On Wed, 27 Feb 2019 18:14:22 +0200
Stefan Popa <stefan.p...@analog.com> wrote:
> The FNCTIO_CTRL register provides configuration control for each I/O pin
> (DIO1, DIO2, DIO3 and DIO4).
>
> This patch adds the option to configure each DIOx pin as data ready
> indicator with positive or negative polarity by reading the 'interrupts'
> and 'interrupt-names' properties from the devicetree. The
> 'interrupt-names' property is optional, if it is not specified, then the
> DIO1 pin is used as default data ready signal.
>
> Although the factory default assigns DIO2 as data ready signal, in the
> versions previous this patch, DIO1 pin was used. We should leave this
> configuration as is, since some devices might be expecting the interrupt
> on the wrong physical pin.
>
> Signed-off-by: Stefan Popa <stefan.p...@analog.com>
Nice detailed description.
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.
Thanks,
Jonathan
> ---
> drivers/iio/imu/adis16480.c | 97
> ++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 95 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/imu/adis16480.c b/drivers/iio/imu/adis16480.c
> index a27fe20..98a23ac 100644
> --- a/drivers/iio/imu/adis16480.c
> +++ b/drivers/iio/imu/adis16480.c
> @@ -9,6 +9,8 @@
> *
> */
>
> +#include <linux/bitfield.h>
> +#include <linux/of_irq.h>
> #include <linux/interrupt.h>
> #include <linux/delay.h>
> #include <linux/mutex.h>
> @@ -107,6 +109,14 @@
> #define ADIS16480_FIR_COEF_C(x)
> ADIS16480_FIR_COEF(0x09, (x))
> #define ADIS16480_FIR_COEF_D(x)
> ADIS16480_FIR_COEF(0x0B, (x))
>
> +/* ADIS16480_REG_FNCTIO_CTRL */
> +#define ADIS16480_DRDY_SEL_MSK GENMASK(1, 0)
> +#define ADIS16480_DRDY_SEL(x)
> FIELD_PREP(ADIS16480_DRDY_SEL_MSK, x)
> +#define ADIS16480_DRDY_POL_MSK BIT(2)
> +#define ADIS16480_DRDY_POL(x)
> FIELD_PREP(ADIS16480_DRDY_POL_MSK, x)
> +#define ADIS16480_DRDY_EN_MSK BIT(3)
> +#define ADIS16480_DRDY_EN(x) FIELD_PREP(ADIS16480_DRDY_EN_MSK, x)
> +
> struct adis16480_chip_info {
> unsigned int num_channels;
> const struct iio_chan_spec *channels;
> @@ -116,12 +126,26 @@ struct adis16480_chip_info {
> unsigned int accel_max_scale;
> };
>
> +enum adis16480_int_pin {
> + ADIS16480_PIN_DIO1,
> + ADIS16480_PIN_DIO2,
> + ADIS16480_PIN_DIO3,
> + ADIS16480_PIN_DIO4
> +};
> +
> struct adis16480 {
> const struct adis16480_chip_info *chip_info;
>
> struct adis adis;
> };
>
> +static const char * const adis16480_int_pin_names[4] = {
> + [ADIS16480_PIN_DIO1] = "DIO1",
> + [ADIS16480_PIN_DIO2] = "DIO2",
> + [ADIS16480_PIN_DIO3] = "DIO3",
> + [ADIS16480_PIN_DIO4] = "DIO4",
> +};
> +
> #ifdef CONFIG_DEBUG_FS
>
> static ssize_t adis16480_show_firmware_revision(struct file *file,
> @@ -741,8 +765,17 @@ static int adis16480_stop_device(struct iio_dev
> *indio_dev)
>
> static int adis16480_enable_irq(struct adis *adis, bool enable)
> {
> - return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
> - enable ? BIT(3) : 0);
> + uint16_t val;
> + int ret;
> +
> + ret = adis_read_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, &val);
> + if (ret < 0)
> + return ret;
> +
> + val &= ~ADIS16480_DRDY_EN_MSK;
> + val |= ADIS16480_DRDY_EN(enable);
> +
> + return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, val);
> }
>
> static int adis16480_initial_setup(struct iio_dev *indio_dev)
> @@ -826,6 +859,62 @@ static const struct adis_data adis16480_data = {
> .enable_irq = adis16480_enable_irq,
> };
>
> +static int adis16480_config_irq_pin(struct device_node *of_node,
> + struct adis16480 *st)
> +{
> + struct irq_data *desc;
> + enum adis16480_int_pin pin;
> + unsigned int irq_type;
> + uint16_t val;
> + int i, irq = 0;
> +
> + desc = irq_get_irq_data(st->adis.spi->irq);
> + if (!desc) {
> + dev_err(&st->adis.spi->dev, "Could not find IRQ %d\n", irq);
> + return -EINVAL;
> + }
> +
> + /* Disable data ready since the default after reset is on */
> + val = ADIS16480_DRDY_EN(0);
> +
> + /*
> + * Get the interrupt from the devicetre by reading the interrupt-names
> + * property. If it is not specified, use DIO1 pin as default.
> + * According to the datasheet, the factory default assigns DIO2 as data
> + * ready signal. However, in the previous versions of the driver, DIO1
> + * pin was used. So, we should leave it as is since some devices might
> + * be expecting the interrupt on the wrong physical pin.
> + */
> + pin = ADIS16480_PIN_DIO1;
> + for (i = 0; i < ARRAY_SIZE(adis16480_int_pin_names); i++) {
> + irq = of_irq_get_byname(of_node, adis16480_int_pin_names[i]);
> + if (irq > 0) {
> + pin = i;
> + break;
> + }
> + }
> +
> + val |= ADIS16480_DRDY_SEL(pin);
> +
> + /*
> + * Get the interrupt line behaviour. The data ready polarity can be
> + * configured as positive or negative, corresponding to
> + * IRQF_TRIGGER_RISING or IRQF_TRIGGER_FALLING respectively.
> + */
> + irq_type = irqd_get_trigger_type(desc);
> + if (irq_type == IRQF_TRIGGER_RISING) { /* Default */
> + val |= ADIS16480_DRDY_POL(1);
> + } else if (irq_type == IRQF_TRIGGER_FALLING) {
> + val |= ADIS16480_DRDY_POL(0);
> + } else {
> + dev_err(&st->adis.spi->dev,
> + "Invalid interrupt type 0x%x specified\n", irq_type);
> + return -EINVAL;
> + }
> + /* Write the data ready configuration to the FNCTIO_CTRL register */
> + return adis_write_reg_16(&st->adis, ADIS16480_REG_FNCTIO_CTRL, val);
> +}
> +
> static int adis16480_probe(struct spi_device *spi)
> {
> const struct spi_device_id *id = spi_get_device_id(spi);
> @@ -853,6 +942,10 @@ static int adis16480_probe(struct spi_device *spi)
> if (ret)
> return ret;
>
> + ret = adis16480_config_irq_pin(spi->dev.of_node, st);
> + if (ret)
> + return ret;
> +
> ret = adis_setup_buffer_and_trigger(&st->adis, indio_dev, NULL);
> if (ret)
> return ret;
