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pic32_gpio.c 3.62 KiB
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  • /*
     * Copyright (c) 2015 Microchip Technology Inc
     * Purna Chandra Mandal <purna.mandal@microchip.com>
     *
     * SPDX-License-Identifier:	GPL-2.0+
     */
    
    #include <common.h>
    #include <dm.h>
    #include <errno.h>
    #include <malloc.h>
    #include <asm/io.h>
    #include <asm/gpio.h>
    #include <linux/compat.h>
    #include <mach/pic32.h>
    
    DECLARE_GLOBAL_DATA_PTR;
    
    /* Peripheral Pin Control */
    struct pic32_reg_port {
    	struct pic32_reg_atomic ansel;
    	struct pic32_reg_atomic tris;
    	struct pic32_reg_atomic port;
    	struct pic32_reg_atomic lat;
    	struct pic32_reg_atomic open_drain;
    	struct pic32_reg_atomic cnpu;
    	struct pic32_reg_atomic cnpd;
    	struct pic32_reg_atomic cncon;
    };
    
    enum {
    	MICROCHIP_GPIO_DIR_OUT,
    	MICROCHIP_GPIO_DIR_IN,
    	MICROCHIP_GPIOS_PER_BANK = 16,
    };
    
    struct pic32_gpio_priv {
    	struct pic32_reg_port *regs;
    	char name[2];
    };
    
    static int pic32_gpio_get_value(struct udevice *dev, unsigned offset)
    {
    	struct pic32_gpio_priv *priv = dev_get_priv(dev);
    
    	return !!(readl(&priv->regs->port.raw) & BIT(offset));
    }
    
    static int pic32_gpio_set_value(struct udevice *dev, unsigned offset,
    				int value)
    {
    	struct pic32_gpio_priv *priv = dev_get_priv(dev);
    	int mask = BIT(offset);
    
    	if (value)
    		writel(mask, &priv->regs->port.set);
    	else
    		writel(mask, &priv->regs->port.clr);
    
    	return 0;
    }
    
    static int pic32_gpio_direction(struct udevice *dev, unsigned offset)
    {
    	struct pic32_gpio_priv *priv = dev_get_priv(dev);
    
    	/* pin in analog mode ? */
    	if (readl(&priv->regs->ansel.raw) & BIT(offset))
    		return -EPERM;
    
    	if (readl(&priv->regs->tris.raw) & BIT(offset))
    		return MICROCHIP_GPIO_DIR_IN;
    	else
    		return MICROCHIP_GPIO_DIR_OUT;
    }
    
    static int pic32_gpio_direction_input(struct udevice *dev, unsigned offset)
    {
    	struct pic32_gpio_priv *priv = dev_get_priv(dev);
    	int mask = BIT(offset);
    
    	writel(mask, &priv->regs->ansel.clr);
    	writel(mask, &priv->regs->tris.set);
    
    	return 0;
    }
    
    static int pic32_gpio_direction_output(struct udevice *dev,
    				       unsigned offset, int value)
    {
    	struct pic32_gpio_priv *priv = dev_get_priv(dev);
    	int mask = BIT(offset);
    
    	writel(mask, &priv->regs->ansel.clr);
    	writel(mask, &priv->regs->tris.clr);
    
    	pic32_gpio_set_value(dev, offset, value);
    	return 0;
    }
    
    static int pic32_gpio_get_function(struct udevice *dev, unsigned offset)
    {
    	int ret = GPIOF_UNUSED;
    
    	switch (pic32_gpio_direction(dev, offset)) {
    	case MICROCHIP_GPIO_DIR_OUT:
    		ret = GPIOF_OUTPUT;
    		break;
    	case MICROCHIP_GPIO_DIR_IN:
    		ret = GPIOF_INPUT;
    		break;
    	default:
    		ret = GPIOF_UNUSED;
    		break;
    	}
    	return ret;
    }
    
    static const struct dm_gpio_ops gpio_pic32_ops = {
    	.direction_input	= pic32_gpio_direction_input,
    	.direction_output	= pic32_gpio_direction_output,
    	.get_value		= pic32_gpio_get_value,
    	.set_value		= pic32_gpio_set_value,
    	.get_function		= pic32_gpio_get_function,
    };
    
    static int pic32_gpio_probe(struct udevice *dev)
    {
    	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
    	struct pic32_gpio_priv *priv = dev_get_priv(dev);
    	fdt_addr_t addr;
    	fdt_size_t size;
    	char *end;
    	int bank;
    
    	addr = fdtdec_get_addr_size(gd->fdt_blob, dev->of_offset, "reg", &size);
    	if (addr == FDT_ADDR_T_NONE)
    		return -EINVAL;
    
    	priv->regs = ioremap(addr, size);
    
    	uc_priv->gpio_count = MICROCHIP_GPIOS_PER_BANK;
    	/* extract bank name */
    	end = strrchr(dev->name, '@');
    	bank = trailing_strtoln(dev->name, end);
    	priv->name[0] = 'A' + bank;
    	uc_priv->bank_name = priv->name;
    
    	return 0;
    }
    
    static const struct udevice_id pic32_gpio_ids[] = {
    	{ .compatible = "microchip,pic32mzda-gpio" },
    	{ }
    };
    
    U_BOOT_DRIVER(gpio_pic32) = {
    	.name		= "gpio_pic32",
    	.id		= UCLASS_GPIO,
    	.of_match	= pic32_gpio_ids,
    	.ops		= &gpio_pic32_ops,
    	.probe		= pic32_gpio_probe,
    	.priv_auto_alloc_size	= sizeof(struct pic32_gpio_priv),
    };