diff options
Diffstat (limited to 'drivers/iio/adc/berlin2-adc.c')
| -rw-r--r-- | drivers/iio/adc/berlin2-adc.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/drivers/iio/adc/berlin2-adc.c b/drivers/iio/adc/berlin2-adc.c new file mode 100644 index 000000000..fa2c87946 --- /dev/null +++ b/drivers/iio/adc/berlin2-adc.c @@ -0,0 +1,381 @@ +/* + * Marvell Berlin2 ADC driver + * + * Copyright (C) 2015 Marvell Technology Group Ltd. + * + * Antoine Tenart <antoine.tenart@free-electrons.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/iio/iio.h> +#include <linux/iio/driver.h> +#include <linux/iio/machine.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> +#include <linux/sched.h> +#include <linux/wait.h> + +#define BERLIN2_SM_CTRL 0x14 +#define BERLIN2_SM_CTRL_SM_SOC_INT BIT(1) +#define BERLIN2_SM_CTRL_SOC_SM_INT BIT(2) +#define BERLIN2_SM_CTRL_ADC_SEL(x) ((x) << 5) /* 0-15 */ +#define BERLIN2_SM_CTRL_ADC_SEL_MASK GENMASK(8, 5) +#define BERLIN2_SM_CTRL_ADC_POWER BIT(9) +#define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV2 (0x0 << 10) +#define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV3 (0x1 << 10) +#define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV4 (0x2 << 10) +#define BERLIN2_SM_CTRL_ADC_CLKSEL_DIV8 (0x3 << 10) +#define BERLIN2_SM_CTRL_ADC_CLKSEL_MASK GENMASK(11, 10) +#define BERLIN2_SM_CTRL_ADC_START BIT(12) +#define BERLIN2_SM_CTRL_ADC_RESET BIT(13) +#define BERLIN2_SM_CTRL_ADC_BANDGAP_RDY BIT(14) +#define BERLIN2_SM_CTRL_ADC_CONT_SINGLE (0x0 << 15) +#define BERLIN2_SM_CTRL_ADC_CONT_CONTINUOUS (0x1 << 15) +#define BERLIN2_SM_CTRL_ADC_BUFFER_EN BIT(16) +#define BERLIN2_SM_CTRL_ADC_VREF_EXT (0x0 << 17) +#define BERLIN2_SM_CTRL_ADC_VREF_INT (0x1 << 17) +#define BERLIN2_SM_CTRL_ADC_ROTATE BIT(19) +#define BERLIN2_SM_CTRL_TSEN_EN BIT(20) +#define BERLIN2_SM_CTRL_TSEN_CLK_SEL_125 (0x0 << 21) /* 1.25 MHz */ +#define BERLIN2_SM_CTRL_TSEN_CLK_SEL_250 (0x1 << 21) /* 2.5 MHz */ +#define BERLIN2_SM_CTRL_TSEN_MODE_0_125 (0x0 << 22) /* 0-125 C */ +#define BERLIN2_SM_CTRL_TSEN_MODE_10_50 (0x1 << 22) /* 10-50 C */ +#define BERLIN2_SM_CTRL_TSEN_RESET BIT(29) +#define BERLIN2_SM_ADC_DATA 0x20 +#define BERLIN2_SM_ADC_MASK GENMASK(9, 0) +#define BERLIN2_SM_ADC_STATUS 0x1c +#define BERLIN2_SM_ADC_STATUS_DATA_RDY(x) BIT(x) /* 0-15 */ +#define BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK GENMASK(15, 0) +#define BERLIN2_SM_ADC_STATUS_INT_EN(x) (BIT(x) << 16) /* 0-15 */ +#define BERLIN2_SM_ADC_STATUS_INT_EN_MASK GENMASK(31, 16) +#define BERLIN2_SM_TSEN_STATUS 0x24 +#define BERLIN2_SM_TSEN_STATUS_DATA_RDY BIT(0) +#define BERLIN2_SM_TSEN_STATUS_INT_EN BIT(1) +#define BERLIN2_SM_TSEN_DATA 0x28 +#define BERLIN2_SM_TSEN_MASK GENMASK(9, 0) +#define BERLIN2_SM_TSEN_CTRL 0x74 +#define BERLIN2_SM_TSEN_CTRL_START BIT(8) +#define BERLIN2_SM_TSEN_CTRL_SETTLING_4 (0x0 << 21) /* 4 us */ +#define BERLIN2_SM_TSEN_CTRL_SETTLING_12 (0x1 << 21) /* 12 us */ +#define BERLIN2_SM_TSEN_CTRL_SETTLING_MASK BIT(21) +#define BERLIN2_SM_TSEN_CTRL_TRIM(x) ((x) << 22) +#define BERLIN2_SM_TSEN_CTRL_TRIM_MASK GENMASK(25, 22) + +struct berlin2_adc_priv { + struct regmap *regmap; + struct mutex lock; + wait_queue_head_t wq; + bool data_available; + int data; +}; + +#define BERLIN2_ADC_CHANNEL(n, t) \ + { \ + .channel = n, \ + .datasheet_name = "channel"#n, \ + .type = t, \ + .indexed = 1, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + } + +static const struct iio_chan_spec berlin2_adc_channels[] = { + BERLIN2_ADC_CHANNEL(0, IIO_VOLTAGE), /* external input */ + BERLIN2_ADC_CHANNEL(1, IIO_VOLTAGE), /* external input */ + BERLIN2_ADC_CHANNEL(2, IIO_VOLTAGE), /* external input */ + BERLIN2_ADC_CHANNEL(3, IIO_VOLTAGE), /* external input */ + BERLIN2_ADC_CHANNEL(4, IIO_VOLTAGE), /* reserved */ + BERLIN2_ADC_CHANNEL(5, IIO_VOLTAGE), /* reserved */ + { /* temperature sensor */ + .channel = 6, + .datasheet_name = "channel6", + .type = IIO_TEMP, + .indexed = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + }, + BERLIN2_ADC_CHANNEL(7, IIO_VOLTAGE), /* reserved */ + IIO_CHAN_SOFT_TIMESTAMP(8), /* timestamp */ +}; + +static int berlin2_adc_read(struct iio_dev *indio_dev, int channel) +{ + struct berlin2_adc_priv *priv = iio_priv(indio_dev); + int data, ret; + + mutex_lock(&priv->lock); + + /* Enable the interrupts */ + regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, + BERLIN2_SM_ADC_STATUS_INT_EN(channel)); + + /* Configure the ADC */ + regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, + BERLIN2_SM_CTRL_ADC_RESET | + BERLIN2_SM_CTRL_ADC_SEL_MASK | + BERLIN2_SM_CTRL_ADC_START, + BERLIN2_SM_CTRL_ADC_SEL(channel) | + BERLIN2_SM_CTRL_ADC_START); + + ret = wait_event_interruptible_timeout(priv->wq, priv->data_available, + msecs_to_jiffies(1000)); + + /* Disable the interrupts */ + regmap_update_bits(priv->regmap, BERLIN2_SM_ADC_STATUS, + BERLIN2_SM_ADC_STATUS_INT_EN(channel), 0); + + if (ret == 0) + ret = -ETIMEDOUT; + if (ret < 0) { + mutex_unlock(&priv->lock); + return ret; + } + + regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, + BERLIN2_SM_CTRL_ADC_START, 0); + + data = priv->data; + priv->data_available = false; + + mutex_unlock(&priv->lock); + + return data; +} + +static int berlin2_adc_tsen_read(struct iio_dev *indio_dev) +{ + struct berlin2_adc_priv *priv = iio_priv(indio_dev); + int data, ret; + + mutex_lock(&priv->lock); + + /* Enable interrupts */ + regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, + BERLIN2_SM_TSEN_STATUS_INT_EN); + + /* Configure the ADC */ + regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, + BERLIN2_SM_CTRL_TSEN_RESET | + BERLIN2_SM_CTRL_ADC_ROTATE, + BERLIN2_SM_CTRL_ADC_ROTATE); + + /* Configure the temperature sensor */ + regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL, + BERLIN2_SM_TSEN_CTRL_TRIM_MASK | + BERLIN2_SM_TSEN_CTRL_SETTLING_MASK | + BERLIN2_SM_TSEN_CTRL_START, + BERLIN2_SM_TSEN_CTRL_TRIM(3) | + BERLIN2_SM_TSEN_CTRL_SETTLING_12 | + BERLIN2_SM_TSEN_CTRL_START); + + ret = wait_event_interruptible_timeout(priv->wq, priv->data_available, + msecs_to_jiffies(1000)); + + /* Disable interrupts */ + regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_STATUS, + BERLIN2_SM_TSEN_STATUS_INT_EN, 0); + + if (ret == 0) + ret = -ETIMEDOUT; + if (ret < 0) { + mutex_unlock(&priv->lock); + return ret; + } + + regmap_update_bits(priv->regmap, BERLIN2_SM_TSEN_CTRL, + BERLIN2_SM_TSEN_CTRL_START, 0); + + data = priv->data; + priv->data_available = false; + + mutex_unlock(&priv->lock); + + return data; +} + +static int berlin2_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + int temp; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (chan->type != IIO_VOLTAGE) + return -EINVAL; + + *val = berlin2_adc_read(indio_dev, chan->channel); + if (*val < 0) + return *val; + + return IIO_VAL_INT; + case IIO_CHAN_INFO_PROCESSED: + if (chan->type != IIO_TEMP) + return -EINVAL; + + temp = berlin2_adc_tsen_read(indio_dev); + if (temp < 0) + return temp; + + if (temp > 2047) + temp -= 4096; + + /* Convert to milli Celsius */ + *val = ((temp * 100000) / 264 - 270000); + return IIO_VAL_INT; + default: + break; + } + + return -EINVAL; +} + +static irqreturn_t berlin2_adc_irq(int irq, void *private) +{ + struct berlin2_adc_priv *priv = iio_priv(private); + unsigned val; + + regmap_read(priv->regmap, BERLIN2_SM_ADC_STATUS, &val); + if (val & BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK) { + regmap_read(priv->regmap, BERLIN2_SM_ADC_DATA, &priv->data); + priv->data &= BERLIN2_SM_ADC_MASK; + + val &= ~BERLIN2_SM_ADC_STATUS_DATA_RDY_MASK; + regmap_write(priv->regmap, BERLIN2_SM_ADC_STATUS, val); + + priv->data_available = true; + wake_up_interruptible(&priv->wq); + } + + return IRQ_HANDLED; +} + +static irqreturn_t berlin2_adc_tsen_irq(int irq, void *private) +{ + struct berlin2_adc_priv *priv = iio_priv(private); + unsigned val; + + regmap_read(priv->regmap, BERLIN2_SM_TSEN_STATUS, &val); + if (val & BERLIN2_SM_TSEN_STATUS_DATA_RDY) { + regmap_read(priv->regmap, BERLIN2_SM_TSEN_DATA, &priv->data); + priv->data &= BERLIN2_SM_TSEN_MASK; + + val &= ~BERLIN2_SM_TSEN_STATUS_DATA_RDY; + regmap_write(priv->regmap, BERLIN2_SM_TSEN_STATUS, val); + + priv->data_available = true; + wake_up_interruptible(&priv->wq); + } + + return IRQ_HANDLED; +} + +static const struct iio_info berlin2_adc_info = { + .read_raw = berlin2_adc_read_raw, +}; + +static int berlin2_adc_probe(struct platform_device *pdev) +{ + struct iio_dev *indio_dev; + struct berlin2_adc_priv *priv; + struct device_node *parent_np = of_get_parent(pdev->dev.of_node); + int irq, tsen_irq; + int ret; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv)); + if (!indio_dev) { + of_node_put(parent_np); + return -ENOMEM; + } + + priv = iio_priv(indio_dev); + platform_set_drvdata(pdev, indio_dev); + + priv->regmap = syscon_node_to_regmap(parent_np); + of_node_put(parent_np); + if (IS_ERR(priv->regmap)) + return PTR_ERR(priv->regmap); + + irq = platform_get_irq_byname(pdev, "adc"); + if (irq < 0) + return irq; + + tsen_irq = platform_get_irq_byname(pdev, "tsen"); + if (tsen_irq < 0) + return tsen_irq; + + ret = devm_request_irq(&pdev->dev, irq, berlin2_adc_irq, 0, + pdev->dev.driver->name, indio_dev); + if (ret) + return ret; + + ret = devm_request_irq(&pdev->dev, tsen_irq, berlin2_adc_tsen_irq, + 0, pdev->dev.driver->name, indio_dev); + if (ret) + return ret; + + init_waitqueue_head(&priv->wq); + mutex_init(&priv->lock); + + indio_dev->name = dev_name(&pdev->dev); + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &berlin2_adc_info; + + indio_dev->channels = berlin2_adc_channels; + indio_dev->num_channels = ARRAY_SIZE(berlin2_adc_channels); + + /* Power up the ADC */ + regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, + BERLIN2_SM_CTRL_ADC_POWER, + BERLIN2_SM_CTRL_ADC_POWER); + + ret = iio_device_register(indio_dev); + if (ret) { + /* Power down the ADC */ + regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, + BERLIN2_SM_CTRL_ADC_POWER, 0); + return ret; + } + + return 0; +} + +static int berlin2_adc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct berlin2_adc_priv *priv = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + + /* Power down the ADC */ + regmap_update_bits(priv->regmap, BERLIN2_SM_CTRL, + BERLIN2_SM_CTRL_ADC_POWER, 0); + + return 0; +} + +static const struct of_device_id berlin2_adc_match[] = { + { .compatible = "marvell,berlin2-adc", }, + { }, +}; +MODULE_DEVICE_TABLE(of, berlin2_adc_match); + +static struct platform_driver berlin2_adc_driver = { + .driver = { + .name = "berlin2-adc", + .of_match_table = berlin2_adc_match, + }, + .probe = berlin2_adc_probe, + .remove = berlin2_adc_remove, +}; +module_platform_driver(berlin2_adc_driver); + +MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); +MODULE_DESCRIPTION("Marvell Berlin2 ADC driver"); +MODULE_LICENSE("GPL v2"); |