diff options
Diffstat (limited to 'drivers/gpio/gpio-rdc321x.c')
| -rw-r--r-- | drivers/gpio/gpio-rdc321x.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-rdc321x.c b/drivers/gpio/gpio-rdc321x.c new file mode 100644 index 0000000000..01ed2517e9 --- /dev/null +++ b/drivers/gpio/gpio-rdc321x.c @@ -0,0 +1,197 @@ +// 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"); |