diff mbox series

[2/7] gpiolib: of: consolidate simple renames into a single quirk

Message ID 20221011-gpiolib-quirks-v1-2-e01d9d3e7b29@gmail.com
State Superseded
Headers show
Series gpiolib: more quirks to handle legacy names | expand

Commit Message

Dmitry Torokhov Oct. 11, 2022, 10:19 p.m. UTC 
This consolidates all quirks doing simple renames (either allowing
suffix-less names or trivial renames, when index changes are not
required) into a single quirk.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/gpio/gpiolib-of.c | 176 +++++++++++++++++-----------------------------
 1 file changed, 64 insertions(+), 112 deletions(-)

Comments

Daniel Thompson Oct. 13, 2022, 12:59 p.m. UTC | #1 
On Wed, Oct 12, 2022 at 12:20:50PM -0700, Dmitry Torokhov wrote:
> On Wed, Oct 12, 2022 at 11:12:03AM +0100, Daniel Thompson wrote:
> > On Tue, Oct 11, 2022 at 03:19:30PM -0700, Dmitry Torokhov wrote:
> > > diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> > > index cef4f6634125..619aae0c5476 100644
> > > @@ -365,127 +365,83 @@ struct gpio_desc *gpiod_get_from_of_node(const struct device_node *node,
> > > +static struct gpio_desc *of_find_gpio_rename(struct device_node *np,
> > >  					     const char *con_id,
> > >  					     unsigned int idx,
> > >  					     enum of_gpio_flags *of_flags)
> > >  {
> > > +	static const struct of_rename_gpio {
> > > +		const char *con_id;
> > > +		const char *legacy_id;	/* NULL - same as con_id */
> > > +		const char *compatible; /* NULL - don't check */
> >
> > "don't check" doesn't seem desirable. It's not too big a deal here
> > because everything affected has a vendor prefix (meaning incorrect
> > matching is unlikely). Should there be a comment about the general care
> > needed for a NULL compatible?

There were certainly a lot of compatibles affected by this translation
and given the structure of the drivers it is a tough code review to be
sure you have picked up *all* of them!


> I'll add the wording that NULL is only acceptable if property has a
> vendor prefi, Will that be OK? Otherwise I'll have to add a lot of
> entries for Arizona and Madera.
>
> >
> >
> > > +	} gpios[] = {
> > > +#if IS_ENABLED(CONFIG_MFD_ARIZONA)
> > > +		{ "wlf,reset",	NULL,		NULL },
> >
> > CONFIG_REGULATOR_ARIZONA_LDO1 is better guard for this con id.
>
> Are you sure? I see reset handling happening in
> drivers/mfd/arizona-core.c independently of regulator code...

Looks like I grepped for the wrong string so I was completely wrong
here... and in two different ways!

Firstly I'm wrong about replacing the guard. Existing guard is correct!

Secondly, I didn't notice until now that wm8804 also uses the
"wlf,reset" and it is a little odd that the wm8804 driver will accept
or refuse a misspelled binding based whether the kernel has enabled the
arizona drivers.

Overall I can live with the code we have today but this makes me wonder
if the comment discussed above should be stronger. Something like:
"the NULL compatible code is used there to support legacy entries in
the table; try to avoid adding new NULL entries".


Daniel.
diff mbox series

Patch

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index cef4f6634125..619aae0c5476 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -365,127 +365,83 @@  struct gpio_desc *gpiod_get_from_of_node(const struct device_node *node,
 }
 EXPORT_SYMBOL_GPL(gpiod_get_from_of_node);
 
-/*
- * The SPI GPIO bindings happened before we managed to establish that GPIO
- * properties should be named "foo-gpios" so we have this special kludge for
- * them.
- */
-static struct gpio_desc *of_find_spi_gpio(struct device_node *np,
-					  const char *con_id,
-					  unsigned int idx,
-					  enum of_gpio_flags *of_flags)
-{
-	char prop_name[32]; /* 32 is max size of property name */
-
-	/*
-	 * Hopefully the compiler stubs the rest of the function if this
-	 * is false.
-	 */
-	if (!IS_ENABLED(CONFIG_SPI_MASTER))
-		return ERR_PTR(-ENOENT);
-
-	/* Allow this specifically for "spi-gpio" devices */
-	if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
-		return ERR_PTR(-ENOENT);
-
-	/* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
-	snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
-
-	return of_get_named_gpiod_flags(np, prop_name, idx, of_flags);
-}
-
-/*
- * The old Freescale bindings use simply "gpios" as name for the chip select
- * lines rather than "cs-gpios" like all other SPI hardware. Account for this
- * with a special quirk.
- */
-static struct gpio_desc *of_find_spi_cs_gpio(struct device_node *np,
+static struct gpio_desc *of_find_gpio_rename(struct device_node *np,
 					     const char *con_id,
 					     unsigned int idx,
 					     enum of_gpio_flags *of_flags)
 {
-	if (!IS_ENABLED(CONFIG_SPI_MASTER))
-		return ERR_PTR(-ENOENT);
-
-	/* Allow this specifically for Freescale and PPC devices */
-	if (!of_device_is_compatible(np, "fsl,spi") &&
-	    !of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
-	    !of_device_is_compatible(np, "ibm,ppc4xx-spi"))
-		return ERR_PTR(-ENOENT);
-	/* Allow only if asking for "cs-gpios" */
-	if (!con_id || strcmp(con_id, "cs"))
-		return ERR_PTR(-ENOENT);
+	static const struct of_rename_gpio {
+		const char *con_id;
+		const char *legacy_id;	/* NULL - same as con_id */
+		const char *compatible; /* NULL - don't check */
+	} gpios[] = {
+#if IS_ENABLED(CONFIG_MFD_ARIZONA)
+		{ "wlf,reset",	NULL,		NULL },
+#endif
+#if IS_ENABLED(CONFIG_REGULATOR)
+		/*
+		 * Some regulator bindings happened before we managed to
+		 * establish that GPIO properties should be named
+		 * "foo-gpios" so we have this special kludge for them.
+		 */
+		{ "wlf,ldoena",  NULL,		NULL }, /* Arizona */
+		{ "wlf,ldo1ena", NULL,		NULL }, /* WM8994 */
+		{ "wlf,ldo2ena", NULL,		NULL }, /* WM8994 */
+#endif
+#if IS_ENABLED(CONFIG_SPI_MASTER)
 
-	/*
-	 * While all other SPI controllers use "cs-gpios" the Freescale
-	 * uses just "gpios" so translate to that when "cs-gpios" is
-	 * requested.
-	 */
-	return of_get_named_gpiod_flags(np, "gpios", idx, of_flags);
-}
+		/*
+		 * The SPI GPIO bindings happened before we managed to
+		 * establish that GPIO properties should be named
+		 * "foo-gpios" so we have this special kludge for them.
+		 */
+		{ "miso",	"gpio-miso",	"spi-gpio" },
+		{ "mosi",	"gpio-mosi",	"spi-gpio" },
+		{ "sck",	"gpio-sck",	"spi-gpio" },
 
-/*
- * Some regulator bindings happened before we managed to establish that GPIO
- * properties should be named "foo-gpios" so we have this special kludge for
- * them.
- */
-static struct gpio_desc *of_find_regulator_gpio(struct device_node *np,
-						const char *con_id,
-						unsigned int idx,
-						enum of_gpio_flags *of_flags)
-{
-	/* These are the connection IDs we accept as legacy GPIO phandles */
-	const char *whitelist[] = {
-		"wlf,ldoena", /* Arizona */
-		"wlf,ldo1ena", /* WM8994 */
-		"wlf,ldo2ena", /* WM8994 */
+		/*
+		 * The old Freescale bindings use simply "gpios" as name
+		 * for the chip select lines rather than "cs-gpios" like
+		 * all other SPI hardware. Allow this specifically for
+		 * Freescale and PPC devices.
+		 */
+		{ "cs",		"gpios",	"fsl,spi" },
+		{ "cs",		"gpios",	"aeroflexgaisler,spictrl" },
+		{ "cs",		"gpios",	"ibm,ppc4xx-spi" },
+#endif
+#if IS_ENABLED(CONFIG_TYPEC_FUSB302)
+		/*
+		 * Fairchild FUSB302 host is using undocumented "fcs,int_n"
+		 * property without the compulsory "-gpios" suffix.
+		 */
+		{ "fcs,int_n",	NULL,		"fcs,fusb302" },
+#endif
 	};
-	int i;
-
-	if (!IS_ENABLED(CONFIG_REGULATOR))
-		return ERR_PTR(-ENOENT);
+	struct gpio_desc *desc;
+	const char *legacy_id;
+	unsigned int i;
 
 	if (!con_id)
 		return ERR_PTR(-ENOENT);
 
-	i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
-	if (i < 0)
-		return ERR_PTR(-ENOENT);
-
-	return of_get_named_gpiod_flags(np, con_id, idx, of_flags);
-}
-
-static struct gpio_desc *of_find_arizona_gpio(struct device_node *np,
-					      const char *con_id,
-					      unsigned int idx,
-					      enum of_gpio_flags *of_flags)
-{
-	if (!IS_ENABLED(CONFIG_MFD_ARIZONA))
-		return ERR_PTR(-ENOENT);
-
-	if (!con_id || strcmp(con_id, "wlf,reset"))
-		return ERR_PTR(-ENOENT);
-
-	return of_get_named_gpiod_flags(np, con_id, idx, of_flags);
-}
+	for (i = 0; i < ARRAY_SIZE(gpios); i++) {
+		if (strcmp(con_id, gpios[i].con_id))
+			continue;
 
-static struct gpio_desc *of_find_usb_gpio(struct device_node *np,
-					  const char *con_id,
-					  unsigned int idx,
-					  enum of_gpio_flags *of_flags)
-{
-	/*
-	 * Currently this USB quirk is only for the Fairchild FUSB302 host
-	 * which is using an undocumented DT GPIO line named "fcs,int_n"
-	 * without the compulsory "-gpios" suffix.
-	 */
-	if (!IS_ENABLED(CONFIG_TYPEC_FUSB302))
-		return ERR_PTR(-ENOENT);
+		if (gpios[i].compatible &&
+		    !of_device_is_compatible(np, gpios[i].compatible))
+			continue;
 
-	if (!con_id || strcmp(con_id, "fcs,int_n"))
-		return ERR_PTR(-ENOENT);
+		legacy_id = gpios[i].legacy_id ?: gpios[i].con_id;
+		desc = of_get_named_gpiod_flags(np, legacy_id, idx, of_flags);
+		if (!gpiod_not_found(desc)) {
+			pr_info("%s uses legacy gpio name '%s' instead of '%s-gpios'\n",
+				of_node_full_name(np), legacy_id, con_id);
+			return desc;
+		}
+	}
 
-	return of_get_named_gpiod_flags(np, con_id, idx, of_flags);
+	return ERR_PTR(-ENOENT);
 }
 
 static struct gpio_desc *of_find_mt2701_gpio(struct device_node *np,
@@ -525,11 +481,7 @@  typedef struct gpio_desc *(*of_find_gpio_quirk)(struct device_node *np,
 						unsigned int idx,
 						enum of_gpio_flags *of_flags);
 static const of_find_gpio_quirk of_find_gpio_quirks[] = {
-	of_find_spi_gpio,
-	of_find_spi_cs_gpio,
-	of_find_regulator_gpio,
-	of_find_arizona_gpio,
-	of_find_usb_gpio,
+	of_find_gpio_rename,
 	of_find_mt2701_gpio,
 	NULL
 };