--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * x9250.c -- Renesas X9250 potentiometers IIO driver
+ *
+ * Copyright 2023 CS GROUP France
+ *
+ * Author: Herve Codina <herve.codina@bootlin.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+struct x9250_cfg {
+ const char *name;
+ int kohms;
+};
+
+struct x9250 {
+ struct spi_device *spi;
+ const struct x9250_cfg *cfg;
+ struct gpio_desc *wp_gpio;
+};
+
+#define X9250_ID 0x50
+#define X9250_CMD_RD_WCR(_p) (0x90 | (_p))
+#define X9250_CMD_WR_WCR(_p) (0xa0 | (_p))
+
+static int x9250_write8(struct x9250 *x9250, u8 cmd, u8 val)
+{
+ u8 txbuf[3];
+
+ txbuf[0] = X9250_ID;
+ txbuf[1] = cmd;
+ txbuf[2] = val;
+
+ return spi_write_then_read(x9250->spi, txbuf, ARRAY_SIZE(txbuf), NULL, 0);
+}
+
+static int x9250_read8(struct x9250 *x9250, u8 cmd, u8 *val)
+{
+ u8 txbuf[2];
+
+ txbuf[0] = X9250_ID;
+ txbuf[1] = cmd;
+
+ return spi_write_then_read(x9250->spi, txbuf, ARRAY_SIZE(txbuf), val, 1);
+}
+
+#define X9250_CHANNEL(ch) { \
+ .type = IIO_RESISTANCE, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = (ch), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW), \
+}
+
+static const struct iio_chan_spec x9250_channels[] = {
+ X9250_CHANNEL(0),
+ X9250_CHANNEL(1),
+ X9250_CHANNEL(2),
+ X9250_CHANNEL(3),
+};
+
+static int x9250_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct x9250 *x9250 = iio_priv(indio_dev);
+ int ch = chan->channel;
+ int ret;
+ u8 v;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = x9250_read8(x9250, X9250_CMD_RD_WCR(ch), &v);
+ if (ret)
+ return ret;
+ *val = v;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = 1000 * x9250->cfg->kohms;
+ *val2 = U8_MAX;
+ return IIO_VAL_FRACTIONAL;
+ }
+
+ return -EINVAL;
+}
+
+static int x9250_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length, long mask)
+{
+ static const int range[] = {0, 1, 255}; /* min, step, max */
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ *length = ARRAY_SIZE(range);
+ *vals = range;
+ *type = IIO_VAL_INT;
+ return IIO_AVAIL_RANGE;
+ }
+
+ return -EINVAL;
+}
+
+static int x9250_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct x9250 *x9250 = iio_priv(indio_dev);
+ int ch = chan->channel;
+ int ret;
+
+ if (mask != IIO_CHAN_INFO_RAW)
+ return -EINVAL;
+
+ if (val > U8_MAX || val < 0)
+ return -EINVAL;
+
+ gpiod_set_value_cansleep(x9250->wp_gpio, 0);
+ ret = x9250_write8(x9250, X9250_CMD_WR_WCR(ch), val);
+ gpiod_set_value_cansleep(x9250->wp_gpio, 1);
+
+ return ret;
+}
+
+static const struct iio_info x9250_info = {
+ .read_raw = x9250_read_raw,
+ .read_avail = x9250_read_avail,
+ .write_raw = x9250_write_raw,
+};
+
+enum x9250_type {
+ X9250T,
+ X9250U,
+};
+
+static const struct x9250_cfg x9250_cfg[] = {
+ [X9250T] = { .name = "x9250t", .kohms = 100, },
+ [X9250U] = { .name = "x9250u", .kohms = 50, },
+};
+
+static const char *const x9250_regulator_names[] = {
+ "vcc",
+ "avp",
+ "avn",
+};
+
+static int x9250_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct x9250 *x9250;
+ int ret;
+
+ ret = devm_regulator_bulk_get_enable(&spi->dev, ARRAY_SIZE(x9250_regulator_names),
+ x9250_regulator_names);
+ if (ret)
+ return dev_err_probe(&spi->dev, ret, "Failed to get regulators\n");
+
+ /*
+ * The x9250 needs a 5ms maximum delay after the power-supplies are set
+ * before performing the first write (1ms for the first read).
+ */
+ usleep_range(5000, 6000);
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*x9250));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ x9250 = iio_priv(indio_dev);
+ x9250->spi = spi;
+ x9250->cfg = spi_get_device_match_data(spi);
+ x9250->wp_gpio = devm_gpiod_get_optional(&spi->dev, "wp", GPIOD_OUT_LOW);
+ if (IS_ERR(x9250->wp_gpio))
+ return dev_err_probe(&spi->dev, PTR_ERR(x9250->wp_gpio),
+ "failed to get wp gpio\n");
+
+ indio_dev->info = &x9250_info;
+ indio_dev->channels = x9250_channels;
+ indio_dev->num_channels = ARRAY_SIZE(x9250_channels);
+ indio_dev->name = x9250->cfg->name;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct of_device_id x9250_of_match[] = {
+ { .compatible = "renesas,x9250t", .data = &x9250_cfg[X9250T]},
+ { .compatible = "renesas,x9250u", .data = &x9250_cfg[X9250U]},
+ { }
+};
+MODULE_DEVICE_TABLE(of, x9250_of_match);
+
+static const struct spi_device_id x9250_id_table[] = {
+ { "x9250t", (kernel_ulong_t)&x9250_cfg[X9250T] },
+ { "x9250u", (kernel_ulong_t)&x9250_cfg[X9250U] },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, x9250_id_table);
+
+static struct spi_driver x9250_spi_driver = {
+ .driver = {
+ .name = "x9250",
+ .of_match_table = x9250_of_match,
+ },
+ .id_table = x9250_id_table,
+ .probe = x9250_probe,
+};
+
+module_spi_driver(x9250_spi_driver);
+
+MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
+MODULE_DESCRIPTION("X9250 ALSA SoC driver");
+MODULE_LICENSE("GPL");
git.samba.org / sfrench / cifs-2.6.git / commitdiff