From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752542AbdEHJFO (ORCPT ); Mon, 8 May 2017 05:05:14 -0400 Received: from mga05.intel.com ([192.55.52.43]:63195 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751255AbdEHJFM (ORCPT ); Mon, 8 May 2017 05:05:12 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.38,308,1491289200"; d="scan'208";a="965724222" Message-ID: <1494234036.30052.48.camel@linux.intel.com> Subject: Re: [PATCH v5] iio: adc: Add support for TI ADC108S102 and ADC128S102 From: Andy Shevchenko To: Jan Kiszka , Jonathan Cameron Cc: linux-iio@vger.kernel.org, Linux Kernel Mailing List , Sascha Weisenberger , Mika Westerberg , Peter Meerwald-Stadler , Rob Herring Date: Mon, 08 May 2017 12:00:36 +0300 In-Reply-To: <9d7366c4-7965-d92a-e806-f20a8d63242e@siemens.com> References: <9d7366c4-7965-d92a-e806-f20a8d63242e@siemens.com> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2017-05-08 at 10:46 +0200, Jan Kiszka wrote: > This is an upstream port of an IIO driver for the TI ADC108S102 and > ADC128S102. The former can be found on the Intel Galileo Gen2 and the > Siemens SIMATIC IOT2000. For those boards, ACPI-based enumeration is > included. > > Due to the lack of regulators under ACPI, we hard-code the voltage > provided to the VA pin of the ADC to 5 V, the value used on Galileo > and > IOT2000. For DT usage, the regulator "vref-supply" provides this > information. Note that DT usage has not been tested. > > Original author: Bogdan Pricop > Ported from Intel Galileo Gen2 BSP to Intel Yocto kernel: > Todor Minchev . > Okay, it looks like it most what we can do right now about regulator framework appearance in this driver. FWIW: Reviewed-by: Andy Shevchenko > Signed-off-by: Jan Kiszka > --- > > Changes in v5: >  - refactor error handling in adc108s102_read_raw >  - removed no longer needed checks before regulator_disable >    (v3 left-over) > >  .../devicetree/bindings/iio/adc/ti-adc108s102.txt  |  18 ++ >  drivers/iio/adc/Kconfig                            |  12 + >  drivers/iio/adc/Makefile                           |   1 + >  drivers/iio/adc/ti-adc108s102.c                    | 342 > +++++++++++++++++++++ >  4 files changed, 373 insertions(+) >  create mode 100644 Documentation/devicetree/bindings/iio/adc/ti- > adc108s102.txt >  create mode 100644 drivers/iio/adc/ti-adc108s102.c > > diff --git a/Documentation/devicetree/bindings/iio/adc/ti- > adc108s102.txt b/Documentation/devicetree/bindings/iio/adc/ti- > adc108s102.txt > new file mode 100644 > index 000000000000..bbbbb4a9f58f > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/ti-adc108s102.txt > @@ -0,0 +1,18 @@ > +* Texas Instruments' ADC108S102 and ADC128S102 ADC chip > + > +Required properties: > + - compatible: Should be "ti,adc108s102" > + - reg: spi chip select number for the device > + - vref-supply: The regulator supply for ADC reference voltage > + > +Recommended properties: > + - spi-max-frequency: Definition as per > + Documentation/devicetree/bindings/spi/spi-bus.txt > + > +Example: > +adc@0 { > + compatible = "ti,adc108s102"; > + reg = <0>; > + vref-supply = <&vdd_supply>; > + spi-max-frequency = <1000000>; > +}; > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index dedae7adbce9..8b7dae5604f2 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -572,6 +572,18 @@ config TI_ADC12138 >     This driver can also be built as a module. If so, the > module will be >     called ti-adc12138. >   > +config TI_ADC108S102 > + tristate "Texas Instruments ADC108S102 and ADC128S102 driver" > + depends on SPI > + select IIO_BUFFER > + select IIO_TRIGGERED_BUFFER > + help > +   Say yes here to build support for Texas Instruments > ADC108S102 and > +   ADC128S102 ADC. > + > +   To compile this driver as a module, choose M here: the > module will > +   be called ti-adc108s102. > + >  config TI_ADC128S052 >   tristate "Texas Instruments ADC128S052/ADC122S021/ADC124S021" >   depends on SPI > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index d0012620cd1c..e6c20fe3d4eb 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -52,6 +52,7 @@ obj-$(CONFIG_STM32_ADC) += stm32-adc.o >  obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o >  obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o >  obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o > +obj-$(CONFIG_TI_ADC108S102) += ti-adc108s102.o >  obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o >  obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o >  obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o > diff --git a/drivers/iio/adc/ti-adc108s102.c b/drivers/iio/adc/ti- > adc108s102.c > new file mode 100644 > index 000000000000..bdf3254619a3 > --- /dev/null > +++ b/drivers/iio/adc/ti-adc108s102.c > @@ -0,0 +1,342 @@ > +/* > + * TI ADC108S102 SPI ADC driver > + * > + * Copyright (c) 2013-2015 Intel Corporation. > + * Copyright (c) 2017 Siemens AG > + * > + * This program is free software; you can redistribute it and/or > modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope 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. > + * > + * This IIO device driver is designed to work with the following > + * analog to digital converters from Texas Instruments: > + *  ADC108S102 > + *  ADC128S102 > + * The communication with ADC chip is via the SPI bus (mode 3). > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* > + * In case of ACPI, we use the hard-wired 5000 mV of the Galileo and > IOT2000 > + * boards as default for the reference pin VA. Device tree users > encode that > + * via the vref-supply regulator. > + */ > +#define ADC108S102_VA_MV_ACPI_DEFAULT 5000 > + > +/* > + * Defining the ADC resolution being 12 bits, we can use the same > driver for > + * both ADC108S102 (10 bits resolution) and ADC128S102 (12 bits > resolution) > + * chips. The ADC108S102 effectively returns a 12-bit result with the > 2 > + * least-significant bits unset. > + */ > +#define ADC108S102_BITS 12 > +#define ADC108S102_MAX_CHANNELS 8 > + > +/* > + * 16-bit SPI command format: > + *   [15:14] Ignored > + *   [13:11] 3-bit channel address > + *   [10:0]  Ignored > + */ > +#define ADC108S102_CMD(ch) ((u16)(ch) << 11) > + > +/* > + * 16-bit SPI response format: > + *   [15:12] Zeros > + *   [11:0]  12-bit ADC sample (for ADC108S102, [1:0] will always be > 0). > + */ > +#define ADC108S102_RES_DATA(res) ((u16)res & GENMASK(11, 0)) > + > +struct adc108s102_state { > + struct spi_device *spi; > + struct regulator *reg; > + u32 va_millivolt; > + /* SPI transfer used by triggered buffer handler*/ > + struct spi_transfer ring_xfer; > + /* SPI transfer used by direct scan */ > + struct spi_transfer scan_single_xfer; > + /* SPI message used by ring_xfer SPI transfer */ > + struct spi_message ring_msg; > + /* SPI message used by scan_single_xfer SPI transfer */ > + struct spi_message scan_single_msg; > + > + /* > +  * SPI message buffers: > +  *  tx_buf: |C0|C1|C2|C3|C4|C5|C6|C7|XX| > +  *  rx_buf: |XX|R0|R1|R2|R3|R4|R5|R6|R7|tt|tt|tt|tt| > +  * > +  *  tx_buf: 8 channel read commands, plus 1 dummy command > +  *  rx_buf: 1 dummy response, 8 channel responses, plus 64- > bit timestamp > +  */ > + __be16 rx_buf[13] > ____cacheline_aligned; > + __be16 tx_buf[9] > ____cacheline_aligned; > +}; > + > +#define ADC108S102_V_CHAN(index) > \ > + { > \ > + .type = IIO_VOLTAGE, > \ > + .indexed = 1, > \ > + .channel = index, > \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > \ > + BIT(IIO_CHAN_INFO_SCALE), > \ > + .address = index, > \ > + .scan_index = index, > \ > + .scan_type = { > \ > + .sign = 'u', > \ > + .realbits = ADC108S102_BITS, > \ > + .storagebits = 16, > \ > + .endianness = IIO_BE, > \ > + }, > \ > + } > + > +static const struct iio_chan_spec adc108s102_channels[] = { > + ADC108S102_V_CHAN(0), > + ADC108S102_V_CHAN(1), > + ADC108S102_V_CHAN(2), > + ADC108S102_V_CHAN(3), > + ADC108S102_V_CHAN(4), > + ADC108S102_V_CHAN(5), > + ADC108S102_V_CHAN(6), > + ADC108S102_V_CHAN(7), > + IIO_CHAN_SOFT_TIMESTAMP(8), > +}; > + > +static int adc108s102_update_scan_mode(struct iio_dev *indio_dev, > + unsigned long const *active_scan_mask) > +{ > + struct adc108s102_state *st = iio_priv(indio_dev); > + unsigned int bit, cmds; > + > + /* > +  * Fill in the first x shorts of tx_buf with the number of > channels > +  * enabled for sampling by the triggered buffer. > +  */ > + cmds = 0; > + for_each_set_bit(bit, active_scan_mask, > ADC108S102_MAX_CHANNELS) > + st->tx_buf[cmds++] = > cpu_to_be16(ADC108S102_CMD(bit)); > + > + /* One dummy command added, to clock in the last response */ > + st->tx_buf[cmds++] = 0x00; > + > + /* build SPI ring message */ > + st->ring_xfer.tx_buf = &st->tx_buf[0]; > + st->ring_xfer.rx_buf = &st->rx_buf[0]; > + st->ring_xfer.len = cmds * sizeof(st->tx_buf[0]); > + > + spi_message_init_with_transfers(&st->ring_msg, &st- > >ring_xfer, 1); > + > + return 0; > +} > + > +static irqreturn_t adc108s102_trigger_handler(int irq, void *p) > +{ > + struct iio_poll_func *pf = p; > + struct iio_dev *indio_dev = pf->indio_dev; > + struct adc108s102_state *st = iio_priv(indio_dev); > + int ret; > + > + ret = spi_sync(st->spi, &st->ring_msg); > + if (ret < 0) > + goto out_notify; > + > + /* Skip the dummy response in the first slot */ > + iio_push_to_buffers_with_timestamp(indio_dev, > +    (u8 *)&st->rx_buf[1], > +    iio_get_time_ns(indio_dev) > ); > + > +out_notify: > + iio_trigger_notify_done(indio_dev->trig); > + > + return IRQ_HANDLED; > +} > + > +static int adc108s102_scan_direct(struct adc108s102_state *st, > unsigned int ch) > +{ > + int ret; > + > + st->tx_buf[0] = cpu_to_be16(ADC108S102_CMD(ch)); > + ret = spi_sync(st->spi, &st->scan_single_msg); > + if (ret) > + return ret; > + > + /* Skip the dummy response in the first slot */ > + return be16_to_cpu(st->rx_buf[1]); > +} > + > +static int adc108s102_read_raw(struct iio_dev *indio_dev, > +        struct iio_chan_spec const *chan, > +        int *val, int *val2, long m) > +{ > + struct adc108s102_state *st = iio_priv(indio_dev); > + int ret; > + > + switch (m) { > + case IIO_CHAN_INFO_RAW: > + ret = iio_device_claim_direct_mode(indio_dev); > + if (ret) > + return ret; > + > + ret = adc108s102_scan_direct(st, chan->address); > + > + iio_device_release_direct_mode(indio_dev); > + > + if (ret < 0) > + return ret; > + > + *val = ADC108S102_RES_DATA(ret); > + > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + if (chan->type != IIO_VOLTAGE) > + break; > + > + *val = st->va_millivolt; > + *val2 = chan->scan_type.realbits; > + > + return IIO_VAL_FRACTIONAL_LOG2; > + default: > + break; > + } > + > + return -EINVAL; > +} > + > +static const struct iio_info adc108s102_info = { > + .read_raw = &adc108s102_read_raw, > + .update_scan_mode = &adc108s102_update_scan_mode, > + .driver_module = THIS_MODULE, > +}; > + > +static int adc108s102_probe(struct spi_device *spi) > +{ > + struct adc108s102_state *st; > + struct iio_dev *indio_dev; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); > + if (!indio_dev) > + return -ENOMEM; > + > + st = iio_priv(indio_dev); > + > + if (ACPI_COMPANION(&spi->dev)) { > + st->va_millivolt = ADC108S102_VA_MV_ACPI_DEFAULT; > + } else { > + 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 < 0) { > + dev_err(&spi->dev, "Cannot enable vref > regulator\n"); > + return ret; > + } > + > + ret = regulator_get_voltage(st->reg); > + if (ret < 0) { > + dev_err(&spi->dev, "vref get voltage > failed\n"); > + return ret; > + } > + > + st->va_millivolt = ret / 1000; > + } > + > + spi_set_drvdata(spi, indio_dev); > + st->spi = spi; > + > + indio_dev->name = spi->modalias; > + indio_dev->dev.parent = &spi->dev; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = adc108s102_channels; > + indio_dev->num_channels = ARRAY_SIZE(adc108s102_channels); > + indio_dev->info = &adc108s102_info; > + > + /* Setup default message */ > + st->scan_single_xfer.tx_buf = st->tx_buf; > + st->scan_single_xfer.rx_buf = st->rx_buf; > + st->scan_single_xfer.len = 2 * sizeof(st->tx_buf[0]); > + > + spi_message_init_with_transfers(&st->scan_single_msg, > + &st->scan_single_xfer, 1); > + > + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, > NULL, > + &adc108s102_trigger_handler, NULL); > + if (ret) > + goto error_disable_reg; > + > + ret = devm_iio_device_register(&spi->dev, indio_dev); > + if (ret) { > + dev_err(&spi->dev, "Failed to register IIO > device\n"); > + goto error_disable_reg; > + } > + return 0; > + > +error_disable_reg: > + regulator_disable(st->reg); > + > + return ret; > +} > + > +static int adc108s102_remove(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev = spi_get_drvdata(spi); > + struct adc108s102_state *st = iio_priv(indio_dev); > + > + regulator_disable(st->reg); > + > + return 0; > +} > + > +#ifdef CONFIG_OF > +static const struct of_device_id adc108s102_of_match[] = { > + { .compatible = "ti,adc108s102" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, adc108s102_of_match); > +#endif > + > +#ifdef CONFIG_ACPI > +static const struct acpi_device_id adc108s102_acpi_ids[] = { > + { "INT3495", 0 }, > + { } > +}; > +MODULE_DEVICE_TABLE(acpi, adc108s102_acpi_ids); > +#endif > + > +static const struct spi_device_id adc108s102_id[] = { > + { "adc108s102", 0 }, > + { } > +}; > +MODULE_DEVICE_TABLE(spi, adc108s102_id); > + > +static struct spi_driver adc108s102_driver = { > + .driver = { > + .name   = "adc108s102", > + .of_match_table = of_match_ptr(adc108s102_of_match), > + .acpi_match_table = ACPI_PTR(adc108s102_acpi_ids), > + }, > + .probe = adc108s102_probe, > + .remove = adc108s102_remove, > + .id_table = adc108s102_id, > +}; > +module_spi_driver(adc108s102_driver); > + > +MODULE_AUTHOR("Bogdan Pricop "); > +MODULE_DESCRIPTION("Texas Instruments ADC108S102 and ADC128S102 > driver"); > +MODULE_LICENSE("GPL v2"); -- Andy Shevchenko Intel Finland Oy