| Message ID | 1549653856-47409-1-git-send-email-justinpopo6@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | iio: adc: ti-ads7950: add GPIO support | expand |
On Fri, 8 Feb 2019 11:24:16 -0800 justinpopo6@gmail.com wrote: > From: Justin Chen <justinpopo6@gmail.com> > > The ADS79XX has GPIO pins that can be used. Add support for the GPIO > pins using the GPIO chip framework. > > Signed-off-by: Justin Chen <justinpopo6@gmail.com> Hi Justin, Unfortunately the existing driver is making incorrect use of the indio_dev->mlock mutex. That used to get abused a lot before we clamped down on it being for only one purpose, protection of the 'mode' of the iio device. It's about stopping anything interfering with buffered captures by talking to the device in a way that breaks them. I'm not sure if the original driver was trying to use it for this purpose and protecting it's buffers. Even if so, there should be an additional local lock to cover those chip specific elements. Any use of mlock should be through the iio_device_claim_direct_mode function etc. Thanks, Jonathan > --- > drivers/iio/adc/ti-ads7950.c | 166 ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 164 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c > index 0ad6359..c54706ad 100644 > --- a/drivers/iio/adc/ti-ads7950.c > +++ b/drivers/iio/adc/ti-ads7950.c > @@ -17,6 +17,7 @@ > #include <linux/bitops.h> > #include <linux/device.h> > #include <linux/err.h> > +#include <linux/gpio/driver.h> > #include <linux/interrupt.h> > #include <linux/kernel.h> > #include <linux/module.h> > @@ -36,10 +37,14 @@ > */ > #define TI_ADS7950_VA_MV_ACPI_DEFAULT 5000 > > +#define TI_ADS7950_CR_GPIO BIT(14) > #define TI_ADS7950_CR_MANUAL BIT(12) > #define TI_ADS7950_CR_WRITE BIT(11) > #define TI_ADS7950_CR_CHAN(ch) ((ch) << 7) > #define TI_ADS7950_CR_RANGE_5V BIT(6) > +#define TI_ADS7950_CR_GPIO_DATA BIT(5) > +#define TI_ADS7950_NUM_GPIOS 4 > +#define TI_ADS7950_GPIO_MASK GENMASK(TI_ADS7950_NUM_GPIOS - 1, 0) > > #define TI_ADS7950_MAX_CHAN 16 > > @@ -56,11 +61,17 @@ struct ti_ads7950_state { > struct spi_message ring_msg; > struct spi_message scan_single_msg; > > + struct iio_dev *indio_dev; > + struct gpio_chip *chip; > + > struct regulator *reg; > unsigned int vref_mv; > > unsigned int settings; > > + unsigned int gpio_direction_bitmask; > + unsigned int gpio_signal_bitmask; > + > /* > * DMA (thus cache coherency maintenance) requires the > * transfer buffers to live in their own cache lines. > @@ -248,7 +259,8 @@ static int ti_ads7950_update_scan_mode(struct iio_dev *indio_dev, > > len = 0; > for_each_set_bit(i, active_scan_mask, indio_dev->num_channels) { > - cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings; > + cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings > + | (st->gpio_signal_bitmask & TI_ADS7950_GPIO_MASK); > st->tx_buf[len++] = cmd; > } > > @@ -288,7 +300,8 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch) > > mutex_lock(&indio_dev->mlock); > > - cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings; > + cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings > + | (st->gpio_signal_bitmask & TI_ADS7950_GPIO_MASK); > st->single_tx = cmd; > > ret = spi_sync(st->spi, &st->scan_single_msg); > @@ -362,10 +375,149 @@ static const struct iio_info ti_ads7950_info = { > .update_scan_mode = ti_ads7950_update_scan_mode, > }; > > +static void ti_ads7950_set(struct gpio_chip *chip, unsigned int offset, > + int value) > +{ > + struct ti_ads7950_state *st = gpiochip_get_data(chip); > + > + mutex_lock(&st->indio_dev->mlock); > + > + if (value) > + st->gpio_signal_bitmask |= BIT(offset); > + else > + st->gpio_signal_bitmask &= ~BIT(offset); > + > + st->single_tx = cpu_to_be16(TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_WRITE | > + (st->gpio_signal_bitmask & TI_ADS7950_GPIO_MASK)); > + spi_sync(st->spi, &st->scan_single_msg); > + > + mutex_unlock(&st->indio_dev->mlock); > +} > + > +static int ti_ads7950_get(struct gpio_chip *chip, unsigned int offset) > +{ > + struct ti_ads7950_state *st = gpiochip_get_data(chip); > + int ret; > + > + mutex_lock(&st->indio_dev->mlock); > + > + /* If set as output, return the output */ > + if (st->gpio_direction_bitmask & BIT(offset)) { > + ret = st->gpio_signal_bitmask & BIT(offset); > + goto out; > + } > + > + st->single_tx = cpu_to_be16(TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_WRITE | > + TI_ADS7950_CR_GPIO_DATA); > + ret = spi_sync(st->spi, &st->scan_single_msg); > + if (ret) > + goto out; > + > + ret = ((st->single_rx >> 12) & BIT(offset)) ? 1 : 0; > + > +out: > + mutex_unlock(&st->indio_dev->mlock); > + > + return ret; > +} > + > +static int ti_ads7950_get_direction(struct gpio_chip *chip, > + unsigned int offset) > +{ > + struct ti_ads7950_state *st = gpiochip_get_data(chip); > + > + return !(st->gpio_direction_bitmask & BIT(offset)); > +} > + > +static int _ti_ads7950_set_direction(struct gpio_chip *chip, int offset, > + int input) > +{ > + struct ti_ads7950_state *st = gpiochip_get_data(chip); > + int ret = 0; > + > + mutex_lock(&st->indio_dev->mlock); > + > + if (input && (st->gpio_direction_bitmask & BIT(offset))) > + st->gpio_direction_bitmask &= ~BIT(offset); > + else if (!input && !(st->gpio_direction_bitmask & BIT(offset))) > + st->gpio_direction_bitmask |= BIT(offset); > + else > + goto out; > + > + > + st->single_tx = cpu_to_be16(TI_ADS7950_CR_GPIO | > + (st->gpio_direction_bitmask & > + TI_ADS7950_GPIO_MASK)); > + ret = spi_sync(st->spi, &st->scan_single_msg); > + > +out: > + mutex_unlock(&st->indio_dev->mlock); > + > + return ret; > +} > + > +static int ti_ads7950_direction_input(struct gpio_chip *chip, > + unsigned int offset) > +{ > + return _ti_ads7950_set_direction(chip, offset, 1); > +} > + > +static int ti_ads7950_direction_output(struct gpio_chip *chip, > + unsigned int offset, int value) > +{ > + ti_ads7950_set(chip, offset, value); > + > + return _ti_ads7950_set_direction(chip, offset, 0); > +} > + > +static int ti_ads7950_init_gpio(struct ti_ads7950_state *st) > +{ > + int ret; > + > + /* Initialize GPIO */ > + mutex_lock(&st->indio_dev->mlock); > + > + /* Default to GPIO input */ > + st->gpio_direction_bitmask = 0x0; > + st->single_tx = cpu_to_be16(TI_ADS7950_CR_GPIO | > + (st->gpio_direction_bitmask & > + TI_ADS7950_GPIO_MASK)); > + ret = spi_sync(st->spi, &st->scan_single_msg); > + mutex_unlock(&st->indio_dev->mlock); Nope. This is a state lock used to protect against transitions between different modes of the IIO device (buffered vs polled), it isn't suitable for general use. The driver should be modified to handle that correctly. We have iio_claim_direct_mode etc that deal with the case where a device can't do certain operations whilst in buffered mode. Note it can fail and should. Seems there are more drivers still doing this than I thought. If anyone is bored and wants to clean them out, that would be most appreciated! If you need locking to protect a local buffer or the device state, define a new lock to do it with clearly documented scope. > + if (ret) > + return ret; > + > + /* Default to signal low */ > + st->gpio_signal_bitmask = 0x0; > + st->single_tx = cpu_to_be16(TI_ADS7950_CR_MANUAL | > + TI_ADS7950_CR_WRITE | > + (st->gpio_signal_bitmask & > + TI_ADS7950_GPIO_MASK)); > + ret = spi_sync(st->spi, &st->scan_single_msg); > + mutex_unlock(&st->indio_dev->mlock); > + if (ret) > + return ret; > + > + /* Add GPIO chip */ > + st->chip->label = dev_name(&st->spi->dev); > + st->chip->parent = &st->spi->dev; > + st->chip->owner = THIS_MODULE; > + st->chip->base = -1; > + st->chip->ngpio = TI_ADS7950_NUM_GPIOS; > + st->chip->get_direction = ti_ads7950_get_direction; > + st->chip->direction_input = ti_ads7950_direction_input; > + st->chip->direction_output = ti_ads7950_direction_output; > + st->chip->get = ti_ads7950_get; > + st->chip->set = ti_ads7950_set; > + > + return gpiochip_add_data(st->chip, st); > +} > + > static int ti_ads7950_probe(struct spi_device *spi) > { > struct ti_ads7950_state *st; > struct iio_dev *indio_dev; > + struct gpio_chip *chip; > const struct ti_ads7950_chip_info *info; > int ret; > > @@ -381,6 +533,10 @@ static int ti_ads7950_probe(struct spi_device *spi) > if (!indio_dev) > return -ENOMEM; > > + chip = devm_kzalloc(&spi->dev, sizeof(*chip), GFP_KERNEL); > + if (!chip) > + return -ENOMEM; > + What stops us putting the chip structure inside the existing info structure? That avoids the need to separately allocate memory and to set the pointer. A cleaner option all round. > st = iio_priv(indio_dev); > > spi_set_drvdata(spi, indio_dev); > @@ -396,6 +552,8 @@ static int ti_ads7950_probe(struct spi_device *spi) > indio_dev->channels = info->channels; > indio_dev->num_channels = info->num_channels; > indio_dev->info = &ti_ads7950_info; > + st->indio_dev = indio_dev; Hmm. As a general rule I'm against things having pointers to the structure that contains them as it usual means something is inconsistent in the software architecture. From the above, looks like this is about accessing mlock. The driver shouldn't be doing that directly at all, so a precursor to this patch cleaning that up would be great. > + st->chip = chip; > > /* build spi ring message */ > spi_message_init(&st->ring_msg); > @@ -457,6 +615,10 @@ static int ti_ads7950_probe(struct spi_device *spi) > goto error_cleanup_ring; > } > > + ret = ti_ads7950_init_gpio(st); > + if (ret) > + dev_warn(&spi->dev, "Unable to initialize GPIOs\n"); Why are we not treating this as an error? I can't see any obvious reason to make that choice. > + > return 0; > > error_cleanup_ring:
On 2/9/19 11:00 AM, Jonathan Cameron wrote: > Nope. This is a state lock used to protect against transitions between > different modes of the IIO device (buffered vs polled), it > isn't suitable for general use. > > The driver should be modified to handle that correctly. > We have iio_claim_direct_mode etc that deal with the case > where a device can't do certain operations whilst in buffered > mode. Note it can fail and should. > > Seems there are more drivers still doing this than I thought. > If anyone is bored and wants to clean them out, that would be > most appreciated! > > If you need locking to protect a local buffer or the device > state, define a new lock to do it with clearly documented > scope. Just as a reminder, there is a use case for this particular chip that requires buffered mode and direct mode at the same time. https://patchwork.kernel.org/patch/10539021/ https://patchwork.kernel.org/patch/10527757/
Hi Justin, thanks for your patch! On Fri, Feb 8, 2019 at 8:25 PM <justinpopo6@gmail.com> wrote: > From: Justin Chen <justinpopo6@gmail.com> > > The ADS79XX has GPIO pins that can be used. Add support for the GPIO > pins using the GPIO chip framework. > > Signed-off-by: Justin Chen <justinpopo6@gmail.com> (...) > @@ -56,11 +61,17 @@ struct ti_ads7950_state { > struct spi_message ring_msg; > struct spi_message scan_single_msg; > > + struct iio_dev *indio_dev; > + struct gpio_chip *chip; Why use a pointer here? Correct me if wrong by a struct ti_ads7950_state is always allocated for each instance of the hardware right? So just struct gpio_chip chip; should be fine, then just fill in that struct. > + /* Add GPIO chip */ > + st->chip->label = dev_name(&st->spi->dev); So it would be st->chip.label = ... etc. > + chip = devm_kzalloc(&spi->dev, sizeof(*chip), GFP_KERNEL); > + if (!chip) > + return -ENOMEM; And no need to do this. Apart from that it looks OK to me, but there are some locking comments I see. Yours, Linus Walleij
On Sat, 9 Feb 2019 12:56:11 -0600 David Lechner <david@lechnology.com> wrote: > On 2/9/19 11:00 AM, Jonathan Cameron wrote: > > Nope. This is a state lock used to protect against transitions between > > different modes of the IIO device (buffered vs polled), it > > isn't suitable for general use. > > > > The driver should be modified to handle that correctly. > > We have iio_claim_direct_mode etc that deal with the case > > where a device can't do certain operations whilst in buffered > > mode. Note it can fail and should. > > > > Seems there are more drivers still doing this than I thought. > > If anyone is bored and wants to clean them out, that would be > > most appreciated! > > > > If you need locking to protect a local buffer or the device > > state, define a new lock to do it with clearly documented > > scope. > > Just as a reminder, there is a use case for this particular > chip that requires buffered mode and direct mode at the same > time. > > https://patchwork.kernel.org/patch/10539021/ > https://patchwork.kernel.org/patch/10527757/ Thanks, I had indeed forgotten that entirely. So it should have a local lock and not take mlock explicitly at all. Jonathan
On Mon, Feb 11, 2019 at 12:06 PM Jonathan Cameron <jic23@kernel.org> wrote: > > On Sat, 9 Feb 2019 12:56:11 -0600 > David Lechner <david@lechnology.com> wrote: > > > On 2/9/19 11:00 AM, Jonathan Cameron wrote: > > > Nope. This is a state lock used to protect against transitions between > > > different modes of the IIO device (buffered vs polled), it > > > isn't suitable for general use. > > > > > > The driver should be modified to handle that correctly. > > > We have iio_claim_direct_mode etc that deal with the case > > > where a device can't do certain operations whilst in buffered > > > mode. Note it can fail and should. > > > > > > Seems there are more drivers still doing this than I thought. > > > If anyone is bored and wants to clean them out, that would be > > > most appreciated! > > > > > > If you need locking to protect a local buffer or the device > > > state, define a new lock to do it with clearly documented > > > scope. > > > > Just as a reminder, there is a use case for this particular > > chip that requires buffered mode and direct mode at the same > > time. > > > > https://patchwork.kernel.org/patch/10539021/ > > https://patchwork.kernel.org/patch/10527757/ > > Thanks, I had indeed forgotten that entirely. > So it should have a local lock and not take mlock explicitly at all. > Thanks for all the feedback. So If I am understanding this correctly. I should create a local lock to synchronize three different type of transactions (buffered, direct, gpio). I do not want to use iio_claim_direct_mode because that doesn't allow simultaneous use of buffered mode and direct mode, which is necessary for this driver because of the above mentioned patch. Justin > Jonathan
On Mon, 11 Feb 2019 12:17:37 -0800 Justin Chen <justinpopo6@gmail.com> wrote: > On Mon, Feb 11, 2019 at 12:06 PM Jonathan Cameron <jic23@kernel.org> wrote: > > > > On Sat, 9 Feb 2019 12:56:11 -0600 > > David Lechner <david@lechnology.com> wrote: > > > > > On 2/9/19 11:00 AM, Jonathan Cameron wrote: > > > > Nope. This is a state lock used to protect against transitions between > > > > different modes of the IIO device (buffered vs polled), it > > > > isn't suitable for general use. > > > > > > > > The driver should be modified to handle that correctly. > > > > We have iio_claim_direct_mode etc that deal with the case > > > > where a device can't do certain operations whilst in buffered > > > > mode. Note it can fail and should. > > > > > > > > Seems there are more drivers still doing this than I thought. > > > > If anyone is bored and wants to clean them out, that would be > > > > most appreciated! > > > > > > > > If you need locking to protect a local buffer or the device > > > > state, define a new lock to do it with clearly documented > > > > scope. > > > > > > Just as a reminder, there is a use case for this particular > > > chip that requires buffered mode and direct mode at the same > > > time. > > > > > > https://patchwork.kernel.org/patch/10539021/ > > > https://patchwork.kernel.org/patch/10527757/ > > > > Thanks, I had indeed forgotten that entirely. > > So it should have a local lock and not take mlock explicitly at all. > > > Thanks for all the feedback. > So If I am understanding this correctly. I should create a local lock > to synchronize three different type of transactions (buffered, direct, > gpio). > I do not want to use iio_claim_direct_mode because that doesn't allow > simultaneous use of buffered mode and direct mode, which is necessary > for this driver because of the above mentioned patch. No, you should create a local lock to do just one thing. Protect the buffers used in those transactions. There is no need to protect anything else explicitly. On some devices there are multiple transaction writes, but I don't recall that being the case here. Jonathan > > Justin > > Jonathan
diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c index 0ad6359..c54706ad 100644 --- a/drivers/iio/adc/ti-ads7950.c +++ b/drivers/iio/adc/ti-ads7950.c @@ -17,6 +17,7 @@ #include <linux/bitops.h> #include <linux/device.h> #include <linux/err.h> +#include <linux/gpio/driver.h> #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/module.h> @@ -36,10 +37,14 @@ */ #define TI_ADS7950_VA_MV_ACPI_DEFAULT 5000 +#define TI_ADS7950_CR_GPIO BIT(14) #define TI_ADS7950_CR_MANUAL BIT(12) #define TI_ADS7950_CR_WRITE BIT(11) #define TI_ADS7950_CR_CHAN(ch) ((ch) << 7) #define TI_ADS7950_CR_RANGE_5V BIT(6) +#define TI_ADS7950_CR_GPIO_DATA BIT(5) +#define TI_ADS7950_NUM_GPIOS 4 +#define TI_ADS7950_GPIO_MASK GENMASK(TI_ADS7950_NUM_GPIOS - 1, 0) #define TI_ADS7950_MAX_CHAN 16 @@ -56,11 +61,17 @@ struct ti_ads7950_state { struct spi_message ring_msg; struct spi_message scan_single_msg; + struct iio_dev *indio_dev; + struct gpio_chip *chip; + struct regulator *reg; unsigned int vref_mv; unsigned int settings; + unsigned int gpio_direction_bitmask; + unsigned int gpio_signal_bitmask; + /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. @@ -248,7 +259,8 @@ static int ti_ads7950_update_scan_mode(struct iio_dev *indio_dev, len = 0; for_each_set_bit(i, active_scan_mask, indio_dev->num_channels) { - cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings; + cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings + | (st->gpio_signal_bitmask & TI_ADS7950_GPIO_MASK); st->tx_buf[len++] = cmd; } @@ -288,7 +300,8 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch) mutex_lock(&indio_dev->mlock); - cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings; + cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings + | (st->gpio_signal_bitmask & TI_ADS7950_GPIO_MASK); st->single_tx = cmd; ret = spi_sync(st->spi, &st->scan_single_msg); @@ -362,10 +375,149 @@ static const struct iio_info ti_ads7950_info = { .update_scan_mode = ti_ads7950_update_scan_mode, }; +static void ti_ads7950_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct ti_ads7950_state *st = gpiochip_get_data(chip); + + mutex_lock(&st->indio_dev->mlock); + + if (value) + st->gpio_signal_bitmask |= BIT(offset); + else + st->gpio_signal_bitmask &= ~BIT(offset); + + st->single_tx = cpu_to_be16(TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_WRITE | + (st->gpio_signal_bitmask & TI_ADS7950_GPIO_MASK)); + spi_sync(st->spi, &st->scan_single_msg); + + mutex_unlock(&st->indio_dev->mlock); +} + +static int ti_ads7950_get(struct gpio_chip *chip, unsigned int offset) +{ + struct ti_ads7950_state *st = gpiochip_get_data(chip); + int ret; + + mutex_lock(&st->indio_dev->mlock); + + /* If set as output, return the output */ + if (st->gpio_direction_bitmask & BIT(offset)) { + ret = st->gpio_signal_bitmask & BIT(offset); + goto out; + } + + st->single_tx = cpu_to_be16(TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_WRITE | + TI_ADS7950_CR_GPIO_DATA); + ret = spi_sync(st->spi, &st->scan_single_msg); + if (ret) + goto out; + + ret = ((st->single_rx >> 12) & BIT(offset)) ? 1 : 0; + +out: + mutex_unlock(&st->indio_dev->mlock); + + return ret; +} + +static int ti_ads7950_get_direction(struct gpio_chip *chip, + unsigned int offset) +{ + struct ti_ads7950_state *st = gpiochip_get_data(chip); + + return !(st->gpio_direction_bitmask & BIT(offset)); +} + +static int _ti_ads7950_set_direction(struct gpio_chip *chip, int offset, + int input) +{ + struct ti_ads7950_state *st = gpiochip_get_data(chip); + int ret = 0; + + mutex_lock(&st->indio_dev->mlock); + + if (input && (st->gpio_direction_bitmask & BIT(offset))) + st->gpio_direction_bitmask &= ~BIT(offset); + else if (!input && !(st->gpio_direction_bitmask & BIT(offset))) + st->gpio_direction_bitmask |= BIT(offset); + else + goto out; + + + st->single_tx = cpu_to_be16(TI_ADS7950_CR_GPIO | + (st->gpio_direction_bitmask & + TI_ADS7950_GPIO_MASK)); + ret = spi_sync(st->spi, &st->scan_single_msg); + +out: + mutex_unlock(&st->indio_dev->mlock); + + return ret; +} + +static int ti_ads7950_direction_input(struct gpio_chip *chip, + unsigned int offset) +{ + return _ti_ads7950_set_direction(chip, offset, 1); +} + +static int ti_ads7950_direction_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + ti_ads7950_set(chip, offset, value); + + return _ti_ads7950_set_direction(chip, offset, 0); +} + +static int ti_ads7950_init_gpio(struct ti_ads7950_state *st) +{ + int ret; + + /* Initialize GPIO */ + mutex_lock(&st->indio_dev->mlock); + + /* Default to GPIO input */ + st->gpio_direction_bitmask = 0x0; + st->single_tx = cpu_to_be16(TI_ADS7950_CR_GPIO | + (st->gpio_direction_bitmask & + TI_ADS7950_GPIO_MASK)); + ret = spi_sync(st->spi, &st->scan_single_msg); + mutex_unlock(&st->indio_dev->mlock); + if (ret) + return ret; + + /* Default to signal low */ + st->gpio_signal_bitmask = 0x0; + st->single_tx = cpu_to_be16(TI_ADS7950_CR_MANUAL | + TI_ADS7950_CR_WRITE | + (st->gpio_signal_bitmask & + TI_ADS7950_GPIO_MASK)); + ret = spi_sync(st->spi, &st->scan_single_msg); + mutex_unlock(&st->indio_dev->mlock); + if (ret) + return ret; + + /* Add GPIO chip */ + st->chip->label = dev_name(&st->spi->dev); + st->chip->parent = &st->spi->dev; + st->chip->owner = THIS_MODULE; + st->chip->base = -1; + st->chip->ngpio = TI_ADS7950_NUM_GPIOS; + st->chip->get_direction = ti_ads7950_get_direction; + st->chip->direction_input = ti_ads7950_direction_input; + st->chip->direction_output = ti_ads7950_direction_output; + st->chip->get = ti_ads7950_get; + st->chip->set = ti_ads7950_set; + + return gpiochip_add_data(st->chip, st); +} + static int ti_ads7950_probe(struct spi_device *spi) { struct ti_ads7950_state *st; struct iio_dev *indio_dev; + struct gpio_chip *chip; const struct ti_ads7950_chip_info *info; int ret; @@ -381,6 +533,10 @@ static int ti_ads7950_probe(struct spi_device *spi) if (!indio_dev) return -ENOMEM; + chip = devm_kzalloc(&spi->dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + st = iio_priv(indio_dev); spi_set_drvdata(spi, indio_dev); @@ -396,6 +552,8 @@ static int ti_ads7950_probe(struct spi_device *spi) indio_dev->channels = info->channels; indio_dev->num_channels = info->num_channels; indio_dev->info = &ti_ads7950_info; + st->indio_dev = indio_dev; + st->chip = chip; /* build spi ring message */ spi_message_init(&st->ring_msg); @@ -457,6 +615,10 @@ static int ti_ads7950_probe(struct spi_device *spi) goto error_cleanup_ring; } + ret = ti_ads7950_init_gpio(st); + if (ret) + dev_warn(&spi->dev, "Unable to initialize GPIOs\n"); + return 0; error_cleanup_ring: