Commit 09107a51 authored by Alexandre Belloni's avatar Alexandre Belloni Committed by Linus Walleij
Browse files

pinctrl: at91-pio4: implement .get_multiple and .set_multiple 



Implement .get_multiple and .set_multiple to allow reading or setting
multiple pins simultaneously. Pins in the same bank will all be switched at
the same time, improving synchronization and performances.

Keep the driver future proof by allowing its use on 64bits platforms if
they ever appear with this IP and we end up with a mismatch between
ATMEL_PIO_NPINS_PER_BANK and BITS_PER_LONG.

Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: default avatarLudovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20190918113657.25998-1-alexandre.belloni@bootlin.com


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 0074a66c

drivers/pinctrl/pinctrl-at91-pio4.c

+62 −0
Original line number Diff line number Diff line
@@ -328,6 +328,33 @@ static int atmel_gpio_get(struct gpio_chip *chip, unsigned offset) 
	return !!(reg & BIT(pin->line));

}



static int atmel_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,

				   unsigned long *bits)

{

	struct atmel_pioctrl *atmel_pioctrl = gpiochip_get_data(chip);

	unsigned int bank;



	bitmap_zero(bits, atmel_pioctrl->npins);



	for (bank = 0; bank < atmel_pioctrl->nbanks; bank++) {

		unsigned int word = bank;

		unsigned int offset = 0;

		unsigned int reg;



#if ATMEL_PIO_NPINS_PER_BANK != BITS_PER_LONG

		word = BIT_WORD(bank * ATMEL_PIO_NPINS_PER_BANK);

		offset = bank * ATMEL_PIO_NPINS_PER_BANK % BITS_PER_LONG;

#endif

		if (!mask[word])

			continue;



		reg = atmel_gpio_read(atmel_pioctrl, bank, ATMEL_PIO_PDSR);

		bits[word] |= mask[word] & (reg << offset);

	}



	return 0;

}



static int atmel_gpio_direction_output(struct gpio_chip *chip, unsigned offset,

				       int value)

{
@@ -358,11 +385,46 @@ static void atmel_gpio_set(struct gpio_chip *chip, unsigned offset, int val) 
			 BIT(pin->line));

}



static void atmel_gpio_set_multiple(struct gpio_chip *chip, unsigned long *mask,

				    unsigned long *bits)

{

	struct atmel_pioctrl *atmel_pioctrl = gpiochip_get_data(chip);

	unsigned int bank;



	for (bank = 0; bank < atmel_pioctrl->nbanks; bank++) {

		unsigned int bitmask;

		unsigned int word = bank;



/*

 * On a 64-bit platform, BITS_PER_LONG is 64 so it is necessary to iterate over

 * two 32bit words to handle the whole  bitmask

 */

#if ATMEL_PIO_NPINS_PER_BANK != BITS_PER_LONG

		word = BIT_WORD(bank * ATMEL_PIO_NPINS_PER_BANK);

#endif

		if (!mask[word])

			continue;



		bitmask = mask[word] & bits[word];

		atmel_gpio_write(atmel_pioctrl, bank, ATMEL_PIO_SODR, bitmask);



		bitmask = mask[word] & ~bits[word];

		atmel_gpio_write(atmel_pioctrl, bank, ATMEL_PIO_CODR, bitmask);



#if ATMEL_PIO_NPINS_PER_BANK != BITS_PER_LONG

		mask[word] >>= ATMEL_PIO_NPINS_PER_BANK;

		bits[word] >>= ATMEL_PIO_NPINS_PER_BANK;

#endif

	}

}



static struct gpio_chip atmel_gpio_chip = {

	.direction_input        = atmel_gpio_direction_input,

	.get                    = atmel_gpio_get,

	.get_multiple           = atmel_gpio_get_multiple,

	.direction_output       = atmel_gpio_direction_output,

	.set                    = atmel_gpio_set,

	.set_multiple           = atmel_gpio_set_multiple,

	.to_irq                 = atmel_gpio_to_irq,

	.base                   = 0,

};

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