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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 | // SPDX-License-Identifier: GPL-2.0-or-later /* * RDC321x GPIO driver * * Copyright (C) 2008, Volker Weiss <dev@tintuc.de> * Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org> */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/spinlock.h> #include <linux/platform_device.h> #include <linux/pci.h> #include <linux/gpio/driver.h> #include <linux/mfd/rdc321x.h> #include <linux/slab.h> struct rdc321x_gpio { spinlock_t lock; struct pci_dev *sb_pdev; u32 data_reg[2]; int reg1_ctrl_base; int reg1_data_base; int reg2_ctrl_base; int reg2_data_base; struct gpio_chip chip; }; /* read GPIO pin */ static int rdc_gpio_get_value(struct gpio_chip *chip, unsigned gpio) { struct rdc321x_gpio *gpch; u32 value = 0; int reg; gpch = gpiochip_get_data(chip); reg = gpio < 32 ? gpch->reg1_data_base : gpch->reg2_data_base; spin_lock(&gpch->lock); pci_write_config_dword(gpch->sb_pdev, reg, gpch->data_reg[gpio < 32 ? 0 : 1]); pci_read_config_dword(gpch->sb_pdev, reg, &value); spin_unlock(&gpch->lock); return (1 << (gpio & 0x1f)) & value ? 1 : 0; } static void rdc_gpio_set_value_impl(struct gpio_chip *chip, unsigned gpio, int value) { struct rdc321x_gpio *gpch; int reg = (gpio < 32) ? 0 : 1; gpch = gpiochip_get_data(chip); if (value) gpch->data_reg[reg] |= 1 << (gpio & 0x1f); else gpch->data_reg[reg] &= ~(1 << (gpio & 0x1f)); pci_write_config_dword(gpch->sb_pdev, reg ? gpch->reg2_data_base : gpch->reg1_data_base, gpch->data_reg[reg]); } /* set GPIO pin to value */ static void rdc_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value) { struct rdc321x_gpio *gpch; gpch = gpiochip_get_data(chip); spin_lock(&gpch->lock); rdc_gpio_set_value_impl(chip, gpio, value); spin_unlock(&gpch->lock); } static int rdc_gpio_config(struct gpio_chip *chip, unsigned gpio, int value) { struct rdc321x_gpio *gpch; int err; u32 reg; gpch = gpiochip_get_data(chip); spin_lock(&gpch->lock); err = pci_read_config_dword(gpch->sb_pdev, gpio < 32 ? gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, ®); if (err) goto unlock; reg |= 1 << (gpio & 0x1f); err = pci_write_config_dword(gpch->sb_pdev, gpio < 32 ? gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, reg); if (err) goto unlock; rdc_gpio_set_value_impl(chip, gpio, value); unlock: spin_unlock(&gpch->lock); return err; } /* configure GPIO pin as input */ static int rdc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio) { return rdc_gpio_config(chip, gpio, 1); } /* * Cache the initial value of both GPIO data registers */ static int rdc321x_gpio_probe(struct platform_device *pdev) { int err; struct resource *r; struct rdc321x_gpio *rdc321x_gpio_dev; struct rdc321x_gpio_pdata *pdata; pdata = dev_get_platdata(&pdev->dev); if (!pdata) { dev_err(&pdev->dev, "no platform data supplied\n"); return -ENODEV; } rdc321x_gpio_dev = devm_kzalloc(&pdev->dev, sizeof(struct rdc321x_gpio), GFP_KERNEL); if (!rdc321x_gpio_dev) return -ENOMEM; r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg1"); if (!r) { dev_err(&pdev->dev, "failed to get gpio-reg1 resource\n"); return -ENODEV; } spin_lock_init(&rdc321x_gpio_dev->lock); rdc321x_gpio_dev->sb_pdev = pdata->sb_pdev; rdc321x_gpio_dev->reg1_ctrl_base = r->start; rdc321x_gpio_dev->reg1_data_base = r->start + 0x4; r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg2"); if (!r) { dev_err(&pdev->dev, "failed to get gpio-reg2 resource\n"); return -ENODEV; } rdc321x_gpio_dev->reg2_ctrl_base = r->start; rdc321x_gpio_dev->reg2_data_base = r->start + 0x4; rdc321x_gpio_dev->chip.label = "rdc321x-gpio"; rdc321x_gpio_dev->chip.owner = THIS_MODULE; rdc321x_gpio_dev->chip.direction_input = rdc_gpio_direction_input; rdc321x_gpio_dev->chip.direction_output = rdc_gpio_config; rdc321x_gpio_dev->chip.get = rdc_gpio_get_value; rdc321x_gpio_dev->chip.set = rdc_gpio_set_value; rdc321x_gpio_dev->chip.base = 0; rdc321x_gpio_dev->chip.ngpio = pdata->max_gpios; platform_set_drvdata(pdev, rdc321x_gpio_dev); /* This might not be, what others (BIOS, bootloader, etc.) wrote to these registers before, but it's a good guess. Still better than just using 0xffffffff. */ err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev, rdc321x_gpio_dev->reg1_data_base, &rdc321x_gpio_dev->data_reg[0]); if (err) return err; err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev, rdc321x_gpio_dev->reg2_data_base, &rdc321x_gpio_dev->data_reg[1]); if (err) return err; dev_info(&pdev->dev, "registering %d GPIOs\n", rdc321x_gpio_dev->chip.ngpio); return devm_gpiochip_add_data(&pdev->dev, &rdc321x_gpio_dev->chip, rdc321x_gpio_dev); } static struct platform_driver rdc321x_gpio_driver = { .driver.name = "rdc321x-gpio", .probe = rdc321x_gpio_probe, }; module_platform_driver(rdc321x_gpio_driver); MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); MODULE_DESCRIPTION("RDC321x GPIO driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:rdc321x-gpio"); |