Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753106AbaA3KL2 (ORCPT ); Thu, 30 Jan 2014 05:11:28 -0500 Received: from mail-pa0-f41.google.com ([209.85.220.41]:51773 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751445AbaA3KLJ (ORCPT ); Thu, 30 Jan 2014 05:11:09 -0500 From: Matt Ranostay To: linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org Cc: matt.porter@linaro.org, koen@dominion.thruhere.net, pantelis.antoniou@gmail.com, Matt Ranostay Subject: [PATCH 2/2] iio: Add AS3935 lightning sensor support Date: Thu, 30 Jan 2014 02:11:13 -0800 Message-Id: <1391076673-5623-2-git-send-email-mranostay@gmail.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1391076673-5623-1-git-send-email-mranostay@gmail.com> References: <1391076673-5623-1-git-send-email-mranostay@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org AS3935 chipset can detect lightning strikes and reports those back as events and the esimated distance to the storm. Signed-off-by: Matt Ranostay --- .../devicetree/bindings/iio/distance/as3935.txt | 25 ++ drivers/iio/Kconfig | 1 + drivers/iio/Makefile | 1 + drivers/iio/distance/Kconfig | 19 + drivers/iio/distance/Makefile | 6 + drivers/iio/distance/as3935.c | 459 +++++++++++++++++++++ 6 files changed, 511 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/distance/as3935.txt create mode 100644 drivers/iio/distance/Kconfig create mode 100644 drivers/iio/distance/Makefile create mode 100644 drivers/iio/distance/as3935.c diff --git a/Documentation/devicetree/bindings/iio/distance/as3935.txt b/Documentation/devicetree/bindings/iio/distance/as3935.txt new file mode 100644 index 0000000..af35827 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/distance/as3935.txt @@ -0,0 +1,25 @@ +Austrian Microsystems AS3935 Franklin lightning sensor device driver + +Required properties: + - compatible: must be "ams,as3935" + - reg: SPI chip select number for the device + - spi-max-frequency: Max SPI frequency to use + - spi-cpha: SPI Mode 1 + - gpios: GPIO input of interrupt line from IRQ pin of AS3935 IC + +Optional properties: + - ams,tune-cap: Calibration tuning capacitor stepping value 0 - 15. + Range of 0 to 120 pF, 8pF steps. This will require using the calibration + data from the manufacturer. + + +Example: + + as3935@0 { + compatible = "ams,as3935"; + reg = <0>; + spi-max-frequency = <100000>; + spi-cpha; + ams,tune-cap = /bits/ 8 <10>; + gpios = <&gpio1 16 10>; + }; diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig index 5dd0e12..5164a68 100644 --- a/drivers/iio/Kconfig +++ b/drivers/iio/Kconfig @@ -63,6 +63,7 @@ source "drivers/iio/adc/Kconfig" source "drivers/iio/amplifiers/Kconfig" source "drivers/iio/common/Kconfig" source "drivers/iio/dac/Kconfig" +source "drivers/iio/distance/Kconfig" source "drivers/iio/frequency/Kconfig" source "drivers/iio/gyro/Kconfig" source "drivers/iio/humidity/Kconfig" diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile index 887d390..1574731 100644 --- a/drivers/iio/Makefile +++ b/drivers/iio/Makefile @@ -16,6 +16,7 @@ obj-y += adc/ obj-y += amplifiers/ obj-y += common/ obj-y += dac/ +obj-y += distance/ obj-y += gyro/ obj-y += frequency/ obj-y += humidity/ diff --git a/drivers/iio/distance/Kconfig b/drivers/iio/distance/Kconfig new file mode 100644 index 0000000..753352c --- /dev/null +++ b/drivers/iio/distance/Kconfig @@ -0,0 +1,19 @@ +# +# Distance sensors +# + +menu "Lightning sensors" + +config AS3935 + tristate "AS3935 Franklin lightning sensor" + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + depends on SPI + help + If you say yes here you get support for the Austrian Microsystems + AS3935 lightning detection sensor. + + This driver can also be built as a module. If so, the module + will be called as3935 + +endmenu diff --git a/drivers/iio/distance/Makefile b/drivers/iio/distance/Makefile new file mode 100644 index 0000000..f63b70d --- /dev/null +++ b/drivers/iio/distance/Makefile @@ -0,0 +1,6 @@ +# +# Makefile for IIO distance sensors +# + +# When adding new entries keep the list in alphabetical order +obj-$(CONFIG_AS3935) += as3935.o diff --git a/drivers/iio/distance/as3935.c b/drivers/iio/distance/as3935.c new file mode 100644 index 0000000..1a8f48d --- /dev/null +++ b/drivers/iio/distance/as3935.c @@ -0,0 +1,459 @@ +/* + * as3935.c - Support for AS3935 Franklin lightning sensor + * + * Copyright (C) 2014 Matt Ranostay + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +#define AS3935_AFE_GAIN 0x00 +#define AS3935_AFE_MASK 0x3F +#define AS3935_AFE_GAIN_MAX 0x1F + +#define AS3935_INT 0x03 +#define AS3935_INT_MASK 0x07 +#define AS3935_DATA 0x07 +#define AS3935_DATA_MASK 0x1F + +#define AS3935_TUNE_CAP 0x08 +#define AS3935_CALIBRATE 0x3D + +#define AS3935_WRITE_DATA (0x1 << 15) +#define AS3935_READ_DATA (0x1 << 14) +#define AS3935_ADDRESS(x) (x << 8) + +#define AS3935_EVENT_INT (1<<3) +#define AS3935_NOISE_INT (1<<0) + +struct as3935_state { + struct spi_device *spi; + struct mutex lock; + + struct iio_trigger *trig; + struct delayed_work work; + + u8 tune_cap; +}; + +static const struct iio_chan_spec as3935_channels[] = { + { + .type = IIO_DISTANCE, + .channel = 0, + .info_mask_separate = + BIT(IIO_CHAN_INFO_RAW), + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 6, + .storagebits = 6, + }, + .modified = 0, + }, + IIO_CHAN_SOFT_TIMESTAMP(1), +}; + +static const unsigned long as3935_available_scan_masks[] = { 0x01, 0x0 }; + +static int as3935_read(struct as3935_state *st, unsigned int reg, int *val) +{ + u8 tx, rx; + int ret; + + struct spi_transfer xfers[] = { + { + .tx_buf = &tx, + .bits_per_word = 8, + .len = 1, + }, { + .rx_buf = &rx, + .bits_per_word = 8, + .len = 1, + }, + }; + + mutex_lock(&st->lock); + tx = (AS3935_READ_DATA | AS3935_ADDRESS(reg)) >> 8; + + ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers)); + mutex_unlock(&st->lock); + + *val = rx; + + return ret; +}; + +static int as3935_write(struct as3935_state *st, + unsigned int reg, + unsigned int val) +{ + u8 buf[2]; + int ret; + + mutex_lock(&st->lock); + buf[0] = AS3935_WRITE_DATA | AS3935_ADDRESS(reg) >> 8; + buf[1] = val; + + ret = spi_write(st->spi, (u8 *) &buf, 2); + mutex_unlock(&st->lock); + + return ret; +}; + +static ssize_t gain_boost_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct as3935_state *st = iio_priv(dev_to_iio_dev(dev)); + int val, ret; + + ret = as3935_read(st, AS3935_AFE_GAIN, &val); + if (ret) + return ret; + val = (val & AS3935_AFE_MASK) >> 1; + + return sprintf(buf, "%d\n", val); +}; + +static ssize_t gain_boost_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct as3935_state *st = iio_priv(dev_to_iio_dev(dev)); + unsigned long val; + int ret; + + ret = kstrtoul((const char *) buf, 10, &val); + if (ret) + return -EINVAL; + + if (val > AS3935_AFE_GAIN_MAX) + return -EINVAL; + + as3935_write(st, AS3935_AFE_GAIN, val << 1); + + return len; +}; + +static IIO_DEVICE_ATTR(gain_boost, S_IRUGO | S_IWUSR, + gain_boost_show, gain_boost_store, 0); + + +static struct attribute *as3935_attributes[] = { + &iio_dev_attr_gain_boost.dev_attr.attr, + NULL, +}; + +static struct attribute_group as3935_attribute_group = { + .attrs = as3935_attributes, +}; + +static int as3935_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long m) +{ + struct as3935_state *st = iio_priv(indio_dev); + + if (m == IIO_CHAN_INFO_RAW) { + int ret; + *val = 0; + ret = as3935_read(st, AS3935_DATA, val2); + if (ret) + return ret; + return IIO_VAL_INT; + } + + return -EINVAL; +} + +static const struct iio_info as3935_info = { + .driver_module = THIS_MODULE, + .attrs = &as3935_attribute_group, + .read_raw = &as3935_read_raw, +}; + +static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = { + .postenable = &iio_triggered_buffer_postenable, + .predisable = &iio_triggered_buffer_predisable, +}; + +static irqreturn_t as3935_trigger_handler(int irq, void *private) +{ + struct iio_poll_func *pf = private; + struct iio_dev *indio_dev = pf->indio_dev; + struct as3935_state *st = iio_priv(indio_dev); + int val, ret; + + ret = as3935_read(st, AS3935_DATA, &val); + if (ret) + goto err_read; + val &= AS3935_DATA_MASK; + iio_push_to_buffers_with_timestamp(indio_dev, &val, iio_get_time_ns()); + + iio_trigger_notify_done(indio_dev->trig); +err_read: + + return IRQ_HANDLED; +}; + +static const struct iio_trigger_ops iio_interrupt_trigger_ops = { + .owner = THIS_MODULE, +}; + +static void as3935_event_work(struct work_struct *work) +{ + struct as3935_state *st; + struct spi_device *spi; + int val; + + st = container_of(work, struct as3935_state, work.work); + spi = st->spi; + + as3935_read(st, AS3935_INT, &val); + val &= AS3935_INT_MASK; + + switch (val) { + case AS3935_EVENT_INT: + iio_trigger_poll(st->trig, 0); + break; + case AS3935_NOISE_INT: + dev_warn(&spi->dev, "noise level is too high"); + break; + } +}; + +static irqreturn_t as3935_interrupt_handler(int irq, void *private) +{ + struct iio_dev *indio_dev = private; + struct as3935_state *st = iio_priv(indio_dev); + + cancel_delayed_work(&st->work); + schedule_delayed_work(&st->work, jiffies_to_msecs(3)); + return IRQ_HANDLED; +} + +static void calibrate_as3935(struct as3935_state *st) +{ + /* mask disturber interrupt bit */ + as3935_write(st, AS3935_INT, 1 << 5); + + as3935_write(st, AS3935_CALIBRATE, 0x96); + as3935_write(st, AS3935_TUNE_CAP, 1 << 5 | st->tune_cap); + + mdelay(2); + as3935_write(st, AS3935_TUNE_CAP, st->tune_cap); +} + +#ifdef CONFIG_PM_SLEEP +static int as3935_suspend(struct spi_device *spi, pm_message_t msg) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct as3935_state *st = iio_priv(indio_dev); + int val, ret; + + ret = as3935_read(st, AS3935_AFE_GAIN, &val); + if (ret) + return ret; + val |= 0x01; + + return as3935_write(st, AS3935_AFE_GAIN, val); +} + +static int as3935_resume(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + struct as3935_state *st = iio_priv(indio_dev); + int val, ret; + + ret = as3935_read(st, AS3935_AFE_GAIN, &val); + if (ret) + return ret; + val &= ~1; + + return as3935_write(st, AS3935_AFE_GAIN, val); +} +#else +#define as3935_suspend NULL +#define as3935_resume NULL +#endif + +static int as3935_probe(struct spi_device *spi) +{ + struct iio_dev *indio_dev; + struct iio_trigger *trig; + struct as3935_state *st; + struct device_node *np = spi->dev.of_node; + int gpio; + int irq; + int ret; + + /* Grab the GPIO to use for lightning event interrupt */ + if (np) + gpio = of_get_gpio(spi->dev.of_node, 0); + else { + dev_err(&spi->dev, "unable to get interrupt gpio\n"); + return -EINVAL; + } + + /* GPIO event setup */ + ret = devm_gpio_request(&spi->dev, gpio, "as3935"); + if (ret) { + dev_err(&spi->dev, "failed to request GPIO %u\n", gpio); + return ret; + } + + ret = gpio_direction_input(gpio); + if (ret) { + dev_err(&spi->dev, "failed to set pin direction\n"); + return -EINVAL; + } + + /* IRQ setup */ + irq = gpio_to_irq(gpio); + if (irq < 0) { + dev_err(&spi->dev, "failed to map GPIO to IRQ: %d\n", irq); + return -EINVAL; + } + + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(st)); + if (!indio_dev) + return -ENOMEM; + + st = iio_priv(indio_dev); + st->spi = spi; + st->tune_cap = 0; + spi_set_drvdata(spi, indio_dev); + mutex_init(&st->lock); + INIT_DELAYED_WORK(&st->work, as3935_event_work); + + of_property_read_u8(np, "ams,tune-cap", &st->tune_cap); + if (st->tune_cap > 15) { + dev_err(&spi->dev, + "wrong tune_cap setting of %d\n", st->tune_cap); + return -EINVAL; + } + + indio_dev->dev.parent = &spi->dev; + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->channels = as3935_channels; + indio_dev->num_channels = ARRAY_SIZE(as3935_channels); + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->available_scan_masks = as3935_available_scan_masks; + indio_dev->info = &as3935_info; + + trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d", + indio_dev->name, indio_dev->id); + + if (!trig) + return -ENOMEM; + + st->trig = trig; + trig->dev.parent = indio_dev->dev.parent; + iio_trigger_set_drvdata(trig, indio_dev); + trig->ops = &iio_interrupt_trigger_ops; + + ret = iio_trigger_register(trig); + if (ret) { + dev_err(&spi->dev, "failed to register trigger\n"); + return ret; + } + + ret = iio_triggered_buffer_setup(indio_dev, NULL, + &as3935_trigger_handler, + &iio_triggered_buffer_setup_ops); + + if (ret) { + dev_err(&spi->dev, "cannot setup iio trigger\n"); + return -EINVAL; + } + + calibrate_as3935(st); + + ret = devm_request_irq(&spi->dev, irq, + &as3935_interrupt_handler, + IRQF_TRIGGER_RISING, + dev_name(&spi->dev), + indio_dev); + + if (ret) { + dev_err(&spi->dev, "unable to request irq\n"); + goto uninit_buffer; + } + + ret = iio_device_register(indio_dev); + if (ret < 0) { + dev_err(&spi->dev, "unable to register device\n"); + goto uninit_buffer; + } + + return 0; + +uninit_buffer: + iio_triggered_buffer_cleanup(indio_dev); + + return ret; +}; + +static int as3935_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + + iio_device_unregister(indio_dev); + return 0; +}; + +static const struct spi_device_id as3935_id[] = { + {"as3935", 0}, + {}, +}; +MODULE_DEVICE_TABLE(spi, as3935_id); + +static struct spi_driver as3935_driver = { + .driver = { + .name = "as3935", + .owner = THIS_MODULE, + }, + .probe = as3935_probe, + .remove = as3935_remove, + .id_table = as3935_id, + .suspend = as3935_suspend, + .resume = as3935_resume, +}; +module_spi_driver(as3935_driver); + +MODULE_AUTHOR("Matt Ranostay "); +MODULE_DESCRIPTION("AS3935 lightning sensor"); +MODULE_LICENSE("GPL"); -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/