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	Nomadik GPIO is a fairly simple GPIO module used in the ST-Ericsson Ux500 SoCs (and some older Nomadik SoCs). It uses registers where each GPIO is represented as a single bit, plus "set" and "clear" registers that allow updating the state without having to read the existing state. The driver implements support for it for use together with DM_GPIO and the existing ste-dbx5x0.dtsi device tree. Cc: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Stephan Gerhold <stephan@gerhold.net> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
		
			
				
	
	
		
			126 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			126 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0+
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/* Copyright (C) 2019 Stephan Gerhold */
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#include <common.h>
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#include <dm.h>
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#include <asm/gpio.h>
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#include <asm/io.h>
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struct nmk_gpio_regs {
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	u32 dat;	/* data */
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	u32 dats;	/* data set */
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	u32 datc;	/* data clear */
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	u32 pdis;	/* pull disable */
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	u32 dir;	/* direction */
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	u32 dirs;	/* direction set */
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	u32 dirc;	/* direction clear */
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	u32 slpm;	/* sleep mode */
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	u32 afsla;	/* alternate function select A */
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	u32 afslb;	/* alternate function select B */
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	u32 lowemi;	/* low EMI mode */
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};
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struct nmk_gpio {
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	struct nmk_gpio_regs *regs;
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};
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static int nmk_gpio_get_value(struct udevice *dev, unsigned offset)
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{
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	struct nmk_gpio *priv = dev_get_priv(dev);
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	return !!(readl(&priv->regs->dat) & BIT(offset));
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}
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static int nmk_gpio_set_value(struct udevice *dev, unsigned offset, int value)
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{
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	struct nmk_gpio *priv = dev_get_priv(dev);
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	if (value)
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		writel(BIT(offset), &priv->regs->dats);
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	else
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		writel(BIT(offset), &priv->regs->datc);
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	return 0;
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}
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static int nmk_gpio_get_function(struct udevice *dev, unsigned offset)
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{
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	struct nmk_gpio *priv = dev_get_priv(dev);
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	if (readl(&priv->regs->afsla) & BIT(offset) ||
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	    readl(&priv->regs->afslb) & BIT(offset))
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		return GPIOF_FUNC;
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	if (readl(&priv->regs->dir) & BIT(offset))
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		return GPIOF_OUTPUT;
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	else
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		return GPIOF_INPUT;
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}
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static int nmk_gpio_direction_input(struct udevice *dev, unsigned offset)
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{
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	struct nmk_gpio *priv = dev_get_priv(dev);
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	writel(BIT(offset), &priv->regs->dirc);
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	return 0;
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}
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static int nmk_gpio_direction_output(struct udevice *dev, unsigned offset,
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				     int value)
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{
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	struct nmk_gpio *priv = dev_get_priv(dev);
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	writel(BIT(offset), &priv->regs->dirs);
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	return nmk_gpio_set_value(dev, offset, value);
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}
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static const struct dm_gpio_ops nmk_gpio_ops = {
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	.get_value		= nmk_gpio_get_value,
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	.set_value		= nmk_gpio_set_value,
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	.get_function		= nmk_gpio_get_function,
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	.direction_input	= nmk_gpio_direction_input,
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	.direction_output	= nmk_gpio_direction_output,
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};
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static int nmk_gpio_probe(struct udevice *dev)
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{
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	struct nmk_gpio *priv = dev_get_priv(dev);
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	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
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	char buf[20];
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	u32 bank;
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	int ret;
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	priv->regs = dev_read_addr_ptr(dev);
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	if (!priv->regs)
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		return -EINVAL;
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	ret = dev_read_u32(dev, "gpio-bank", &bank);
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	if (ret < 0) {
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		printf("nmk_gpio(%s): Failed to read gpio-bank\n", dev->name);
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		return ret;
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	}
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	sprintf(buf, "nmk%u-gpio", bank);
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	uc_priv->bank_name = strdup(buf);
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	if (!uc_priv->bank_name)
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		return -ENOMEM;
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	uc_priv->gpio_count = sizeof(priv->regs->dat) * BITS_PER_BYTE;
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	return 0;
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}
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static const struct udevice_id nmk_gpio_ids[] = {
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	{ .compatible = "st,nomadik-gpio" },
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	{ }
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};
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U_BOOT_DRIVER(gpio_nmk) = {
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	.name		= "nmk_gpio",
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	.id		= UCLASS_GPIO,
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	.of_match	= nmk_gpio_ids,
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	.probe		= nmk_gpio_probe,
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	.ops		= &nmk_gpio_ops,
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	.priv_auto	= sizeof(struct nmk_gpio),
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};
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