger\n"); return ret; } st->trig->ops = &max1027_trigger_ops; iio_trigger_set_drvdata(st->trig, indio_dev); ret = devm_iio_trigger_register(&indio_dev->dev, st->trig); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to register iio trigger\n"); return ret; } ret = devm_request_irq(&spi->dev, spi->irq, max1027_handler, IRQF_TRIGGER_FALLING, spi->dev.driver->name, indio_dev); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n"); return ret; } } /* Internal reset */ st->reg = MAX1027_RST_REG; ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to reset the ADC\n"); return ret; } /* Disable averaging */ st->reg = MAX1027_AVG_REG; ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to configure averaging register\n"); return ret; } /* Assume conversion on register write for now */ ret = max1027_enable_trigger(indio_dev, false); if (ret) return ret; return devm_iio_device_register(&spi->dev, indio_dev); } static struct spi_driver max1027_driver = { .driver = { .name = "max1027", .of_match_table = max1027_adc_dt_ids, }, .probe = max1027_probe, .id_table = max1027_id, }; module_spi_driver(max1027_driver); MODULE_AUTHOR("Philippe Reynes "); MODULE_DESCRIPTION("MAX1X27/MAX1X29/MAX1X31 ADC"); MODULE_LICENSE("GPL v2");