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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * RDC321x GPIO driver4 *5 * Copyright (C) 2008, Volker Weiss <dev@tintuc.de>6 * Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>7 */8#include <linux/module.h>9#include <linux/kernel.h>10#include <linux/init.h>11#include <linux/spinlock.h>12#include <linux/platform_device.h>13#include <linux/pci.h>14#include <linux/gpio/driver.h>15#include <linux/mfd/rdc321x.h>16#include <linux/slab.h>17 18struct rdc321x_gpio {19 spinlock_t lock;20 struct pci_dev *sb_pdev;21 u32 data_reg[2];22 int reg1_ctrl_base;23 int reg1_data_base;24 int reg2_ctrl_base;25 int reg2_data_base;26 struct gpio_chip chip;27};28 29/* read GPIO pin */30static int rdc_gpio_get_value(struct gpio_chip *chip, unsigned gpio)31{32 struct rdc321x_gpio *gpch;33 u32 value = 0;34 int reg;35 36 gpch = gpiochip_get_data(chip);37 reg = gpio < 32 ? gpch->reg1_data_base : gpch->reg2_data_base;38 39 spin_lock(&gpch->lock);40 pci_write_config_dword(gpch->sb_pdev, reg,41 gpch->data_reg[gpio < 32 ? 0 : 1]);42 pci_read_config_dword(gpch->sb_pdev, reg, &value);43 spin_unlock(&gpch->lock);44 45 return (1 << (gpio & 0x1f)) & value ? 1 : 0;46}47 48static void rdc_gpio_set_value_impl(struct gpio_chip *chip,49 unsigned gpio, int value)50{51 struct rdc321x_gpio *gpch;52 int reg = (gpio < 32) ? 0 : 1;53 54 gpch = gpiochip_get_data(chip);55 56 if (value)57 gpch->data_reg[reg] |= 1 << (gpio & 0x1f);58 else59 gpch->data_reg[reg] &= ~(1 << (gpio & 0x1f));60 61 pci_write_config_dword(gpch->sb_pdev,62 reg ? gpch->reg2_data_base : gpch->reg1_data_base,63 gpch->data_reg[reg]);64}65 66/* set GPIO pin to value */67static void rdc_gpio_set_value(struct gpio_chip *chip,68 unsigned gpio, int value)69{70 struct rdc321x_gpio *gpch;71 72 gpch = gpiochip_get_data(chip);73 spin_lock(&gpch->lock);74 rdc_gpio_set_value_impl(chip, gpio, value);75 spin_unlock(&gpch->lock);76}77 78static int rdc_gpio_config(struct gpio_chip *chip,79 unsigned gpio, int value)80{81 struct rdc321x_gpio *gpch;82 int err;83 u32 reg;84 85 gpch = gpiochip_get_data(chip);86 87 spin_lock(&gpch->lock);88 err = pci_read_config_dword(gpch->sb_pdev, gpio < 32 ?89 gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, ®);90 if (err)91 goto unlock;92 93 reg |= 1 << (gpio & 0x1f);94 95 err = pci_write_config_dword(gpch->sb_pdev, gpio < 32 ?96 gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, reg);97 if (err)98 goto unlock;99 100 rdc_gpio_set_value_impl(chip, gpio, value);101 102unlock:103 spin_unlock(&gpch->lock);104 105 return pcibios_err_to_errno(err);106}107 108/* configure GPIO pin as input */109static int rdc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)110{111 return rdc_gpio_config(chip, gpio, 1);112}113 114/*115 * Cache the initial value of both GPIO data registers116 */117static int rdc321x_gpio_probe(struct platform_device *pdev)118{119 int err;120 struct resource *r;121 struct rdc321x_gpio *rdc321x_gpio_dev;122 struct rdc321x_gpio_pdata *pdata;123 124 pdata = dev_get_platdata(&pdev->dev);125 if (!pdata) {126 dev_err(&pdev->dev, "no platform data supplied\n");127 return -ENODEV;128 }129 130 rdc321x_gpio_dev = devm_kzalloc(&pdev->dev, sizeof(struct rdc321x_gpio),131 GFP_KERNEL);132 if (!rdc321x_gpio_dev)133 return -ENOMEM;134 135 r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg1");136 if (!r) {137 dev_err(&pdev->dev, "failed to get gpio-reg1 resource\n");138 return -ENODEV;139 }140 141 spin_lock_init(&rdc321x_gpio_dev->lock);142 rdc321x_gpio_dev->sb_pdev = pdata->sb_pdev;143 rdc321x_gpio_dev->reg1_ctrl_base = r->start;144 rdc321x_gpio_dev->reg1_data_base = r->start + 0x4;145 146 r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg2");147 if (!r) {148 dev_err(&pdev->dev, "failed to get gpio-reg2 resource\n");149 return -ENODEV;150 }151 152 rdc321x_gpio_dev->reg2_ctrl_base = r->start;153 rdc321x_gpio_dev->reg2_data_base = r->start + 0x4;154 155 rdc321x_gpio_dev->chip.label = "rdc321x-gpio";156 rdc321x_gpio_dev->chip.owner = THIS_MODULE;157 rdc321x_gpio_dev->chip.direction_input = rdc_gpio_direction_input;158 rdc321x_gpio_dev->chip.direction_output = rdc_gpio_config;159 rdc321x_gpio_dev->chip.get = rdc_gpio_get_value;160 rdc321x_gpio_dev->chip.set = rdc_gpio_set_value;161 rdc321x_gpio_dev->chip.base = 0;162 rdc321x_gpio_dev->chip.ngpio = pdata->max_gpios;163 164 platform_set_drvdata(pdev, rdc321x_gpio_dev);165 166 /* This might not be, what others (BIOS, bootloader, etc.)167 wrote to these registers before, but it's a good guess. Still168 better than just using 0xffffffff. */169 err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev,170 rdc321x_gpio_dev->reg1_data_base,171 &rdc321x_gpio_dev->data_reg[0]);172 if (err)173 return pcibios_err_to_errno(err);174 175 err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev,176 rdc321x_gpio_dev->reg2_data_base,177 &rdc321x_gpio_dev->data_reg[1]);178 if (err)179 return pcibios_err_to_errno(err);180 181 dev_info(&pdev->dev, "registering %d GPIOs\n",182 rdc321x_gpio_dev->chip.ngpio);183 return devm_gpiochip_add_data(&pdev->dev, &rdc321x_gpio_dev->chip,184 rdc321x_gpio_dev);185}186 187static struct platform_driver rdc321x_gpio_driver = {188 .driver.name = "rdc321x-gpio",189 .probe = rdc321x_gpio_probe,190};191 192module_platform_driver(rdc321x_gpio_driver);193 194MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");195MODULE_DESCRIPTION("RDC321x GPIO driver");196MODULE_LICENSE("GPL");197MODULE_ALIAS("platform:rdc321x-gpio");198