Commit 00aaae60 authored by Ioana Ciornei's avatar Ioana Ciornei Committed by Bartosz Golaszewski
Browse files

gpio: regmap: add the .fixed_direction_output configuration parameter 



There are GPIO controllers such as the one present in the LX2160ARDB
QIXIS FPGA which have fixed-direction input and output GPIO lines mixed
together in a single register. This cannot be modeled using the
gpio-regmap as-is since there is no way to present the true direction of
a GPIO line.

In order to make this use case possible, add a new configuration
parameter - fixed_direction_output - into the gpio_regmap_config
structure. This will enable user drivers to provide a bitmap that
represents the fixed direction of the GPIO lines.

Signed-off-by: default avatarIoana Ciornei <ioana.ciornei@nxp.com>
Acked-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: default avatarMichael Walle <mwalle@kernel.org>
Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent d3762313

drivers/gpio/gpio-regmap.c

+24 −2
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ struct gpio_regmap { 
	unsigned int reg_clr_base;

	unsigned int reg_dir_in_base;

	unsigned int reg_dir_out_base;

	unsigned long *fixed_direction_output;



#ifdef CONFIG_REGMAP_IRQ

	int regmap_irq_line;
@@ -134,6 +135,13 @@ static int gpio_regmap_get_direction(struct gpio_chip *chip, 
	unsigned int base, val, reg, mask;

	int invert, ret;



	if (gpio->fixed_direction_output) {

		if (test_bit(offset, gpio->fixed_direction_output))

			return GPIO_LINE_DIRECTION_OUT;

		else

			return GPIO_LINE_DIRECTION_IN;

	}



	if (gpio->reg_dat_base && !gpio->reg_set_base)

		return GPIO_LINE_DIRECTION_IN;

	if (gpio->reg_set_base && !gpio->reg_dat_base)
@@ -284,6 +292,17 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config 
			goto err_free_gpio;

	}



	if (config->fixed_direction_output) {

		gpio->fixed_direction_output = bitmap_alloc(chip->ngpio,

							    GFP_KERNEL);

		if (!gpio->fixed_direction_output) {

			ret = -ENOMEM;

			goto err_free_gpio;

		}

		bitmap_copy(gpio->fixed_direction_output,

			    config->fixed_direction_output, chip->ngpio);

	}



	/* if not set, assume there is only one register */

	gpio->ngpio_per_reg = config->ngpio_per_reg;

	if (!gpio->ngpio_per_reg)
@@ -300,7 +319,7 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config 


	ret = gpiochip_add_data(chip, gpio);

	if (ret < 0)

		goto err_free_gpio;

		goto err_free_bitmap;



#ifdef CONFIG_REGMAP_IRQ

	if (config->regmap_irq_chip) {
@@ -309,7 +328,7 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config 
						 config->regmap_irq_line, config->regmap_irq_flags,

						 0, config->regmap_irq_chip, &gpio->irq_chip_data);

		if (ret)

			goto err_free_gpio;

			goto err_free_bitmap;



		irq_domain = regmap_irq_get_domain(gpio->irq_chip_data);

	} else
@@ -326,6 +345,8 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config 


err_remove_gpiochip:

	gpiochip_remove(chip);

err_free_bitmap:

	bitmap_free(gpio->fixed_direction_output);

err_free_gpio:

	kfree(gpio);

	return ERR_PTR(ret);
@@ -344,6 +365,7 @@ void gpio_regmap_unregister(struct gpio_regmap *gpio) 
#endif



	gpiochip_remove(&gpio->gpio_chip);

	bitmap_free(gpio->fixed_direction_output);

	kfree(gpio);

}

EXPORT_SYMBOL_GPL(gpio_regmap_unregister);

include/linux/gpio/regmap.h

+5 −0
Original line number Diff line number Diff line
@@ -38,6 +38,10 @@ struct regmap; 
 *			offset to a register/bitmask pair. If not

 *			given the default gpio_regmap_simple_xlate()

 *			is used.

 * @fixed_direction_output:

 *			(Optional) Bitmap representing the fixed direction of

 *			the GPIO lines. Useful when there are GPIO lines with a

 *			fixed direction mixed together in the same register.

 * @drvdata:		(Optional) Pointer to driver specific data which is

 *			not used by gpio-remap but is provided "as is" to the

 *			driver callback(s).
@@ -85,6 +89,7 @@ struct gpio_regmap_config { 
	int reg_stride;

	int ngpio_per_reg;

	struct irq_domain *irq_domain;

	unsigned long *fixed_direction_output;



#ifdef CONFIG_REGMAP_IRQ

	struct regmap_irq_chip *regmap_irq_chip;