From 9bf85fbc9d8f7fe927d47af886846c56ead6d2d3 Mon Sep 17 00:00:00 2001 From: Tomer Maimon Date: Wed, 16 Jan 2019 18:48:55 +0200 Subject: [PATCH] iio: adc: add NPCM ADC driver Add Nuvoton NPCM BMC Analog-to-Digital Converter(ADC) driver. The NPCM ADC is a 10-bit converter for eight channel inputs. Signed-off-by: Tomer Maimon Signed-off-by: Jonathan Cameron --- drivers/iio/adc/Kconfig | 10 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/npcm_adc.c | 335 +++++++++++++++++++++++++++++++++++++ 3 files changed, 346 insertions(+) create mode 100644 drivers/iio/adc/npcm_adc.c diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index f782d81137b3..f9354e5ee65c 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -603,6 +603,16 @@ config NAU7802 To compile this driver as a module, choose M here: the module will be called nau7802. +config NPCM_ADC + tristate "Nuvoton NPCM ADC driver" + depends on ARCH_NPCM || COMPILE_TEST + depends on HAS_IOMEM + help + Say yes here to build support for Nuvoton NPCM ADC. + + This driver can also be built as a module. If so, the module + will be called npcm_adc. + config PALMAS_GPADC tristate "TI Palmas General Purpose ADC" depends on MFD_PALMAS diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 2e7101e8a811..b5d40d000474 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -58,6 +58,7 @@ obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o obj-$(CONFIG_MESON_SARADC) += meson_saradc.o obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o obj-$(CONFIG_NAU7802) += nau7802.o +obj-$(CONFIG_NPCM_ADC) += npcm_adc.o obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o obj-$(CONFIG_QCOM_SPMI_ADC5) += qcom-spmi-adc5.o obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o diff --git a/drivers/iio/adc/npcm_adc.c b/drivers/iio/adc/npcm_adc.c new file mode 100644 index 000000000000..9e25bbec9c70 --- /dev/null +++ b/drivers/iio/adc/npcm_adc.c @@ -0,0 +1,335 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2019 Nuvoton Technology corporation. + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct npcm_adc { + bool int_status; + u32 adc_sample_hz; + struct device *dev; + void __iomem *regs; + struct clk *adc_clk; + wait_queue_head_t wq; + struct regulator *vref; + struct regmap *rst_regmap; +}; + +/* NPCM7xx reset module */ +#define NPCM7XX_IPSRST1_OFFSET 0x020 +#define NPCM7XX_IPSRST1_ADC_RST BIT(27) + +/* ADC registers */ +#define NPCM_ADCCON 0x00 +#define NPCM_ADCDATA 0x04 + +/* ADCCON Register Bits */ +#define NPCM_ADCCON_ADC_INT_EN BIT(21) +#define NPCM_ADCCON_REFSEL BIT(19) +#define NPCM_ADCCON_ADC_INT_ST BIT(18) +#define NPCM_ADCCON_ADC_EN BIT(17) +#define NPCM_ADCCON_ADC_RST BIT(16) +#define NPCM_ADCCON_ADC_CONV BIT(13) + +#define NPCM_ADCCON_CH_MASK GENMASK(27, 24) +#define NPCM_ADCCON_CH(x) ((x) << 24) +#define NPCM_ADCCON_DIV_SHIFT 1 +#define NPCM_ADCCON_DIV_MASK GENMASK(8, 1) +#define NPCM_ADC_DATA_MASK(x) ((x) & GENMASK(9, 0)) + +#define NPCM_ADC_ENABLE (NPCM_ADCCON_ADC_EN | NPCM_ADCCON_ADC_INT_EN) + +/* ADC General Definition */ +#define NPCM_RESOLUTION_BITS 10 +#define NPCM_INT_VREF_MV 2000 + +#define NPCM_ADC_CHAN(ch) { \ + .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) | \ + BIT(IIO_CHAN_INFO_SAMP_FREQ), \ +} + +static const struct iio_chan_spec npcm_adc_iio_channels[] = { + NPCM_ADC_CHAN(0), + NPCM_ADC_CHAN(1), + NPCM_ADC_CHAN(2), + NPCM_ADC_CHAN(3), + NPCM_ADC_CHAN(4), + NPCM_ADC_CHAN(5), + NPCM_ADC_CHAN(6), + NPCM_ADC_CHAN(7), +}; + +static irqreturn_t npcm_adc_isr(int irq, void *data) +{ + u32 regtemp; + struct iio_dev *indio_dev = data; + struct npcm_adc *info = iio_priv(indio_dev); + + regtemp = ioread32(info->regs + NPCM_ADCCON); + if (regtemp & NPCM_ADCCON_ADC_INT_ST) { + iowrite32(regtemp, info->regs + NPCM_ADCCON); + wake_up_interruptible(&info->wq); + info->int_status = true; + } + + return IRQ_HANDLED; +} + +static int npcm_adc_read(struct npcm_adc *info, int *val, u8 channel) +{ + int ret; + u32 regtemp; + + /* Select ADC channel */ + regtemp = ioread32(info->regs + NPCM_ADCCON); + regtemp &= ~NPCM_ADCCON_CH_MASK; + info->int_status = false; + iowrite32(regtemp | NPCM_ADCCON_CH(channel) | + NPCM_ADCCON_ADC_CONV, info->regs + NPCM_ADCCON); + + ret = wait_event_interruptible_timeout(info->wq, info->int_status, + msecs_to_jiffies(10)); + if (ret == 0) { + regtemp = ioread32(info->regs + NPCM_ADCCON); + if ((regtemp & NPCM_ADCCON_ADC_CONV) && info->rst_regmap) { + /* if conversion failed - reset ADC module */ + regmap_write(info->rst_regmap, NPCM7XX_IPSRST1_OFFSET, + NPCM7XX_IPSRST1_ADC_RST); + msleep(100); + regmap_write(info->rst_regmap, NPCM7XX_IPSRST1_OFFSET, + 0x0); + msleep(100); + + /* Enable ADC and start conversion module */ + iowrite32(NPCM_ADC_ENABLE | NPCM_ADCCON_ADC_CONV, + info->regs + NPCM_ADCCON); + dev_err(info->dev, "RESET ADC Complete\n"); + } + return -ETIMEDOUT; + } + if (ret < 0) + return ret; + + *val = NPCM_ADC_DATA_MASK(ioread32(info->regs + NPCM_ADCDATA)); + + return 0; +} + +static int npcm_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, + int *val2, long mask) +{ + int ret; + int vref_uv; + struct npcm_adc *info = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&indio_dev->mlock); + ret = npcm_adc_read(info, val, chan->channel); + mutex_unlock(&indio_dev->mlock); + if (ret) { + dev_err(info->dev, "NPCM ADC read failed\n"); + return ret; + } + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + if (info->vref) { + vref_uv = regulator_get_voltage(info->vref); + *val = vref_uv / 1000; + } else { + *val = NPCM_INT_VREF_MV; + } + *val2 = NPCM_RESOLUTION_BITS; + return IIO_VAL_FRACTIONAL_LOG2; + case IIO_CHAN_INFO_SAMP_FREQ: + *val = info->adc_sample_hz; + return IIO_VAL_INT; + default: + return -EINVAL; + } + + return 0; +} + +static const struct iio_info npcm_adc_iio_info = { + .read_raw = &npcm_adc_read_raw, +}; + +static const struct of_device_id npcm_adc_match[] = { + { .compatible = "nuvoton,npcm750-adc", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, npcm_adc_match); + +static int npcm_adc_probe(struct platform_device *pdev) +{ + int ret; + int irq; + u32 div; + u32 reg_con; + struct resource *res; + struct npcm_adc *info; + struct iio_dev *indio_dev; + struct device *dev = &pdev->dev; + struct device_node *np = pdev->dev.of_node; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info)); + if (!indio_dev) + return -ENOMEM; + info = iio_priv(indio_dev); + + info->dev = &pdev->dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + info->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(info->regs)) + return PTR_ERR(info->regs); + + info->adc_clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(info->adc_clk)) { + dev_warn(&pdev->dev, "ADC clock failed: can't read clk\n"); + return PTR_ERR(info->adc_clk); + } + + /* calculate ADC clock sample rate */ + reg_con = ioread32(info->regs + NPCM_ADCCON); + div = reg_con & NPCM_ADCCON_DIV_MASK; + div = div >> NPCM_ADCCON_DIV_SHIFT; + info->adc_sample_hz = clk_get_rate(info->adc_clk) / ((div + 1) * 2); + + if (of_device_is_compatible(np, "nuvoton,npcm750-adc")) { + info->rst_regmap = syscon_regmap_lookup_by_compatible + ("nuvoton,npcm750-rst"); + if (IS_ERR(info->rst_regmap)) { + dev_err(&pdev->dev, "Failed to find nuvoton,npcm750-rst\n"); + ret = PTR_ERR(info->rst_regmap); + goto err_disable_clk; + } + } + + irq = platform_get_irq(pdev, 0); + if (irq <= 0) { + dev_err(dev, "failed getting interrupt resource\n"); + ret = -EINVAL; + goto err_disable_clk; + } + + ret = devm_request_irq(&pdev->dev, irq, npcm_adc_isr, 0, + "NPCM_ADC", indio_dev); + if (ret < 0) { + dev_err(dev, "failed requesting interrupt\n"); + goto err_disable_clk; + } + + reg_con = ioread32(info->regs + NPCM_ADCCON); + info->vref = devm_regulator_get_optional(&pdev->dev, "vref"); + if (!IS_ERR(info->vref)) { + ret = regulator_enable(info->vref); + if (ret) { + dev_err(&pdev->dev, "Can't enable ADC reference voltage\n"); + goto err_disable_clk; + } + + iowrite32(reg_con & ~NPCM_ADCCON_REFSEL, + info->regs + NPCM_ADCCON); + } else { + /* + * Any error which is not ENODEV indicates the regulator + * has been specified and so is a failure case. + */ + if (PTR_ERR(info->vref) != -ENODEV) { + ret = PTR_ERR(info->vref); + goto err_disable_clk; + } + + /* Use internal reference */ + iowrite32(reg_con | NPCM_ADCCON_REFSEL, + info->regs + NPCM_ADCCON); + } + + init_waitqueue_head(&info->wq); + + reg_con = ioread32(info->regs + NPCM_ADCCON); + reg_con |= NPCM_ADC_ENABLE; + + /* Enable the ADC Module */ + iowrite32(reg_con, info->regs + NPCM_ADCCON); + + /* Start ADC conversion */ + iowrite32(reg_con | NPCM_ADCCON_ADC_CONV, info->regs + NPCM_ADCCON); + + platform_set_drvdata(pdev, indio_dev); + indio_dev->name = dev_name(&pdev->dev); + indio_dev->dev.parent = &pdev->dev; + indio_dev->info = &npcm_adc_iio_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = npcm_adc_iio_channels; + indio_dev->num_channels = ARRAY_SIZE(npcm_adc_iio_channels); + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(&pdev->dev, "Couldn't register the device.\n"); + goto err_iio_register; + } + + pr_info("NPCM ADC driver probed\n"); + + return 0; + +err_iio_register: + iowrite32(reg_con & ~NPCM_ADCCON_ADC_EN, info->regs + NPCM_ADCCON); + if (!IS_ERR(info->vref)) + regulator_disable(info->vref); +err_disable_clk: + clk_disable_unprepare(info->adc_clk); + + return ret; +} + +static int npcm_adc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct npcm_adc *info = iio_priv(indio_dev); + u32 regtemp; + + iio_device_unregister(indio_dev); + + regtemp = ioread32(info->regs + NPCM_ADCCON); + iowrite32(regtemp & ~NPCM_ADCCON_ADC_EN, info->regs + NPCM_ADCCON); + if (!IS_ERR(info->vref)) + regulator_disable(info->vref); + clk_disable_unprepare(info->adc_clk); + + return 0; +} + +static struct platform_driver npcm_adc_driver = { + .probe = npcm_adc_probe, + .remove = npcm_adc_remove, + .driver = { + .name = "npcm_adc", + .of_match_table = npcm_adc_match, + }, +}; + +module_platform_driver(npcm_adc_driver); + +MODULE_DESCRIPTION("Nuvoton NPCM ADC Driver"); +MODULE_AUTHOR("Tomer Maimon "); +MODULE_LICENSE("GPL v2"); -- 2.30.2