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gpio: aggregator: Set up a parser of delay line parameters

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The aggregator mode can also handle properties of the platform,
that do not belong to the GPIO controller itself. One of such
a property is a signal delay line. Set up a parser to support it.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Andy Shevchenko 2023-06-15 16:20:22 +03:00 committed by Bartosz Golaszewski
parent b466622cec
commit 81674bea19
1 changed files with 70 additions and 2 deletions
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72
drivers/gpio/gpio-aggregator.c
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@ -18,6 +18,7 @@
#include <linux/mutex.h>
#include <linux/overflow.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
@ -422,6 +423,59 @@ static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset)
return gpiod_to_irq(fwd->descs[offset]);
}
/*
* The GPIO delay provides a way to configure platform specific delays
* for the GPIO ramp-up or ramp-down delays. This can serve the following
* purposes:
* - Open-drain output using an RC filter
*/
#define FWD_FEATURE_DELAY BIT(0)
#ifdef CONFIG_OF_GPIO
static int gpiochip_fwd_delay_of_xlate(struct gpio_chip *chip,
const struct of_phandle_args *gpiospec,
u32 *flags)
{
struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
struct gpiochip_fwd_timing *timings;
u32 line;
if (gpiospec->args_count != chip->of_gpio_n_cells)
return -EINVAL;
line = gpiospec->args[0];
if (line >= chip->ngpio)
return -EINVAL;
timings = &fwd->delay_timings[line];
timings->ramp_up_us = gpiospec->args[1];
timings->ramp_down_us = gpiospec->args[2];
return line;
}
static int gpiochip_fwd_setup_delay_line(struct device *dev, struct gpio_chip *chip,
struct gpiochip_fwd *fwd)
{
fwd->delay_timings = devm_kcalloc(dev, chip->ngpio,
sizeof(*fwd->delay_timings),
GFP_KERNEL);
if (!fwd->delay_timings)
return -ENOMEM;
chip->of_xlate = gpiochip_fwd_delay_of_xlate;
chip->of_gpio_n_cells = 3;
return 0;
}
#else
static int gpiochip_fwd_setup_delay_line(struct device *dev, struct gpio_chip *chip,
struct gpiochip_fwd *fwd)
{
return 0;
}
#endif /* !CONFIG_OF_GPIO */
/**
* gpiochip_fwd_create() - Create a new GPIO forwarder
* @dev: Parent device pointer
@ -429,6 +483,7 @@ static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset)
* @descs: Array containing the GPIO descriptors to forward to.
* This array must contain @ngpios entries, and must not be deallocated
* before the forwarder has been destroyed again.
* @features: Bitwise ORed features as defined with FWD_FEATURE_*.
*
* This function creates a new gpiochip, which forwards all GPIO operations to
* the passed GPIO descriptors.
@ -438,7 +493,8 @@ static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset)
*/
static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
unsigned int ngpios,
struct gpio_desc *descs[])
struct gpio_desc *descs[],
unsigned long features)
{
const char *label = dev_name(dev);
struct gpiochip_fwd *fwd;
@ -491,6 +547,12 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
else
spin_lock_init(&fwd->slock);
if (features & FWD_FEATURE_DELAY) {
error = gpiochip_fwd_setup_delay_line(dev, chip, fwd);
if (error)
return ERR_PTR(error);
}
error = devm_gpiochip_add_data(dev, chip, fwd);
if (error)
return ERR_PTR(error);
@ -508,6 +570,7 @@ static int gpio_aggregator_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct gpio_desc **descs;
struct gpiochip_fwd *fwd;
unsigned long features;
int i, n;
n = gpiod_count(dev, NULL);
@ -524,7 +587,8 @@ static int gpio_aggregator_probe(struct platform_device *pdev)
return PTR_ERR(descs[i]);
}
fwd = gpiochip_fwd_create(dev, n, descs);
features = (uintptr_t)device_get_match_data(dev);
fwd = gpiochip_fwd_create(dev, n, descs, features);
if (IS_ERR(fwd))
return PTR_ERR(fwd);
@ -533,6 +597,10 @@ static int gpio_aggregator_probe(struct platform_device *pdev)
}
static const struct of_device_id gpio_aggregator_dt_ids[] = {
{
.compatible = "gpio-delay",
.data = (void *)FWD_FEATURE_DELAY,
},
/*
* Add GPIO-operated devices controlled from userspace below,
* or use "driver_override" in sysfs.