[PATCH 2/5] gpio: of: drop needless gpio_chip look-up in of_parse_own_gpio()

From: Masahiro Yamada
Date: Tue Jun 14 2016 - 06:07:45 EST


This function is doing more complicated than needed. The caller of
this function, of_gpiochip_scan_gpios() already knows the pointer to
the gpio_chip. It can pass it to of_parse_own_gpio() instead of
looking up the gpio_chip by gpiochip_find().

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

drivers/gpio/gpiolib-of.c | 39 ++++++++++++++++++++-------------------
1 file changed, 20 insertions(+), 19 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 99fc40e..27b1729 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -122,6 +122,7 @@ EXPORT_SYMBOL(of_get_named_gpio_flags);
/**
* of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
* @np: device node to get GPIO from
+ * @chip: GPIO chip whose hog is parsed
* @name: GPIO line name
* @lflags: gpio_lookup_flags - returned from of_find_gpio() or
* of_parse_own_gpio()
@@ -131,19 +132,19 @@ EXPORT_SYMBOL(of_get_named_gpio_flags);
* value on the error condition.
*/
static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
+ struct gpio_chip *chip,
const char **name,
enum gpio_lookup_flags *lflags,
enum gpiod_flags *dflags)
{
struct device_node *chip_np;
enum of_gpio_flags xlate_flags;
- struct gg_data gg_data = {
- .flags = &xlate_flags,
- };
+ struct of_phandle_args gpiospec;
+ struct gpio_desc *desc;
u32 tmp;
int ret;

- chip_np = np->parent;
+ chip_np = chip->of_node;
if (!chip_np)
return ERR_PTR(-EINVAL);

@@ -155,23 +156,23 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
if (ret)
return ERR_PTR(ret);

- if (tmp > MAX_PHANDLE_ARGS)
+ if (tmp > MAX_PHANDLE_ARGS || tmp != chip->of_gpio_n_cells)
return ERR_PTR(-EINVAL);

- gg_data.gpiospec.args_count = tmp;
- gg_data.gpiospec.np = chip_np;
- ret = of_property_read_u32_array(np, "gpios", gg_data.gpiospec.args,
- tmp);
+ gpiospec.np = chip_np;
+ gpiospec.args_count = tmp;
+
+ ret = of_property_read_u32_array(np, "gpios", gpiospec.args, tmp);
if (ret)
return ERR_PTR(ret);

- gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
- if (!gg_data.out_gpio) {
- if (np->parent == np)
- return ERR_PTR(-ENXIO);
- else
- return ERR_PTR(-EINVAL);
- }
+ ret = chip->of_xlate(chip, &gpiospec, &xlate_flags);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ desc = gpiochip_get_desc(chip, ret);
+ if (IS_ERR(desc))
+ return desc;

if (xlate_flags & OF_GPIO_ACTIVE_LOW)
*lflags |= GPIO_ACTIVE_LOW;
@@ -184,14 +185,14 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
*dflags |= GPIOD_OUT_HIGH;
else {
pr_warn("GPIO line %d (%s): no hogging state specified, bailing out\n",
- desc_to_gpio(gg_data.out_gpio), np->name);
+ desc_to_gpio(desc), np->name);
return ERR_PTR(-EINVAL);
}

if (name && of_property_read_string(np, "line-name", name))
*name = np->name;

- return gg_data.out_gpio;
+ return desc;
}

/**
@@ -260,7 +261,7 @@ static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
if (!of_property_read_bool(np, "gpio-hog"))
continue;

- desc = of_parse_own_gpio(np, &name, &lflags, &dflags);
+ desc = of_parse_own_gpio(np, chip, &name, &lflags, &dflags);
if (IS_ERR(desc))
continue;

--
1.9.1