This adds TI's tlc4541 16-bit ADC driver. Which is a single channel
ADC. Supports raw and trigger buffer access.
Also supports the tlc3541 14-bit device, which has not been tested.
Implementation of the tlc3541 is fairly straight forward thou.
Acked-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Phil Reid <preid@xxxxxxxxxxxxxxxxx>
---
Notes:
Changes from v2:
- Fix paste error in binding document.
- Remove index from channel description. Note this break libiio.
libiio will no longer recognise that the cahnnel is buffer enabled.
- Add brackets to macro parameter bitshift
- Make tcl3541 / tcl4541 order in code consistent.
- Use spi_message_init_with_transfers
- Cleanup whitespace lines
- Add TLC3541 to kconfig description
- Add Robs Ack.
Changes from v1:
- Add tlc3541 support and chan spec.
- remove fields that where already 0 from TLC4541_V_CHAN macro
- Increase rx_buf size in tlc4541_state to avoid copy in tlc4541_trigger_handle
- Remove erroneous be16_to_cpu in tlc4541_trigger_handle
- Docs/binding: spi -> SPI & add ti,tlc3541
.../devicetree/bindings/iio/adc/ti-tlc4541.txt | 17 ++
drivers/iio/adc/Kconfig | 12 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-tlc4541.c | 271 +++++++++++++++++++++
4 files changed, 301 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-tlc4541.txt
create mode 100644 drivers/iio/adc/ti-tlc4541.c
diff --git a/Documentation/devicetree/bindings/iio/adc/ti-tlc4541.txt b/Documentation/devicetree/bindings/iio/adc/ti-tlc4541.txt
new file mode 100644
index 0000000..6b26927
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/ti-tlc4541.txt
@@ -0,0 +1,17 @@
+* Texas Instruments' TLC4541
+
+Required properties:
+ - compatible: Should be one of
+ * "ti,tlc4541"
+ * "ti,tlc3541"
+ - reg: SPI chip select number for the device
+ - vref-supply: The regulator supply for ADC reference voltage
+ - spi-max-frequency: Max SPI frequency to use (<= 200000)
+
+Example:
+adc@0 {
+ compatible = "ti,tlc4541";
+ reg = <0>;
+ vref-supply = <&vdd_supply>;
+ spi-max-frequency = <200000>;
+};
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 99c0514..fb9ede7 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -525,6 +525,18 @@ config TI_AM335X_ADC
To compile this driver as a module, choose M here: the module will be
called ti_am335x_adc.
+config TI_TLC4541
+ tristate "Texas Instruments TLC4541 ADC driver"
+ depends on SPI
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for Texas Instruments TLC4541 / TLC3541
+ ADC chips.
+
+ This driver can also be built as a module. If so, the module will be
+ called ti-tlc4541.
+
config TWL4030_MADC
tristate "TWL4030 MADC (Monitoring A/D Converter)"
depends on TWL4030_CORE
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 7a40c04..9bf2377 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o
obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
+obj-$(CONFIG_TI_TLC4541) += ti-tlc4541.o
obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
obj-$(CONFIG_TWL6030_GPADC) += twl6030-gpadc.o
obj-$(CONFIG_VF610_ADC) += vf610_adc.o
diff --git a/drivers/iio/adc/ti-tlc4541.c b/drivers/iio/adc/ti-tlc4541.c
new file mode 100644
index 0000000..78d91a0
--- /dev/null
+++ b/drivers/iio/adc/ti-tlc4541.c
@@ -0,0 +1,271 @@
+/*
+ * TI tlc4541 ADC Driver
+ *
+ * Copyright (C) 2017 Phil Reid
+ *
+ * Datasheets can be found here:
+ * http://www.ti.com/lit/gpn/tlc3541
+ * http://www.ti.com/lit/gpn/tlc4541
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * The tlc4541 requires 24 clock cycles to start a transfer.
+ * Conversion then takes 2.94us to complete before data is ready
+ * Data is returned MSB first.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/sysfs.h>
+
+struct tlc4541_state {
+ struct spi_device *spi;
+ struct regulator *reg;
+ struct spi_transfer scan_single_xfer[3];
+ struct spi_message scan_single_msg;
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ * 2 bytes data + 6 bytes padding + 8 bytes timestamp when
+ * call iio_push_to_buffers_with_timestamp.
+ */
+ __be16 rx_buf[8] ____cacheline_aligned;
+};
+
+struct tlc4541_chip_info {
+ const struct iio_chan_spec *channels;
+ unsigned int num_channels;
+};
+
+enum tlc4541_id {
+ TLC3541,
+ TLC4541,
+};
+
+#define TLC4541_V_CHAN(bits, bitshift) { \
+ .type = IIO_VOLTAGE, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = (bits), \
+ .storagebits = 16, \
+ .shift = (bitshift), \
+ .endianness = IIO_BE, \
+ }, \
+ }
+
+#define DECLARE_TLC4541_CHANNELS(name, bits, bitshift) \
+const struct iio_chan_spec name ## _channels[] = { \
+ TLC4541_V_CHAN(bits, bitshift), \
+ IIO_CHAN_SOFT_TIMESTAMP(1), \
+}
+
+static DECLARE_TLC4541_CHANNELS(tlc3541, 14, 2);
+static DECLARE_TLC4541_CHANNELS(tlc4541, 16, 0);
+
+static const struct tlc4541_chip_info tlc4541_chip_info[] = {
+ [TLC3541] = {
+ .channels = tlc3541_channels,
+ .num_channels = ARRAY_SIZE(tlc3541_channels),
+ },
+ [TLC4541] = {
+ .channels = tlc4541_channels,
+ .num_channels = ARRAY_SIZE(tlc4541_channels),
+ },
+};
+
+static irqreturn_t tlc4541_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct tlc4541_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = spi_sync(st->spi, &st->scan_single_msg);
+ if (ret < 0)
+ goto done;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
+ iio_get_time_ns(indio_dev));
+
+done:
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
+static int tlc4541_get_range(struct tlc4541_state *st)
+{
+ int vref;
+
+ vref = regulator_get_voltage(st->reg);
+ if (vref < 0)
+ return vref;
+
+ vref /= 1000;
+
+ return vref;
+}
+
+static int tlc4541_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long m)
+{
+ int ret = 0;
+ struct tlc4541_state *st = iio_priv(indio_dev);
+
+ switch (m) {
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+ ret = spi_sync(st->spi, &st->scan_single_msg);
+ iio_device_release_direct_mode(indio_dev);
+ if (ret < 0)
+ return ret;
+ *val = be16_to_cpu(st->rx_buf[0]);
+ *val = *val >> chan->scan_type.shift;
+ *val &= GENMASK(chan->scan_type.realbits - 1, 0);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ ret = tlc4541_get_range(st);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ }
+ return -EINVAL;
+}
+
+static const struct iio_info tlc4541_info = {
+ .read_raw = &tlc4541_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int tlc4541_probe(struct spi_device *spi)
+{
+ struct tlc4541_state *st;
+ struct iio_dev *indio_dev;
+ const struct tlc4541_chip_info *info;
+ int ret;
+ int8_t device_init = 0;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (indio_dev == NULL)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+
+ spi_set_drvdata(spi, indio_dev);
+
+ st->spi = spi;
+
+ info = &tlc4541_chip_info[spi_get_device_id(spi)->driver_data];
+
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = info->channels;
+ indio_dev->num_channels = info->num_channels;
+ indio_dev->info = &tlc4541_info;
+
+ /* perform reset */
+ spi_write(spi, &device_init, 1);
+
+ /* Setup default message */
+ st->scan_single_xfer[0].rx_buf = &st->rx_buf[0];
+ st->scan_single_xfer[0].len = 3;
+ st->scan_single_xfer[1].delay_usecs = 3;
+ st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
+ st->scan_single_xfer[2].len = 2;
+
+ spi_message_init_with_transfers(&st->scan_single_msg,
+ st->scan_single_xfer, 3);
+
+ st->reg = devm_regulator_get(&spi->dev, "vref");
+ if (IS_ERR(st->reg))
+ return PTR_ERR(st->reg);
+
+ ret = regulator_enable(st->reg);
+ if (ret)
+ return ret;
+
+ ret = iio_triggered_buffer_setup(indio_dev, NULL,
+ &tlc4541_trigger_handler, NULL);
+ if (ret)
+ goto error_disable_reg;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_cleanup_buffer;
+
+ return 0;
+
+error_cleanup_buffer:
+ iio_triggered_buffer_cleanup(indio_dev);
+error_disable_reg:
+ regulator_disable(st->reg);
+
+ return ret;
+}
+
+static int tlc4541_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct tlc4541_state *st = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+ regulator_disable(st->reg);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id tlc4541_dt_ids[] = {
+ { .compatible = "ti,tlc3541", },
+ { .compatible = "ti,tlc4541", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, tlc4541_dt_ids);
+#endif
+
+static const struct spi_device_id tlc4541_id[] = {
+ {"tlc3541", TLC3541},
+ {"tlc4541", TLC4541},
+ {}
+};
+MODULE_DEVICE_TABLE(spi, tlc4541_id);
+
+static struct spi_driver tlc4541_driver = {
+ .driver = {
+ .name = "tlc4541",
+ .of_match_table = of_match_ptr(tlc4541_dt_ids),
+ },
+ .probe = tlc4541_probe,
+ .remove = tlc4541_remove,
+ .id_table = tlc4541_id,
+};
+module_spi_driver(tlc4541_driver);
+
+MODULE_AUTHOR("Phil Reid <preid@xxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Texas Instruments TLC4541 ADC");
+MODULE_LICENSE("GPL v2");
--
1.8.3.1
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