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PPS: pps-gpio PPS ECHO implementation

PATCH Superseded Tom Burkart 2 participants 7 messages Nov 17, 2018 – Nov 24, 2018

Subsystems (2)

v8 of 18 Superseded Latest is v18 →

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#0 lore raw

v8 cover PPS: pps-gpio PPS ECHO implementation

Hi all,
please find attached the PPS-GPIO PPS ECHO implementation patch. The driver claims to have echo functionality in the sysfs interface but this functionality is not present. This patch provides this functionality.

Parts 1 and 2 of the patch change the original driver from the number based GPIO ABI to the descriptor based ABI.

Parts 3 and 4 then add the PPS ECHO functionality. This is enabled if a "echo-gpios" entry is found in the devicetree.

Changes in v8:
Changes requested by Rob Herring and Philipp Zabel:
DT explanation and don't change the DT entry for the PPS gpio.

On the linuxpps mailing list it was suggested to use a hrtimer for resetting the GPIO ECHO active state to the inactive state. Please also comment on whether a hrtimer is necessary/desirable for the purpose of resetting the echo pin active state. I am happy to implement it if there is a need.

Please install, test and comment as it is now a quite major change to the driver.
Please do send suggestions for improvement.

Tom Burkart

Tom Burkart (4):
dt-bindings: pps: capture-clear addition
pps: descriptor-based gpio, capture-clear addition
dt-bindings: pps: pps-gpio PPS ECHO implementation
pps: pps-gpio pps-echo implementation

 Documentation/devicetree/bindings/pps/pps-gpio.txt |  11 ++
 drivers/pps/clients/pps-gpio.c                     | 180 ++++++++++++++++-----
 include/linux/pps-gpio.h                           |   6 +-
 3 files changed, 153 insertions(+), 44 deletions(-)
Signature · 1 line
2.12.3
#1 lore raw

PATCH v8 1/4 dt-bindings: pps: capture-clear addition

It adds documentation for the device tree capture-clear option.

---
 Documentation/devicetree/bindings/pps/pps-gpio.txt | 2 ++
 1 file changed, 2 insertions(+)
Documentation/devicetree/bindings/pps/pps-gpio.txt +2 -0
index 3683874832ae..1155d49c2699 100644
@@ -10,6 +10,7 @@ Required properties:
 Optional properties:
 - assert-falling-edge: when present, assert is indicated by a falling edge
                        (instead of by a rising edge)
+- capture-clear: when present, also capture the PPS clear event
 
 Example:
 	pps {
@@ -18,6 +19,7 @@ Example:
 
 		gpios = <&gpio1 26 GPIO_ACTIVE_HIGH>;
 		assert-falling-edge;
+		capture-clear;
 
 		compatible = "pps-gpio";
 	};
Signature · 1 line
2.12.3
#2 lore raw

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

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.

---
 drivers/pps/clients/pps-gpio.c | 80 +++++++++++++++++++++---------------------
 include/linux/pps-gpio.h       |  3 +-
 2 files changed, 41 insertions(+), 42 deletions(-)
drivers/pps/clients/pps-gpio.c +40 -40
index 333ad7d5b45b..d2fbc91dc8fc 100644
@@ -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;
+
+	if (pdata) {
+		data->gpio_pin = pdata->gpio_pin;
+
+		data->assert_falling_edge = pdata->assert_falling_edge;
+		data->capture_clear = pdata->capture_clear;
+	} 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;
+	}
+	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),
 			GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
-
-	if (pdata) {
-		data->gpio_pin = pdata->gpio_pin;
-		gpio_label = pdata->gpio_label;
-
-		data->assert_falling_edge = pdata->assert_falling_edge;
-		data->capture_clear = pdata->capture_clear;
-	} else {
-		ret = of_get_gpio(np, 0);
-		if (ret < 0) {
-			dev_err(&pdev->dev, "failed to get GPIO from device tree\n");
-			return ret;
-		}
-		data->gpio_pin = ret;
-		gpio_label = PPS_GPIO_NAME;
-
-		if (of_get_property(np, "assert-falling-edge", NULL))
-			data->assert_falling_edge = true;
-	}
+	platform_set_drvdata(pdev, data);
 
 	/* GPIO setup */
-	ret = devm_gpio_request(&pdev->dev, data->gpio_pin, gpio_label);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to request GPIO %u\n",
-			data->gpio_pin);
-		return ret;
-	}
-
-	ret = gpio_direction_input(data->gpio_pin);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to set pin direction\n");
+	ret = pps_gpio_setup(pdev);
+	if (ret)
 		return -EINVAL;
-	}
 
 	/* IRQ setup */
-	ret = gpio_to_irq(data->gpio_pin);
+	ret = gpiod_to_irq(data->gpio_pin);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to map GPIO to IRQ: %d\n", ret);
 		return -EINVAL;
@@ -173,7 +174,6 @@ static int pps_gpio_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	platform_set_drvdata(pdev, data);
 	dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n",
 		 data->irq);
 
@@ -209,4 +209,4 @@ MODULE_AUTHOR("Ricardo Martins <[email protected]>");
 MODULE_AUTHOR("James Nuss <[email protected]>");
 MODULE_DESCRIPTION("Use GPIO pin as PPS source");
 MODULE_LICENSE("GPL");
-MODULE_VERSION("1.0.0");
+MODULE_VERSION("1.1.0");
include/linux/pps-gpio.h +1 -2
index 56f35dd3d01d..f028d2cda6f5 100644
@@ -23,10 +23,9 @@
 #define _PPS_GPIO_H
 
 struct pps_gpio_platform_data {
+	struct gpio_desc *gpio_pin;
 	bool assert_falling_edge;
 	bool capture_clear;
-	unsigned int gpio_pin;
-	const char *gpio_label;
 };
 
 #endif /* _PPS_GPIO_H */
Signature · 1 line
2.12.3
#3 lore raw

PATCH v8 3/4 dt-bindings: pps: pps-gpio PPS ECHO implementation

This patch implements the device tree changes required for the pps echo functionality for pps-gpio, that sysfs claims is available already.

This patch was originally written by Lukas Senger as part of a masters thesis project and modified for inclusion into the linux kernel by Tom Burkart.

---
 Documentation/devicetree/bindings/pps/pps-gpio.txt | 9 +++++++++
 1 file changed, 9 insertions(+)
Documentation/devicetree/bindings/pps/pps-gpio.txt +9 -0
index 1155d49c2699..e09f6f2405c5 100644
@@ -7,10 +7,15 @@ Required properties:
 - compatible: should be "pps-gpio"
 - gpios: one PPS GPIO in the format described by ../gpio/gpio.txt
 
+Additional required properties for the PPS ECHO functionality:
+- echo-gpios: one PPS ECHO GPIO in the format described by ../gpio/gpio.txt
+- echo-active-ms: duration in ms of the active portion of the echo pulse
+
 Optional properties:
 - assert-falling-edge: when present, assert is indicated by a falling edge
                        (instead of by a rising edge)
 - capture-clear: when present, also capture the PPS clear event
+- invert-pps-echo: when present, invert the PPS ECHO pulse
 
 Example:
 	pps {
@@ -21,5 +26,9 @@ Example:
 		assert-falling-edge;
 		capture-clear;
 
+		echo-gpios = <&gpio1 27 GPIO_ACTIVE_HIGH>;
+		echo-active-ms = <100>;
+		invert-pps-echo;
+
 		compatible = "pps-gpio";
 	};
Signature · 1 line
2.12.3
#4 lore raw

PATCH v8 4/4 pps: pps-gpio pps-echo implementation

This patch implements the pps echo functionality for pps-gpio, that sysfs claims is available already.

Configuration is done via device tree bindings.

This patch was originally written by Lukas Senger as part of a masters thesis project and modified for inclusion into the linux kernel by Tom Burkart.

---
 drivers/pps/clients/pps-gpio.c | 102 +++++++++++++++++++++++++++++++++++++++--
 include/linux/pps-gpio.h       |   3 ++
 2 files changed, 102 insertions(+), 3 deletions(-)
drivers/pps/clients/pps-gpio.c +99 -3
index d2fbc91dc8fc..fc12dd7a2cb3 100644
@@ -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 +44,14 @@ 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;
+	bool enable_pps_echo;
+	bool invert_pps_echo;
+	unsigned int echo_active_ms;	/* PPS echo active duration */
+	unsigned long echo_timeout;	/* timer timeout value in jiffies */
 };
 
 /*
@@ -64,27 +72,72 @@ 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;
 }
 
+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;
+
+	info = data;
+
+	switch (event) {
+	case PPS_CAPTUREASSERT:
+		if (pps->params.mode & PPS_ECHOASSERT)
+			gpiod_set_value(info->echo_pin,
+				info->invert_pps_echo ? 0 : 1);
+		break;
+
+	case PPS_CAPTURECLEAR:
+		if (pps->params.mode & PPS_ECHOCLEAR)
+			gpiod_set_value(info->echo_pin,
+				info->invert_pps_echo ? 0 : 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,
+		info->invert_pps_echo ? 1 : 0);
+}
+
 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;
+	u32 value;
 
 	if (pdata) {
 		data->gpio_pin = pdata->gpio_pin;
+		data->echo_pin = pdata->echo_pin;
+		if (pdata->echo_pin != NULL)
+			data->enable_pps_echo = true;
 
 		data->assert_falling_edge = pdata->assert_falling_edge;
 		data->capture_clear = pdata->capture_clear;
+		data->invert_pps_echo = pdata->invert_pps_echo;
+		data->echo_active_ms = pdata->echo_active_ms;
 	} else {
 		data->gpio_pin = devm_gpiod_get(&pdev->dev,
 			NULL,	/* request "gpios" */
@@ -95,11 +148,44 @@ static int pps_gpio_setup(struct platform_device *pdev)
 			return PTR_ERR(data->gpio_pin);
 		}
 
+		if (of_get_property(np, "echo-gpios", NULL)) {
+			data->enable_pps_echo = true;
+
+			data->echo_pin = devm_gpiod_get(&pdev->dev,
+				"echo",
+				GPIOD_OUT_LOW);
+			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;
+		}
+
 		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;
+
+		if (of_get_property(np, "invert-pps-echo", NULL))
+			data->invert_pps_echo = true;
+	}
+	/* sanity check on echo_active_ms */
+	if (data->enable_pps_echo
+			&& (!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;
 	}
 	return 0;
 }
@@ -153,6 +239,11 @@ 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->enable_pps_echo) {
+		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;
@@ -185,6 +276,11 @@ 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->enable_pps_echo) {
+		del_timer_sync(&data->echo_timer);
+		/* reset echo pin in any case */
+		gpiod_set_value(data->echo_pin, data->invert_pps_echo ? 1 : 0);
+	}
 	dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq);
 	return 0;
 }
@@ -209,4 +305,4 @@ MODULE_AUTHOR("Ricardo Martins <[email protected]>");
 MODULE_AUTHOR("James Nuss <[email protected]>");
 MODULE_DESCRIPTION("Use GPIO pin as PPS source");
 MODULE_LICENSE("GPL");
-MODULE_VERSION("1.1.0");
+MODULE_VERSION("1.2.0");
include/linux/pps-gpio.h +3 -0
index f028d2cda6f5..5390f18c73a5 100644
@@ -24,8 +24,11 @@
 
 struct pps_gpio_platform_data {
 	struct gpio_desc *gpio_pin;
+	struct gpio_desc *echo_pin;
 	bool assert_falling_edge;
 	bool capture_clear;
+	bool invert_pps_echo;
+	unsigned int echo_active_ms;
 };
 
 #endif /* _PPS_GPIO_H */
Signature · 1 line
2.12.3
Reviewed-by on v8 2/4
#5 lore raw

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

In reply to Tom Burkart

Hi Tom,

Quoted 4 lines · Tom Burkart

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.

Quoted 44 lines
---
 drivers/pps/clients/pps-gpio.c | 80 +++++++++++++++++++++---------------------
 include/linux/pps-gpio.h       |  3 +-
 2 files changed, 41 insertions(+), 42 deletions(-)
drivers/pps/clients/pps-gpio.c +4 -4
index 333ad7d5b45b..d2fbc91dc8fc 100644
@@ -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);

drivers/pps/clients/pps-gpio.c static irqreturn_t pps_gpio_irq_handler(int irq, void *data) · line 81

Quoted 10 lines
drivers/pps/clients/pps-gpio.c +6 -0
 
        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?

drivers/pps/clients/pps-gpio.c static irqreturn_t pps_gpio_irq_handler(int irq, void *data) · line 87

Quoted 6 lines
drivers/pps/clients/pps-gpio.c +6 -0
+
+       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.

Quoted 5 lines
drivers/pps/clients/pps-gpio.c +5 -0
+       } else {
+               data->gpio_pin = devm_gpiod_get(&pdev->dev,
+                       NULL,   /* request "gpios" */
+                       GPIOD_IN);
+               if (IS_ERR(data->gpio_pin)) {

drivers/pps/clients/pps-gpio.c static irqreturn_t pps_gpio_irq_handler(int irq, void *data) · line 102

Quoted 10 lines
drivers/pps/clients/pps-gpio.c +10 -0
+                       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.

Quoted 9 lines
drivers/pps/clients/pps-gpio.c +4 -0
+       }
+       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)

drivers/pps/clients/pps-gpio.c get_irqf_trigger_flags(const struct pps_gpio_device_data *data) · line 128

Quoted 10 lines
drivers/pps/clients/pps-gpio.c +0 -3
 {
        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,

regards
Philipp

#6 lore raw

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

Hi Philipp,

Quoting Philipp Zabel <[email protected]>:

Quoted 9 lines · Tom Burkart
Quoted 4 lines

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.

Yes, that is in patch 1/4

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---
 drivers/pps/clients/pps-gpio.c | 80  
+++++++++++++++++++++---------------------
 include/linux/pps-gpio.h       |  3 +-
 2 files changed, 41 insertions(+), 42 deletions(-)
drivers/pps/clients/pps-gpio.c +4 -4
index 333ad7d5b45b..d2fbc91dc8fc 100644
@@ -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;
 }
 
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drivers/pps/clients/pps-gpio.c static irqreturn_t pps_gpio_irq_handler(int irq, void *data) · line 81

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drivers/pps/clients/pps-gpio.c +6 -0
+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?

Oops, yes, in this patch (2/4), but not in patch 4/4

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drivers/pps/clients/pps-gpio.c static irqreturn_t pps_gpio_irq_handler(int irq, void *data) · line 87

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drivers/pps/clients/pps-gpio.c +6 -0
+
+       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.

Ok, I am happy to agree as it makes sense.

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drivers/pps/clients/pps-gpio.c +9 -0
+       } 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);
+               }
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drivers/pps/clients/pps-gpio.c static irqreturn_t pps_gpio_irq_handler(int irq, void *data) · line 102

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drivers/pps/clients/pps-gpio.c +6 -0
+
+               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.

Thanks.

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drivers/pps/clients/pps-gpio.c +4 -0
+       }
+       return 0;
+}
+
 static unsigned long

get_irqf_trigger_flags(const struct pps_gpio_device_data *data) {

drivers/pps/clients/pps-gpio.c +0 -3
@@ -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;
 
Quoted 4 lines

drivers/pps/clients/pps-gpio.c get_irqf_trigger_flags(const struct pps_gpio_device_data *data) · line 128

Quoted 2 lines
drivers/pps/clients/pps-gpio.c +0 -0
        /* allocate space for device info */
        data = devm_kzalloc(&pdev->dev, sizeof(struct pps_gpio_device_data),

Could use sizeof(*data) here. Otherwise,

Fine with me.

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Is this for patch 2/4 only or the others as well?

Will generate v10 of the patch and post it again.