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Commit e38a9a43 authored by Stefan Wahren's avatar Stefan Wahren Committed by Linus Walleij
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pinctrl: bcm2835: Add support for BCM2711 pull-up functionality 



The BCM2711 has a new way of selecting the pull-up/pull-down setting
for a GPIO pin. The registers used for the BCM2835, GP_PUD and
GP_PUDCLKn0, are no longer connected. A new set of registers,
GP_GPIO_PUP_PDN_CNTRL_REGx must be used. This commit will add
a new compatible string "brcm,bcm2711-gpio" and the kernel
driver will use it to select which method is used to select
pull-up/pull-down.

This patch based on a patch by Al Cooper which was intended for the
BCM7211. This is a bugfixed and improved version.

Signed-off-by: default avatarStefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/1563776607-8368-3-git-send-email-wahrenst@gmx.net


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 9cd6237d

drivers/pinctrl/bcm/pinctrl-bcm2835.c

+100 −5
Original line number Diff line number Diff line
@@ -57,15 +57,24 @@ 
#define GPAFEN0		0x88	/* Pin Async Falling Edge Detect */

#define GPPUD		0x94	/* Pin Pull-up/down Enable */

#define GPPUDCLK0	0x98	/* Pin Pull-up/down Enable Clock */

#define GP_GPIO_PUP_PDN_CNTRL_REG0 0xe4 /* 2711 Pin Pull-up/down select */



#define FSEL_REG(p)		(GPFSEL0 + (((p) / 10) * 4))

#define FSEL_SHIFT(p)		(((p) % 10) * 3)

#define GPIO_REG_OFFSET(p)	((p) / 32)

#define GPIO_REG_SHIFT(p)	((p) % 32)



#define PUD_2711_MASK		0x3

#define PUD_2711_REG_OFFSET(p)	((p) / 16)

#define PUD_2711_REG_SHIFT(p)	(((p) % 16) * 2)



/* argument: bcm2835_pinconf_pull */

#define BCM2835_PINCONF_PARAM_PULL	(PIN_CONFIG_END + 1)



#define BCM2711_PULL_NONE	0x0

#define BCM2711_PULL_UP		0x1

#define BCM2711_PULL_DOWN	0x2



struct bcm2835_pinctrl {

	struct device *dev;

	void __iomem *base;
@@ -975,6 +984,77 @@ static const struct pinconf_ops bcm2835_pinconf_ops = { 
	.pin_config_set = bcm2835_pinconf_set,

};



static void bcm2711_pull_config_set(struct bcm2835_pinctrl *pc,

				    unsigned int pin, unsigned int arg)

{

	u32 shifter;

	u32 value;

	u32 off;



	off = PUD_2711_REG_OFFSET(pin);

	shifter = PUD_2711_REG_SHIFT(pin);



	value = bcm2835_gpio_rd(pc, GP_GPIO_PUP_PDN_CNTRL_REG0 + (off * 4));

	value &= ~(PUD_2711_MASK << shifter);

	value |= (arg << shifter);

	bcm2835_gpio_wr(pc, GP_GPIO_PUP_PDN_CNTRL_REG0 + (off * 4), value);

}



static int bcm2711_pinconf_set(struct pinctrl_dev *pctldev,

			       unsigned int pin, unsigned long *configs,

			       unsigned int num_configs)

{

	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);

	u32 param, arg;

	int i;



	for (i = 0; i < num_configs; i++) {

		param = pinconf_to_config_param(configs[i]);

		arg = pinconf_to_config_argument(configs[i]);



		switch (param) {

		/* convert legacy brcm,pull */

		case BCM2835_PINCONF_PARAM_PULL:

			if (arg == BCM2835_PUD_UP)

				arg = BCM2711_PULL_UP;

			else if (arg == BCM2835_PUD_DOWN)

				arg = BCM2711_PULL_DOWN;

			else

				arg = BCM2711_PULL_NONE;



			bcm2711_pull_config_set(pc, pin, arg);

			break;



		/* Set pull generic bindings */

		case PIN_CONFIG_BIAS_DISABLE:

			bcm2711_pull_config_set(pc, pin, BCM2711_PULL_NONE);

			break;

		case PIN_CONFIG_BIAS_PULL_DOWN:

			bcm2711_pull_config_set(pc, pin, BCM2711_PULL_DOWN);

			break;

		case PIN_CONFIG_BIAS_PULL_UP:

			bcm2711_pull_config_set(pc, pin, BCM2711_PULL_UP);

			break;



		/* Set output-high or output-low */

		case PIN_CONFIG_OUTPUT:

			bcm2835_gpio_set_bit(pc, arg ? GPSET0 : GPCLR0, pin);

			break;



		default:

			return -ENOTSUPP;

		}

	} /* for each config */



	return 0;

}



static const struct pinconf_ops bcm2711_pinconf_ops = {

	.is_generic = true,

	.pin_config_get = bcm2835_pinconf_get,

	.pin_config_set = bcm2711_pinconf_set,

};



static struct pinctrl_desc bcm2835_pinctrl_desc = {

	.name = MODULE_NAME,

	.pins = bcm2835_gpio_pins,
@@ -990,6 +1070,18 @@ static struct pinctrl_gpio_range bcm2835_pinctrl_gpio_range = { 
	.npins = BCM2835_NUM_GPIOS,

};



static const struct of_device_id bcm2835_pinctrl_match[] = {

	{

		.compatible = "brcm,bcm2835-gpio",

		.data = &bcm2835_pinconf_ops,

	},

	{

		.compatible = "brcm,bcm2711-gpio",

		.data = &bcm2711_pinconf_ops,

	},

	{}

};



static int bcm2835_pinctrl_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;
@@ -997,6 +1089,8 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev) 
	struct bcm2835_pinctrl *pc;

	struct resource iomem;

	int err, i;

	const struct of_device_id *match;



	BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_pins) != BCM2835_NUM_GPIOS);

	BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_groups) != BCM2835_NUM_GPIOS);
@@ -1073,6 +1167,12 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev) 
					     bcm2835_gpio_irq_handler);

	}



	match = of_match_node(bcm2835_pinctrl_match, pdev->dev.of_node);

	if (match) {

		bcm2835_pinctrl_desc.confops =

			(const struct pinconf_ops *)match->data;

	}



	pc->pctl_dev = devm_pinctrl_register(dev, &bcm2835_pinctrl_desc, pc);

	if (IS_ERR(pc->pctl_dev)) {

		gpiochip_remove(&pc->gpio_chip);
@@ -1087,11 +1187,6 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev) 
	return 0;

}



static const struct of_device_id bcm2835_pinctrl_match[] = {

	{ .compatible = "brcm,bcm2835-gpio" },

	{}

};



static struct platform_driver bcm2835_pinctrl_driver = {

	.probe = bcm2835_pinctrl_probe,

	.driver = {