On 11 January 2017 06:51:11 GMT+00:00, Phil Reid <preid@xxxxxxxxxxxxxxxxx> wrote:
>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.
>
>Signed-off-by: Phil Reid <preid@xxxxxxxxxxxxxxxxx>
One minor suggestion from me.
J
>---
>
>Notes:
> 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
>
> I haven't add Rob's Ack due to adding a new compatible string.
>
>I tried to ".index = 1" from the spec as suggested by Peter, but that
>didn't
> seem to work. Perhaps remove of .channel was the intended target.
>
> Example output from iio_readdev
>
> with ".index = 1"
> root@cyclone5:~# mkdir /sys/kernel/config/iio/triggers/hrtimer/hr1
> root@cyclone5:~# iio_readdev -t hr1 -b 32 -s 10 tlc4541 | hexdump
> WARNING: High-speed mode not enabled
> 0000000 af00 0000 0000 0000 b922 ca99 93da 1492
> 0000010 a800 00ff 0000 0000 b246 cb30 93da 1492
> 0000020 a900 0000 0000 0000 4f9c cbc9 93da 1492
> 0000030 aa00 00ff 0000 0000 bd2c cc61 93da 1492
> 0000040 aa00 00ff 0000 0000 544c ccfa 93da 1492
> 0000050 ab00 00ff 0000 0000 e806 cd92 93da 1492
> 0000060 a900 00ff 0000 0000 846c ce2b 93da 1492
> 0000070 ab00 0000 0000 0000 2efc cec8 93da 1492
> 0000080 a800 00ff 0000 0000 b090 cf5c 93da 1492
> 0000090 a900 00ff 0000 0000 476a cff5 93da 1492
>
> without .index
> root@cyclone5:~# mkdir /sys/kernel/config/iio/triggers/hrtimer/hr1
> root@cyclone5:~# iio_readdev -t hr1 -b 32 -s 10 tlc4541 | hexdump
> WARNING: High-speed mode not enabled
> 0000000 6db0 eeb6 93e3 1492 35e0 ef4f 93e3 1492
> 0000010 4b34 efe5 93e3 1492 e9f2 f07d 93e3 1492
> 0000020 6182 f116 93e3 1492 090a f1af 93e3 1492
> 0000030 409c f249 93e3 1492 6c1a f2e0 93e3 1492
> 0000040 cd02 f378 93e3 1492 9582 f411 93e3 1492
>
> .../devicetree/bindings/iio/adc/ti-tlc4541.txt | 17 ++
> drivers/iio/adc/Kconfig | 11 +
> drivers/iio/adc/Makefile | 1 +
>drivers/iio/adc/ti-tlc4541.c | 276
>+++++++++++++++++++++
> 4 files changed, 305 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..e1de2bd
>--- /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,adc0832";
>+ reg = <0>;
>+ vref-supply = <&vdd_supply>;
>+ spi-max-frequency = <200000>;
>+};
>diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>index 99c0514..4dda3f0 100644
>--- a/drivers/iio/adc/Kconfig
>+++ b/drivers/iio/adc/Kconfig
>@@ -525,6 +525,17 @@ 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 ADC
>chip.
>+
>+ 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..a0cd5e1
>--- /dev/null
>+++ b/drivers/iio/adc/ti-tlc4541.c
>@@ -0,0 +1,276 @@
>+/*
>+ * 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, \
>+ .indexed = 1, \
>+ .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(tlc4541, 16, 0);
>+static DECLARE_TLC4541_CHANNELS(tlc3541, 14, 2);
>+
>+static const struct tlc4541_chip_info tlc4541_chip_info[] = {
>+ [TLC4541] = {
>+ .channels = tlc4541_channels,
>+ .num_channels = ARRAY_SIZE(tlc4541_channels),
>+ },
>+ [TLC3541] = {
>+ .channels = tlc3541_channels,
>+ .num_channels = ARRAY_SIZE(tlc3541_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(&st->scan_single_msg);
>+ spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
>+ spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
>+ spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg);
spi_init_with_transfers.
>+
>+ 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");
--
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