1 files changed, 602 insertions, 0 deletions

diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
new file mode 100644
index 0000000000..dd94667a62
--- /dev/null
+++ b/drivers/iio/adc/rockchip_saradc.c
@@ -0,0 +1,602 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Rockchip Successive Approximation Register (SAR) A/D Converter
+ * Copyright (C) 2014 ROCKCHIP, Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/reset.h>
+#include <linux/regulator/consumer.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define SARADC_DATA			0x00
+
+#define SARADC_STAS			0x04
+#define SARADC_STAS_BUSY		BIT(0)
+
+#define SARADC_CTRL			0x08
+#define SARADC_CTRL_IRQ_STATUS		BIT(6)
+#define SARADC_CTRL_IRQ_ENABLE		BIT(5)
+#define SARADC_CTRL_POWER_CTRL		BIT(3)
+#define SARADC_CTRL_CHN_MASK		0x7
+
+#define SARADC_DLY_PU_SOC		0x0c
+#define SARADC_DLY_PU_SOC_MASK		0x3f
+
+#define SARADC_TIMEOUT			msecs_to_jiffies(100)
+#define SARADC_MAX_CHANNELS		8
+
+/* v2 registers */
+#define SARADC2_CONV_CON		0x000
+#define SARADC_T_PD_SOC			0x004
+#define SARADC_T_DAS_SOC		0x00c
+#define SARADC2_END_INT_EN		0x104
+#define SARADC2_ST_CON			0x108
+#define SARADC2_STATUS			0x10c
+#define SARADC2_END_INT_ST		0x110
+#define SARADC2_DATA_BASE		0x120
+
+#define SARADC2_EN_END_INT		BIT(0)
+#define SARADC2_START			BIT(4)
+#define SARADC2_SINGLE_MODE		BIT(5)
+
+#define SARADC2_CONV_CHANNELS GENMASK(15, 0)
+
+struct rockchip_saradc;
+
+struct rockchip_saradc_data {
+	const struct iio_chan_spec	*channels;
+	int				num_channels;
+	unsigned long			clk_rate;
+	void (*start)(struct rockchip_saradc *info, int chn);
+	int (*read)(struct rockchip_saradc *info);
+	void (*power_down)(struct rockchip_saradc *info);
+};
+
+struct rockchip_saradc {
+	void __iomem		*regs;
+	struct clk		*pclk;
+	struct clk		*clk;
+	struct completion	completion;
+	struct regulator	*vref;
+	/* lock to protect against multiple access to the device */
+	struct mutex		lock;
+	int			uv_vref;
+	struct reset_control	*reset;
+	const struct rockchip_saradc_data *data;
+	u16			last_val;
+	const struct iio_chan_spec *last_chan;
+	struct notifier_block nb;
+};
+
+static void rockchip_saradc_reset_controller(struct reset_control *reset);
+
+static void rockchip_saradc_start_v1(struct rockchip_saradc *info, int chn)
+{
+	/* 8 clock periods as delay between power up and start cmd */
+	writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);
+	/* Select the channel to be used and trigger conversion */
+	writel(SARADC_CTRL_POWER_CTRL | (chn & SARADC_CTRL_CHN_MASK) |
+	       SARADC_CTRL_IRQ_ENABLE, info->regs + SARADC_CTRL);
+}
+
+static void rockchip_saradc_start_v2(struct rockchip_saradc *info, int chn)
+{
+	int val;
+
+	if (info->reset)
+		rockchip_saradc_reset_controller(info->reset);
+
+	writel_relaxed(0xc, info->regs + SARADC_T_DAS_SOC);
+	writel_relaxed(0x20, info->regs + SARADC_T_PD_SOC);
+	val = FIELD_PREP(SARADC2_EN_END_INT, 1);
+	val |= val << 16;
+	writel_relaxed(val, info->regs + SARADC2_END_INT_EN);
+	val = FIELD_PREP(SARADC2_START, 1) |
+	      FIELD_PREP(SARADC2_SINGLE_MODE, 1) |
+	      FIELD_PREP(SARADC2_CONV_CHANNELS, chn);
+	val |= val << 16;
+	writel(val, info->regs + SARADC2_CONV_CON);
+}
+
+static void rockchip_saradc_start(struct rockchip_saradc *info, int chn)
+{
+	info->data->start(info, chn);
+}
+
+static int rockchip_saradc_read_v1(struct rockchip_saradc *info)
+{
+	return readl_relaxed(info->regs + SARADC_DATA);
+}
+
+static int rockchip_saradc_read_v2(struct rockchip_saradc *info)
+{
+	int offset;
+
+	/* Clear irq */
+	writel_relaxed(0x1, info->regs + SARADC2_END_INT_ST);
+
+	offset = SARADC2_DATA_BASE + info->last_chan->channel * 0x4;
+
+	return readl_relaxed(info->regs + offset);
+}
+
+static int rockchip_saradc_read(struct rockchip_saradc *info)
+{
+	return info->data->read(info);
+}
+
+static void rockchip_saradc_power_down_v1(struct rockchip_saradc *info)
+{
+	writel_relaxed(0, info->regs + SARADC_CTRL);
+}
+
+static void rockchip_saradc_power_down(struct rockchip_saradc *info)
+{
+	if (info->data->power_down)
+		info->data->power_down(info);
+}
+
+static int rockchip_saradc_conversion(struct rockchip_saradc *info,
+				      struct iio_chan_spec const *chan)
+{
+	reinit_completion(&info->completion);
+
+	info->last_chan = chan;
+	rockchip_saradc_start(info, chan->channel);
+
+	if (!wait_for_completion_timeout(&info->completion, SARADC_TIMEOUT))
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
+				    struct iio_chan_spec const *chan,
+				    int *val, int *val2, long mask)
+{
+	struct rockchip_saradc *info = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&info->lock);
+
+		ret = rockchip_saradc_conversion(info, chan);
+		if (ret) {
+			rockchip_saradc_power_down(info);
+			mutex_unlock(&info->lock);
+			return ret;
+		}
+
+		*val = info->last_val;
+		mutex_unlock(&info->lock);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = info->uv_vref / 1000;
+		*val2 = chan->scan_type.realbits;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	default:
+		return -EINVAL;
+	}
+}
+
+static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id)
+{
+	struct rockchip_saradc *info = dev_id;
+
+	/* Read value */
+	info->last_val = rockchip_saradc_read(info);
+	info->last_val &= GENMASK(info->last_chan->scan_type.realbits - 1, 0);
+
+	rockchip_saradc_power_down(info);
+
+	complete(&info->completion);
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_info rockchip_saradc_iio_info = {
+	.read_raw = rockchip_saradc_read_raw,
+};
+
+#define SARADC_CHANNEL(_index, _id, _res) {			\
+	.type = IIO_VOLTAGE,					\
+	.indexed = 1,						\
+	.channel = _index,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+	.datasheet_name = _id,					\
+	.scan_index = _index,					\
+	.scan_type = {						\
+		.sign = 'u',					\
+		.realbits = _res,				\
+		.storagebits = 16,				\
+		.endianness = IIO_CPU,				\
+	},							\
+}
+
+static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
+	SARADC_CHANNEL(0, "adc0", 10),
+	SARADC_CHANNEL(1, "adc1", 10),
+	SARADC_CHANNEL(2, "adc2", 10),
+};
+
+static const struct rockchip_saradc_data saradc_data = {
+	.channels = rockchip_saradc_iio_channels,
+	.num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels),
+	.clk_rate = 1000000,
+	.start = rockchip_saradc_start_v1,
+	.read = rockchip_saradc_read_v1,
+	.power_down = rockchip_saradc_power_down_v1,
+};
+
+static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
+	SARADC_CHANNEL(0, "adc0", 12),
+	SARADC_CHANNEL(1, "adc1", 12),
+};
+
+static const struct rockchip_saradc_data rk3066_tsadc_data = {
+	.channels = rockchip_rk3066_tsadc_iio_channels,
+	.num_channels = ARRAY_SIZE(rockchip_rk3066_tsadc_iio_channels),
+	.clk_rate = 50000,
+	.start = rockchip_saradc_start_v1,
+	.read = rockchip_saradc_read_v1,
+	.power_down = rockchip_saradc_power_down_v1,
+};
+
+static const struct iio_chan_spec rockchip_rk3399_saradc_iio_channels[] = {
+	SARADC_CHANNEL(0, "adc0", 10),
+	SARADC_CHANNEL(1, "adc1", 10),
+	SARADC_CHANNEL(2, "adc2", 10),
+	SARADC_CHANNEL(3, "adc3", 10),
+	SARADC_CHANNEL(4, "adc4", 10),
+	SARADC_CHANNEL(5, "adc5", 10),
+};
+
+static const struct rockchip_saradc_data rk3399_saradc_data = {
+	.channels = rockchip_rk3399_saradc_iio_channels,
+	.num_channels = ARRAY_SIZE(rockchip_rk3399_saradc_iio_channels),
+	.clk_rate = 1000000,
+	.start = rockchip_saradc_start_v1,
+	.read = rockchip_saradc_read_v1,
+	.power_down = rockchip_saradc_power_down_v1,
+};
+
+static const struct iio_chan_spec rockchip_rk3568_saradc_iio_channels[] = {
+	SARADC_CHANNEL(0, "adc0", 10),
+	SARADC_CHANNEL(1, "adc1", 10),
+	SARADC_CHANNEL(2, "adc2", 10),
+	SARADC_CHANNEL(3, "adc3", 10),
+	SARADC_CHANNEL(4, "adc4", 10),
+	SARADC_CHANNEL(5, "adc5", 10),
+	SARADC_CHANNEL(6, "adc6", 10),
+	SARADC_CHANNEL(7, "adc7", 10),
+};
+
+static const struct rockchip_saradc_data rk3568_saradc_data = {
+	.channels = rockchip_rk3568_saradc_iio_channels,
+	.num_channels = ARRAY_SIZE(rockchip_rk3568_saradc_iio_channels),
+	.clk_rate = 1000000,
+	.start = rockchip_saradc_start_v1,
+	.read = rockchip_saradc_read_v1,
+	.power_down = rockchip_saradc_power_down_v1,
+};
+
+static const struct iio_chan_spec rockchip_rk3588_saradc_iio_channels[] = {
+	SARADC_CHANNEL(0, "adc0", 12),
+	SARADC_CHANNEL(1, "adc1", 12),
+	SARADC_CHANNEL(2, "adc2", 12),
+	SARADC_CHANNEL(3, "adc3", 12),
+	SARADC_CHANNEL(4, "adc4", 12),
+	SARADC_CHANNEL(5, "adc5", 12),
+	SARADC_CHANNEL(6, "adc6", 12),
+	SARADC_CHANNEL(7, "adc7", 12),
+};
+
+static const struct rockchip_saradc_data rk3588_saradc_data = {
+	.channels = rockchip_rk3588_saradc_iio_channels,
+	.num_channels = ARRAY_SIZE(rockchip_rk3588_saradc_iio_channels),
+	.clk_rate = 1000000,
+	.start = rockchip_saradc_start_v2,
+	.read = rockchip_saradc_read_v2,
+};
+
+static const struct of_device_id rockchip_saradc_match[] = {
+	{
+		.compatible = "rockchip,saradc",
+		.data = &saradc_data,
+	}, {
+		.compatible = "rockchip,rk3066-tsadc",
+		.data = &rk3066_tsadc_data,
+	}, {
+		.compatible = "rockchip,rk3399-saradc",
+		.data = &rk3399_saradc_data,
+	}, {
+		.compatible = "rockchip,rk3568-saradc",
+		.data = &rk3568_saradc_data,
+	}, {
+		.compatible = "rockchip,rk3588-saradc",
+		.data = &rk3588_saradc_data,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, rockchip_saradc_match);
+
+/*
+ * Reset SARADC Controller.
+ */
+static void rockchip_saradc_reset_controller(struct reset_control *reset)
+{
+	reset_control_assert(reset);
+	usleep_range(10, 20);
+	reset_control_deassert(reset);
+}
+
+static void rockchip_saradc_regulator_disable(void *data)
+{
+	struct rockchip_saradc *info = data;
+
+	regulator_disable(info->vref);
+}
+
+static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *i_dev = pf->indio_dev;
+	struct rockchip_saradc *info = iio_priv(i_dev);
+	/*
+	 * @values: each channel takes an u16 value
+	 * @timestamp: will be 8-byte aligned automatically
+	 */
+	struct {
+		u16 values[SARADC_MAX_CHANNELS];
+		int64_t timestamp;
+	} data;
+	int ret;
+	int i, j = 0;
+
+	mutex_lock(&info->lock);
+
+	for_each_set_bit(i, i_dev->active_scan_mask, i_dev->masklength) {
+		const struct iio_chan_spec *chan = &i_dev->channels[i];
+
+		ret = rockchip_saradc_conversion(info, chan);
+		if (ret) {
+			rockchip_saradc_power_down(info);
+			goto out;
+		}
+
+		data.values[j] = info->last_val;
+		j++;
+	}
+
+	iio_push_to_buffers_with_timestamp(i_dev, &data, iio_get_time_ns(i_dev));
+out:
+	mutex_unlock(&info->lock);
+
+	iio_trigger_notify_done(i_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int rockchip_saradc_volt_notify(struct notifier_block *nb,
+				       unsigned long event, void *data)
+{
+	struct rockchip_saradc *info =
+			container_of(nb, struct rockchip_saradc, nb);
+
+	if (event & REGULATOR_EVENT_VOLTAGE_CHANGE)
+		info->uv_vref = (unsigned long)data;
+
+	return NOTIFY_OK;
+}
+
+static void rockchip_saradc_regulator_unreg_notifier(void *data)
+{
+	struct rockchip_saradc *info = data;
+
+	regulator_unregister_notifier(info->vref, &info->nb);
+}
+
+static int rockchip_saradc_probe(struct platform_device *pdev)
+{
+	const struct rockchip_saradc_data *match_data;
+	struct rockchip_saradc *info = NULL;
+	struct device_node *np = pdev->dev.of_node;
+	struct iio_dev *indio_dev = NULL;
+	int ret;
+	int irq;
+
+	if (!np)
+		return -ENODEV;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info));
+	if (!indio_dev)
+		return dev_err_probe(&pdev->dev, -ENOMEM,
+				     "failed allocating iio device\n");
+
+	info = iio_priv(indio_dev);
+
+	match_data = of_device_get_match_data(&pdev->dev);
+	if (!match_data)
+		return dev_err_probe(&pdev->dev, -ENODEV,
+				     "failed to match device\n");
+
+	info->data = match_data;
+
+	/* Sanity check for possible later IP variants with more channels */
+	if (info->data->num_channels > SARADC_MAX_CHANNELS)
+		return dev_err_probe(&pdev->dev, -EINVAL,
+				     "max channels exceeded");
+
+	info->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(info->regs))
+		return PTR_ERR(info->regs);
+
+	/*
+	 * The reset should be an optional property, as it should work
+	 * with old devicetrees as well
+	 */
+	info->reset = devm_reset_control_get_exclusive(&pdev->dev,
+						       "saradc-apb");
+	if (IS_ERR(info->reset)) {
+		ret = PTR_ERR(info->reset);
+		if (ret != -ENOENT)
+			return dev_err_probe(&pdev->dev, ret,
+					     "failed to get saradc-apb\n");
+
+		dev_dbg(&pdev->dev, "no reset control found\n");
+		info->reset = NULL;
+	}
+
+	init_completion(&info->completion);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_irq(&pdev->dev, irq, rockchip_saradc_isr,
+			       0, dev_name(&pdev->dev), info);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed requesting irq %d\n", irq);
+		return ret;
+	}
+
+	info->vref = devm_regulator_get(&pdev->dev, "vref");
+	if (IS_ERR(info->vref))
+		return dev_err_probe(&pdev->dev, PTR_ERR(info->vref),
+				     "failed to get regulator\n");
+
+	if (info->reset)
+		rockchip_saradc_reset_controller(info->reset);
+
+	/*
+	 * Use a default value for the converter clock.
+	 * This may become user-configurable in the future.
+	 */
+	ret = clk_set_rate(info->clk, info->data->clk_rate);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret,
+				     "failed to set adc clk rate\n");
+
+	ret = regulator_enable(info->vref);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret,
+				     "failed to enable vref regulator\n");
+
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       rockchip_saradc_regulator_disable, info);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret,
+				     "failed to register devm action\n");
+
+	ret = regulator_get_voltage(info->vref);
+	if (ret < 0)
+		return ret;
+
+	info->uv_vref = ret;
+
+	info->pclk = devm_clk_get_enabled(&pdev->dev, "apb_pclk");
+	if (IS_ERR(info->pclk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(info->pclk),
+				     "failed to get pclk\n");
+
+	info->clk = devm_clk_get_enabled(&pdev->dev, "saradc");
+	if (IS_ERR(info->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(info->clk),
+				     "failed to get adc clock\n");
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->info = &rockchip_saradc_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	indio_dev->channels = info->data->channels;
+	indio_dev->num_channels = info->data->num_channels;
+	ret = devm_iio_triggered_buffer_setup(&indio_dev->dev, indio_dev, NULL,
+					      rockchip_saradc_trigger_handler,
+					      NULL);
+	if (ret)
+		return ret;
+
+	info->nb.notifier_call = rockchip_saradc_volt_notify;
+	ret = regulator_register_notifier(info->vref, &info->nb);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       rockchip_saradc_regulator_unreg_notifier,
+				       info);
+	if (ret)
+		return ret;
+
+	mutex_init(&info->lock);
+
+	return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static int rockchip_saradc_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct rockchip_saradc *info = iio_priv(indio_dev);
+
+	clk_disable_unprepare(info->clk);
+	clk_disable_unprepare(info->pclk);
+	regulator_disable(info->vref);
+
+	return 0;
+}
+
+static int rockchip_saradc_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct rockchip_saradc *info = iio_priv(indio_dev);
+	int ret;
+
+	ret = regulator_enable(info->vref);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(info->pclk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(info->clk);
+	if (ret)
+		clk_disable_unprepare(info->pclk);
+
+	return ret;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(rockchip_saradc_pm_ops,
+				rockchip_saradc_suspend,
+				rockchip_saradc_resume);
+
+static struct platform_driver rockchip_saradc_driver = {
+	.probe		= rockchip_saradc_probe,
+	.driver		= {
+		.name	= "rockchip-saradc",
+		.of_match_table = rockchip_saradc_match,
+		.pm	= pm_sleep_ptr(&rockchip_saradc_pm_ops),
+	},
+};
+
+module_platform_driver(rockchip_saradc_driver);
+
+MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
+MODULE_DESCRIPTION("Rockchip SARADC driver");
+MODULE_LICENSE("GPL v2");