Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/iio/dac/ti-dac7612.c b/drivers/iio/dac/ti-dac7612.c
new file mode 100644
index 0000000..c468051
--- /dev/null
+++ b/drivers/iio/dac/ti-dac7612.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DAC7612 Dual, 12-Bit Serial input Digital-to-Analog Converter
+ *
+ * Copyright 2019 Qtechnology A/S
+ * 2019 Ricardo Ribalda <ricardo@ribalda.com>
+ *
+ * Licensed under the GPL-2.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+
+#define DAC7612_RESOLUTION 12
+#define DAC7612_ADDRESS 4
+#define DAC7612_START 5
+
+struct dac7612 {
+ struct spi_device *spi;
+ struct gpio_desc *loaddacs;
+ uint16_t cache[2];
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ uint8_t data[2] ____cacheline_aligned;
+};
+
+static int dac7612_cmd_single(struct dac7612 *priv, int channel, u16 val)
+{
+ int ret;
+
+ priv->data[0] = BIT(DAC7612_START) | (channel << DAC7612_ADDRESS);
+ priv->data[0] |= val >> 8;
+ priv->data[1] = val & 0xff;
+
+ priv->cache[channel] = val;
+
+ ret = spi_write(priv->spi, priv->data, sizeof(priv->data));
+ if (ret)
+ return ret;
+
+ gpiod_set_value(priv->loaddacs, 1);
+ gpiod_set_value(priv->loaddacs, 0);
+
+ return 0;
+}
+
+#define dac7612_CHANNEL(chan, name) { \
+ .type = IIO_VOLTAGE, \
+ .channel = (chan), \
+ .indexed = 1, \
+ .output = 1, \
+ .datasheet_name = name, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+}
+
+static const struct iio_chan_spec dac7612_channels[] = {
+ dac7612_CHANNEL(0, "OUTA"),
+ dac7612_CHANNEL(1, "OUTB"),
+};
+
+static int dac7612_read_raw(struct iio_dev *iio_dev,
+ const struct iio_chan_spec *chan,
+ int *val, int *val2, long mask)
+{
+ struct dac7612 *priv;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ priv = iio_priv(iio_dev);
+ *val = priv->cache[chan->channel];
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = 1;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int dac7612_write_raw(struct iio_dev *iio_dev,
+ const struct iio_chan_spec *chan,
+ int val, int val2, long mask)
+{
+ struct dac7612 *priv = iio_priv(iio_dev);
+ int ret;
+
+ if (mask != IIO_CHAN_INFO_RAW)
+ return -EINVAL;
+
+ if ((val >= BIT(DAC7612_RESOLUTION)) || val < 0 || val2)
+ return -EINVAL;
+
+ if (val == priv->cache[chan->channel])
+ return 0;
+
+ mutex_lock(&iio_dev->mlock);
+ ret = dac7612_cmd_single(priv, chan->channel, val);
+ mutex_unlock(&iio_dev->mlock);
+
+ return ret;
+}
+
+static const struct iio_info dac7612_info = {
+ .read_raw = dac7612_read_raw,
+ .write_raw = dac7612_write_raw,
+};
+
+static int dac7612_probe(struct spi_device *spi)
+{
+ struct iio_dev *iio_dev;
+ struct dac7612 *priv;
+ int i;
+ int ret;
+
+ iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*priv));
+ if (!iio_dev)
+ return -ENOMEM;
+
+ priv = iio_priv(iio_dev);
+ /*
+ * LOADDACS pin can be controlled by the driver or externally.
+ * When controlled by the driver, the DAC value is updated after
+ * every write.
+ * When the driver does not control the PIN, the user or an external
+ * event can change the value of all DACs by pulsing down the LOADDACs
+ * pin.
+ */
+ priv->loaddacs = devm_gpiod_get_optional(&spi->dev, "ti,loaddacs",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(priv->loaddacs))
+ return PTR_ERR(priv->loaddacs);
+ priv->spi = spi;
+ spi_set_drvdata(spi, iio_dev);
+ iio_dev->dev.parent = &spi->dev;
+ iio_dev->info = &dac7612_info;
+ iio_dev->modes = INDIO_DIRECT_MODE;
+ iio_dev->channels = dac7612_channels;
+ iio_dev->num_channels = ARRAY_SIZE(priv->cache);
+ iio_dev->name = spi_get_device_id(spi)->name;
+
+ for (i = 0; i < ARRAY_SIZE(priv->cache); i++) {
+ ret = dac7612_cmd_single(priv, i, 0);
+ if (ret)
+ return ret;
+ }
+
+ return devm_iio_device_register(&spi->dev, iio_dev);
+}
+
+static const struct spi_device_id dac7612_id[] = {
+ {"ti-dac7612"},
+ {}
+};
+MODULE_DEVICE_TABLE(spi, dac7612_id);
+
+static const struct of_device_id dac7612_of_match[] = {
+ { .compatible = "ti,dac7612" },
+ { .compatible = "ti,dac7612u" },
+ { .compatible = "ti,dac7612ub" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, dac7612_of_match);
+
+static struct spi_driver dac7612_driver = {
+ .driver = {
+ .name = "ti-dac7612",
+ .of_match_table = dac7612_of_match,
+ },
+ .probe = dac7612_probe,
+ .id_table = dac7612_id,
+};
+module_spi_driver(dac7612_driver);
+
+MODULE_AUTHOR("Ricardo Ribalda <ricardo@ribalda.com>");
+MODULE_DESCRIPTION("Texas Instruments DAC7612 DAC driver");
+MODULE_LICENSE("GPL v2");