1 files changed, 602 insertions, 0 deletions

diff --git a/drivers/iio/adc/rzg2l_adc.c b/drivers/iio/adc/rzg2l_adc.c
new file mode 100644
index 000000000..0921ff2d9
--- /dev/null
+++ b/drivers/iio/adc/rzg2l_adc.c
@@ -0,0 +1,602 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RZ/G2L A/D Converter driver
+ *
+ *  Copyright (c) 2021 Renesas Electronics Europe GmbH
+ *
+ * Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/reset.h>
+
+#define DRIVER_NAME		"rzg2l-adc"
+
+#define RZG2L_ADM(n)			((n) * 0x4)
+#define RZG2L_ADM0_ADCE			BIT(0)
+#define RZG2L_ADM0_ADBSY		BIT(1)
+#define RZG2L_ADM0_PWDWNB		BIT(2)
+#define RZG2L_ADM0_SRESB		BIT(15)
+#define RZG2L_ADM1_TRG			BIT(0)
+#define RZG2L_ADM1_MS			BIT(2)
+#define RZG2L_ADM1_BS			BIT(4)
+#define RZG2L_ADM1_EGA_MASK		GENMASK(13, 12)
+#define RZG2L_ADM2_CHSEL_MASK		GENMASK(7, 0)
+#define RZG2L_ADM3_ADIL_MASK		GENMASK(31, 24)
+#define RZG2L_ADM3_ADCMP_MASK		GENMASK(23, 16)
+#define RZG2L_ADM3_ADCMP_E		FIELD_PREP(RZG2L_ADM3_ADCMP_MASK, 0xe)
+#define RZG2L_ADM3_ADSMP_MASK		GENMASK(15, 0)
+
+#define RZG2L_ADINT			0x20
+#define RZG2L_ADINT_INTEN_MASK		GENMASK(7, 0)
+#define RZG2L_ADINT_CSEEN		BIT(16)
+#define RZG2L_ADINT_INTS		BIT(31)
+
+#define RZG2L_ADSTS			0x24
+#define RZG2L_ADSTS_CSEST		BIT(16)
+#define RZG2L_ADSTS_INTST_MASK		GENMASK(7, 0)
+
+#define RZG2L_ADIVC			0x28
+#define RZG2L_ADIVC_DIVADC_MASK		GENMASK(8, 0)
+#define RZG2L_ADIVC_DIVADC_4		FIELD_PREP(RZG2L_ADIVC_DIVADC_MASK, 0x4)
+
+#define RZG2L_ADFIL			0x2c
+
+#define RZG2L_ADCR(n)			(0x30 + ((n) * 0x4))
+#define RZG2L_ADCR_AD_MASK		GENMASK(11, 0)
+
+#define RZG2L_ADSMP_DEFAULT_SAMPLING	0x578
+
+#define RZG2L_ADC_MAX_CHANNELS		8
+#define RZG2L_ADC_CHN_MASK		0x7
+#define RZG2L_ADC_TIMEOUT		usecs_to_jiffies(1 * 4)
+
+struct rzg2l_adc_data {
+	const struct iio_chan_spec *channels;
+	u8 num_channels;
+};
+
+struct rzg2l_adc {
+	void __iomem *base;
+	struct clk *pclk;
+	struct clk *adclk;
+	struct reset_control *presetn;
+	struct reset_control *adrstn;
+	struct completion completion;
+	const struct rzg2l_adc_data *data;
+	struct mutex lock;
+	u16 last_val[RZG2L_ADC_MAX_CHANNELS];
+};
+
+static const char * const rzg2l_adc_channel_name[] = {
+	"adc0",
+	"adc1",
+	"adc2",
+	"adc3",
+	"adc4",
+	"adc5",
+	"adc6",
+	"adc7",
+};
+
+static unsigned int rzg2l_adc_readl(struct rzg2l_adc *adc, u32 reg)
+{
+	return readl(adc->base + reg);
+}
+
+static void rzg2l_adc_writel(struct rzg2l_adc *adc, unsigned int reg, u32 val)
+{
+	writel(val, adc->base + reg);
+}
+
+static void rzg2l_adc_pwr(struct rzg2l_adc *adc, bool on)
+{
+	u32 reg;
+
+	reg = rzg2l_adc_readl(adc, RZG2L_ADM(0));
+	if (on)
+		reg |= RZG2L_ADM0_PWDWNB;
+	else
+		reg &= ~RZG2L_ADM0_PWDWNB;
+	rzg2l_adc_writel(adc, RZG2L_ADM(0), reg);
+	udelay(2);
+}
+
+static void rzg2l_adc_start_stop(struct rzg2l_adc *adc, bool start)
+{
+	int timeout = 5;
+	u32 reg;
+
+	reg = rzg2l_adc_readl(adc, RZG2L_ADM(0));
+	if (start)
+		reg |= RZG2L_ADM0_ADCE;
+	else
+		reg &= ~RZG2L_ADM0_ADCE;
+	rzg2l_adc_writel(adc, RZG2L_ADM(0), reg);
+
+	if (start)
+		return;
+
+	do {
+		usleep_range(100, 200);
+		reg = rzg2l_adc_readl(adc, RZG2L_ADM(0));
+		timeout--;
+		if (!timeout) {
+			pr_err("%s stopping ADC timed out\n", __func__);
+			break;
+		}
+	} while (((reg & RZG2L_ADM0_ADBSY) || (reg & RZG2L_ADM0_ADCE)));
+}
+
+static void rzg2l_set_trigger(struct rzg2l_adc *adc)
+{
+	u32 reg;
+
+	/*
+	 * Setup ADM1 for SW trigger
+	 * EGA[13:12] - Set 00 to indicate hardware trigger is invalid
+	 * BS[4] - Enable 1-buffer mode
+	 * MS[1] - Enable Select mode
+	 * TRG[0] - Enable software trigger mode
+	 */
+	reg = rzg2l_adc_readl(adc, RZG2L_ADM(1));
+	reg &= ~RZG2L_ADM1_EGA_MASK;
+	reg &= ~RZG2L_ADM1_BS;
+	reg &= ~RZG2L_ADM1_TRG;
+	reg |= RZG2L_ADM1_MS;
+	rzg2l_adc_writel(adc, RZG2L_ADM(1), reg);
+}
+
+static int rzg2l_adc_conversion_setup(struct rzg2l_adc *adc, u8 ch)
+{
+	u32 reg;
+
+	if (rzg2l_adc_readl(adc, RZG2L_ADM(0)) & RZG2L_ADM0_ADBSY)
+		return -EBUSY;
+
+	rzg2l_set_trigger(adc);
+
+	/* Select analog input channel subjected to conversion. */
+	reg = rzg2l_adc_readl(adc, RZG2L_ADM(2));
+	reg &= ~RZG2L_ADM2_CHSEL_MASK;
+	reg |= BIT(ch);
+	rzg2l_adc_writel(adc, RZG2L_ADM(2), reg);
+
+	/*
+	 * Setup ADINT
+	 * INTS[31] - Select pulse signal
+	 * CSEEN[16] - Enable channel select error interrupt
+	 * INTEN[7:0] - Select channel interrupt
+	 */
+	reg = rzg2l_adc_readl(adc, RZG2L_ADINT);
+	reg &= ~RZG2L_ADINT_INTS;
+	reg &= ~RZG2L_ADINT_INTEN_MASK;
+	reg |= (RZG2L_ADINT_CSEEN | BIT(ch));
+	rzg2l_adc_writel(adc, RZG2L_ADINT, reg);
+
+	return 0;
+}
+
+static int rzg2l_adc_set_power(struct iio_dev *indio_dev, bool on)
+{
+	struct device *dev = indio_dev->dev.parent;
+
+	if (on)
+		return pm_runtime_resume_and_get(dev);
+
+	return pm_runtime_put_sync(dev);
+}
+
+static int rzg2l_adc_conversion(struct iio_dev *indio_dev, struct rzg2l_adc *adc, u8 ch)
+{
+	int ret;
+
+	ret = rzg2l_adc_set_power(indio_dev, true);
+	if (ret)
+		return ret;
+
+	ret = rzg2l_adc_conversion_setup(adc, ch);
+	if (ret) {
+		rzg2l_adc_set_power(indio_dev, false);
+		return ret;
+	}
+
+	reinit_completion(&adc->completion);
+
+	rzg2l_adc_start_stop(adc, true);
+
+	if (!wait_for_completion_timeout(&adc->completion, RZG2L_ADC_TIMEOUT)) {
+		rzg2l_adc_writel(adc, RZG2L_ADINT,
+				 rzg2l_adc_readl(adc, RZG2L_ADINT) & ~RZG2L_ADINT_INTEN_MASK);
+		rzg2l_adc_start_stop(adc, false);
+		rzg2l_adc_set_power(indio_dev, false);
+		return -ETIMEDOUT;
+	}
+
+	return rzg2l_adc_set_power(indio_dev, false);
+}
+
+static int rzg2l_adc_read_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int *val, int *val2, long mask)
+{
+	struct rzg2l_adc *adc = iio_priv(indio_dev);
+	int ret;
+	u8 ch;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (chan->type != IIO_VOLTAGE)
+			return -EINVAL;
+
+		mutex_lock(&adc->lock);
+		ch = chan->channel & RZG2L_ADC_CHN_MASK;
+		ret = rzg2l_adc_conversion(indio_dev, adc, ch);
+		if (ret) {
+			mutex_unlock(&adc->lock);
+			return ret;
+		}
+		*val = adc->last_val[ch];
+		mutex_unlock(&adc->lock);
+
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int rzg2l_adc_read_label(struct iio_dev *iio_dev,
+				const struct iio_chan_spec *chan,
+				char *label)
+{
+	return sysfs_emit(label, "%s\n", rzg2l_adc_channel_name[chan->channel]);
+}
+
+static const struct iio_info rzg2l_adc_iio_info = {
+	.read_raw = rzg2l_adc_read_raw,
+	.read_label = rzg2l_adc_read_label,
+};
+
+static irqreturn_t rzg2l_adc_isr(int irq, void *dev_id)
+{
+	struct rzg2l_adc *adc = dev_id;
+	unsigned long intst;
+	u32 reg;
+	int ch;
+
+	reg = rzg2l_adc_readl(adc, RZG2L_ADSTS);
+
+	/* A/D conversion channel select error interrupt */
+	if (reg & RZG2L_ADSTS_CSEST) {
+		rzg2l_adc_writel(adc, RZG2L_ADSTS, reg);
+		return IRQ_HANDLED;
+	}
+
+	intst = reg & RZG2L_ADSTS_INTST_MASK;
+	if (!intst)
+		return IRQ_NONE;
+
+	for_each_set_bit(ch, &intst, RZG2L_ADC_MAX_CHANNELS)
+		adc->last_val[ch] = rzg2l_adc_readl(adc, RZG2L_ADCR(ch)) & RZG2L_ADCR_AD_MASK;
+
+	/* clear the channel interrupt */
+	rzg2l_adc_writel(adc, RZG2L_ADSTS, reg);
+
+	complete(&adc->completion);
+
+	return IRQ_HANDLED;
+}
+
+static int rzg2l_adc_parse_properties(struct platform_device *pdev, struct rzg2l_adc *adc)
+{
+	struct iio_chan_spec *chan_array;
+	struct fwnode_handle *fwnode;
+	struct rzg2l_adc_data *data;
+	unsigned int channel;
+	int num_channels;
+	int ret;
+	u8 i;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	num_channels = device_get_child_node_count(&pdev->dev);
+	if (!num_channels) {
+		dev_err(&pdev->dev, "no channel children\n");
+		return -ENODEV;
+	}
+
+	if (num_channels > RZG2L_ADC_MAX_CHANNELS) {
+		dev_err(&pdev->dev, "num of channel children out of range\n");
+		return -EINVAL;
+	}
+
+	chan_array = devm_kcalloc(&pdev->dev, num_channels, sizeof(*chan_array),
+				  GFP_KERNEL);
+	if (!chan_array)
+		return -ENOMEM;
+
+	i = 0;
+	device_for_each_child_node(&pdev->dev, fwnode) {
+		ret = fwnode_property_read_u32(fwnode, "reg", &channel);
+		if (ret) {
+			fwnode_handle_put(fwnode);
+			return ret;
+		}
+
+		if (channel >= RZG2L_ADC_MAX_CHANNELS) {
+			fwnode_handle_put(fwnode);
+			return -EINVAL;
+		}
+
+		chan_array[i].type = IIO_VOLTAGE;
+		chan_array[i].indexed = 1;
+		chan_array[i].channel = channel;
+		chan_array[i].info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+		chan_array[i].datasheet_name = rzg2l_adc_channel_name[channel];
+		i++;
+	}
+
+	data->num_channels = num_channels;
+	data->channels = chan_array;
+	adc->data = data;
+
+	return 0;
+}
+
+static int rzg2l_adc_hw_init(struct rzg2l_adc *adc)
+{
+	int timeout = 5;
+	u32 reg;
+	int ret;
+
+	ret = clk_prepare_enable(adc->pclk);
+	if (ret)
+		return ret;
+
+	/* SW reset */
+	reg = rzg2l_adc_readl(adc, RZG2L_ADM(0));
+	reg |= RZG2L_ADM0_SRESB;
+	rzg2l_adc_writel(adc, RZG2L_ADM(0), reg);
+
+	while (!(rzg2l_adc_readl(adc, RZG2L_ADM(0)) & RZG2L_ADM0_SRESB)) {
+		if (!timeout) {
+			ret = -EBUSY;
+			goto exit_hw_init;
+		}
+		timeout--;
+		usleep_range(100, 200);
+	}
+
+	/* Only division by 4 can be set */
+	reg = rzg2l_adc_readl(adc, RZG2L_ADIVC);
+	reg &= ~RZG2L_ADIVC_DIVADC_MASK;
+	reg |= RZG2L_ADIVC_DIVADC_4;
+	rzg2l_adc_writel(adc, RZG2L_ADIVC, reg);
+
+	/*
+	 * Setup AMD3
+	 * ADIL[31:24] - Should be always set to 0
+	 * ADCMP[23:16] - Should be always set to 0xe
+	 * ADSMP[15:0] - Set default (0x578) sampling period
+	 */
+	reg = rzg2l_adc_readl(adc, RZG2L_ADM(3));
+	reg &= ~RZG2L_ADM3_ADIL_MASK;
+	reg &= ~RZG2L_ADM3_ADCMP_MASK;
+	reg &= ~RZG2L_ADM3_ADSMP_MASK;
+	reg |= (RZG2L_ADM3_ADCMP_E | RZG2L_ADSMP_DEFAULT_SAMPLING);
+	rzg2l_adc_writel(adc, RZG2L_ADM(3), reg);
+
+exit_hw_init:
+	clk_disable_unprepare(adc->pclk);
+
+	return ret;
+}
+
+static void rzg2l_adc_pm_runtime_disable(void *data)
+{
+	struct device *dev = data;
+
+	pm_runtime_disable(dev->parent);
+}
+
+static void rzg2l_adc_pm_runtime_set_suspended(void *data)
+{
+	struct device *dev = data;
+
+	pm_runtime_set_suspended(dev->parent);
+}
+
+static void rzg2l_adc_reset_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
+static int rzg2l_adc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct iio_dev *indio_dev;
+	struct rzg2l_adc *adc;
+	int ret;
+	int irq;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	adc = iio_priv(indio_dev);
+
+	ret = rzg2l_adc_parse_properties(pdev, adc);
+	if (ret)
+		return ret;
+
+	mutex_init(&adc->lock);
+
+	adc->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(adc->base))
+		return PTR_ERR(adc->base);
+
+	adc->pclk = devm_clk_get(dev, "pclk");
+	if (IS_ERR(adc->pclk)) {
+		dev_err(dev, "Failed to get pclk");
+		return PTR_ERR(adc->pclk);
+	}
+
+	adc->adclk = devm_clk_get(dev, "adclk");
+	if (IS_ERR(adc->adclk)) {
+		dev_err(dev, "Failed to get adclk");
+		return PTR_ERR(adc->adclk);
+	}
+
+	adc->adrstn = devm_reset_control_get_exclusive(dev, "adrst-n");
+	if (IS_ERR(adc->adrstn)) {
+		dev_err(dev, "failed to get adrstn\n");
+		return PTR_ERR(adc->adrstn);
+	}
+
+	adc->presetn = devm_reset_control_get_exclusive(dev, "presetn");
+	if (IS_ERR(adc->presetn)) {
+		dev_err(dev, "failed to get presetn\n");
+		return PTR_ERR(adc->presetn);
+	}
+
+	ret = reset_control_deassert(adc->adrstn);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to deassert adrstn pin, %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       rzg2l_adc_reset_assert, adc->adrstn);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register adrstn assert devm action, %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = reset_control_deassert(adc->presetn);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to deassert presetn pin, %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       rzg2l_adc_reset_assert, adc->presetn);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register presetn assert devm action, %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = rzg2l_adc_hw_init(adc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to initialize ADC HW, %d\n", ret);
+		return ret;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_irq(dev, irq, rzg2l_adc_isr,
+			       0, dev_name(dev), adc);
+	if (ret < 0)
+		return ret;
+
+	init_completion(&adc->completion);
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	indio_dev->name = DRIVER_NAME;
+	indio_dev->info = &rzg2l_adc_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = adc->data->channels;
+	indio_dev->num_channels = adc->data->num_channels;
+
+	pm_runtime_set_suspended(dev);
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       rzg2l_adc_pm_runtime_set_suspended, &indio_dev->dev);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(dev);
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       rzg2l_adc_pm_runtime_disable, &indio_dev->dev);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id rzg2l_adc_match[] = {
+	{ .compatible = "renesas,rzg2l-adc",},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzg2l_adc_match);
+
+static int __maybe_unused rzg2l_adc_pm_runtime_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct rzg2l_adc *adc = iio_priv(indio_dev);
+
+	rzg2l_adc_pwr(adc, false);
+	clk_disable_unprepare(adc->adclk);
+	clk_disable_unprepare(adc->pclk);
+
+	return 0;
+}
+
+static int __maybe_unused rzg2l_adc_pm_runtime_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct rzg2l_adc *adc = iio_priv(indio_dev);
+	int ret;
+
+	ret = clk_prepare_enable(adc->pclk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(adc->adclk);
+	if (ret) {
+		clk_disable_unprepare(adc->pclk);
+		return ret;
+	}
+
+	rzg2l_adc_pwr(adc, true);
+
+	return 0;
+}
+
+static const struct dev_pm_ops rzg2l_adc_pm_ops = {
+	SET_RUNTIME_PM_OPS(rzg2l_adc_pm_runtime_suspend,
+			   rzg2l_adc_pm_runtime_resume,
+			   NULL)
+};
+
+static struct platform_driver rzg2l_adc_driver = {
+	.probe		= rzg2l_adc_probe,
+	.driver		= {
+		.name		= DRIVER_NAME,
+		.of_match_table = rzg2l_adc_match,
+		.pm		= &rzg2l_adc_pm_ops,
+	},
+};
+
+module_platform_driver(rzg2l_adc_driver);
+
+MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/G2L ADC driver");
+MODULE_LICENSE("GPL v2");