diff options
Diffstat (limited to 'drivers/pps')
| -rw-r--r-- | drivers/pps/clients/pps-gpio.c | 88 |
1 files changed, 85 insertions, 3 deletions
diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c index 4e5e9229814b..4b6418039387 100644 --- a/drivers/pps/clients/pps-gpio.c +++ b/drivers/pps/clients/pps-gpio.c @@ -35,6 +35,8 @@ #include <linux/list.h> #include <linux/of_device.h> #include <linux/of_gpio.h> +#include <linux/timer.h> +#include <linux/jiffies.h> /* Info for each registered platform device */ struct pps_gpio_device_data { @@ -42,8 +44,12 @@ struct pps_gpio_device_data { struct pps_device *pps; /* PPS source device */ struct pps_source_info info; /* PPS source information */ struct gpio_desc *gpio_pin; /* GPIO port descriptors */ + struct gpio_desc *echo_pin; + struct timer_list echo_timer; /* timer to reset echo active state */ bool assert_falling_edge; bool capture_clear; + unsigned int echo_active_ms; /* PPS echo active duration */ + unsigned long echo_timeout; /* timer timeout value in jiffies */ }; /* @@ -64,19 +70,56 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data) 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); + pps_event(info->pps, &ts, PPS_CAPTUREASSERT, data); else if (info->capture_clear && ((rising_edge && info->assert_falling_edge) || (!rising_edge && !info->assert_falling_edge))) - pps_event(info->pps, &ts, PPS_CAPTURECLEAR, NULL); + pps_event(info->pps, &ts, PPS_CAPTURECLEAR, data); return IRQ_HANDLED; } +/* This function will only be called when an ECHO GPIO is defined */ +static void pps_gpio_echo(struct pps_device *pps, int event, void *data) +{ + /* add_timer() needs to write into info->echo_timer */ + struct pps_gpio_device_data *info = data; + + switch (event) { + case PPS_CAPTUREASSERT: + if (pps->params.mode & PPS_ECHOASSERT) + gpiod_set_value(info->echo_pin, 1); + break; + + case PPS_CAPTURECLEAR: + if (pps->params.mode & PPS_ECHOCLEAR) + gpiod_set_value(info->echo_pin, 1); + break; + } + + /* fire the timer */ + if (info->pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) { + info->echo_timer.expires = jiffies + info->echo_timeout; + add_timer(&info->echo_timer); + } +} + +/* Timer callback to reset the echo pin to the inactive state */ +static void pps_gpio_echo_timer_callback(struct timer_list *t) +{ + const struct pps_gpio_device_data *info; + + info = from_timer(info, t, echo_timer); + + gpiod_set_value(info->echo_pin, 0); +} + static int pps_gpio_setup(struct platform_device *pdev) { struct pps_gpio_device_data *data = platform_get_drvdata(pdev); struct device_node *np = pdev->dev.of_node; + int ret; + u32 value; data->gpio_pin = devm_gpiod_get(&pdev->dev, NULL, /* request "gpios" */ @@ -87,6 +130,33 @@ static int pps_gpio_setup(struct platform_device *pdev) return PTR_ERR(data->gpio_pin); } + data->echo_pin = devm_gpiod_get_optional(&pdev->dev, + "echo", + GPIOD_OUT_LOW); + if (data->echo_pin) { + if (IS_ERR(data->echo_pin)) { + dev_err(&pdev->dev, "failed to request ECHO GPIO\n"); + return PTR_ERR(data->echo_pin); + } + + ret = of_property_read_u32(np, + "echo-active-ms", + &value); + if (ret) { + dev_err(&pdev->dev, + "failed to get echo-active-ms from OF\n"); + return ret; + } + data->echo_active_ms = value; + /* sanity check on echo_active_ms */ + if (!data->echo_active_ms || data->echo_active_ms > 999) { + dev_err(&pdev->dev, + "echo-active-ms: %u - bad value from OF\n", + data->echo_active_ms); + return -EINVAL; + } + } + if (of_property_read_bool(np, "assert-falling-edge")) data->assert_falling_edge = true; return 0; @@ -122,9 +192,11 @@ static int pps_gpio_probe(struct platform_device *pdev) /* GPIO setup */ if (pdata) { data->gpio_pin = pdata->gpio_pin; + data->echo_pin = pdata->echo_pin; data->assert_falling_edge = pdata->assert_falling_edge; data->capture_clear = pdata->capture_clear; + data->echo_active_ms = pdata->echo_active_ms; } else { ret = pps_gpio_setup(pdev); if (ret) @@ -148,6 +220,11 @@ static int pps_gpio_probe(struct platform_device *pdev) data->info.owner = THIS_MODULE; snprintf(data->info.name, PPS_MAX_NAME_LEN - 1, "%s.%d", pdev->name, pdev->id); + if (data->echo_pin) { + data->info.echo = pps_gpio_echo; + data->echo_timeout = msecs_to_jiffies(data->echo_active_ms); + timer_setup(&data->echo_timer, pps_gpio_echo_timer_callback, 0); + } /* register PPS source */ pps_default_params = PPS_CAPTUREASSERT | PPS_OFFSETASSERT; @@ -180,6 +257,11 @@ static int pps_gpio_remove(struct platform_device *pdev) struct pps_gpio_device_data *data = platform_get_drvdata(pdev); pps_unregister_source(data->pps); + if (data->echo_pin) { + del_timer_sync(&data->echo_timer); + /* reset echo pin in any case */ + gpiod_set_value(data->echo_pin, 0); + } dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq); return 0; } @@ -204,4 +286,4 @@ MODULE_AUTHOR("Ricardo Martins <rasm@fe.up.pt>"); MODULE_AUTHOR("James Nuss <jamesnuss@nanometrics.ca>"); MODULE_DESCRIPTION("Use GPIO pin as PPS source"); MODULE_LICENSE("GPL"); -MODULE_VERSION("1.1.0"); +MODULE_VERSION("1.2.0"); |