--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * NXP i.MX93 ADC driver
+ *
+ * Copyright 2023 NXP
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/err.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/regulator/consumer.h>
+
+#define IMX93_ADC_DRIVER_NAME "imx93-adc"
+
+/* Register map definition */
+#define IMX93_ADC_MCR 0x00
+#define IMX93_ADC_MSR 0x04
+#define IMX93_ADC_ISR 0x10
+#define IMX93_ADC_IMR 0x20
+#define IMX93_ADC_CIMR0 0x24
+#define IMX93_ADC_CTR0 0x94
+#define IMX93_ADC_NCMR0 0xA4
+#define IMX93_ADC_PCDR0 0x100
+#define IMX93_ADC_PCDR1 0x104
+#define IMX93_ADC_PCDR2 0x108
+#define IMX93_ADC_PCDR3 0x10c
+#define IMX93_ADC_PCDR4 0x110
+#define IMX93_ADC_PCDR5 0x114
+#define IMX93_ADC_PCDR6 0x118
+#define IMX93_ADC_PCDR7 0x11c
+#define IMX93_ADC_CALSTAT 0x39C
+
+/* ADC bit shift */
+#define IMX93_ADC_MCR_MODE_MASK BIT(29)
+#define IMX93_ADC_MCR_NSTART_MASK BIT(24)
+#define IMX93_ADC_MCR_CALSTART_MASK BIT(14)
+#define IMX93_ADC_MCR_ADCLKSE_MASK BIT(8)
+#define IMX93_ADC_MCR_PWDN_MASK BIT(0)
+#define IMX93_ADC_MSR_CALFAIL_MASK BIT(30)
+#define IMX93_ADC_MSR_CALBUSY_MASK BIT(29)
+#define IMX93_ADC_MSR_ADCSTATUS_MASK GENMASK(2, 0)
+#define IMX93_ADC_ISR_ECH_MASK BIT(0)
+#define IMX93_ADC_ISR_EOC_MASK BIT(1)
+#define IMX93_ADC_ISR_EOC_ECH_MASK (IMX93_ADC_ISR_EOC_MASK | \
+ IMX93_ADC_ISR_ECH_MASK)
+#define IMX93_ADC_IMR_JEOC_MASK BIT(3)
+#define IMX93_ADC_IMR_JECH_MASK BIT(2)
+#define IMX93_ADC_IMR_EOC_MASK BIT(1)
+#define IMX93_ADC_IMR_ECH_MASK BIT(0)
+#define IMX93_ADC_PCDR_CDATA_MASK GENMASK(11, 0)
+
+/* ADC status */
+#define IMX93_ADC_MSR_ADCSTATUS_IDLE 0
+#define IMX93_ADC_MSR_ADCSTATUS_POWER_DOWN 1
+#define IMX93_ADC_MSR_ADCSTATUS_WAIT_STATE 2
+#define IMX93_ADC_MSR_ADCSTATUS_BUSY_IN_CALIBRATION 3
+#define IMX93_ADC_MSR_ADCSTATUS_SAMPLE 4
+#define IMX93_ADC_MSR_ADCSTATUS_CONVERSION 6
+
+#define IMX93_ADC_TIMEOUT msecs_to_jiffies(100)
+
+struct imx93_adc {
+ struct device *dev;
+ void __iomem *regs;
+ struct clk *ipg_clk;
+ int irq;
+ struct regulator *vref;
+ /* lock to protect against multiple access to the device */
+ struct mutex lock;
+ struct completion completion;
+};
+
+#define IMX93_ADC_CHAN(_idx) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = (_idx), \
+ .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 imx93_adc_iio_channels[] = {
+ IMX93_ADC_CHAN(0),
+ IMX93_ADC_CHAN(1),
+ IMX93_ADC_CHAN(2),
+ IMX93_ADC_CHAN(3),
+};
+
+static void imx93_adc_power_down(struct imx93_adc *adc)
+{
+ u32 mcr, msr;
+ int ret;
+
+ mcr = readl(adc->regs + IMX93_ADC_MCR);
+ mcr |= FIELD_PREP(IMX93_ADC_MCR_PWDN_MASK, 1);
+ writel(mcr, adc->regs + IMX93_ADC_MCR);
+
+ ret = readl_poll_timeout(adc->regs + IMX93_ADC_MSR, msr,
+ ((msr & IMX93_ADC_MSR_ADCSTATUS_MASK) ==
+ IMX93_ADC_MSR_ADCSTATUS_POWER_DOWN),
+ 1, 50);
+ if (ret == -ETIMEDOUT)
+ dev_warn(adc->dev,
+ "ADC do not in power down mode, current MSR is %x\n",
+ msr);
+}
+
+static void imx93_adc_power_up(struct imx93_adc *adc)
+{
+ u32 mcr;
+
+ /* bring ADC out of power down state, in idle state */
+ mcr = readl(adc->regs + IMX93_ADC_MCR);
+ mcr &= ~FIELD_PREP(IMX93_ADC_MCR_PWDN_MASK, 1);
+ writel(mcr, adc->regs + IMX93_ADC_MCR);
+}
+
+static void imx93_adc_config_ad_clk(struct imx93_adc *adc)
+{
+ u32 mcr;
+
+ /* put adc in power down mode */
+ imx93_adc_power_down(adc);
+
+ /* config the AD_CLK equal to bus clock */
+ mcr = readl(adc->regs + IMX93_ADC_MCR);
+ mcr |= FIELD_PREP(IMX93_ADC_MCR_ADCLKSE_MASK, 1);
+ writel(mcr, adc->regs + IMX93_ADC_MCR);
+
+ imx93_adc_power_up(adc);
+}
+
+static int imx93_adc_calibration(struct imx93_adc *adc)
+{
+ u32 mcr, msr;
+ int ret;
+
+ /* make sure ADC in power down mode */
+ imx93_adc_power_down(adc);
+
+ /* config SAR controller operating clock */
+ mcr = readl(adc->regs + IMX93_ADC_MCR);
+ mcr &= ~FIELD_PREP(IMX93_ADC_MCR_ADCLKSE_MASK, 1);
+ writel(mcr, adc->regs + IMX93_ADC_MCR);
+
+ imx93_adc_power_up(adc);
+
+ /*
+ * TODO: we use the default TSAMP/NRSMPL/AVGEN in MCR,
+ * can add the setting of these bit if need in future.
+ */
+
+ /* run calibration */
+ mcr = readl(adc->regs + IMX93_ADC_MCR);
+ mcr |= FIELD_PREP(IMX93_ADC_MCR_CALSTART_MASK, 1);
+ writel(mcr, adc->regs + IMX93_ADC_MCR);
+
+ /* wait calibration to be finished */
+ ret = readl_poll_timeout(adc->regs + IMX93_ADC_MSR, msr,
+ !(msr & IMX93_ADC_MSR_CALBUSY_MASK), 1000, 2000000);
+ if (ret == -ETIMEDOUT) {
+ dev_warn(adc->dev, "ADC do not finish calibration in 2 min!\n");
+ imx93_adc_power_down(adc);
+ return ret;
+ }
+
+ /* check whether calbration is success or not */
+ msr = readl(adc->regs + IMX93_ADC_MSR);
+ if (msr & IMX93_ADC_MSR_CALFAIL_MASK) {
+ dev_warn(adc->dev, "ADC calibration failed!\n");
+ imx93_adc_power_down(adc);
+ return -EAGAIN;
+ }
+
+ return 0;
+}
+
+static int imx93_adc_read_channel_conversion(struct imx93_adc *adc,
+ int channel_number,
+ int *result)
+{
+ u32 channel;
+ u32 imr, mcr, pcda;
+ long ret;
+
+ reinit_completion(&adc->completion);
+
+ /* config channel mask register */
+ channel = 1 << channel_number;
+ writel(channel, adc->regs + IMX93_ADC_NCMR0);
+
+ /* TODO: can config desired sample time in CTRn if need */
+
+ /* config interrupt mask */
+ imr = FIELD_PREP(IMX93_ADC_IMR_EOC_MASK, 1);
+ writel(imr, adc->regs + IMX93_ADC_IMR);
+ writel(channel, adc->regs + IMX93_ADC_CIMR0);
+
+ /* config one-shot mode */
+ mcr = readl(adc->regs + IMX93_ADC_MCR);
+ mcr &= ~FIELD_PREP(IMX93_ADC_MCR_MODE_MASK, 1);
+ writel(mcr, adc->regs + IMX93_ADC_MCR);
+
+ /* start normal conversion */
+ mcr = readl(adc->regs + IMX93_ADC_MCR);
+ mcr |= FIELD_PREP(IMX93_ADC_MCR_NSTART_MASK, 1);
+ writel(mcr, adc->regs + IMX93_ADC_MCR);
+
+ ret = wait_for_completion_interruptible_timeout(&adc->completion,
+ IMX93_ADC_TIMEOUT);
+ if (ret == 0)
+ return -ETIMEDOUT;
+
+ if (ret < 0)
+ return ret;
+
+ pcda = readl(adc->regs + IMX93_ADC_PCDR0 + channel_number * 4);
+
+ *result = FIELD_GET(IMX93_ADC_PCDR_CDATA_MASK, pcda);
+
+ return ret;
+}
+
+static int imx93_adc_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct imx93_adc *adc = iio_priv(indio_dev);
+ struct device *dev = adc->dev;
+ long ret;
+ u32 vref_uv;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ pm_runtime_get_sync(dev);
+ mutex_lock(&adc->lock);
+ ret = imx93_adc_read_channel_conversion(adc, chan->channel, val);
+ mutex_unlock(&adc->lock);
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_sync_autosuspend(dev);
+ if (ret < 0)
+ return ret;
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ ret = vref_uv = regulator_get_voltage(adc->vref);
+ if (ret < 0)
+ return ret;
+ *val = vref_uv / 1000;
+ *val2 = 12;
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = clk_get_rate(adc->ipg_clk);
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static irqreturn_t imx93_adc_isr(int irq, void *dev_id)
+{
+ struct imx93_adc *adc = dev_id;
+ u32 isr, eoc, unexpected;
+
+ isr = readl(adc->regs + IMX93_ADC_ISR);
+
+ if (FIELD_GET(IMX93_ADC_ISR_EOC_ECH_MASK, isr)) {
+ eoc = isr & IMX93_ADC_ISR_EOC_ECH_MASK;
+ writel(eoc, adc->regs + IMX93_ADC_ISR);
+ complete(&adc->completion);
+ }
+
+ unexpected = isr & ~IMX93_ADC_ISR_EOC_ECH_MASK;
+ if (unexpected) {
+ writel(unexpected, adc->regs + IMX93_ADC_ISR);
+ dev_err(adc->dev, "Unexpected interrupt 0x%08x.\n", unexpected);
+ return IRQ_NONE;
+ }
+
+ return IRQ_HANDLED;
+}
+
+static const struct iio_info imx93_adc_iio_info = {
+ .read_raw = &imx93_adc_read_raw,
+};
+
+static int imx93_adc_probe(struct platform_device *pdev)
+{
+ struct imx93_adc *adc;
+ struct iio_dev *indio_dev;
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
+ if (!indio_dev)
+ return dev_err_probe(dev, -ENOMEM,
+ "Failed allocating iio device\n");
+
+ adc = iio_priv(indio_dev);
+ adc->dev = dev;
+
+ mutex_init(&adc->lock);
+ adc->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(adc->regs))
+ return dev_err_probe(dev, PTR_ERR(adc->regs),
+ "Failed geting ioremap resource\n");
+
+ /* The third irq is for ADC conversion usage */
+ adc->irq = platform_get_irq(pdev, 2);
+ if (adc->irq < 0)
+ return adc->irq;
+
+ adc->ipg_clk = devm_clk_get(dev, "ipg");
+ if (IS_ERR(adc->ipg_clk))
+ return dev_err_probe(dev, PTR_ERR(adc->ipg_clk),
+ "Failed getting clock.\n");
+
+ adc->vref = devm_regulator_get(dev, "vref");
+ if (IS_ERR(adc->vref))
+ return dev_err_probe(dev, PTR_ERR(adc->vref),
+ "Failed getting reference voltage.\n");
+
+ ret = regulator_enable(adc->vref);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to enable reference voltage.\n");
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ init_completion(&adc->completion);
+
+ indio_dev->name = "imx93-adc";
+ indio_dev->info = &imx93_adc_iio_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = imx93_adc_iio_channels;
+ indio_dev->num_channels = ARRAY_SIZE(imx93_adc_iio_channels);
+
+ ret = clk_prepare_enable(adc->ipg_clk);
+ if (ret) {
+ dev_err_probe(dev, ret,
+ "Failed to enable ipg clock.\n");
+ goto error_regulator_disable;
+ }
+
+ ret = request_irq(adc->irq, imx93_adc_isr, 0, IMX93_ADC_DRIVER_NAME, adc);
+ if (ret < 0) {
+ dev_err_probe(dev, ret,
+ "Failed requesting irq, irq = %d\n", adc->irq);
+ goto error_ipg_clk_disable;
+ }
+
+ ret = imx93_adc_calibration(adc);
+ if (ret < 0)
+ goto error_free_adc_irq;
+
+ imx93_adc_config_ad_clk(adc);
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ dev_err_probe(dev, ret,
+ "Failed to register this iio device.\n");
+ goto error_adc_power_down;
+ }
+
+ pm_runtime_set_active(dev);
+ pm_runtime_set_autosuspend_delay(dev, 50);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_enable(dev);
+
+ return 0;
+
+error_adc_power_down:
+ imx93_adc_power_down(adc);
+error_free_adc_irq:
+ free_irq(adc->irq, adc);
+error_ipg_clk_disable:
+ clk_disable_unprepare(adc->ipg_clk);
+error_regulator_disable:
+ regulator_disable(adc->vref);
+
+ return ret;
+}
+
+static int imx93_adc_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct imx93_adc *adc = iio_priv(indio_dev);
+ struct device *dev = adc->dev;
+
+ /* adc power down need clock on */
+ pm_runtime_get_sync(dev);
+
+ pm_runtime_disable(dev);
+ pm_runtime_dont_use_autosuspend(dev);
+ pm_runtime_put_noidle(dev);
+
+ iio_device_unregister(indio_dev);
+ imx93_adc_power_down(adc);
+ free_irq(adc->irq, adc);
+ clk_disable_unprepare(adc->ipg_clk);
+ regulator_disable(adc->vref);
+
+ return 0;
+}
+
+static int imx93_adc_runtime_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct imx93_adc *adc = iio_priv(indio_dev);
+
+ imx93_adc_power_down(adc);
+ clk_disable_unprepare(adc->ipg_clk);
+ regulator_disable(adc->vref);
+
+ return 0;
+}
+
+static int imx93_adc_runtime_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct imx93_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ ret = regulator_enable(adc->vref);
+ if (ret) {
+ dev_err(dev,
+ "Can't enable adc reference top voltage, err = %d\n",
+ ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(adc->ipg_clk);
+ if (ret) {
+ dev_err(dev, "Could not prepare or enable clock.\n");
+ goto err_disable_reg;
+ }
+
+ imx93_adc_power_up(adc);
+
+ return 0;
+
+err_disable_reg:
+ regulator_disable(adc->vref);
+
+ return ret;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(imx93_adc_pm_ops,
+ imx93_adc_runtime_suspend,
+ imx93_adc_runtime_resume, NULL);
+
+static const struct of_device_id imx93_adc_match[] = {
+ { .compatible = "nxp,imx93-adc", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx93_adc_match);
+
+static struct platform_driver imx93_adc_driver = {
+ .probe = imx93_adc_probe,
+ .remove = imx93_adc_remove,
+ .driver = {
+ .name = IMX93_ADC_DRIVER_NAME,
+ .of_match_table = imx93_adc_match,
+ .pm = pm_ptr(&imx93_adc_pm_ops),
+ },
+};
+
+module_platform_driver(imx93_adc_driver);
+
+MODULE_DESCRIPTION("NXP i.MX93 ADC driver");
+MODULE_AUTHOR("Haibo Chen <haibo.chen@nxp.com>");
+MODULE_LICENSE("GPL");
projects / linux.git / commitdiff