From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755439AbcBHRvA (ORCPT ); Mon, 8 Feb 2016 12:51:00 -0500 Received: from mail-yw0-f196.google.com ([209.85.161.196]:34289 "EHLO mail-yw0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754889AbcBHRuo (ORCPT ); Mon, 8 Feb 2016 12:50:44 -0500 Date: Mon, 8 Feb 2016 12:50:34 -0500 From: William Breathitt Gray To: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] iio: Add IIO support for the DAC on the Apex Embedded Systems STX104 Message-ID: <20160208175034.GA14727@sophia> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The Apex Embedded Systems STX104 is a 16-channel 16-bit analog input and 2-channel 16-bit analog output PC/104 card. The STX104 incorporates a large one mega-sample FIFO. This driver provides IIO support for the 2-channel DAC on the STX104. The base port addresses for the devices may be configured via the stx104_base module parameter array. Signed-off-by: William Breathitt Gray --- Changes in v2: - Inline use of dev_name macro - Use devm_iio_device_register to simplify cleanup code - Use ISA bus driver instead of platform driver - Provide stx104_base module parameter as an array in order to support multiple instances MAINTAINERS | 6 ++ drivers/iio/dac/Kconfig | 9 +++ drivers/iio/dac/Makefile | 1 + drivers/iio/dac/stx104.c | 152 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 168 insertions(+) create mode 100644 drivers/iio/dac/stx104.c diff --git a/MAINTAINERS b/MAINTAINERS index 6ddb488..3905b31 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -763,6 +763,12 @@ L: alsa-devel@alsa-project.org (moderated for non-subscribers) S: Maintained F: sound/aoa/ +APEX EMBEDDED SYSTEMS STX104 DAC DRIVER +M: William Breathitt Gray +L: linux-iio@vger.kernel.org +S: Maintained +F: drivers/iio/dac/stx104.c + APM DRIVER M: Jiri Kosina S: Odd fixes diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig index 5dc7150..6cf1066 100644 --- a/drivers/iio/dac/Kconfig +++ b/drivers/iio/dac/Kconfig @@ -206,4 +206,13 @@ config MCP4922 To compile this driver as a module, choose M here: the module will be called mcp4922. +config STX104 + tristate "Apex Embedded Systems STX104 DAC driver" + depends on ISA + help + Say yes here to build support for the 2-channel DAC on the Apex + Embedded Systems STX104 integrated analog PC/104 card. The base port + addresses for the devices may be configured via the stx104_base module + parameter array. + endmenu diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile index cb525b5..e2deda9 100644 --- a/drivers/iio/dac/Makefile +++ b/drivers/iio/dac/Makefile @@ -22,3 +22,4 @@ obj-$(CONFIG_MAX517) += max517.o obj-$(CONFIG_MAX5821) += max5821.o obj-$(CONFIG_MCP4725) += mcp4725.o obj-$(CONFIG_MCP4922) += mcp4922.o +obj-$(CONFIG_STX104) += stx104.o diff --git a/drivers/iio/dac/stx104.c b/drivers/iio/dac/stx104.c new file mode 100644 index 0000000..f183e3f --- /dev/null +++ b/drivers/iio/dac/stx104.c @@ -0,0 +1,152 @@ +/* + * DAC driver for the Apex Embedded Systems STX104 + * Copyright (C) 2016 William Breathitt Gray + * + * 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. + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define STX104_NUM_CHAN 2 + +#define STX104_CHAN(chan) { \ + .type = IIO_VOLTAGE, \ + .channel = chan, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .indexed = 1, \ + .output = 1 \ +} + +#define STX104_EXTENT 16 +/** + * The highest base address possible for an ISA device is 0x3FF; this results in + * 1024 possible base addresses. Dividing the number of possible base addresses + * by the address extent taken by each device results in the maximum number of + * devices on a system. + */ +#define MAX_NUM_STX104 (1024 / STX104_EXTENT) + +static unsigned stx104_base[MAX_NUM_STX104]; +static unsigned num_stx104; +module_param_array(stx104_base, uint, &num_stx104, 0); +MODULE_PARM_DESC(stx104_base, "Apex Embedded Systems STX104 base addresses"); + +/** + * struct stx104_iio - IIO device private data structure + * @chan_out_states: channels' output states + * @base: base port address of the IIO device + */ +struct stx104_iio { + unsigned chan_out_states[STX104_NUM_CHAN]; + unsigned base; +}; + +static int stx104_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, int *val2, long mask) +{ + struct stx104_iio *const priv = iio_priv(indio_dev); + + if (mask != IIO_CHAN_INFO_RAW) + return -EINVAL; + + *val = priv->chan_out_states[chan->channel]; + + return IIO_VAL_INT; +} + +static int stx104_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, int val2, long mask) +{ + struct stx104_iio *const priv = iio_priv(indio_dev); + const unsigned chan_addr_offset = 2 * chan->channel; + + if (mask != IIO_CHAN_INFO_RAW) + return -EINVAL; + + priv->chan_out_states[chan->channel] = val; + outw(val, priv->base + 4 + chan_addr_offset); + + return 0; +} + +static const struct iio_info stx104_info = { + .driver_module = THIS_MODULE, + .read_raw = stx104_read_raw, + .write_raw = stx104_write_raw +}; + +static const struct iio_chan_spec stx104_channels[STX104_NUM_CHAN] = { + STX104_CHAN(0), + STX104_CHAN(1) +}; + +static int stx104_probe(struct device *dev, unsigned int id) +{ + struct iio_dev *indio_dev; + struct stx104_iio *priv; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); + if (!indio_dev) + return -ENOMEM; + + if (!devm_request_region(dev, stx104_base[id], STX104_EXTENT, + dev_name(dev))) { + dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", + stx104_base[id], stx104_base[id] + STX104_EXTENT); + return -EBUSY; + } + + indio_dev->info = &stx104_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = stx104_channels; + indio_dev->num_channels = STX104_NUM_CHAN; + indio_dev->name = dev_name(dev); + + priv = iio_priv(indio_dev); + priv->base = stx104_base[id]; + + /* initialize DAC output to 0V */ + outw(0, stx104_base[id] + 4); + outw(0, stx104_base[id] + 6); + + return devm_iio_device_register(dev, indio_dev); +} + +static struct isa_driver stx104_driver = { + .probe = stx104_probe, + .driver = { + .name = "stx104" + } +}; + +static void __exit stx104_exit(void) +{ + isa_unregister_driver(&stx104_driver); +} + +static int __init stx104_init(void) +{ + return isa_register_driver(&stx104_driver, num_stx104); +} + +module_init(stx104_init); +module_exit(stx104_exit); + +MODULE_AUTHOR("William Breathitt Gray "); +MODULE_DESCRIPTION("Apex Embedded Systems STX104 DAC driver"); +MODULE_LICENSE("GPL v2"); -- 2.4.10