Re: [PATCH v5 1/4] gpiolib: Pass bitmaps, not integer arrays, to get/set array

Peter Rosin
2018-08-30T04:30:32Z

On 2018-08-29 22:48, Janusz Krzysztofik wrote:
> Most users of get/set array functions iterate consecutive bits of data,
> usually a single integer, while processing array of results obtained
> from, or building an array of values to be passed to those functions.
> Save time wasted on those iterations by changing the functions' API to
> accept bitmaps.
>
> All current users are updated as well.
>
> More benefits from the change are expected as soon as planned support
> for accepting/passing those bitmaps directly from/to respective GPIO
> chip callbacks if applicable is implemented.
> diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
> index 401308e3d036..4e36e0eac7a3 100644
> --- a/drivers/i2c/muxes/i2c-mux-gpio.c
> +++ b/drivers/i2c/muxes/i2c-mux-gpio.c
> @@ -22,18 +22,16 @@ struct gpiomux {
> struct i2c_mux_gpio_platform_data data;
> unsigned gpio_base;
> struct gpio_desc **gpios;
> - int *values;
> + int *values; /* FIXME: no longer needed */

That's a half-measure...

> };
>
> static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)
> {
> + unsigned long value_bitmap[1] = { val, };
> int i;

...and i is no longer needed. Hmm, I'd expect a warning about that?

>
> - for (i = 0; i < mux->data.n_gpios; i++)
> - mux->values[i] = (val >> i) & 1;
> -
> gpiod_set_array_value_cansleep(mux->data.n_gpios,
> - mux->gpios, mux->values);
> + mux->gpios, value_bitmap);
> }
>
> static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan)
> diff --git a/drivers/mux/gpio.c b/drivers/mux/gpio.c
> index 6fdd9316db8b..734e1b43aed6 100644
> --- a/drivers/mux/gpio.c
> +++ b/drivers/mux/gpio.c
> @@ -17,20 +17,17 @@
>
> struct mux_gpio {
> struct gpio_descs *gpios;
> - int *val;
> + int *val; /* FIXME: no longer needed */
> };
>
> static int mux_gpio_set(struct mux_control *mux, int state)
> {
> struct mux_gpio *mux_gpio = mux_chip_priv(mux->chip);
> + unsigned long value_bitmap[1] = { state, };
> int i;
>
> - for (i = 0; i < mux_gpio->gpios->ndescs; i++)
> - mux_gpio->val[i] = (state >> i) & 1;
> -
> gpiod_set_array_value_cansleep(mux_gpio->gpios->ndescs,
> - mux_gpio->gpios->desc,
> - mux_gpio->val);
> + mux_gpio->gpios->desc, value_bitmap);
>
> return 0;
> }

Dito for this driver. Just squash the following and be done with
it, no attribution needed...

With that (for the changes in i2c-mux-gpio.c and mux/gpio.c)

Reviewed-by: Peter Rosin <peda@axentia.se>

Linus, I expect this will will end up in some immutable branch for me
to pick up, in case I need to? Not that I expect further work to clash
in these two drivers, but...

Cheers,
Peter

diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
index 4e36e0eac7a3..06a89a29250a 100644
--- a/drivers/i2c/muxes/i2c-mux-gpio.c
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c
@@ -22,13 +22,11 @@ struct gpiomux {
struct i2c_mux_gpio_platform_data data;
unsigned gpio_base;
struct gpio_desc **gpios;
- int *values; /* FIXME: no longer needed */
};

static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)
{
unsigned long value_bitmap[1] = { val, };
- int i;

gpiod_set_array_value_cansleep(mux->data.n_gpios,
mux->gpios, value_bitmap);
@@ -180,15 +178,13 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
return -EPROBE_DEFER;

muxc = i2c_mux_alloc(parent, &pdev->dev, mux->data.n_values,
- mux->data.n_gpios * sizeof(*mux->gpios) +
- mux->data.n_gpios * sizeof(*mux->values), 0,
+ mux->data.n_gpios * sizeof(*mux->gpios), 0,
i2c_mux_gpio_select, NULL);
if (!muxc) {
ret = -ENOMEM;
goto alloc_failed;
}
mux->gpios = muxc->priv;
- mux->values = (int *)(mux->gpios + mux->data.n_gpios);
muxc->priv = mux;

platform_set_drvdata(pdev, muxc);
diff --git a/drivers/mux/gpio.c b/drivers/mux/gpio.c
index 734e1b43aed6..eb1798677dfd 100644
--- a/drivers/mux/gpio.c
+++ b/drivers/mux/gpio.c
@@ -17,14 +17,12 @@

struct mux_gpio {
struct gpio_descs *gpios;
- int *val; /* FIXME: no longer needed */
};

static int mux_gpio_set(struct mux_control *mux, int state)
{
struct mux_gpio *mux_gpio = mux_chip_priv(mux->chip);
unsigned long value_bitmap[1] = { state, };
- int i;

gpiod_set_array_value_cansleep(mux_gpio->gpios->ndescs,
mux_gpio->gpios->desc, value_bitmap);
@@ -55,13 +53,11 @@ static int mux_gpio_probe(struct platform_device *pdev)
if (pins < 0)
return pins;

- mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio) +
- pins * sizeof(*mux_gpio->val));
+ mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio));
if (IS_ERR(mux_chip))
return PTR_ERR(mux_chip);

mux_gpio = mux_chip_priv(mux_chip);
- mux_gpio->val = (int *)(mux_gpio + 1);
mux_chip->ops = &mux_gpio_ops;

mux_gpio->gpios = devm_gpiod_get_array(dev, "mux", GPIOD_OUT_LOW);