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gpio-uniphier.c 3.52 KiB
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  • /*
     * Copyright (C) 2016 Masahiro Yamada <yamada.masahiro@socionext.com>
     *
     * SPDX-License-Identifier:	GPL-2.0+
     */
    
    #include <common.h>
    #include <dm/device.h>
    #include <mapmem.h>
    #include <linux/bitops.h>
    #include <linux/io.h>
    #include <asm/errno.h>
    #include <asm/gpio.h>
    
    #define UNIPHIER_GPIO_PORTS_PER_BANK	8
    
    #define UNIPHIER_GPIO_REG_DATA		0	/* data */
    #define UNIPHIER_GPIO_REG_DIR		4	/* direction (1:in, 0:out) */
    
    struct uniphier_gpio_priv {
    	void __iomem *base;
    	char bank_name[16];
    };
    
    static void uniphier_gpio_offset_write(struct udevice *dev, unsigned offset,
    				       unsigned reg, int value)
    {
    	struct uniphier_gpio_priv *priv = dev_get_priv(dev);
    	u32 tmp;
    
    	tmp = readl(priv->base + reg);
    	if (value)
    		tmp |= BIT(offset);
    	else
    		tmp &= ~BIT(offset);
    	writel(tmp, priv->base + reg);
    }
    
    static int uniphier_gpio_offset_read(struct udevice *dev, unsigned offset,
    				     unsigned reg)
    {
    	struct uniphier_gpio_priv *priv = dev_get_priv(dev);
    
    	return !!(readl(priv->base + reg) & BIT(offset));
    }
    
    static int uniphier_gpio_direction_input(struct udevice *dev, unsigned offset)
    {
    	uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_REG_DIR, 1);
    
    	return 0;
    }
    
    static int uniphier_gpio_direction_output(struct udevice *dev, unsigned offset,
    					  int value)
    {
    	uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_REG_DATA, value);
    	uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_REG_DIR, 0);
    
    	return 0;
    }
    
    static int uniphier_gpio_get_value(struct udevice *dev, unsigned offset)
    {
    	return uniphier_gpio_offset_read(dev, offset, UNIPHIER_GPIO_REG_DATA);
    }
    
    static int uniphier_gpio_set_value(struct udevice *dev, unsigned offset,
    				   int value)
    {
    	uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_REG_DATA, value);
    
    	return 0;
    }
    
    static int uniphier_gpio_get_function(struct udevice *dev, unsigned offset)
    {
    	return uniphier_gpio_offset_read(dev, offset, UNIPHIER_GPIO_REG_DIR) ?
    						GPIOF_INPUT : GPIOF_OUTPUT;
    }
    
    static const struct dm_gpio_ops uniphier_gpio_ops = {
    	.direction_input	= uniphier_gpio_direction_input,
    	.direction_output	= uniphier_gpio_direction_output,
    	.get_value		= uniphier_gpio_get_value,
    	.set_value		= uniphier_gpio_set_value,
    	.get_function		= uniphier_gpio_get_function,
    };
    
    static int uniphier_gpio_probe(struct udevice *dev)
    {
    	struct uniphier_gpio_priv *priv = dev_get_priv(dev);
    	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
    	DECLARE_GLOBAL_DATA_PTR;
    	fdt_addr_t addr;
    	fdt_size_t size;
    	unsigned int tmp;
    
    	addr = fdtdec_get_addr_size(gd->fdt_blob, dev->of_offset, "reg",
    				    &size);
    	if (addr == FDT_ADDR_T_NONE)
    		return -EINVAL;
    
    	priv->base = map_sysmem(addr, size);
    	if (!priv->base)
    		return -ENOMEM;
    
    	uc_priv->gpio_count = UNIPHIER_GPIO_PORTS_PER_BANK;
    
    	tmp = (addr & 0xfff);
    
    	/* Unfortunately, there is a register hole at offset 0x90-0x9f. */
    	if (tmp > 0x90)
    		tmp -= 0x10;
    
    	snprintf(priv->bank_name, sizeof(priv->bank_name) - 1,
    		 "port%d-", (tmp - 8) / 8);
    
    	uc_priv->bank_name = priv->bank_name;
    
    	return 0;
    }
    
    static int uniphier_gpio_remove(struct udevice *dev)
    {
    	struct uniphier_gpio_priv *priv = dev_get_priv(dev);
    
    	unmap_sysmem(priv->base);
    
    	return 0;
    }
    
    /* .data = the number of GPIO banks */
    static const struct udevice_id uniphier_gpio_match[] = {
    	{ .compatible = "socionext,uniphier-gpio" },
    	{ /* sentinel */ }
    };
    
    U_BOOT_DRIVER(uniphier_gpio) = {
    	.name	= "uniphier_gpio",
    	.id	= UCLASS_GPIO,
    	.of_match = uniphier_gpio_match,
    	.probe	= uniphier_gpio_probe,
    	.remove	= uniphier_gpio_remove,
    	.priv_auto_alloc_size = sizeof(struct uniphier_gpio_priv),
    	.ops	= &uniphier_gpio_ops,
    };