diff options
Diffstat (limited to 'drivers/iio/adc/rzt2h_adc.c')
| -rw-r--r-- | drivers/iio/adc/rzt2h_adc.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/drivers/iio/adc/rzt2h_adc.c b/drivers/iio/adc/rzt2h_adc.c new file mode 100644 index 000000000000..33ce5cc44ff4 --- /dev/null +++ b/drivers/iio/adc/rzt2h_adc.c @@ -0,0 +1,304 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/bitfield.h> +#include <linux/cleanup.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/iio/adc-helpers.h> +#include <linux/iio/iio.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/property.h> + +#define RZT2H_ADCSR_REG 0x00 +#define RZT2H_ADCSR_ADIE_MASK BIT(12) +#define RZT2H_ADCSR_ADCS_MASK GENMASK(14, 13) +#define RZT2H_ADCSR_ADCS_SINGLE 0b00 +#define RZT2H_ADCSR_ADST_MASK BIT(15) + +#define RZT2H_ADANSA0_REG 0x04 +#define RZT2H_ADANSA0_CH_MASK(x) BIT(x) + +#define RZT2H_ADDR_REG(x) (0x20 + 0x2 * (x)) + +#define RZT2H_ADCALCTL_REG 0x1f0 +#define RZT2H_ADCALCTL_CAL_MASK BIT(0) +#define RZT2H_ADCALCTL_CAL_RDY_MASK BIT(1) +#define RZT2H_ADCALCTL_CAL_ERR_MASK BIT(2) + +#define RZT2H_ADC_MAX_CHANNELS 16 + +struct rzt2h_adc { + void __iomem *base; + struct device *dev; + + struct completion completion; + /* lock to protect against multiple access to the device */ + struct mutex lock; + + const struct iio_chan_spec *channels; + unsigned int num_channels; + unsigned int max_channels; +}; + +static void rzt2h_adc_start(struct rzt2h_adc *adc, unsigned int conversion_type) +{ + u16 reg; + + reg = readw(adc->base + RZT2H_ADCSR_REG); + + /* Set conversion type */ + FIELD_MODIFY(RZT2H_ADCSR_ADCS_MASK, ®, conversion_type); + + /* Set end of conversion interrupt and start bit. */ + reg |= RZT2H_ADCSR_ADIE_MASK | RZT2H_ADCSR_ADST_MASK; + + writew(reg, adc->base + RZT2H_ADCSR_REG); +} + +static void rzt2h_adc_stop(struct rzt2h_adc *adc) +{ + u16 reg; + + reg = readw(adc->base + RZT2H_ADCSR_REG); + + /* Clear end of conversion interrupt and start bit. */ + reg &= ~(RZT2H_ADCSR_ADIE_MASK | RZT2H_ADCSR_ADST_MASK); + + writew(reg, adc->base + RZT2H_ADCSR_REG); +} + +static int rzt2h_adc_read_single(struct rzt2h_adc *adc, unsigned int ch, int *val) +{ + int ret; + + ret = pm_runtime_resume_and_get(adc->dev); + if (ret) + return ret; + + mutex_lock(&adc->lock); + + reinit_completion(&adc->completion); + + /* Enable a single channel */ + writew(RZT2H_ADANSA0_CH_MASK(ch), adc->base + RZT2H_ADANSA0_REG); + + rzt2h_adc_start(adc, RZT2H_ADCSR_ADCS_SINGLE); + + /* + * Datasheet Page 2770, Table 41.1: + * 0.32us per channel when sample-and-hold circuits are not in use. + */ + ret = wait_for_completion_timeout(&adc->completion, usecs_to_jiffies(1)); + if (!ret) { + ret = -ETIMEDOUT; + goto disable; + } + + *val = readw(adc->base + RZT2H_ADDR_REG(ch)); + ret = IIO_VAL_INT; + +disable: + rzt2h_adc_stop(adc); + + mutex_unlock(&adc->lock); + + pm_runtime_put_autosuspend(adc->dev); + + return ret; +} + +static void rzt2h_adc_set_cal(struct rzt2h_adc *adc, bool cal) +{ + u16 val; + + val = readw(adc->base + RZT2H_ADCALCTL_REG); + if (cal) + val |= RZT2H_ADCALCTL_CAL_MASK; + else + val &= ~RZT2H_ADCALCTL_CAL_MASK; + + writew(val, adc->base + RZT2H_ADCALCTL_REG); +} + +static int rzt2h_adc_calibrate(struct rzt2h_adc *adc) +{ + u16 val; + int ret; + + rzt2h_adc_set_cal(adc, true); + + ret = read_poll_timeout(readw, val, val & RZT2H_ADCALCTL_CAL_RDY_MASK, + 200, 1000, true, adc->base + RZT2H_ADCALCTL_REG); + if (ret) { + dev_err(adc->dev, "Calibration timed out: %d\n", ret); + return ret; + } + + rzt2h_adc_set_cal(adc, false); + + if (val & RZT2H_ADCALCTL_CAL_ERR_MASK) { + dev_err(adc->dev, "Calibration failed\n"); + return -EINVAL; + } + + return 0; +} + +static int rzt2h_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct rzt2h_adc *adc = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return rzt2h_adc_read_single(adc, chan->channel, val); + case IIO_CHAN_INFO_SCALE: + *val = 1800; + *val2 = 12; + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } +} + +static const struct iio_info rzt2h_adc_iio_info = { + .read_raw = rzt2h_adc_read_raw, +}; + +static irqreturn_t rzt2h_adc_isr(int irq, void *private) +{ + struct rzt2h_adc *adc = private; + + complete(&adc->completion); + + return IRQ_HANDLED; +} + +static const struct iio_chan_spec rzt2h_adc_chan_template = { + .indexed = 1, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .type = IIO_VOLTAGE, +}; + +static int rzt2h_adc_parse_properties(struct rzt2h_adc *adc) +{ + struct iio_chan_spec *chan_array; + unsigned int i; + int ret; + + ret = devm_iio_adc_device_alloc_chaninfo_se(adc->dev, + &rzt2h_adc_chan_template, + RZT2H_ADC_MAX_CHANNELS - 1, + &chan_array); + if (ret < 0) + return dev_err_probe(adc->dev, ret, "Failed to read channel info"); + + adc->num_channels = ret; + adc->channels = chan_array; + + for (i = 0; i < adc->num_channels; i++) + if (chan_array[i].channel + 1 > adc->max_channels) + adc->max_channels = chan_array[i].channel + 1; + + return 0; +} + +static int rzt2h_adc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct iio_dev *indio_dev; + struct rzt2h_adc *adc; + int ret, irq; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*adc)); + if (!indio_dev) + return -ENOMEM; + + adc = iio_priv(indio_dev); + adc->dev = dev; + init_completion(&adc->completion); + + ret = devm_mutex_init(dev, &adc->lock); + if (ret) + return ret; + + platform_set_drvdata(pdev, adc); + + ret = rzt2h_adc_parse_properties(adc); + if (ret) + return ret; + + adc->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(adc->base)) + return PTR_ERR(adc->base); + + pm_runtime_set_autosuspend_delay(dev, 300); + pm_runtime_use_autosuspend(dev); + ret = devm_pm_runtime_enable(dev); + if (ret) + return ret; + + irq = platform_get_irq_byname(pdev, "adi"); + if (irq < 0) + return irq; + + ret = devm_request_irq(dev, irq, rzt2h_adc_isr, 0, dev_name(dev), adc); + if (ret) + return ret; + + indio_dev->name = "rzt2h-adc"; + indio_dev->info = &rzt2h_adc_iio_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = adc->channels; + indio_dev->num_channels = adc->num_channels; + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct of_device_id rzt2h_adc_match[] = { + { .compatible = "renesas,r9a09g077-adc" }, + { } +}; +MODULE_DEVICE_TABLE(of, rzt2h_adc_match); + +static int rzt2h_adc_pm_runtime_resume(struct device *dev) +{ + struct rzt2h_adc *adc = dev_get_drvdata(dev); + + /* + * Datasheet Page 2810, Section 41.5.6: + * After release from the module-stop state, wait for at least + * 0.5 µs before starting A/D conversion. + */ + fsleep(1); + + return rzt2h_adc_calibrate(adc); +} + +static const struct dev_pm_ops rzt2h_adc_pm_ops = { + RUNTIME_PM_OPS(NULL, rzt2h_adc_pm_runtime_resume, NULL) +}; + +static struct platform_driver rzt2h_adc_driver = { + .probe = rzt2h_adc_probe, + .driver = { + .name = "rzt2h-adc", + .of_match_table = rzt2h_adc_match, + .pm = pm_ptr(&rzt2h_adc_pm_ops), + }, +}; + +module_platform_driver(rzt2h_adc_driver); + +MODULE_AUTHOR("Cosmin Tanislav <cosmin-gabriel.tanislav.xa@renesas.com>"); +MODULE_DESCRIPTION("Renesas RZ/T2H / RZ/N2H ADC driver"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS("IIO_DRIVER"); |