// SPDX-License-Identifier: GPL-2.0 /* * Texas Instruments ADS7950 SPI ADC driver * * Copyright 2016 David Lechner * * 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 - https://www.ti.com/ * Nishanth Menon */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * In case of ACPI, we use the 5000 mV as default for the reference pin. * Device tree users encode that via the vref-supply regulator. */ #define TI_ADS7950_VA_MV_ACPI_DEFAULT 5000 #define TI_ADS7950_CR_GPIO BIT(14) #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_CR_GPIO_DATA BIT(4) #define TI_ADS7950_MAX_CHAN 16 #define TI_ADS7950_NUM_GPIOS 4 #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)) #define TI_ADS7950_MAN_CMD(cmd) (TI_ADS7950_CR_MANUAL | (cmd)) #define TI_ADS7950_GPIO_CMD(cmd) (TI_ADS7950_CR_GPIO | (cmd)) /* Manual mode configuration */ #define TI_ADS7950_MAN_CMD_SETTINGS(st) \ (TI_ADS7950_MAN_CMD(TI_ADS7950_CR_WRITE | st->cmd_settings_bitmask)) /* GPIO mode configuration */ #define TI_ADS7950_GPIO_CMD_SETTINGS(st) \ (TI_ADS7950_GPIO_CMD(st->gpio_cmd_settings_bitmask)) struct ti_ads7950_state { struct spi_device *spi; struct spi_transfer ring_xfer; struct spi_transfer scan_single_xfer[3]; struct spi_message ring_msg; struct spi_message scan_single_msg; /* Lock to protect the spi xfer buffers */ struct mutex slock; struct gpio_chip chip; struct regulator *reg; unsigned int vref_mv; /* * Bitmask of lower 7 bits used for configuration * These bits only can be written when TI_ADS7950_CR_WRITE * is set, otherwise it retains its original state. * [0-3] GPIO signal * [4] Set following frame to return GPIO signal values * [5] Powers down device * [6] Sets Vref range1(2.5v) or range2(5v) * * Bits present on Manual/Auto1/Auto2 commands */ unsigned int cmd_settings_bitmask; /* * Bitmask of GPIO command * [0-3] GPIO direction * [4-6] Different GPIO alarm mode configurations * [7] GPIO 2 as device range input * [8] GPIO 3 as device power down input * [9] Reset all registers * [10-11] N/A */ unsigned int gpio_cmd_settings_bitmask; /* * DMA (thus cache coherency maintenance) may require the * transfer buffers to live in their own cache lines. */ u16 rx_buf[TI_ADS7950_MAX_CHAN + 2 + TI_ADS7950_TIMESTAMP_SIZE] __aligned(IIO_DMA_MINALIGN); u16 tx_buf[TI_ADS7950_MAX_CHAN + 2]; u16 single_tx; u16 single_rx; }; 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_CPU, \ }, \ } #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_MAN_CMD(TI_ADS7950_CR_CHAN(i)); st->tx_buf[len++] = cmd; } /* Data for the 1st channel is not returned until the 3rd transfer */ st->tx_buf[len++] = 0; st->tx_buf[len++] = 0; st->ring_xfer.len = len * 2; 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; mutex_lock(&st->slock); ret = spi_sync(st->spi, &st->ring_msg); if (ret < 0) goto out; iio_push_to_buffers_with_timestamp(indio_dev, &st->rx_buf[2], iio_get_time_ns(indio_dev)); out: mutex_unlock(&st->slock); iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch) { struct ti_ads7950_state *st = iio_priv(indio_dev); int ret, cmd; mutex_lock(&st->slock); cmd = TI_ADS7950_MAN_CMD(TI_ADS7950_CR_CHAN(ch)); st->single_tx = cmd; ret = spi_sync(st->spi, &st->scan_single_msg); if (ret) goto out; ret = st->single_rx; out: mutex_unlock(&st->slock); return ret; } static int ti_ads7950_get_range(struct ti_ads7950_state *st) { int vref; if (st->vref_mv) { vref = st->vref_mv; } else { vref = regulator_get_voltage(st->reg); if (vref < 0) return vref; vref /= 1000; } if (st->cmd_settings_bitmask & 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 = ti_ads7950_scan_direct(indio_dev, chan->address); 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, }; static void ti_ads7950_set(struct gpio_chip *chip, unsigned int offset, int value) { struct ti_ads7950_state *st = gpiochip_get_data(chip); mutex_lock(&st->slock); if (value) st->cmd_settings_bitmask |= BIT(offset); else st->cmd_settings_bitmask &= ~BIT(offset); st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st); spi_sync(st->spi, &st->scan_single_msg); mutex_unlock(&st->slock); } static int ti_ads7950_get(struct gpio_chip *chip, unsigned int offset) { struct ti_ads7950_state *st = gpiochip_get_data(chip); int ret; mutex_lock(&st->slock); /* If set as output, return the output */ if (st->gpio_cmd_settings_bitmask & BIT(offset)) { ret = st->cmd_settings_bitmask & BIT(offset); goto out; } /* GPIO data bit sets SDO bits 12-15 to GPIO input */ st->cmd_settings_bitmask |= TI_ADS7950_CR_GPIO_DATA; st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st); ret = spi_sync(st->spi, &st->scan_single_msg); if (ret) goto out; ret = ((st->single_rx >> 12) & BIT(offset)) ? 1 : 0; /* Revert back to original settings */ st->cmd_settings_bitmask &= ~TI_ADS7950_CR_GPIO_DATA; st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st); ret = spi_sync(st->spi, &st->scan_single_msg); if (ret) goto out; out: mutex_unlock(&st->slock); return ret; } static int ti_ads7950_get_direction(struct gpio_chip *chip, unsigned int offset) { struct ti_ads7950_state *st = gpiochip_get_data(chip); /* Bitmask is inverted from GPIO framework 0=input/1=output */ return !(st->gpio_cmd_settings_bitmask & BIT(offset)); } static int _ti_ads7950_set_direction(struct gpio_chip *chip, int offset, int input) { struct ti_ads7950_state *st = gpiochip_get_data(chip); int ret = 0; mutex_lock(&st->slock); /* Only change direction if needed */ if (input && (st->gpio_cmd_settings_bitmask & BIT(offset))) st->gpio_cmd_settings_bitmask &= ~BIT(offset); else if (!input && !(st->gpio_cmd_settings_bitmask & BIT(offset))) st->gpio_cmd_settings_bitmask |= BIT(offset); else goto out; st->single_tx = TI_ADS7950_GPIO_CMD_SETTINGS(st); ret = spi_sync(st->spi, &st->scan_single_msg); out: mutex_unlock(&st->slock); return ret; } static int ti_ads7950_direction_input(struct gpio_chip *chip, unsigned int offset) { return _ti_ads7950_set_direction(chip, offset, 1); } static int ti_ads7950_direction_output(struct gpio_chip *chip, unsigned int offset, int value) { ti_ads7950_set(chip, offset, value); return _ti_ads7950_set_direction(chip, offset, 0); } static int ti_ads7950_init_hw(struct ti_ads7950_state *st) { int ret = 0; mutex_lock(&st->slock); /* Settings for Manual/Auto1/Auto2 commands */ /* Default to 5v ref */ st->cmd_settings_bitmask = TI_ADS7950_CR_RANGE_5V; st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st); ret = spi_sync(st->spi, &st->scan_single_msg); if (ret) goto out; /* Settings for GPIO command */ st->gpio_cmd_settings_bitmask = 0x0; st->single_tx = TI_ADS7950_GPIO_CMD_SETTINGS(st); ret = spi_sync(st->spi, &st->scan_single_msg); out: mutex_unlock(&st->slock); return ret; } 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; spi->bits_per_word = 16; spi->mode |= SPI_CS_WORD; ret = spi_setup(spi); if (ret < 0) { dev_err(&spi->dev, "Error in spi setup\n"); return 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; info = &ti_ads7950_chip_info[spi_get_device_id(spi)->driver_data]; indio_dev->name = spi_get_device_id(spi)->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = info->channels; indio_dev->num_channels = info->num_channels; indio_dev->info = &ti_ads7950_info; /* build spi ring message */ spi_message_init(&st->ring_msg); st->ring_xfer.tx_buf = &st->tx_buf[0]; st->ring_xfer.rx_buf = &st->rx_buf[0]; /* len will be set later */ spi_message_add_tail(&st->ring_xfer, &st->ring_msg); /* * 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->single_tx; st->scan_single_xfer[0].len = 2; st->scan_single_xfer[0].cs_change = 1; st->scan_single_xfer[1].tx_buf = &st->single_tx; st->scan_single_xfer[1].len = 2; st->scan_single_xfer[1].cs_change = 1; st->scan_single_xfer[2].rx_buf = &st->single_rx; st->scan_single_xfer[2].len = 2; spi_message_init_with_transfers(&st->scan_single_msg, st->scan_single_xfer, 3); /* Use hard coded value for reference voltage in ACPI case */ if (ACPI_COMPANION(&spi->dev)) st->vref_mv = TI_ADS7950_VA_MV_ACPI_DEFAULT; mutex_init(&st->slock); st->reg = devm_regulator_get(&spi->dev, "vref"); if (IS_ERR(st->reg)) { ret = dev_err_probe(&spi->dev, PTR_ERR(st->reg), "Failed to get regulator \"vref\"\n"); goto error_destroy_mutex; } ret = regulator_enable(st->reg); if (ret) { dev_err(&spi->dev, "Failed to enable regulator \"vref\"\n"); goto error_destroy_mutex; } 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 = ti_ads7950_init_hw(st); if (ret) { dev_err(&spi->dev, "Failed to init adc chip\n"); goto error_cleanup_ring; } ret = iio_device_register(indio_dev); if (ret) { dev_err(&spi->dev, "Failed to register iio device\n"); goto error_cleanup_ring; } /* Add GPIO chip */ st->chip.label = dev_name(&st->spi->dev); st->chip.parent = &st->spi->dev; st->chip.owner = THIS_MODULE; st->chip.can_sleep = true; st->chip.base = -1; st->chip.ngpio = TI_ADS7950_NUM_GPIOS; st->chip.get_direction = ti_ads7950_get_direction; st->chip.direction_input = ti_ads7950_direction_input; st->chip.direction_output = ti_ads7950_direction_output; st->chip.get = ti_ads7950_get; st->chip.set = ti_ads7950_set; ret = gpiochip_add_data(&st->chip, st); if (ret) { dev_err(&spi->dev, "Failed to init GPIOs\n"); goto error_iio_device; } return 0; error_iio_device: iio_device_unregister(indio_dev); error_cleanup_ring: iio_triggered_buffer_cleanup(indio_dev); error_disable_reg: regulator_disable(st->reg); error_destroy_mutex: mutex_destroy(&st->slock); return ret; } static void 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); gpiochip_remove(&st->chip); iio_device_unregister(indio_dev); iio_triggered_buffer_cleanup(indio_dev); regulator_disable(st->reg); mutex_destroy(&st->slock); } static const struct spi_device_id ti_ads7950_id[] = { { "ads7950", TI_ADS7950 }, { "ads7951", TI_ADS7951 }, { "ads7952", TI_ADS7952 }, { "ads7953", TI_ADS7953 }, { "ads7954", TI_ADS7954 }, { "ads7955", TI_ADS7955 }, { "ads7956", TI_ADS7956 }, { "ads7957", TI_ADS7957 }, { "ads7958", TI_ADS7958 }, { "ads7959", TI_ADS7959 }, { "ads7960", TI_ADS7960 }, { "ads7961", TI_ADS7961 }, { } }; MODULE_DEVICE_TABLE(spi, ti_ads7950_id); static const struct of_device_id ads7950_of_table[] = { { .compatible = "ti,ads7950", .data = &ti_ads7950_chip_info[TI_ADS7950] }, { .compatible = "ti,ads7951", .data = &ti_ads7950_chip_info[TI_ADS7951] }, { .compatible = "ti,ads7952", .data = &ti_ads7950_chip_info[TI_ADS7952] }, { .compatible = "ti,ads7953", .data = &ti_ads7950_chip_info[TI_ADS7953] }, { .compatible = "ti,ads7954", .data = &ti_ads7950_chip_info[TI_ADS7954] }, { .compatible = "ti,ads7955", .data = &ti_ads7950_chip_info[TI_ADS7955] }, { .compatible = "ti,ads7956", .data = &ti_ads7950_chip_info[TI_ADS7956] }, { .compatible = "ti,ads7957", .data = &ti_ads7950_chip_info[TI_ADS7957] }, { .compatible = "ti,ads7958", .data = &ti_ads7950_chip_info[TI_ADS7958] }, { .compatible = "ti,ads7959", .data = &ti_ads7950_chip_info[TI_ADS7959] }, { .compatible = "ti,ads7960", .data = &ti_ads7950_chip_info[TI_ADS7960] }, { .compatible = "ti,ads7961", .data = &ti_ads7950_chip_info[TI_ADS7961] }, { } }; MODULE_DEVICE_TABLE(of, ads7950_of_table); static struct spi_driver ti_ads7950_driver = { .driver = { .name = "ads7950", .of_match_table = ads7950_of_table, }, .probe = ti_ads7950_probe, .remove = ti_ads7950_remove, .id_table = ti_ads7950_id, }; module_spi_driver(ti_ads7950_driver); MODULE_AUTHOR("David Lechner "); MODULE_DESCRIPTION("TI TI_ADS7950 ADC"); MODULE_LICENSE("GPL v2");