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pca953x_gpio.c 8.99 KiB
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  • /*
     * Take linux kernel driver drivers/gpio/gpio-pca953x.c for reference.
     *
     * Copyright (C) 2016 Peng Fan <van.freenix@gmail.com>
     *
     * SPDX-License-Identifier:	GPL-2.0+
     *
     */
    
    /*
     * Note:
     * The driver's compatible table is borrowed from Linux Kernel,
     * but now max supported gpio pins is 24 and only PCA953X_TYPE
     * is supported. PCA957X_TYPE is not supported now.
     * Also the Polarity Inversion feature is not supported now.
     *
     * TODO:
     * 1. Support PCA957X_TYPE
    
     * 2. Support 24 gpio pins
     * 3. Support Polarity Inversion
    
     */
    
    #include <common.h>
    #include <errno.h>
    #include <dm.h>
    #include <fdtdec.h>
    #include <i2c.h>
    #include <malloc.h>
    #include <asm/gpio.h>
    #include <asm/io.h>
    #include <dt-bindings/gpio/gpio.h>
    
    #define PCA953X_INPUT           0
    #define PCA953X_OUTPUT          1
    #define PCA953X_INVERT          2
    #define PCA953X_DIRECTION       3
    
    #define PCA_GPIO_MASK           0x00FF
    #define PCA_INT                 0x0100
    #define PCA953X_TYPE            0x1000
    #define PCA957X_TYPE            0x2000
    #define PCA_TYPE_MASK           0xF000
    #define PCA_CHIP_TYPE(x)        ((x) & PCA_TYPE_MASK)
    
    enum {
    	PCA953X_DIRECTION_IN,
    	PCA953X_DIRECTION_OUT,
    };
    
    
    #define BANK_SZ 8
    
    DECLARE_GLOBAL_DATA_PTR;
    
    /*
     * struct pca953x_info - Data for pca953x
     *
     * @dev: udevice structure for the device
     * @addr: i2c slave address
     * @invert: Polarity inversion or not
     * @gpio_count: the number of gpio pins that the device supports
     * @chip_type: indicate the chip type,PCA953X or PCA957X
     * @bank_count: the number of banks that the device supports
     * @reg_output: array to hold the value of output registers
     * @reg_direction: array to hold the value of direction registers
     */
    struct pca953x_info {
    	struct udevice *dev;
    	int addr;
    	int invert;
    	int gpio_count;
    	int chip_type;
    	int bank_count;
    	u8 reg_output[MAX_BANK];
    	u8 reg_direction[MAX_BANK];
    };
    
    static int pca953x_write_single(struct udevice *dev, int reg, u8 val,
    				int offset)
    {
    	struct pca953x_info *info = dev_get_platdata(dev);
    	int bank_shift = fls((info->gpio_count - 1) / BANK_SZ);
    	int off = offset / BANK_SZ;
    	int ret = 0;
    
    	ret = dm_i2c_write(dev, (reg << bank_shift) + off, &val, 1);
    	if (ret) {
    		dev_err(dev, "%s error\n", __func__);
    		return ret;
    	}
    
    	return 0;
    }
    
    static int pca953x_read_single(struct udevice *dev, int reg, u8 *val,
    			       int offset)
    {
    	struct pca953x_info *info = dev_get_platdata(dev);
    	int bank_shift = fls((info->gpio_count - 1) / BANK_SZ);
    	int off = offset / BANK_SZ;
    	int ret;
    	u8 byte;
    
    	ret = dm_i2c_read(dev, (reg << bank_shift) + off, &byte, 1);
    	if (ret) {
    		dev_err(dev, "%s error\n", __func__);
    		return ret;
    	}
    
    	*val = byte;
    
    	return 0;
    }
    
    static int pca953x_read_regs(struct udevice *dev, int reg, u8 *val)
    {
    	struct pca953x_info *info = dev_get_platdata(dev);
    	int ret = 0;
    
    	if (info->gpio_count <= 8) {
    		ret = dm_i2c_read(dev, reg, val, 1);
    	} else if (info->gpio_count <= 16) {
    		ret = dm_i2c_read(dev, reg << 1, val, info->bank_count);
    
    	} else if (info->gpio_count == 40) {
    		/* Auto increment */
    		ret = dm_i2c_read(dev, (reg << 3) | 0x80, val, info->bank_count);
    
    	} else {
    		dev_err(dev, "Unsupported now\n");
    		return -EINVAL;
    	}
    
    	return ret;
    }
    
    static int pca953x_is_output(struct udevice *dev, int offset)
    {
    	struct pca953x_info *info = dev_get_platdata(dev);
    
    	int bank = offset / BANK_SZ;
    	int off = offset % BANK_SZ;
    
    	/*0: output; 1: input */
    	return !(info->reg_direction[bank] & (1 << off));
    }
    
    static int pca953x_get_value(struct udevice *dev, unsigned offset)
    {
    	int ret;
    	u8 val = 0;
    
    
    	ret = pca953x_read_single(dev, PCA953X_INPUT, &val, offset);
    	if (ret)
    		return ret;
    
    
    	return (val >> off) & 0x1;
    
    }
    
    static int pca953x_set_value(struct udevice *dev, unsigned offset,
    			     int value)
    {
    	struct pca953x_info *info = dev_get_platdata(dev);
    	int bank = offset / BANK_SZ;
    	int off = offset % BANK_SZ;
    	u8 val;
    	int ret;
    
    	if (value)
    		val = info->reg_output[bank] | (1 << off);
    	else
    		val = info->reg_output[bank] & ~(1 << off);
    
    	ret = pca953x_write_single(dev, PCA953X_OUTPUT, val, offset);
    	if (ret)
    		return ret;
    
    	info->reg_output[bank] = val;
    
    	return 0;
    }
    
    static int pca953x_set_direction(struct udevice *dev, unsigned offset, int dir)
    {
    	struct pca953x_info *info = dev_get_platdata(dev);
    	int bank = offset / BANK_SZ;
    	int off = offset % BANK_SZ;
    	u8 val;
    	int ret;
    
    	if (dir == PCA953X_DIRECTION_IN)
    		val = info->reg_direction[bank] | (1 << off);
    	else
    		val = info->reg_direction[bank] & ~(1 << off);
    
    	ret = pca953x_write_single(dev, PCA953X_DIRECTION, val, offset);
    	if (ret)
    		return ret;
    
    	info->reg_direction[bank] = val;
    
    	return 0;
    }
    
    static int pca953x_direction_input(struct udevice *dev, unsigned offset)
    {
    	return pca953x_set_direction(dev, offset, PCA953X_DIRECTION_IN);
    }
    
    static int pca953x_direction_output(struct udevice *dev, unsigned offset,
    				    int value)
    {
    	/* Configure output value. */
    	pca953x_set_value(dev, offset, value);
    
    	/* Configure direction as output. */
    	pca953x_set_direction(dev, offset, PCA953X_DIRECTION_OUT);
    
    	return 0;
    }
    
    static int pca953x_get_function(struct udevice *dev, unsigned offset)
    {
    	if (pca953x_is_output(dev, offset))
    		return GPIOF_OUTPUT;
    	else
    		return GPIOF_INPUT;
    }
    
    static int pca953x_xlate(struct udevice *dev, struct gpio_desc *desc,
    			 struct fdtdec_phandle_args *args)
    {
    	desc->offset = args->args[0];
    	desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0;
    
    	return 0;
    }
    
    static const struct dm_gpio_ops pca953x_ops = {
    	.direction_input	= pca953x_direction_input,
    	.direction_output	= pca953x_direction_output,
    	.get_value		= pca953x_get_value,
    	.set_value		= pca953x_set_value,
    	.get_function		= pca953x_get_function,
    	.xlate			= pca953x_xlate,
    };
    
    static int pca953x_probe(struct udevice *dev)
    {
    	struct pca953x_info *info = dev_get_platdata(dev);
    	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
    	struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
    	char name[32], *str;
    	int addr;
    	ulong driver_data;
    	int ret;
    
    	if (!info) {
    		dev_err(dev, "platdata not ready\n");
    		return -ENOMEM;
    	}
    
    	if (!chip) {
    		dev_err(dev, "i2c not ready\n");
    		return -ENODEV;
    	}
    
    	addr = fdtdec_get_int(gd->fdt_blob, dev->of_offset, "reg", 0);
    	if (addr == 0)
    		return -ENODEV;
    
    	info->addr = addr;
    
    	driver_data = dev_get_driver_data(dev);
    
    	info->gpio_count = driver_data & PCA_GPIO_MASK;
    	if (info->gpio_count > MAX_BANK * BANK_SZ) {
    		dev_err(dev, "Max support %d pins now\n", MAX_BANK * BANK_SZ);
    		return -EINVAL;
    	}
    
    	info->chip_type = PCA_CHIP_TYPE(driver_data);
    	if (info->chip_type != PCA953X_TYPE) {
    		dev_err(dev, "Only support PCA953X chip type now.\n");
    		return -EINVAL;
    	}
    
    	info->bank_count = DIV_ROUND_UP(info->gpio_count, BANK_SZ);
    
    	ret = pca953x_read_regs(dev, PCA953X_OUTPUT, info->reg_output);
    	if (ret) {
    		dev_err(dev, "Error reading output register\n");
    		return ret;
    	}
    
    	ret = pca953x_read_regs(dev, PCA953X_DIRECTION, info->reg_direction);
    	if (ret) {
    		dev_err(dev, "Error reading direction register\n");
    		return ret;
    	}
    
    	snprintf(name, sizeof(name), "gpio@%x_", info->addr);
    	str = strdup(name);
    	if (!str)
    		return -ENOMEM;
    	uc_priv->bank_name = str;
    	uc_priv->gpio_count = info->gpio_count;
    
    	dev_dbg(dev, "%s is ready\n", str);
    
    	return 0;
    }
    
    #define OF_953X(__nrgpio, __int) (ulong)(__nrgpio | PCA953X_TYPE | __int)
    #define OF_957X(__nrgpio, __int) (ulong)(__nrgpio | PCA957X_TYPE | __int)
    
    static const struct udevice_id pca953x_ids[] = {
    	{ .compatible = "nxp,pca9505", .data = OF_953X(40, PCA_INT), },
    	{ .compatible = "nxp,pca9534", .data = OF_953X(8, PCA_INT), },
    	{ .compatible = "nxp,pca9535", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "nxp,pca9536", .data = OF_953X(4, 0), },
    	{ .compatible = "nxp,pca9537", .data = OF_953X(4, PCA_INT), },
    	{ .compatible = "nxp,pca9538", .data = OF_953X(8, PCA_INT), },
    	{ .compatible = "nxp,pca9539", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "nxp,pca9554", .data = OF_953X(8, PCA_INT), },
    	{ .compatible = "nxp,pca9555", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "nxp,pca9556", .data = OF_953X(8, 0), },
    	{ .compatible = "nxp,pca9557", .data = OF_953X(8, 0), },
    	{ .compatible = "nxp,pca9574", .data = OF_957X(8, PCA_INT), },
    	{ .compatible = "nxp,pca9575", .data = OF_957X(16, PCA_INT), },
    	{ .compatible = "nxp,pca9698", .data = OF_953X(40, 0), },
    
    	{ .compatible = "maxim,max7310", .data = OF_953X(8, 0), },
    	{ .compatible = "maxim,max7312", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "maxim,max7313", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "maxim,max7315", .data = OF_953X(8, PCA_INT), },
    
    	{ .compatible = "ti,pca6107", .data = OF_953X(8, PCA_INT), },
    	{ .compatible = "ti,tca6408", .data = OF_953X(8, PCA_INT), },
    	{ .compatible = "ti,tca6416", .data = OF_953X(16, PCA_INT), },
    	{ .compatible = "ti,tca6424", .data = OF_953X(24, PCA_INT), },
    
    	{ .compatible = "onsemi,pca9654", .data = OF_953X(8, PCA_INT), },
    
    	{ .compatible = "exar,xra1202", .data = OF_953X(8, 0), },
    	{ }
    };
    
    U_BOOT_DRIVER(pca953x) = {
    	.name		= "pca953x",
    	.id		= UCLASS_GPIO,
    	.ops		= &pca953x_ops,
    	.probe		= pca953x_probe,
    	.platdata_auto_alloc_size = sizeof(struct pca953x_info),
    	.of_match	= pca953x_ids,
    };