From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752171AbcFKQnj (ORCPT ); Sat, 11 Jun 2016 12:43:39 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:52365 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751180AbcFKQnh (ORCPT ); Sat, 11 Jun 2016 12:43:37 -0400 Subject: Re: [PATCH v2] iio: stx104: Add GPIO support for the Apex Embedded Systems STX104 To: William Breathitt Gray , knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net References: <1464975762-24052-1-git-send-email-vilhelm.gray@gmail.com> Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Walleij , Alexandre Courbot , "linux-gpio@vger.kernel.org" From: Jonathan Cameron Message-ID: Date: Sat, 11 Jun 2016 17:43:34 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <1464975762-24052-1-git-send-email-vilhelm.gray@gmail.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/06/16 18:42, William Breathitt Gray wrote: > The Apex Embedded Systems STX104 device features eight lines of digital > I/O (four digital inputs and four digital outputs). This patch adds GPIO > support for these eight lines of digital I/O via GPIOLIB. > > Signed-off-by: William Breathitt Gray This is a gpio chip support patch. Even though the driver is in IIO we need to get it reviewed by appropriate maintainer. Cc'd Linus, Alexandre and the list. > --- > Changes in v2: > - Change GPIOLIB Kconfig selection to a dependency for the STX104 Kconfig > option; STX104 should only be available to systems configured for GPIOLIB > > drivers/iio/dac/Kconfig | 11 +++-- > drivers/iio/dac/stx104.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++- > 2 files changed, 122 insertions(+), 7 deletions(-) > > diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig > index 61d5008..35a3d49 100644 > --- a/drivers/iio/dac/Kconfig > +++ b/drivers/iio/dac/Kconfig > @@ -246,13 +246,14 @@ config MCP4922 > will be called mcp4922. > > config STX104 > - tristate "Apex Embedded Systems STX104 DAC driver" > + tristate "Apex Embedded Systems STX104 driver" > depends on ISA > + depends on GPIOLIB > 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 "base" module > - parameter array. > + Say yes here to build support for the 2-channel DAC and GPIO on the > + Apex Embedded Systems STX104 integrated analog PC/104 card. The base > + port addresses for the devices may be configured via the base array > + module parameter. > > config VF610_DAC > tristate "Vybrid vf610 DAC driver" > diff --git a/drivers/iio/dac/stx104.c b/drivers/iio/dac/stx104.c > index 174f4b7..dc445cf 100644 > --- a/drivers/iio/dac/stx104.c > +++ b/drivers/iio/dac/stx104.c > @@ -14,6 +14,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -21,6 +22,7 @@ > #include > #include > #include > +#include > > #define STX104_NUM_CHAN 2 > > @@ -56,6 +58,20 @@ struct stx104_iio { > unsigned base; > }; > > +/** > + * struct stx104_gpio - GPIO device private data structure > + * @chip: instance of the gpio_chip > + * @lock: synchronization lock to prevent I/O race conditions > + * @base: base port address of the GPIO device > + * @out_state: output bits state > + */ > +struct stx104_gpio { > + struct gpio_chip chip; > + spinlock_t lock; > + unsigned int base; > + unsigned int out_state; > +}; > + > static int stx104_read_raw(struct iio_dev *indio_dev, > struct iio_chan_spec const *chan, int *val, int *val2, long mask) > { > @@ -95,15 +111,74 @@ static const struct iio_chan_spec stx104_channels[STX104_NUM_CHAN] = { > STX104_CHAN(1) > }; > > +static int stx104_gpio_get_direction(struct gpio_chip *chip, > + unsigned int offset) > +{ > + if (offset < 4) > + return 1; > + > + return 0; > +} > + > +static int stx104_gpio_direction_input(struct gpio_chip *chip, > + unsigned int offset) > +{ > + return 0; > +} > + > +static int stx104_gpio_direction_output(struct gpio_chip *chip, > + unsigned int offset, int value) > +{ > + return 0; Not return an error if the relevant pin can't be an output? > +} > + > +static int stx104_gpio_get(struct gpio_chip *chip, unsigned int offset) > +{ > + struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip); > + > + if (offset >= 4) > + return -EINVAL; > + > + return !!(inb(stx104gpio->base) & BIT(offset)); > +} > + > +static void stx104_gpio_set(struct gpio_chip *chip, unsigned int offset, > + int value) > +{ > + struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip); > + const unsigned int mask = BIT(offset) >> 4; > + unsigned long flags; > + > + if (offset < 4) > + return; > + > + spin_lock_irqsave(&stx104gpio->lock, flags); > + > + if (value) > + stx104gpio->out_state |= mask; > + else > + stx104gpio->out_state &= ~mask; > + > + outb(stx104gpio->out_state, stx104gpio->base); > + > + spin_unlock_irqrestore(&stx104gpio->lock, flags); > +} > + > static int stx104_probe(struct device *dev, unsigned int id) > { > struct iio_dev *indio_dev; > struct stx104_iio *priv; > + struct stx104_gpio *stx104gpio; > + int err; > > indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); > if (!indio_dev) > return -ENOMEM; > > + stx104gpio = devm_kzalloc(dev, sizeof(*stx104gpio), GFP_KERNEL); > + if (!stx104gpio) > + return -ENOMEM; > + > if (!devm_request_region(dev, base[id], STX104_EXTENT, > dev_name(dev))) { > dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", > @@ -124,14 +199,53 @@ static int stx104_probe(struct device *dev, unsigned int id) > outw(0, base[id] + 4); > outw(0, base[id] + 6); > > - return devm_iio_device_register(dev, indio_dev); > + err = devm_iio_device_register(dev, indio_dev); > + if (err) { > + dev_err(dev, "IIO device registering failed (%d)\n", err); > + return err; > + } > + > + stx104gpio->chip.label = dev_name(dev); > + stx104gpio->chip.parent = dev; > + stx104gpio->chip.owner = THIS_MODULE; > + stx104gpio->chip.base = -1; > + stx104gpio->chip.ngpio = 8; > + stx104gpio->chip.get_direction = stx104_gpio_get_direction; > + stx104gpio->chip.direction_input = stx104_gpio_direction_input; > + stx104gpio->chip.direction_output = stx104_gpio_direction_output; > + stx104gpio->chip.get = stx104_gpio_get; > + stx104gpio->chip.set = stx104_gpio_set; > + stx104gpio->base = base[id] + 3; > + stx104gpio->out_state = 0x0; > + > + spin_lock_init(&stx104gpio->lock); > + > + dev_set_drvdata(dev, stx104gpio); > + > + err = gpiochip_add_data(&stx104gpio->chip, stx104gpio); > + if (err) { > + dev_err(dev, "GPIO registering failed (%d)\n", err); > + return err; > + } > + > + return 0; > +} > + > +static int stx104_remove(struct device *dev, unsigned int id) > +{ > + struct stx104_gpio *const stx104gpio = dev_get_drvdata(dev); > + > + gpiochip_remove(&stx104gpio->chip); > + > + return 0; > } > > static struct isa_driver stx104_driver = { > .probe = stx104_probe, > .driver = { > .name = "stx104" > - } > + }, > + .remove = stx104_remove > }; > > static void __exit stx104_exit(void) >