Re: [PATCH v8 2/4] pps: descriptor-based gpio, capture-clear addition

From: Philipp Zabel
Date: Fri Nov 23 2018 - 02:46:43 EST


Hi Tom,

On Sat, Nov 17, 2018 at 2:07 PM Tom Burkart <tom@xxxxxxxxxx> wrote:
>
> This patch changes the GPIO access for the pps-gpio driver from the
> integer based ABI to the descriptor based ABI. It also adds the
> extraction of the device tree capture-clear option.

Is the capture-clear property documented in
Documentation/devicetree/bindings/pps/pps-gpio.txt?
If not, you should add a binding documentation patch.

> Signed-off-by: Tom Burkart <tom@xxxxxxxxxx>
> ---
> drivers/pps/clients/pps-gpio.c | 80 +++++++++++++++++++++---------------------
> include/linux/pps-gpio.h | 3 +-
> 2 files changed, 41 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c
> index 333ad7d5b45b..d2fbc91dc8fc 100644
> --- a/drivers/pps/clients/pps-gpio.c
> +++ b/drivers/pps/clients/pps-gpio.c
> @@ -31,7 +31,7 @@
> #include <linux/slab.h>
> #include <linux/pps_kernel.h>
> #include <linux/pps-gpio.h>
> -#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/list.h>
> #include <linux/of_device.h>
> #include <linux/of_gpio.h>
> @@ -41,9 +41,9 @@ struct pps_gpio_device_data {
> int irq; /* IRQ used as PPS source */
> struct pps_device *pps; /* PPS source device */
> struct pps_source_info info; /* PPS source information */
> + struct gpio_desc *gpio_pin; /* GPIO port descriptors */
> bool assert_falling_edge;
> bool capture_clear;
> - unsigned int gpio_pin;
> };
>
> /*
> @@ -61,18 +61,49 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data)
>
> info = data;
>
> - rising_edge = gpio_get_value(info->gpio_pin);
> + rising_edge = gpiod_get_value(info->gpio_pin);
> if ((rising_edge && !info->assert_falling_edge) ||
> (!rising_edge && info->assert_falling_edge))
> pps_event(info->pps, &ts, PPS_CAPTUREASSERT, NULL);
> else if (info->capture_clear &&
> ((rising_edge && info->assert_falling_edge) ||
> - (!rising_edge && !info->assert_falling_edge)))
> + (!rising_edge && !info->assert_falling_edge)))
> pps_event(info->pps, &ts, PPS_CAPTURECLEAR, NULL);
>
> return IRQ_HANDLED;
> }
>
> +static int pps_gpio_setup(struct platform_device *pdev)
> +{
> + struct pps_gpio_device_data *data = platform_get_drvdata(pdev);
> + const struct pps_gpio_platform_data *pdata = pdev->dev.platform_data;
> + struct device_node *np = pdev->dev.of_node;
> + int ret;

Unused variable?

> +
> + if (pdata) {
> + data->gpio_pin = pdata->gpio_pin;
> +
> + data->assert_falling_edge = pdata->assert_falling_edge;
> + data->capture_clear = pdata->capture_clear;

This is just a matter of personal taste, so feel free to ignore:
I would keep the pdata branch in pps_gpio_probe and call this function
pps_gpio_dt_setup, to reduce indentation of the OF branch.

> + } else {
> + data->gpio_pin = devm_gpiod_get(&pdev->dev,
> + NULL, /* request "gpios" */
> + GPIOD_IN);
> + if (IS_ERR(data->gpio_pin)) {
> + dev_err(&pdev->dev,
> + "failed to request PPS GPIO\n");
> + return PTR_ERR(data->gpio_pin);
> + }
> +
> + if (of_get_property(np, "assert-falling-edge", NULL))
> + data->assert_falling_edge = true;
> +
> + if (of_get_property(np, "capture-clear", NULL))
> + data->capture_clear = true;

Those two should use the of_property_read_bool wrapper.

> + }
> + return 0;
> +}
> +
> static unsigned long
> get_irqf_trigger_flags(const struct pps_gpio_device_data *data)
> {
> @@ -90,53 +121,23 @@ get_irqf_trigger_flags(const struct pps_gpio_device_data *data)
> static int pps_gpio_probe(struct platform_device *pdev)
> {
> struct pps_gpio_device_data *data;
> - const char *gpio_label;
> int ret;
> int pps_default_params;
> - const struct pps_gpio_platform_data *pdata = pdev->dev.platform_data;
> - struct device_node *np = pdev->dev.of_node;
>
> /* allocate space for device info */
> data = devm_kzalloc(&pdev->dev, sizeof(struct pps_gpio_device_data),

Could use sizeof(*data) here. Otherwise,

Reviewed-by: Philipp Zabel <philipp.zabel@xxxxxxxxx>

regards
Philipp