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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /drivers/iio/adc/lpc32xx_adc.c
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/iio/adc/lpc32xx_adc.c')
-rw-r--r--drivers/iio/adc/lpc32xx_adc.c231
1 files changed, 231 insertions, 0 deletions
diff --git a/drivers/iio/adc/lpc32xx_adc.c b/drivers/iio/adc/lpc32xx_adc.c
new file mode 100644
index 000000000..b56ce1525
--- /dev/null
+++ b/drivers/iio/adc/lpc32xx_adc.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * lpc32xx_adc.c - Support for ADC in LPC32XX
+ *
+ * 3-channel, 10-bit ADC
+ *
+ * Copyright (C) 2011, 2012 Roland Stigge <stigge@antcom.de>
+ */
+
+#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/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+/*
+ * LPC32XX registers definitions
+ */
+#define LPC32XXAD_SELECT(x) ((x) + 0x04)
+#define LPC32XXAD_CTRL(x) ((x) + 0x08)
+#define LPC32XXAD_VALUE(x) ((x) + 0x48)
+
+/* Bit definitions for LPC32XXAD_SELECT: */
+/* constant, always write this value! */
+#define LPC32XXAD_REFm 0x00000200
+/* constant, always write this value! */
+#define LPC32XXAD_REFp 0x00000080
+ /* multiple of this is the channel number: 0, 1, 2 */
+#define LPC32XXAD_IN 0x00000010
+/* constant, always write this value! */
+#define LPC32XXAD_INTERNAL 0x00000004
+
+/* Bit definitions for LPC32XXAD_CTRL: */
+#define LPC32XXAD_STROBE 0x00000002
+#define LPC32XXAD_PDN_CTRL 0x00000004
+
+/* Bit definitions for LPC32XXAD_VALUE: */
+#define LPC32XXAD_VALUE_MASK 0x000003FF
+
+#define LPC32XXAD_NAME "lpc32xx-adc"
+
+struct lpc32xx_adc_state {
+ void __iomem *adc_base;
+ struct clk *clk;
+ struct completion completion;
+ struct regulator *vref;
+
+ u32 value;
+};
+
+static int lpc32xx_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long mask)
+{
+ struct lpc32xx_adc_state *st = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&indio_dev->mlock);
+ ret = clk_prepare_enable(st->clk);
+ if (ret) {
+ mutex_unlock(&indio_dev->mlock);
+ return ret;
+ }
+ /* Measurement setup */
+ __raw_writel(LPC32XXAD_INTERNAL | (chan->address) |
+ LPC32XXAD_REFp | LPC32XXAD_REFm,
+ LPC32XXAD_SELECT(st->adc_base));
+ /* Trigger conversion */
+ __raw_writel(LPC32XXAD_PDN_CTRL | LPC32XXAD_STROBE,
+ LPC32XXAD_CTRL(st->adc_base));
+ wait_for_completion(&st->completion); /* set by ISR */
+ clk_disable_unprepare(st->clk);
+ *val = st->value;
+ mutex_unlock(&indio_dev->mlock);
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = regulator_get_voltage(st->vref) / 1000;
+ *val2 = 10;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info lpc32xx_adc_iio_info = {
+ .read_raw = &lpc32xx_read_raw,
+};
+
+#define LPC32XX_ADC_CHANNEL_BASE(_index) \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = _index, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .address = LPC32XXAD_IN * _index, \
+ .scan_index = _index,
+
+#define LPC32XX_ADC_CHANNEL(_index) { \
+ LPC32XX_ADC_CHANNEL_BASE(_index) \
+}
+
+#define LPC32XX_ADC_SCALE_CHANNEL(_index) { \
+ LPC32XX_ADC_CHANNEL_BASE(_index) \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
+}
+
+static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = {
+ LPC32XX_ADC_CHANNEL(0),
+ LPC32XX_ADC_CHANNEL(1),
+ LPC32XX_ADC_CHANNEL(2),
+};
+
+static const struct iio_chan_spec lpc32xx_adc_iio_scale_channels[] = {
+ LPC32XX_ADC_SCALE_CHANNEL(0),
+ LPC32XX_ADC_SCALE_CHANNEL(1),
+ LPC32XX_ADC_SCALE_CHANNEL(2),
+};
+
+static irqreturn_t lpc32xx_adc_isr(int irq, void *dev_id)
+{
+ struct lpc32xx_adc_state *st = dev_id;
+
+ /* Read value and clear irq */
+ st->value = __raw_readl(LPC32XXAD_VALUE(st->adc_base)) &
+ LPC32XXAD_VALUE_MASK;
+ complete(&st->completion);
+
+ return IRQ_HANDLED;
+}
+
+static int lpc32xx_adc_probe(struct platform_device *pdev)
+{
+ struct lpc32xx_adc_state *st = NULL;
+ struct resource *res;
+ int retval = -ENODEV;
+ struct iio_dev *iodev = NULL;
+ int irq;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "failed to get platform I/O memory\n");
+ return -ENXIO;
+ }
+
+ iodev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
+ if (!iodev)
+ return -ENOMEM;
+
+ st = iio_priv(iodev);
+
+ st->adc_base = devm_ioremap(&pdev->dev, res->start,
+ resource_size(res));
+ if (!st->adc_base) {
+ dev_err(&pdev->dev, "failed mapping memory\n");
+ return -EBUSY;
+ }
+
+ st->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(st->clk)) {
+ dev_err(&pdev->dev, "failed getting clock\n");
+ return PTR_ERR(st->clk);
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq <= 0)
+ return -ENXIO;
+
+ retval = devm_request_irq(&pdev->dev, irq, lpc32xx_adc_isr, 0,
+ LPC32XXAD_NAME, st);
+ if (retval < 0) {
+ dev_err(&pdev->dev, "failed requesting interrupt\n");
+ return retval;
+ }
+
+ st->vref = devm_regulator_get(&pdev->dev, "vref");
+ if (IS_ERR(st->vref)) {
+ iodev->channels = lpc32xx_adc_iio_channels;
+ dev_info(&pdev->dev,
+ "Missing vref regulator: No scaling available\n");
+ } else {
+ iodev->channels = lpc32xx_adc_iio_scale_channels;
+ }
+
+ platform_set_drvdata(pdev, iodev);
+
+ init_completion(&st->completion);
+
+ iodev->name = LPC32XXAD_NAME;
+ iodev->info = &lpc32xx_adc_iio_info;
+ iodev->modes = INDIO_DIRECT_MODE;
+ iodev->num_channels = ARRAY_SIZE(lpc32xx_adc_iio_channels);
+
+ retval = devm_iio_device_register(&pdev->dev, iodev);
+ if (retval)
+ return retval;
+
+ dev_info(&pdev->dev, "LPC32XX ADC driver loaded, IRQ %d\n", irq);
+
+ return 0;
+}
+
+static const struct of_device_id lpc32xx_adc_match[] = {
+ { .compatible = "nxp,lpc3220-adc" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, lpc32xx_adc_match);
+
+static struct platform_driver lpc32xx_adc_driver = {
+ .probe = lpc32xx_adc_probe,
+ .driver = {
+ .name = LPC32XXAD_NAME,
+ .of_match_table = lpc32xx_adc_match,
+ },
+};
+
+module_platform_driver(lpc32xx_adc_driver);
+
+MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
+MODULE_DESCRIPTION("LPC32XX ADC driver");
+MODULE_LICENSE("GPL");