[PATCH 3/5] lmp92001: mfd: iio: dac: Add support LMP92001

From: s . abhisit
Date: Wed Aug 30 2017 - 14:17:30 EST


From: Abhisit Sangjan <s.abhisit@xxxxxxxxx>

TI LMP92001 Analog System Monitor and Controller

8-bit GPIOs.
12 DACs with 12-bit resolution.

The GPIOs and DACs are shared port function with Cy function pin to
take control the pin suddenly from external hardware.
DAC's referance voltage selectable for Internal/External.

16 + 1 ADCs with 12-bit resolution.

Built-in internal Temperature Sensor on channel 17.
Window Comparator Function is supported on channel 1-3 and 9-11 for
monitoring with interrupt signal (pending to implement for interrupt).
ADC's referance voltage selectable for Internal/External.

Signed-off-by: Abhisit Sangjan <s.abhisit@xxxxxxxxx>
---
drivers/iio/dac/Kconfig | 9 ++
drivers/iio/dac/Makefile | 1 +
drivers/iio/dac/lmp92001-dac.c | 337 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 347 insertions(+)
create mode 100644 drivers/iio/dac/lmp92001-dac.c

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 25bed2d7d2b9..3e0d81606927 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -221,6 +221,15 @@ config DPOT_DAC
To compile this driver as a module, choose M here: the module will be
called dpot-dac.

+config LMP92001_DAC
+ tristate "TI LMP92001 DAC Driver"
+ depends on MFD_LMP92001
+ help
+ If you say yes here you get support for TI LMP92001 DACs.
+
+ This driver can also be built as a module. If so, the module will
+ be called lmp92001_dac.
+
config LPC18XX_DAC
tristate "NXP LPC18xx DAC driver"
depends on ARCH_LPC18XX || COMPILE_TEST
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 603587cc2f07..516d2beced7b 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_AD7303) += ad7303.o
obj-$(CONFIG_AD8801) += ad8801.o
obj-$(CONFIG_CIO_DAC) += cio-dac.o
obj-$(CONFIG_DPOT_DAC) += dpot-dac.o
+obj-$(CONFIG_LMP92001_DAC) += lmp92001-dac.o
obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
obj-$(CONFIG_LTC2632) += ltc2632.o
obj-$(CONFIG_M62332) += m62332.o
diff --git a/drivers/iio/dac/lmp92001-dac.c b/drivers/iio/dac/lmp92001-dac.c
new file mode 100644
index 000000000000..072026e9895c
--- /dev/null
+++ b/drivers/iio/dac/lmp92001-dac.c
@@ -0,0 +1,337 @@
+/*
+ * lmp92001-dac.c - Support for TI LMP92001 DACs
+ *
+ * Copyright 2016-2017 Celestica Ltd.
+ *
+ * Author: Abhisit Sangjan <s.abhisit@xxxxxxxxx>
+ *
+ * Inspired by wm831x driver.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <linux/mfd/lmp92001/core.h>
+
+static int lmp92001_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int *val, int *val2, long mask)
+{
+ struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (channel->type) {
+ case IIO_VOLTAGE:
+ mutex_lock(&lmp92001->dac_lock);
+
+ ret = regmap_read(lmp92001->regmap,
+ 0x7F + channel->channel, val);
+
+ mutex_unlock(&lmp92001->dac_lock);
+
+ if (ret < 0)
+ return ret;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int lmp92001_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int val, int val2, long mask)
+{
+ struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+ int ret;
+
+ if (val < 0 || val > 4095)
+ return -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (channel->type) {
+ case IIO_VOLTAGE:
+ mutex_lock(&lmp92001->dac_lock);
+
+ ret = regmap_write(lmp92001->regmap,
+ 0x7F + channel->channel, val);
+
+ mutex_unlock(&lmp92001->dac_lock);
+
+ if (ret < 0)
+ return ret;
+
+ return 0;
+ default:
+ return -EINVAL;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info lmp92001_info = {
+ .read_raw = lmp92001_read_raw,
+ .write_raw = lmp92001_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static ssize_t lmp92001_dvref_read(struct iio_dev *indio_dev,
+ uintptr_t private, struct iio_chan_spec const *channel, char *buf)
+{
+ struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+ unsigned int cref;
+ int ret;
+
+ ret = regmap_read(lmp92001->regmap, LMP92001_CREF, &cref);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%s\n", cref & CREF_DEXT ? "external" : "internal");
+}
+
+static ssize_t lmp92001_dvref_write(struct iio_dev *indio_dev,
+ uintptr_t private, struct iio_chan_spec const *channel, const char *buf,
+ size_t len)
+{
+ struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+ unsigned int cref;
+ int ret;
+
+ if (strncmp("external", buf, 8) == 0)
+ cref = 1;
+ else if (strncmp("internal", buf, 8) == 0)
+ cref = 0;
+ else
+ return -EINVAL;
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CREF, CREF_DEXT,
+ cref);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static ssize_t lmp92001_outx_read(struct iio_dev *indio_dev,
+ uintptr_t private, struct iio_chan_spec const *channel, char *buf)
+{
+ struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+ unsigned int cdac;
+ const char *outx;
+ int ret;
+
+ ret = regmap_read(lmp92001->regmap, LMP92001_CDAC, &cdac);
+ if (ret < 0)
+ return ret;
+
+ if (cdac & CDAC_OFF)
+ outx = "hiz";
+ else {
+ if (cdac & CDAC_OLVL)
+ outx = "1 or dac";
+ else
+ outx = "0 or dac";
+ }
+
+ return sprintf(buf, "%s\n", outx);
+}
+
+static ssize_t lmp92001_outx_write(struct iio_dev *indio_dev,
+ uintptr_t private, struct iio_chan_spec const *channel,
+ const char *buf, size_t len)
+{
+ struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+ unsigned int cdac, mask;
+ int ret;
+
+ if (strncmp("hiz", buf, 3) == 0) {
+ cdac = CDAC_OFF;
+ mask = CDAC_OFF;
+ } else if (strncmp("dac", buf, 3) == 0) {
+ cdac = ~CDAC_OFF;
+ mask = CDAC_OFF;
+ } else if (strncmp("0", buf, 1) == 0) {
+ cdac = ~(CDAC_OLVL | CDAC_OFF);
+ mask = CDAC_OLVL | CDAC_OFF;
+ } else if (strncmp("1", buf, 1) == 0) {
+ cdac = CDAC_OLVL;
+ mask = CDAC_OLVL | CDAC_OFF;
+ } else
+ return -EINVAL;
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CDAC, mask, cdac);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static ssize_t lmp92001_gang_read(struct iio_dev *indio_dev,
+ uintptr_t private, struct iio_chan_spec const *channel, char *buf)
+{
+ struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+ unsigned int cdac;
+ int ret;
+
+ ret = regmap_read(lmp92001->regmap, LMP92001_CDAC, &cdac);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%s\n", cdac & CDAC_GANG ? "1" : "0");
+}
+
+static ssize_t lmp92001_gang_write(struct iio_dev *indio_dev,
+ uintptr_t private, struct iio_chan_spec const *channel,
+ const char *buf, size_t len)
+{
+ struct lmp92001 *lmp92001 = iio_device_get_drvdata(indio_dev);
+ unsigned int cdac = 0;
+ int ret;
+
+ if (strncmp("0", buf, 1) == 0)
+ cdac = ~CDAC_GANG;
+ else if (strncmp("1", buf, 1) == 0)
+ cdac = CDAC_GANG;
+ else
+ return -EINVAL;
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CDAC, CDAC_GANG,
+ cdac);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static const struct iio_chan_spec_ext_info lmp92001_ext_info[] = {
+ {
+ .name = "vref",
+ .read = lmp92001_dvref_read,
+ .write = lmp92001_dvref_write,
+ .shared = IIO_SHARED_BY_ALL,
+ }, {
+ .name = "outx",
+ .read = lmp92001_outx_read,
+ .write = lmp92001_outx_write,
+ .shared = IIO_SHARED_BY_ALL,
+ }, {
+ .name = "gang",
+ .read = lmp92001_gang_read,
+ .write = lmp92001_gang_write,
+ .shared = IIO_SHARED_BY_ALL,
+ }, { },
+};
+
+#define LMP92001_CHAN_SPEC(_ch) \
+{ \
+ .channel = _ch, \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .ext_info = lmp92001_ext_info, \
+ .output = 1, \
+}
+
+static const struct iio_chan_spec lmp92001_dac_channels[] = {
+ LMP92001_CHAN_SPEC(1),
+ LMP92001_CHAN_SPEC(2),
+ LMP92001_CHAN_SPEC(3),
+ LMP92001_CHAN_SPEC(4),
+ LMP92001_CHAN_SPEC(5),
+ LMP92001_CHAN_SPEC(6),
+ LMP92001_CHAN_SPEC(7),
+ LMP92001_CHAN_SPEC(8),
+ LMP92001_CHAN_SPEC(9),
+ LMP92001_CHAN_SPEC(10),
+ LMP92001_CHAN_SPEC(11),
+ LMP92001_CHAN_SPEC(12),
+};
+
+static int lmp92001_dac_probe(struct platform_device *pdev)
+{
+ struct lmp92001 *lmp92001 = dev_get_drvdata(pdev->dev.parent);
+ struct iio_dev *indio_dev;
+ struct device_node *np = pdev->dev.of_node;
+ u8 gang = 0, outx = 0, hiz = 0;
+ unsigned int cdac = 0;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, 0);
+ if (!indio_dev)
+ return -ENOMEM;
+
+ iio_device_set_drvdata(indio_dev, lmp92001);
+
+ mutex_init(&lmp92001->dac_lock);
+
+ indio_dev->name = pdev->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &lmp92001_info;
+ indio_dev->channels = lmp92001_dac_channels;
+ indio_dev->num_channels = ARRAY_SIZE(lmp92001_dac_channels);
+
+ of_property_read_u8(np, "ti,lmp92001-dac-hiz", &hiz);
+ cdac = hiz;
+
+ of_property_read_u8(np, "ti,lmp92001-dac-outx", &outx);
+ cdac |= outx << 1;
+
+ of_property_read_u8(np, "ti,lmp92001-dac-gang", &gang);
+ cdac |= gang << 2;
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CDAC,
+ CDAC_GANG | CDAC_OLVL | CDAC_OFF, cdac);
+ if (ret < 0)
+ return ret;
+
+ return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static int lmp92001_dac_remove(struct platform_device *pdev)
+{
+ return 0;
+}
+
+static struct platform_driver lmp92001_dac_driver = {
+ .driver.name = "lmp92001-dac",
+ .probe = lmp92001_dac_probe,
+ .remove = lmp92001_dac_remove,
+};
+
+static int __init lmp92001_dac_init(void)
+{
+ return platform_driver_register(&lmp92001_dac_driver);
+}
+subsys_initcall(lmp92001_dac_init);
+
+static void __exit lmp92001_dac_exit(void)
+{
+ platform_driver_unregister(&lmp92001_dac_driver);
+}
+module_exit(lmp92001_dac_exit);
+
+MODULE_AUTHOR("Abhisit Sangjan <s.abhisit@xxxxxxxxx>");
+MODULE_DESCRIPTION("IIO DAC interface for TI LMP92001");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lmp92001-dac");
--
2.13.0