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stm32f7_gpio.c 3.25 KiB
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  •  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
     * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
    
     *
     * SPDX-License-Identifier:	GPL-2.0+
     */
    
    #include <common.h>
    #include <clk.h>
    #include <dm.h>
    #include <fdtdec.h>
    #include <asm/arch/gpio.h>
    #include <asm/arch/stm32.h>
    #include <asm/gpio.h>
    #include <asm/io.h>
    #include <linux/errno.h>
    #include <linux/io.h>
    
    #define STM32_GPIOS_PER_BANK		16
    #define MODE_BITS(gpio_pin)		(gpio_pin * 2)
    #define MODE_BITS_MASK			3
    #define IN_OUT_BIT_INDEX(gpio_pin)	(1UL << (gpio_pin))
    
    static int stm32_gpio_direction_input(struct udevice *dev, unsigned offset)
    {
    	struct stm32_gpio_priv *priv = dev_get_priv(dev);
    	struct stm32_gpio_regs *regs = priv->regs;
    	int bits_index = MODE_BITS(offset);
    	int mask = MODE_BITS_MASK << bits_index;
    
    	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_IN << bits_index);
    
    	return 0;
    }
    
    static int stm32_gpio_direction_output(struct udevice *dev, unsigned offset,
    				       int value)
    {
    	struct stm32_gpio_priv *priv = dev_get_priv(dev);
    	struct stm32_gpio_regs *regs = priv->regs;
    	int bits_index = MODE_BITS(offset);
    	int mask = MODE_BITS_MASK << bits_index;
    
    	clrsetbits_le32(&regs->moder, mask, STM32_GPIO_MODE_OUT << bits_index);
    	mask = IN_OUT_BIT_INDEX(offset);
    	clrsetbits_le32(&regs->odr, mask, value ? mask : 0);
    
    	return 0;
    }
    
    static int stm32_gpio_get_value(struct udevice *dev, unsigned offset)
    {
    	struct stm32_gpio_priv *priv = dev_get_priv(dev);
    	struct stm32_gpio_regs *regs = priv->regs;
    
    	return readl(&regs->idr) & IN_OUT_BIT_INDEX(offset) ? 1 : 0;
    }
    
    static int stm32_gpio_set_value(struct udevice *dev, unsigned offset, int value)
    {
    	struct stm32_gpio_priv *priv = dev_get_priv(dev);
    	struct stm32_gpio_regs *regs = priv->regs;
    	int mask = IN_OUT_BIT_INDEX(offset);
    
    	clrsetbits_le32(&regs->odr, mask, value ? mask : 0);
    
    	return 0;
    }
    
    static const struct dm_gpio_ops gpio_stm32_ops = {
    	.direction_input	= stm32_gpio_direction_input,
    	.direction_output	= stm32_gpio_direction_output,
    	.get_value		= stm32_gpio_get_value,
    	.set_value		= stm32_gpio_set_value,
    };
    
    static int gpio_stm32_probe(struct udevice *dev)
    {
    	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
    	struct stm32_gpio_priv *priv = dev_get_priv(dev);
    	fdt_addr_t addr;
    
    	addr = dev_read_addr(dev);
    
    	if (addr == FDT_ADDR_T_NONE)
    		return -EINVAL;
    
    	priv->regs = (struct stm32_gpio_regs *)addr;
    
    	name = dev_read_string(dev, "st,bank-name");
    
    	if (!name)
    		return -EINVAL;
    	uc_priv->bank_name = name;
    	uc_priv->gpio_count = STM32_GPIOS_PER_BANK;
    	debug("%s, addr = 0x%p, bank_name = %s\n", __func__, (u32 *)priv->regs,
    	      uc_priv->bank_name);
    
    #ifdef CONFIG_CLK
    	struct clk clk;
    	int ret;
    	ret = clk_get_by_index(dev, 0, &clk);
    	if (ret < 0)
    		return ret;
    
    	ret = clk_enable(&clk);
    
    	if (ret) {
    		dev_err(dev, "failed to enable clock\n");
    		return ret;
    	}
    	debug("clock enabled for device %s\n", dev->name);
    #endif
    
    	return 0;
    }
    
    static const struct udevice_id stm32_gpio_ids[] = {
    	{ .compatible = "st,stm32-gpio" },
    	{ }
    };
    
    U_BOOT_DRIVER(gpio_stm32) = {
    	.name	= "gpio_stm32",
    	.id	= UCLASS_GPIO,
    	.of_match = stm32_gpio_ids,
    	.probe	= gpio_stm32_probe,
    	.ops	= &gpio_stm32_ops,
    	.flags	= DM_FLAG_PRE_RELOC | DM_UC_FLAG_SEQ_ALIAS,
    	.priv_auto_alloc_size	= sizeof(struct stm32_gpio_priv),
    };