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Subject[PATCH 2/5] iio: Add support for LMP92001 ADC
Date
From: Abhisit Sangjan <s.abhisit@gmail.com>

---
drivers/iio/adc/Kconfig | 10 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/lmp92001-adc.c | 479 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 490 insertions(+)
create mode 100644 drivers/iio/adc/lmp92001-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 614fa41..b623b4d 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -857,4 +857,14 @@ config XILINX_XADC
The driver can also be build as a module. If so, the module will be called
xilinx-xadc.

+config LMP92001_ADC
+ tristate "TI LMP92001 ADC Driver"
+ depends on MFD_LMP92001
+ help
+ If you say yes here you get support for TI LMP92001 ADCs
+ conversion.
+
+ This driver can also be built as a module. If so, the module will
+ be called lmp92001_adc.
+
endmenu
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index b546736a..75b24b1 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -78,3 +78,4 @@ obj-$(CONFIG_VF610_ADC) += vf610_adc.o
obj-$(CONFIG_VIPERBOARD_ADC) += viperboard_adc.o
xilinx-xadc-y := xilinx-xadc-core.o xilinx-xadc-events.o
obj-$(CONFIG_XILINX_XADC) += xilinx-xadc.o
+obj-$(CONFIG_LMP92001_ADC) += lmp92001-adc.o
diff --git a/drivers/iio/adc/lmp92001-adc.c b/drivers/iio/adc/lmp92001-adc.c
new file mode 100644
index 0000000..909ff47
--- /dev/null
+++ b/drivers/iio/adc/lmp92001-adc.c
@@ -0,0 +1,479 @@
+/*
+ * lmp92001-adc.c - Support for TI LMP92001 ADCs
+ *
+ * Copyright 2016-2017 Celestica Ltd.
+ *
+ * Author: Abhisit Sangjan <s.abhisit@gmail.com>
+ *
+ * Inspired by wm831x and ad5064 drivers.
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/mfd/core.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.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);
+ unsigned int code, cgen, sgen, try;
+ int ret;
+
+ ret = regmap_read(lmp92001->regmap, LMP92001_CGEN, &cgen);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Is not continuous conversion?
+ * Lock the registers (if needed).
+ * Triggering single-short conversion.
+ * Waiting for conversion successfully.
+ */
+ if (!(cgen & 1))
+ {
+ if (!(cgen & 2))
+ {
+ ret = regmap_update_bits(lmp92001->regmap,
+ LMP92001_CGEN, 2, 2);
+ if (ret < 0)
+ return ret;
+ }
+
+ ret = regmap_write(lmp92001->regmap, LMP92001_CTRIG, 1);
+ if (ret < 0)
+ return ret;
+
+ try = 10;
+ do {
+ ret = regmap_read(lmp92001->regmap,
+ LMP92001_SGEN, &sgen);
+ if(ret < 0)
+ return ret;
+ } while ((sgen & 1<<7) && (--try > 0));
+
+ if (!try)
+ return -ETIME;
+ }
+
+ ret = regmap_read(lmp92001->regmap, 0x1F + channel->channel, &code);
+ if (ret < 0)
+ return ret;
+
+ switch (mask)
+ {
+ case IIO_CHAN_INFO_RAW:
+ switch (channel->type) {
+ case IIO_VOLTAGE:
+ case IIO_TEMP:
+ *val = code;
+ return IIO_VAL_INT;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
+/*
+ * TODO: do your attributes even handler for
+ * Current limit low/high for CH 1-3, 9-11!
+ * In case INT1 and INT2 were connected to i.MX6.
+ */
+static const struct iio_info lmp92001_info = {
+ .read_raw = lmp92001_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static ssize_t lmp92001_avref_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 & 2 ? "external" : "internal");
+}
+
+static ssize_t lmp92001_avref_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 (strcmp("external\n", buf) == 0)
+ cref = 2;
+ else if (strcmp("internal\n", buf) == 0)
+ cref = 0;
+ else
+ return -EINVAL;
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CREF, 2, cref);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static ssize_t lmp92001_enable_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 reg, cad;
+ int ret;
+
+ switch (channel->channel)
+ {
+ case 1 ... 8:
+ reg = LMP92001_CAD1;
+ break;
+ case 9 ... 16:
+ reg = LMP92001_CAD2;
+ break;
+ case 17:
+ reg = LMP92001_CAD3;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = regmap_read(lmp92001->regmap, reg, &cad);
+ if (ret < 0)
+ return ret;
+
+ if (channel->channel <= 8)
+ cad >>= channel->channel - 1;
+ else if(channel->channel > 8)
+ cad >>= channel->channel - 9;
+ else if(channel->channel > 16)
+ cad >>= channel->channel - 17;
+ else
+ return -EINVAL;
+
+ return sprintf(buf, "%s\n", cad & 1 ? "enable" : "disable");
+}
+
+static ssize_t lmp92001_enable_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 reg, enable, shif, mask;
+ int ret;
+
+ switch (channel->channel)
+ {
+ case 1 ... 8:
+ reg = LMP92001_CAD1;
+ shif = (channel->channel - 1);
+ break;
+ case 9 ... 16:
+ reg = LMP92001_CAD2;
+ shif = (channel->channel - 9);
+ break;
+ case 17:
+ reg = LMP92001_CAD3;
+ shif = (channel->channel - 17);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (strcmp("enable\n", buf) == 0)
+ enable = 1;
+ else if (strcmp("disable\n", buf) == 0)
+ enable = 0;
+ else
+ return -EINVAL;
+
+ enable <<= shif;
+ mask = 1 << shif;
+
+ ret = regmap_update_bits(lmp92001->regmap, reg, mask, enable);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static ssize_t lmp92001_mode_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 cgen;
+ int ret;
+
+ ret = regmap_read(lmp92001->regmap, LMP92001_CGEN, &cgen);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%s\n", cgen & 1 ? "continuous" : "single-shot");
+}
+
+static ssize_t lmp92001_mode_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 cgen;
+ int ret;
+
+ if (strcmp("continuous\n", buf) == 0)
+ cgen = 1;
+ else if (strcmp("single-shot\n", buf) == 0)
+ cgen = 0;
+ else
+ return -EINVAL;
+
+ /*
+ * Unlock the registers.
+ * Set conversion mode.
+ * Lock the registers.
+ */
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CGEN, 2, 0);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CGEN, 1, cgen);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CGEN, 2, 2);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static const struct iio_chan_spec_ext_info lmp92001_ext_info[] = {
+ {
+ .name = "vref",
+ .read = lmp92001_avref_read,
+ .write = lmp92001_avref_write,
+ .shared = IIO_SHARED_BY_ALL,
+ },
+ {
+ .name = "en",
+ .read = lmp92001_enable_read,
+ .write = lmp92001_enable_write,
+ .shared = IIO_SEPARATE,
+ },
+ {
+ .name = "mode",
+ .read = lmp92001_mode_read,
+ .write = lmp92001_mode_write,
+ .shared = IIO_SHARED_BY_ALL,
+ },
+ { },
+};
+
+static const struct iio_event_spec lmp92001_events[] = {
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_RISING,
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+ BIT(IIO_EV_INFO_VALUE),
+ },
+ {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_FALLING,
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+ BIT(IIO_EV_INFO_VALUE),
+ },
+ { },
+};
+
+#define LMP92001_CHAN_SPEC(_ch, _type, _event, _nevent) \
+{ \
+ .channel = _ch, \
+ .scan_index = _ch, \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ .repeat = 1, \
+ .endianness = IIO_BE, \
+ }, \
+ .type = _type, \
+ .indexed = 1, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .event_spec = _event, \
+ .num_event_specs = _nevent, \
+ .ext_info = lmp92001_ext_info, \
+}
+
+/*
+ * TODO: do your ext_info for current low/high limit.
+ * Example driver/iio/dac/ad5064.c
+ */
+static const struct iio_chan_spec lmp92001_adc_channels[] = {
+ LMP92001_CHAN_SPEC( 1, IIO_VOLTAGE, lmp92001_events, ARRAY_SIZE(lmp92001_events)),
+ LMP92001_CHAN_SPEC( 2, IIO_VOLTAGE, lmp92001_events, ARRAY_SIZE(lmp92001_events)),
+ LMP92001_CHAN_SPEC( 3, IIO_VOLTAGE, lmp92001_events, ARRAY_SIZE(lmp92001_events)),
+ LMP92001_CHAN_SPEC( 4, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC( 5, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC( 6, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC( 7, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC( 8, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC( 9, IIO_VOLTAGE, lmp92001_events, ARRAY_SIZE(lmp92001_events)),
+ LMP92001_CHAN_SPEC(10, IIO_VOLTAGE, lmp92001_events, ARRAY_SIZE(lmp92001_events)),
+ LMP92001_CHAN_SPEC(11, IIO_VOLTAGE, lmp92001_events, ARRAY_SIZE(lmp92001_events)),
+ LMP92001_CHAN_SPEC(12, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC(13, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC(14, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC(15, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC(16, IIO_VOLTAGE, NULL, 0),
+ LMP92001_CHAN_SPEC(17, IIO_TEMP, NULL, 0),
+};
+
+static int lmp92001_adc_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;
+ const char *conversion;
+ unsigned int cgen = 0, cad1, cad2, cad3;
+ u32 mask;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*lmp92001));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ iio_device_set_drvdata(indio_dev, lmp92001);
+
+ indio_dev->name = pdev->name;
+ indio_dev->dev.parent = &pdev->dev;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &lmp92001_info;
+ indio_dev->channels = lmp92001_adc_channels;
+ indio_dev->num_channels = ARRAY_SIZE(lmp92001_adc_channels);
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CGEN, 0x80, 0x80);
+ if (ret < 0)
+ {
+ dev_err(&pdev->dev,"failed to self reset all registers\n");
+ return ret;
+ }
+
+ ret = of_property_read_u32(np, "ti,lmp92001-adc-mask", &mask);
+ if (ret < 0)
+ {
+ cad1 = cad2 = cad3 = 0xFF;
+ dev_info(&pdev->dev, "turn on all of channels by default\n");
+ }
+ else
+ {
+ cad1 = mask & 0xFF;
+ cad2 = (mask >> 8) & 0xFF;
+ cad3 = (mask >> 16) & 0xFF;
+ }
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CAD1, 0xFF, cad1);
+ if (ret < 0)
+ {
+ dev_err(&pdev->dev,"failed to enable channels 1-8\n");
+ return ret;
+ }
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CAD2, 0xFF, cad2);
+ if (ret < 0)
+ {
+ dev_err(&pdev->dev, "failed to enable channels 9-16\n");
+ return ret;
+ }
+
+ ret = regmap_update_bits(lmp92001->regmap, LMP92001_CAD3, 1, cad3);
+ if (ret < 0)
+ {
+ dev_err(&pdev->dev, "failed to enable channel 17 (temperature)\n");
+ return ret;
+ }
+
+ ret = of_property_read_string_index(np, "ti,lmp92001-adc-mode", 0,
+ &conversion);
+ if (!ret)
+ {
+ if (strcmp("continuous", conversion) == 0)
+ cgen |= 1;
+ else if (strcmp("single-shot", conversion) == 0)
+ { /* Okay */ }
+ else
+ dev_warn(&pdev->dev,
+ "wrong adc mode! set to single-short conversion\n");
+ }
+ else
+ dev_info(&pdev->dev,
+ "single-short conversion was chosen by default\n");
+
+ /*
+ * Lock the registers and set conversion mode.
+ */
+ ret = regmap_update_bits(lmp92001->regmap,
+ LMP92001_CGEN, 3, cgen | 2);
+ if (ret < 0)
+ return ret;
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ return iio_device_register(indio_dev);
+}
+
+static int lmp92001_adc_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+
+ iio_device_unregister(indio_dev);
+
+ return 0;
+}
+
+static struct platform_driver lmp92001_adc_driver = {
+ .driver.name = "lmp92001-adc",
+ .driver.owner = THIS_MODULE,
+ .probe = lmp92001_adc_probe,
+ .remove = lmp92001_adc_remove,
+};
+
+static int __init lmp92001_adc_init(void)
+{
+ return platform_driver_register(&lmp92001_adc_driver);
+}
+subsys_initcall(lmp92001_adc_init);
+
+static void __exit lmp92001_adc_exit(void)
+{
+ platform_driver_unregister(&lmp92001_adc_driver);
+}
+module_exit(lmp92001_adc_exit);
+
+MODULE_AUTHOR("Abhisit Sangjan <s.abhisit@gmail.com>");
+MODULE_DESCRIPTION("IIO ADC interface for TI LMP92001");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lmp92001-adc");
--
2.7.4
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