diff mbox series

[8/9] gpio: mockup: use the generic 'gpio-line-names' property

Message ID 20200924113842.11670-9-brgl@bgdev.pl
State New
Headers show
Series gpio: mockup: refactoring + documentation | expand

Commit Message

Bartosz Golaszewski Sept. 24, 2020, 11:38 a.m. UTC 
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

GPIO line names are currently created by the driver from the chip label.
We'll want to support custom formats for line names (for instance: to
name all lines the same) for user-space tests so create them in the
module init function and pass them to the driver using the standard
'gpio-line-names' property.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/gpio/gpio-mockup.c | 70 +++++++++++++++++++++-----------------
 1 file changed, 38 insertions(+), 32 deletions(-)

Comments

Andy Shevchenko Sept. 25, 2020, 9:03 a.m. UTC | #1 
On Thu, Sep 24, 2020 at 01:38:41PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> GPIO line names are currently created by the driver from the chip label.
> We'll want to support custom formats for line names (for instance: to
> name all lines the same) for user-space tests so create them in the
> module init function and pass them to the driver using the standard
> 'gpio-line-names' property.

...

> +		if (gpio_mockup_named_lines) {
> +			line_names = gpio_mockup_make_line_names(chip_label,
> +								 ngpio);
> +			if (!line_names) {
> +				platform_driver_unregister(&gpio_mockup_driver);
> +				gpio_mockup_unregister_pdevs();
> +				return -ENOMEM;
> +			}

> +			properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
> +						"gpio-line-names",
> +						line_names, ngpio);

Forgot to update GPIO_MOCKUP_MAX_PROP?

> +		}

...

> +		kfree_strarray(line_names, line_names ? ngpio : 0);

Perhaps you may check for NULL pointer in the kfree_strarray() and drop ternary
here?
Bartosz Golaszewski Sept. 25, 2020, 11:40 a.m. UTC | #2 
On Fri, Sep 25, 2020 at 11:03 AM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Thu, Sep 24, 2020 at 01:38:41PM +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> >
> > GPIO line names are currently created by the driver from the chip label.
> > We'll want to support custom formats for line names (for instance: to
> > name all lines the same) for user-space tests so create them in the
> > module init function and pass them to the driver using the standard
> > 'gpio-line-names' property.
>
> ...
>
> > +             if (gpio_mockup_named_lines) {
> > +                     line_names = gpio_mockup_make_line_names(chip_label,
> > +                                                              ngpio);
> > +                     if (!line_names) {
> > +                             platform_driver_unregister(&gpio_mockup_driver);
> > +                             gpio_mockup_unregister_pdevs();
> > +                             return -ENOMEM;
> > +                     }
>
> > +                     properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
> > +                                             "gpio-line-names",
> > +                                             line_names, ngpio);
>
> Forgot to update GPIO_MOCKUP_MAX_PROP?
>

No, there are still three properties: chip-label, nr-gpios and
gpio-line-names. Same answer to patch 8/9.

> > +             }
>
> ...
>
> > +             kfree_strarray(line_names, line_names ? ngpio : 0);
>
> Perhaps you may check for NULL pointer in the kfree_strarray() and drop ternary
> here?
>

I did in the previous series and you told me to not to. :)

Bartosz
Andy Shevchenko Sept. 25, 2020, 12:30 p.m. UTC | #3 
On Fri, Sep 25, 2020 at 01:40:10PM +0200, Bartosz Golaszewski wrote:
> On Fri, Sep 25, 2020 at 11:03 AM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > On Thu, Sep 24, 2020 at 01:38:41PM +0200, Bartosz Golaszewski wrote:
> > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > >
> > > GPIO line names are currently created by the driver from the chip label.
> > > We'll want to support custom formats for line names (for instance: to
> > > name all lines the same) for user-space tests so create them in the
> > > module init function and pass them to the driver using the standard
> > > 'gpio-line-names' property.
> >
> > ...
> >
> > > +             if (gpio_mockup_named_lines) {
> > > +                     line_names = gpio_mockup_make_line_names(chip_label,
> > > +                                                              ngpio);
> > > +                     if (!line_names) {
> > > +                             platform_driver_unregister(&gpio_mockup_driver);
> > > +                             gpio_mockup_unregister_pdevs();
> > > +                             return -ENOMEM;
> > > +                     }
> >
> > > +                     properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
> > > +                                             "gpio-line-names",
> > > +                                             line_names, ngpio);
> >
> > Forgot to update GPIO_MOCKUP_MAX_PROP?
> >
> 
> No, there are still three properties: chip-label, nr-gpios and
> gpio-line-names. Same answer to patch 8/9.
> 
> > > +             }
> >
> > ...
> >
> > > +             kfree_strarray(line_names, line_names ? ngpio : 0);
> >
> > Perhaps you may check for NULL pointer in the kfree_strarray() and drop ternary
> > here?
> >
> 
> I did in the previous series and you told me to not to. :)

Hmm... What was my argument? What was wrong with me? free() should be NULL-aware.
Bartosz Golaszewski Sept. 28, 2020, 8:44 a.m. UTC | #4 
On Fri, Sep 25, 2020 at 6:41 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Fri, Sep 25, 2020 at 01:40:10PM +0200, Bartosz Golaszewski wrote:
> > On Fri, Sep 25, 2020 at 11:03 AM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > On Thu, Sep 24, 2020 at 01:38:41PM +0200, Bartosz Golaszewski wrote:
> > > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > > >
> > > > GPIO line names are currently created by the driver from the chip label.
> > > > We'll want to support custom formats for line names (for instance: to
> > > > name all lines the same) for user-space tests so create them in the
> > > > module init function and pass them to the driver using the standard
> > > > 'gpio-line-names' property.
> > >
> > > ...
> > >
> > > > +             if (gpio_mockup_named_lines) {
> > > > +                     line_names = gpio_mockup_make_line_names(chip_label,
> > > > +                                                              ngpio);
> > > > +                     if (!line_names) {
> > > > +                             platform_driver_unregister(&gpio_mockup_driver);
> > > > +                             gpio_mockup_unregister_pdevs();
> > > > +                             return -ENOMEM;
> > > > +                     }
> > >
> > > > +                     properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
> > > > +                                             "gpio-line-names",
> > > > +                                             line_names, ngpio);
> > >
> > > Forgot to update GPIO_MOCKUP_MAX_PROP?
> > >
> >
> > No, there are still three properties: chip-label, nr-gpios and
> > gpio-line-names. Same answer to patch 8/9.
> >
> > > > +             }
> > >
> > > ...
> > >
> > > > +             kfree_strarray(line_names, line_names ? ngpio : 0);
> > >
> > > Perhaps you may check for NULL pointer in the kfree_strarray() and drop ternary
> > > here?
> > >
> >
> > I did in the previous series and you told me to not to. :)
>
> Hmm... What was my argument? What was wrong with me? free() should be NULL-aware.
>

Well, it is - your just need to make sure ngpio is 0 too. :)

I'll revert back to having the NULL check.

Bartosz
Andy Shevchenko Sept. 28, 2020, 9:11 a.m. UTC | #5 
On Mon, Sep 28, 2020 at 11:45 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> On Fri, Sep 25, 2020 at 6:41 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > On Fri, Sep 25, 2020 at 01:40:10PM +0200, Bartosz Golaszewski wrote:
> > > On Fri, Sep 25, 2020 at 11:03 AM Andy Shevchenko
> > > <andriy.shevchenko@linux.intel.com> wrote:
> > > > On Thu, Sep 24, 2020 at 01:38:41PM +0200, Bartosz Golaszewski wrote:

...

> > > > > +             kfree_strarray(line_names, line_names ? ngpio : 0);
> > > >
> > > > Perhaps you may check for NULL pointer in the kfree_strarray() and drop ternary
> > > > here?
> > > >
> > >
> > > I did in the previous series and you told me to not to. :)
> >
> > Hmm... What was my argument? What was wrong with me? free() should be NULL-aware.
>
> Well, it is - your just need to make sure ngpio is 0 too. :)

Do you really need that? If you have NULL as a first parameter, the
second one can be anything.

> I'll revert back to having the NULL check.
Bartosz Golaszewski Sept. 28, 2020, 9:58 a.m. UTC | #6 
On Mon, Sep 28, 2020 at 11:11 AM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Mon, Sep 28, 2020 at 11:45 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> > On Fri, Sep 25, 2020 at 6:41 PM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > On Fri, Sep 25, 2020 at 01:40:10PM +0200, Bartosz Golaszewski wrote:
> > > > On Fri, Sep 25, 2020 at 11:03 AM Andy Shevchenko
> > > > <andriy.shevchenko@linux.intel.com> wrote:
> > > > > On Thu, Sep 24, 2020 at 01:38:41PM +0200, Bartosz Golaszewski wrote:
>
> ...
>
> > > > > > +             kfree_strarray(line_names, line_names ? ngpio : 0);
> > > > >
> > > > > Perhaps you may check for NULL pointer in the kfree_strarray() and drop ternary
> > > > > here?
> > > > >
> > > >
> > > > I did in the previous series and you told me to not to. :)
> > >
> > > Hmm... What was my argument? What was wrong with me? free() should be NULL-aware.
> >
> > Well, it is - your just need to make sure ngpio is 0 too. :)
>
> Do you really need that? If you have NULL as a first parameter, the
> second one can be anything.
>
> > I'll revert back to having the NULL check.
>

Yes that's what I'm saying but under patch 1/9 you previously said:

--
Shouldn't we expect that caller will supply NULL, 0 and above check is not
needed?
--

this is why it works like this in v1.

Bartosz
diff mbox series

Patch

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index 5b2686f9e07d..c35fd05de395 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -19,6 +19,7 @@ 
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/slab.h>
+#include <linux/string_helpers.h>
 #include <linux/uaccess.h>
 
 #include "gpiolib.h"
@@ -374,29 +375,6 @@  static void gpio_mockup_debugfs_setup(struct device *dev,
 	}
 }
 
-static int gpio_mockup_name_lines(struct device *dev,
-				  struct gpio_mockup_chip *chip)
-{
-	struct gpio_chip *gc = &chip->gc;
-	char **names;
-	int i;
-
-	names = devm_kcalloc(dev, gc->ngpio, sizeof(char *), GFP_KERNEL);
-	if (!names)
-		return -ENOMEM;
-
-	for (i = 0; i < gc->ngpio; i++) {
-		names[i] = devm_kasprintf(dev, GFP_KERNEL,
-					  "%s-%d", gc->label, i);
-		if (!names[i])
-			return -ENOMEM;
-	}
-
-	gc->names = (const char *const *)names;
-
-	return 0;
-}
-
 static void gpio_mockup_dispose_mappings(void *data)
 {
 	struct gpio_mockup_chip *chip = data;
@@ -464,12 +442,6 @@  static int gpio_mockup_probe(struct platform_device *pdev)
 	for (i = 0; i < gc->ngpio; i++)
 		chip->lines[i].dir = GPIO_LINE_DIRECTION_IN;
 
-	if (device_property_read_bool(dev, "named-gpio-lines")) {
-		rv = gpio_mockup_name_lines(dev, chip);
-		if (rv)
-			return rv;
-	}
-
 	chip->irq_sim_domain = devm_irq_domain_create_sim(dev, NULL,
 							  gc->ngpio);
 	if (IS_ERR(chip->irq_sim_domain))
@@ -510,6 +482,27 @@  static void gpio_mockup_unregister_pdevs(void)
 	}
 }
 
+static __init char **gpio_mockup_make_line_names(const char *label,
+						 unsigned int num_lines)
+{
+	unsigned int i;
+	char **names;
+
+	names = kcalloc(num_lines + 1, sizeof(char *), GFP_KERNEL);
+	if (!names)
+		return NULL;
+
+	for (i = 0; i < num_lines; i++) {
+		names[i] = kasprintf(GFP_KERNEL, "%s-%u", label, i);
+		if (!names[i]) {
+			kfree_strarray(names, i);
+			return NULL;
+		}
+	}
+
+	return names;
+}
+
 static int __init gpio_mockup_init(void)
 {
 	struct property_entry properties[GPIO_MOCKUP_MAX_PROP];
@@ -517,6 +510,7 @@  static int __init gpio_mockup_init(void)
 	struct platform_device_info pdevinfo;
 	struct platform_device *pdev;
 	char chip_label[32];
+	char **line_names;
 	u16 ngpio;
 
 	if ((gpio_mockup_num_ranges < 2) ||
@@ -549,6 +543,7 @@  static int __init gpio_mockup_init(void)
 		memset(properties, 0, sizeof(properties));
 		memset(&pdevinfo, 0, sizeof(pdevinfo));
 		prop = 0;
+		line_names = NULL;
 
 		snprintf(chip_label, sizeof(chip_label),
 			 "gpio-mockup-%c", i + 'A');
@@ -564,15 +559,26 @@  static int __init gpio_mockup_init(void)
 				 : gpio_mockup_range_ngpio(i) - base;
 		properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio);
 
-		if (gpio_mockup_named_lines)
-			properties[prop++] = PROPERTY_ENTRY_BOOL(
-						"named-gpio-lines");
+		if (gpio_mockup_named_lines) {
+			line_names = gpio_mockup_make_line_names(chip_label,
+								 ngpio);
+			if (!line_names) {
+				platform_driver_unregister(&gpio_mockup_driver);
+				gpio_mockup_unregister_pdevs();
+				return -ENOMEM;
+			}
+
+			properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
+						"gpio-line-names",
+						line_names, ngpio);
+		}
 
 		pdevinfo.name = "gpio-mockup";
 		pdevinfo.id = i;
 		pdevinfo.properties = properties;
 
 		pdev = platform_device_register_full(&pdevinfo);
+		kfree_strarray(line_names, line_names ? ngpio : 0);
 		if (IS_ERR(pdev)) {
 			pr_err("error registering device");
 			platform_driver_unregister(&gpio_mockup_driver);