2012-11-20 14:04:54

by Linus Walleij

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Subject: [PATCH 1/7 v2] gpiolib: let gpiochip_add_pin_range() specify offset

From: Linus Walleij <[email protected]>

Like with commit 3c739ad0df5eb41cd7adad879eda6aa09879eb76
it is not always enough to specify all the pins of a gpio_chip
from offset zero to be added to a pin map range, since the
mapping from GPIO to pin controller may not be linear at all,
but need to be broken into a few consecutive sub-ranges or
1-pin entries for complicated cases. The ranges may also be
sparse.

This alters the signature of the function to accept offsets
into both the GPIO-chip local pinspace and the pin controller
local pinspace.

Signed-off-by: Linus Walleij <[email protected]>
---
drivers/gpio/gpiolib.c | 32 +++++++++++++++++++++++++++++---
include/asm-generic/gpio.h | 6 ++++--
include/linux/gpio.h | 3 ++-
3 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index c5f6500..6d13bea 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1187,24 +1187,45 @@ EXPORT_SYMBOL_GPL(gpiochip_find);

#ifdef CONFIG_PINCTRL

+/**
+ * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
+ * @chip: the gpiochip to add the range for
+ * @pinctrl_name: the dev_name() of the pin controller to map to
+ * @offset: the start offset in the current gpio_chip number space
+ * @pin_base: the start offset in the pin controller number space
+ * @npins: the number of pins from the offset of each pin space (GPIO and
+ * pin controller) to accumulate in this range
+ */
int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
- unsigned int pin_base, unsigned int npins)
+ unsigned int offset, unsigned int pin_base,
+ unsigned int npins)
{
struct gpio_pin_range *pin_range;

- pin_range = devm_kzalloc(chip->dev, sizeof(*pin_range), GFP_KERNEL);
+ pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
pr_err("%s: GPIO chip: failed to allocate pin ranges\n",
chip->label);
return -ENOMEM;
}

+ /* Use local offset as range ID */
+ pin_range->range.id = offset;
+ pin_range->range.gc = chip;
pin_range->range.name = chip->label;
- pin_range->range.base = chip->base;
+ pin_range->range.base = chip->base + offset;
pin_range->range.pin_base = pin_base;
pin_range->range.npins = npins;
pin_range->pctldev = find_pinctrl_and_add_gpio_range(pinctl_name,
&pin_range->range);
+ if (!pin_range->pctldev) {
+ pr_err("%s: GPIO chip: could not create pin range\n",
+ chip->label);
+ kfree(pin_range);
+ }
+ pr_debug("%s: GPIO chip: created GPIO range %d->%d ==> PIN %d->%d\n",
+ chip->label, offset, offset + npins - 1,
+ pin_base, pin_base + npins - 1);

list_add_tail(&pin_range->node, &chip->pin_ranges);

@@ -1212,6 +1233,10 @@ int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
}
EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);

+/**
+ * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
+ * @chip: the chip to remove all the mappings for
+ */
void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
{
struct gpio_pin_range *pin_range, *tmp;
@@ -1220,6 +1245,7 @@ void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
list_del(&pin_range->node);
pinctrl_remove_gpio_range(pin_range->pctldev,
&pin_range->range);
+ kfree(pin_range);
}
}
EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 2b84fc3..ec58fdb 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -283,14 +283,16 @@ struct gpio_pin_range {
};

int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
- unsigned int pin_base, unsigned int npins);
+ unsigned int offset, unsigned int pin_base,
+ unsigned int npins);
void gpiochip_remove_pin_ranges(struct gpio_chip *chip);

#else

static inline int
gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
- unsigned int pin_base, unsigned int npins)
+ unsigned int offset, unsigned int pin_base,
+ unsigned int npins)
{
return 0;
}
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 7ba2762..99861c6 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -233,7 +233,8 @@ static inline int irq_to_gpio(unsigned irq)

static inline int
gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
- unsigned int pin_base, unsigned int npins)
+ unsigned int offset, unsigned int pin_base,
+ unsigned int npins)
{
WARN_ON(1);
return -EINVAL;
--
1.7.11.3


2012-11-20 14:18:55

by Viresh Kumar

[permalink] [raw]
Subject: Re: [PATCH 1/7 v2] gpiolib: let gpiochip_add_pin_range() specify offset

On 20 November 2012 19:34, Linus Walleij <[email protected]> wrote:
> From: Linus Walleij <[email protected]>
>
> Like with commit 3c739ad0df5eb41cd7adad879eda6aa09879eb76
> it is not always enough to specify all the pins of a gpio_chip
> from offset zero to be added to a pin map range, since the
> mapping from GPIO to pin controller may not be linear at all,
> but need to be broken into a few consecutive sub-ranges or
> 1-pin entries for complicated cases. The ranges may also be
> sparse.
>
> This alters the signature of the function to accept offsets
> into both the GPIO-chip local pinspace and the pin controller
> local pinspace.
>
> Signed-off-by: Linus Walleij <[email protected]>

For all 7 patches:
Reviewed-by: Viresh Kumar <[email protected]>

2012-11-20 17:32:48

by Stephen Warren

[permalink] [raw]
Subject: Re: [PATCH 1/7 v2] gpiolib: let gpiochip_add_pin_range() specify offset

On 11/20/2012 07:04 AM, Linus Walleij wrote:
> From: Linus Walleij <[email protected]>
>
> Like with commit 3c739ad0df5eb41cd7adad879eda6aa09879eb76
> it is not always enough to specify all the pins of a gpio_chip
> from offset zero to be added to a pin map range, since the
> mapping from GPIO to pin controller may not be linear at all,
> but need to be broken into a few consecutive sub-ranges or
> 1-pin entries for complicated cases. The ranges may also be
> sparse.
>
> This alters the signature of the function to accept offsets
> into both the GPIO-chip local pinspace and the pin controller
> local pinspace.

Aside from the one comment I made, the series,
Reviewed-by: Stephen Warren <[email protected]>