diff options
Diffstat (limited to 'drivers/iio/adc/rzn1-adc.c')
| -rw-r--r-- | drivers/iio/adc/rzn1-adc.c | 490 |
1 files changed, 490 insertions, 0 deletions
diff --git a/drivers/iio/adc/rzn1-adc.c b/drivers/iio/adc/rzn1-adc.c new file mode 100644 index 000000000000..93b0feef8ea0 --- /dev/null +++ b/drivers/iio/adc/rzn1-adc.c @@ -0,0 +1,490 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/N1 ADC driver + * + * Copyright (C) 2025 Schneider-Electric + * + * Author: Herve Codina <herve.codina@bootlin.com> + * + * The RZ/N1 ADC controller can handle channels from its internal ADC1 and/or + * ADC2 cores. The driver use ADC1 and/or ADC2 cores depending on the presence + * of the related power supplies (AVDD and VREF) description in the device-tree. + */ + +#include <linux/array_size.h> +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/cleanup.h> +#include <linux/clk.h> +#include <linux/dev_printk.h> +#include <linux/err.h> +#include <linux/iio/iio.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/regulator/consumer.h> +#include <linux/types.h> + +#define RZN1_ADC_CONTROL_REG 0x02c +#define RZN1_ADC_CONTROL_ADC_BUSY BIT(6) + +#define RZN1_ADC_FORCE_REG 0x030 +#define RZN1_ADC_SET_FORCE_REG 0x034 +#define RZN1_ADC_CLEAR_FORCE_REG 0x038 +#define RZN1_ADC_FORCE_VC(_n) BIT(_n) + +#define RZN1_ADC_CONFIG_REG 0x040 +#define RZN1_ADC_CONFIG_ADC_POWER_DOWN BIT(3) + +#define RZN1_ADC_VC_REG(_n) (0x0c0 + 4 * (_n)) +#define RZN1_ADC_VC_ADC2_ENABLE BIT(16) +#define RZN1_ADC_VC_ADC1_ENABLE BIT(15) +#define RZN1_ADC_VC_ADC2_CHANNEL_SEL_MASK GENMASK(5, 3) +#define RZN1_ADC_VC_ADC1_CHANNEL_SEL_MASK GENMASK(2, 0) + +#define RZN1_ADC_ADC1_DATA_REG(_n) (0x100 + 4 * (_n)) +#define RZN1_ADC_ADC2_DATA_REG(_n) (0x140 + 4 * (_n)) +#define RZN1_ADC_ADCX_DATA_DATA_MASK GENMASK(11, 0) + +#define RZN1_ADC_NO_CHANNEL -1 + +#define RZN1_ADC_CHANNEL_SHARED_SCALE(_ch, _ds_name) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = (_ch), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .datasheet_name = (_ds_name), \ +} + +#define RZN1_ADC_CHANNEL_SEPARATED_SCALE(_ch, _ds_name) { \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = (_ch), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .datasheet_name = (_ds_name), \ +} + +/* + * 8 ADC1_IN signals existed numbered 0..4, 6..8 + * ADCx_IN5 doesn't exist in RZ/N1 datasheet + */ +static struct iio_chan_spec rzn1_adc1_channels[] = { + RZN1_ADC_CHANNEL_SHARED_SCALE(0, "ADC1_IN0"), + RZN1_ADC_CHANNEL_SHARED_SCALE(1, "ADC1_IN1"), + RZN1_ADC_CHANNEL_SHARED_SCALE(2, "ADC1_IN2"), + RZN1_ADC_CHANNEL_SHARED_SCALE(3, "ADC1_IN3"), + RZN1_ADC_CHANNEL_SHARED_SCALE(4, "ADC1_IN4"), + RZN1_ADC_CHANNEL_SHARED_SCALE(5, "ADC1_IN6"), + RZN1_ADC_CHANNEL_SHARED_SCALE(6, "ADC1_IN7"), + RZN1_ADC_CHANNEL_SHARED_SCALE(7, "ADC1_IN8"), +}; + +static struct iio_chan_spec rzn1_adc2_channels[] = { + RZN1_ADC_CHANNEL_SHARED_SCALE(8, "ADC2_IN0"), + RZN1_ADC_CHANNEL_SHARED_SCALE(9, "ADC2_IN1"), + RZN1_ADC_CHANNEL_SHARED_SCALE(10, "ADC2_IN2"), + RZN1_ADC_CHANNEL_SHARED_SCALE(11, "ADC2_IN3"), + RZN1_ADC_CHANNEL_SHARED_SCALE(12, "ADC2_IN4"), + RZN1_ADC_CHANNEL_SHARED_SCALE(13, "ADC2_IN6"), + RZN1_ADC_CHANNEL_SHARED_SCALE(14, "ADC2_IN7"), + RZN1_ADC_CHANNEL_SHARED_SCALE(15, "ADC2_IN8"), +}; + +/* + * If both ADCs core are used, scale cannot be common. Indeed, scale is + * based on Vref connected on each ADC core. + */ +static struct iio_chan_spec rzn1_adc1_adc2_channels[] = { + RZN1_ADC_CHANNEL_SEPARATED_SCALE(0, "ADC1_IN0"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(1, "ADC1_IN1"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(2, "ADC1_IN2"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(3, "ADC1_IN3"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(4, "ADC1_IN4"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(5, "ADC1_IN6"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(6, "ADC1_IN7"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(7, "ADC1_IN8"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(8, "ADC2_IN0"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(9, "ADC2_IN1"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(10, "ADC2_IN2"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(11, "ADC2_IN3"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(12, "ADC2_IN4"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(13, "ADC2_IN6"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(14, "ADC2_IN7"), + RZN1_ADC_CHANNEL_SEPARATED_SCALE(15, "ADC2_IN8"), +}; + +struct rzn1_adc { + struct device *dev; + void __iomem *regs; + struct mutex lock; /* ADC lock */ + int adc1_vref_mV; /* ADC1 Vref in mV. Negative if ADC1 is not used */ + int adc2_vref_mV; /* ADC2 Vref in mV. Negative if ADC2 is not used */ +}; + +static int rzn1_adc_power(struct rzn1_adc *rzn1_adc, bool power) +{ + u32 v; + + writel(power ? 0 : RZN1_ADC_CONFIG_ADC_POWER_DOWN, + rzn1_adc->regs + RZN1_ADC_CONFIG_REG); + + /* Wait for the ADC_BUSY to clear */ + return readl_poll_timeout_atomic(rzn1_adc->regs + RZN1_ADC_CONTROL_REG, + v, !(v & RZN1_ADC_CONTROL_ADC_BUSY), + 0, 500); +} + +static void rzn1_adc_vc_setup_conversion(struct rzn1_adc *rzn1_adc, u32 ch, + int adc1_ch, int adc2_ch) +{ + u32 vc = 0; + + if (adc1_ch != RZN1_ADC_NO_CHANNEL) + vc |= RZN1_ADC_VC_ADC1_ENABLE | + FIELD_PREP(RZN1_ADC_VC_ADC1_CHANNEL_SEL_MASK, adc1_ch); + + if (adc2_ch != RZN1_ADC_NO_CHANNEL) + vc |= RZN1_ADC_VC_ADC2_ENABLE | + FIELD_PREP(RZN1_ADC_VC_ADC2_CHANNEL_SEL_MASK, adc2_ch); + + writel(vc, rzn1_adc->regs + RZN1_ADC_VC_REG(ch)); +} + +static int rzn1_adc_vc_start_conversion(struct rzn1_adc *rzn1_adc, u32 ch) +{ + u32 val; + + val = readl(rzn1_adc->regs + RZN1_ADC_FORCE_REG); + if (val & RZN1_ADC_FORCE_VC(ch)) + return -EBUSY; + + writel(RZN1_ADC_FORCE_VC(ch), rzn1_adc->regs + RZN1_ADC_SET_FORCE_REG); + + return 0; +} + +static void rzn1_adc_vc_stop_conversion(struct rzn1_adc *rzn1_adc, u32 ch) +{ + writel(RZN1_ADC_FORCE_VC(ch), rzn1_adc->regs + RZN1_ADC_CLEAR_FORCE_REG); +} + +static int rzn1_adc_vc_wait_conversion(struct rzn1_adc *rzn1_adc, u32 ch, + u32 *adc1_data, u32 *adc2_data) +{ + u32 data_reg; + int ret; + u32 v; + + /* + * When a VC is selected, it needs 20 ADC clocks to perform the + * conversion. + * + * The worst case is when the 16 VCs need to perform a conversion and + * our VC is the lowest in term of priority. + * + * In that case, the conversion is performed in 16 * 20 ADC clocks. + * + * The ADC clock can be set from 4MHz to 20MHz. This leads to a worst + * case of 16 * 20 * 1/4Mhz = 80us. + * + * Round it up to 100us. + */ + + /* Wait for the ADC_FORCE_VC(n) to clear */ + ret = readl_poll_timeout_atomic(rzn1_adc->regs + RZN1_ADC_FORCE_REG, + v, !(v & RZN1_ADC_FORCE_VC(ch)), + 0, 100); + if (ret) + return ret; + + if (adc1_data) { + data_reg = readl(rzn1_adc->regs + RZN1_ADC_ADC1_DATA_REG(ch)); + *adc1_data = FIELD_GET(RZN1_ADC_ADCX_DATA_DATA_MASK, data_reg); + } + + if (adc2_data) { + data_reg = readl(rzn1_adc->regs + RZN1_ADC_ADC2_DATA_REG(ch)); + *adc2_data = FIELD_GET(RZN1_ADC_ADCX_DATA_DATA_MASK, data_reg); + } + + return 0; +} + +static int rzn1_adc_read_raw_ch(struct rzn1_adc *rzn1_adc, unsigned int chan, int *val) +{ + u32 *adc1_data, *adc2_data; + int adc1_ch, adc2_ch; + u32 adc_data; + int ret; + + /* + * IIO chan are decoupled from chans used in rzn1_adc_vc_*() functions. + * The RZ/N1 ADC VC controller can handle on a single VC chan one + * channel from the ADC1 core and one channel from the ADC2 core. + * + * Even if IIO chans are mapped 1:1 to ADC core chans and so uses only + * a chan from ADC1 or a chan from ADC2, future improvements can define + * an IIO chan that uses one chan from ADC1 and one chan from ADC2. + */ + + if (chan < 8) { + /* chan 0..7 used to get ADC1 ch 0..7 */ + adc1_ch = chan; + adc1_data = &adc_data; + adc2_ch = RZN1_ADC_NO_CHANNEL; + adc2_data = NULL; + } else if (chan < 16) { + /* chan 8..15 used to get ADC2 ch 0..7 */ + adc1_ch = RZN1_ADC_NO_CHANNEL; + adc1_data = NULL; + adc2_ch = chan - 8; + adc2_data = &adc_data; + } else { + return -EINVAL; + } + + ACQUIRE(pm_runtime_active_auto_try_enabled, pm)(rzn1_adc->dev); + ret = ACQUIRE_ERR(pm_runtime_active_auto_try_enabled, &pm); + if (ret < 0) + return ret; + + scoped_guard(mutex, &rzn1_adc->lock) { + rzn1_adc_vc_setup_conversion(rzn1_adc, chan, adc1_ch, adc2_ch); + + ret = rzn1_adc_vc_start_conversion(rzn1_adc, chan); + if (ret) + return ret; + + ret = rzn1_adc_vc_wait_conversion(rzn1_adc, chan, adc1_data, adc2_data); + if (ret) { + rzn1_adc_vc_stop_conversion(rzn1_adc, chan); + return ret; + } + } + + *val = adc_data; + ret = IIO_VAL_INT; + + return 0; +} + +static int rzn1_adc_get_vref_mV(struct rzn1_adc *rzn1_adc, unsigned int chan) +{ + /* chan 0..7 use ADC1 ch 0..7. Vref related to ADC1 core */ + if (chan < 8) + return rzn1_adc->adc1_vref_mV; + + /* chan 8..15 use ADC2 ch 0..7. Vref related to ADC2 core */ + if (chan < 16) + return rzn1_adc->adc2_vref_mV; + + return -EINVAL; +} + +static int rzn1_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct rzn1_adc *rzn1_adc = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = rzn1_adc_read_raw_ch(rzn1_adc, chan->channel, val); + if (ret) + return ret; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + ret = rzn1_adc_get_vref_mV(rzn1_adc, chan->channel); + if (ret < 0) + return ret; + *val = ret; + *val2 = 12; + return IIO_VAL_FRACTIONAL_LOG2; + + default: + return -EINVAL; + } +} + +static const struct iio_info rzn1_adc_info = { + .read_raw = &rzn1_adc_read_raw, +}; + +static int rzn1_adc_set_iio_dev_channels(struct rzn1_adc *rzn1_adc, + struct iio_dev *indio_dev) +{ + /* + * When an ADC core is not used, its related vref_mV is set to a + * negative error code. Use the correct IIO channels table based on + * those vref_mV values. + */ + if (rzn1_adc->adc1_vref_mV >= 0) { + if (rzn1_adc->adc2_vref_mV >= 0) { + indio_dev->channels = rzn1_adc1_adc2_channels; + indio_dev->num_channels = ARRAY_SIZE(rzn1_adc1_adc2_channels); + } else { + indio_dev->channels = rzn1_adc1_channels; + indio_dev->num_channels = ARRAY_SIZE(rzn1_adc1_channels); + } + return 0; + } + + if (rzn1_adc->adc2_vref_mV >= 0) { + indio_dev->channels = rzn1_adc2_channels; + indio_dev->num_channels = ARRAY_SIZE(rzn1_adc2_channels); + return 0; + } + + return dev_err_probe(rzn1_adc->dev, -ENODEV, + "Failed to set IIO channels, no ADC core used\n"); +} + +static int rzn1_adc_core_get_regulators(struct rzn1_adc *rzn1_adc, + int *adc_vref_mV, + const char *avdd_name, const char *vref_name) +{ + struct device *dev = rzn1_adc->dev; + int ret; + + /* + * For a given ADC core (ADC1 or ADC2), both regulators (AVDD and VREF) + * must be available in order to have the ADC core used. + * + * We use the regulators presence to check the usage of the related + * ADC core. If both regulators are available, the ADC core is used. + * Otherwise, the ADC core is not used. + * + * The adc_vref_mV value is set to a negative error code (-ENODEV) when + * the ADC core is not used. Otherwise it is set to the VRef mV value. + */ + + *adc_vref_mV = -ENODEV; + + ret = devm_regulator_get_enable_optional(dev, avdd_name); + if (ret == -ENODEV) + return 0; + if (ret < 0) + return dev_err_probe(dev, ret, "Failed to get '%s' regulator\n", + avdd_name); + + ret = devm_regulator_get_enable_read_voltage(dev, vref_name); + if (ret == -ENODEV) + return 0; + if (ret < 0) + return dev_err_probe(dev, ret, "Failed to get '%s' regulator\n", + vref_name); + + /* + * Both regulators are available. + * Set adc_vref_mV to the Vref value in mV. This, as the value set is + * positive, also signals that the ADC is used. + */ + *adc_vref_mV = ret / 1000; + + return 0; +} + +static int rzn1_adc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct iio_dev *indio_dev; + struct rzn1_adc *rzn1_adc; + struct clk *clk; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*rzn1_adc)); + if (!indio_dev) + return -ENOMEM; + + rzn1_adc = iio_priv(indio_dev); + rzn1_adc->dev = dev; + + ret = devm_mutex_init(dev, &rzn1_adc->lock); + if (ret) + return ret; + + rzn1_adc->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(rzn1_adc->regs)) + return PTR_ERR(rzn1_adc->regs); + + clk = devm_clk_get_enabled(dev, "pclk"); + if (IS_ERR(clk)) + return dev_err_probe(dev, PTR_ERR(clk), "Failed to get pclk\n"); + + clk = devm_clk_get_enabled(dev, "adc"); + if (IS_ERR(clk)) + return dev_err_probe(dev, PTR_ERR(clk), "Failed to get adc clk\n"); + + ret = rzn1_adc_core_get_regulators(rzn1_adc, &rzn1_adc->adc1_vref_mV, + "adc1-avdd", "adc1-vref"); + if (ret) + return ret; + + ret = rzn1_adc_core_get_regulators(rzn1_adc, &rzn1_adc->adc2_vref_mV, + "adc2-avdd", "adc2-vref"); + if (ret) + return ret; + + platform_set_drvdata(pdev, rzn1_adc); + + indio_dev->name = "rzn1-adc"; + indio_dev->info = &rzn1_adc_info; + indio_dev->modes = INDIO_DIRECT_MODE; + ret = rzn1_adc_set_iio_dev_channels(rzn1_adc, indio_dev); + if (ret) + return ret; + + pm_runtime_set_autosuspend_delay(dev, 500); + pm_runtime_use_autosuspend(dev); + ret = devm_pm_runtime_enable(dev); + if (ret) + return dev_err_probe(dev, ret, "Failed to enable runtime PM\n"); + + return devm_iio_device_register(dev, indio_dev); +} + +static int rzn1_adc_pm_runtime_suspend(struct device *dev) +{ + struct rzn1_adc *rzn1_adc = dev_get_drvdata(dev); + + return rzn1_adc_power(rzn1_adc, false); +} + +static int rzn1_adc_pm_runtime_resume(struct device *dev) +{ + struct rzn1_adc *rzn1_adc = dev_get_drvdata(dev); + + return rzn1_adc_power(rzn1_adc, true); +} + +static DEFINE_RUNTIME_DEV_PM_OPS(rzn1_adc_pm_ops, + rzn1_adc_pm_runtime_suspend, + rzn1_adc_pm_runtime_resume, + NULL); + +static const struct of_device_id rzn1_adc_of_match[] = { + { .compatible = "renesas,rzn1-adc" }, + { } +}; +MODULE_DEVICE_TABLE(of, rzn1_adc_of_match); + +static struct platform_driver rzn1_adc_driver = { + .probe = rzn1_adc_probe, + .driver = { + .name = "rzn1-adc", + .of_match_table = rzn1_adc_of_match, + .pm = pm_ptr(&rzn1_adc_pm_ops), + }, +}; +module_platform_driver(rzn1_adc_driver); + +MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>"); +MODULE_DESCRIPTION("Renesas RZ/N1 ADC Driver"); +MODULE_LICENSE("GPL"); |