/* * 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 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * max1027.c * * Partial support for max1027 and similar chips. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/spi/spi.h> #include <linux/delay.h> #include <linux/iio/iio.h> #include <linux/iio/buffer.h> #include <linux/iio/trigger.h> #include <linux/iio/trigger_consumer.h> #include <linux/iio/triggered_buffer.h> #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) enum max1027_id { max1027, max1029, max1031, }; static const struct spi_device_id max1027_id[] = { {"max1027", max1027}, {"max1029", max1029}, {"max1031", max1031}, {} }; MODULE_DEVICE_TABLE(spi, max1027_id); #ifdef CONFIG_OF static const struct of_device_id max1027_adc_dt_ids[] = { { .compatible = "maxim,max1027" }, { .compatible = "maxim,max1029" }, { .compatible = "maxim,max1031" }, {}, }; MODULE_DEVICE_TABLE(of, max1027_adc_dt_ids); #endif #define MAX1027_V_CHAN(index) \ { \ .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 = 10, \ .storagebits = 16, \ .shift = 2, \ .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, \ }, \ } static const struct iio_chan_spec max1027_channels[] = { MAX1027_T_CHAN, MAX1027_V_CHAN(0), MAX1027_V_CHAN(1), MAX1027_V_CHAN(2), MAX1027_V_CHAN(3), MAX1027_V_CHAN(4), MAX1027_V_CHAN(5), MAX1027_V_CHAN(6), MAX1027_V_CHAN(7) }; static const struct iio_chan_spec max1029_channels[] = { MAX1027_T_CHAN, MAX1027_V_CHAN(0), MAX1027_V_CHAN(1), MAX1027_V_CHAN(2), MAX1027_V_CHAN(3), MAX1027_V_CHAN(4), MAX1027_V_CHAN(5), MAX1027_V_CHAN(6), MAX1027_V_CHAN(7), MAX1027_V_CHAN(8), MAX1027_V_CHAN(9), MAX1027_V_CHAN(10), MAX1027_V_CHAN(11) }; static const struct iio_chan_spec max1031_channels[] = { MAX1027_T_CHAN, MAX1027_V_CHAN(0), MAX1027_V_CHAN(1), MAX1027_V_CHAN(2), MAX1027_V_CHAN(3), MAX1027_V_CHAN(4), MAX1027_V_CHAN(5), MAX1027_V_CHAN(6), MAX1027_V_CHAN(7), MAX1027_V_CHAN(8), MAX1027_V_CHAN(9), MAX1027_V_CHAN(10), MAX1027_V_CHAN(11), MAX1027_V_CHAN(12), MAX1027_V_CHAN(13), MAX1027_V_CHAN(14), MAX1027_V_CHAN(15) }; static const unsigned long max1027_available_scan_masks[] = { 0x000001ff, 0x00000000, }; static const unsigned long max1029_available_scan_masks[] = { 0x00001fff, 0x00000000, }; static const unsigned long max1031_available_scan_masks[] = { 0x0001ffff, 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, }, }; struct max1027_state { const struct max1027_chip_info *info; struct spi_device *spi; struct iio_trigger *trig; __be16 *buffer; struct mutex lock; u8 reg ____cacheline_aligned; }; 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); if (iio_buffer_enabled(indio_dev)) { dev_warn(&indio_dev->dev, "trigger mode already enabled"); return -EBUSY; } /* Start acquisition on conversion register write */ st->reg = MAX1027_SETUP_REG | MAX1027_REF_MODE2 | MAX1027_CKS_MODE2; ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to configure setup register\n"); return ret; } /* Configure conversion register with the requested chan */ st->reg = MAX1027_CONV_REG | MAX1027_CHAN(chan->channel) | MAX1027_NOSCAN | !!(chan->type == IIO_TEMP); ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to configure conversion register\n"); return ret; } /* * For an unknown reason, when we use the mode "10" (write * conversion register), the interrupt doesn't occur every time. * So we just wait 1 ms. */ mdelay(1); /* Read result */ ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2); 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 = 10; 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 reg, unsigned writeval, unsigned *readval) { struct max1027_state *st = iio_priv(indio_dev); u8 *val = (u8 *)st->buffer; if (readval != NULL) return -EINVAL; *val = (u8)writeval; return spi_write(st->spi, val, 1); } static int max1027_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig) { struct max1027_state *st = iio_priv(indio_dev); if (st->trig != trig) return -EINVAL; return 0; } static int max1027_set_trigger_state(struct iio_trigger *trig, bool state) { struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); struct max1027_state *st = iio_priv(indio_dev); int ret; if (state) { /* Start acquisition on cnvst */ st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 | MAX1027_REF_MODE2; ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) return ret; /* Scan from 0 to max */ st->reg = MAX1027_CONV_REG | MAX1027_CHAN(0) | MAX1027_SCAN_N_M | MAX1027_TEMP; ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) return ret; } else { /* Start acquisition on conversion register write */ st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE2 | MAX1027_REF_MODE2; ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) return ret; } return 0; } static int max1027_validate_device(struct iio_trigger *trig, struct iio_dev *indio_dev) { struct iio_dev *indio = iio_trigger_get_drvdata(trig); if (indio != indio_dev) return -EINVAL; return 0; } static irqreturn_t max1027_trigger_handler(int irq, void *private) { struct iio_poll_func *pf = (struct iio_poll_func *)private; struct iio_dev *indio_dev = pf->indio_dev; struct max1027_state *st = iio_priv(indio_dev); pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private); /* fill buffer with all channel */ spi_read(st->spi, st->buffer, indio_dev->masklength * 2); iio_push_to_buffers(indio_dev, st->buffer); iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static const struct iio_trigger_ops max1027_trigger_ops = { .owner = THIS_MODULE, .validate_device = &max1027_validate_device, .set_trigger_state = &max1027_set_trigger_state, }; static const struct iio_info max1027_info = { .driver_module = THIS_MODULE, .read_raw = &max1027_read_raw, .validate_trigger = &max1027_validate_trigger, .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; pr_debug("%s: probe(spi = 0x%p)\n", __func__, spi); indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (indio_dev == NULL) { pr_err("Can't allocate iio device\n"); return -ENOMEM; } spi_set_drvdata(spi, indio_dev); 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); indio_dev->name = spi_get_device_id(spi)->name; indio_dev->dev.parent = &spi->dev; 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(&indio_dev->dev, indio_dev->num_channels * 2, GFP_KERNEL); if (st->buffer == NULL) { dev_err(&indio_dev->dev, "Can't allocate buffer\n"); return -ENOMEM; } ret = iio_triggered_buffer_setup(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; } st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-trigger", indio_dev->name); if (st->trig == NULL) { ret = -ENOMEM; dev_err(&indio_dev->dev, "Failed to allocate iio trigger\n"); goto fail_trigger_alloc; } st->trig->ops = &max1027_trigger_ops; st->trig->dev.parent = &spi->dev; iio_trigger_set_drvdata(st->trig, indio_dev); iio_trigger_register(st->trig); ret = devm_request_threaded_irq(&spi->dev, spi->irq, iio_trigger_generic_data_rdy_poll, NULL, IRQF_TRIGGER_FALLING, spi->dev.driver->name, st->trig); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to allocate IRQ.\n"); goto fail_dev_register; } /* 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"); goto fail_dev_register; } ret = iio_device_register(indio_dev); if (ret < 0) { dev_err(&indio_dev->dev, "Failed to register iio device\n"); goto fail_dev_register; } return 0; fail_dev_register: fail_trigger_alloc: iio_triggered_buffer_cleanup(indio_dev); return ret; } static int max1027_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); pr_debug("%s: remove(spi = 0x%p)\n", __func__, spi); iio_device_unregister(indio_dev); iio_triggered_buffer_cleanup(indio_dev); return 0; } static struct spi_driver max1027_driver = { .driver = { .name = "max1027", .owner = THIS_MODULE, }, .probe = max1027_probe, .remove = max1027_remove, .id_table = max1027_id, }; module_spi_driver(max1027_driver); MODULE_AUTHOR("Philippe Reynes <tremyfr@yahoo.fr>"); MODULE_DESCRIPTION("MAX1027/MAX1029/MAX1031 ADC"); MODULE_LICENSE("GPL v2");