diff options
Diffstat (limited to 'drivers/gpio/gpio-amd8111.c')
| -rw-r--r-- | drivers/gpio/gpio-amd8111.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-amd8111.c b/drivers/gpio/gpio-amd8111.c new file mode 100644 index 000000000..6f3ded619 --- /dev/null +++ b/drivers/gpio/gpio-amd8111.c @@ -0,0 +1,248 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * GPIO driver for AMD 8111 south bridges + * + * Copyright (c) 2012 Dmitry Eremin-Solenikov + * + * Based on the AMD RNG driver: + * Copyright 2005 (c) MontaVista Software, Inc. + * with the majority of the code coming from: + * + * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG) + * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com> + * + * derived from + * + * Hardware driver for the AMD 768 Random Number Generator (RNG) + * (c) Copyright 2001 Red Hat Inc + * + * derived from + * + * Hardware driver for Intel i810 Random Number Generator (RNG) + * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com> + * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com> + */ +#include <linux/ioport.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/gpio/driver.h> +#include <linux/pci.h> +#include <linux/spinlock.h> + +#define PMBASE_OFFSET 0xb0 +#define PMBASE_SIZE 0x30 + +#define AMD_REG_GPIO(i) (0x10 + (i)) + +#define AMD_GPIO_LTCH_STS 0x40 /* Latch status, w1 */ +#define AMD_GPIO_RTIN 0x20 /* Real Time in, ro */ +#define AMD_GPIO_DEBOUNCE 0x10 /* Debounce, rw */ +#define AMD_GPIO_MODE_MASK 0x0c /* Pin Mode Select, rw */ +#define AMD_GPIO_MODE_IN 0x00 +#define AMD_GPIO_MODE_OUT 0x04 +/* Enable alternative (e.g. clkout, IRQ, etc) function of the pin */ +#define AMD_GPIO_MODE_ALTFN 0x08 /* Or 0x09 */ +#define AMD_GPIO_X_MASK 0x03 /* In/Out specific, rw */ +#define AMD_GPIO_X_IN_ACTIVEHI 0x01 /* Active High */ +#define AMD_GPIO_X_IN_LATCH 0x02 /* Latched version is selected */ +#define AMD_GPIO_X_OUT_LOW 0x00 +#define AMD_GPIO_X_OUT_HI 0x01 +#define AMD_GPIO_X_OUT_CLK0 0x02 +#define AMD_GPIO_X_OUT_CLK1 0x03 + +/* + * Data for PCI driver interface + * + * This data only exists for exporting the supported + * PCI ids via MODULE_DEVICE_TABLE. We do not actually + * register a pci_driver, because someone else might one day + * want to register another driver on the same PCI id. + */ +static const struct pci_device_id pci_tbl[] = { + { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS), 0 }, + { 0, }, /* terminate list */ +}; +MODULE_DEVICE_TABLE(pci, pci_tbl); + +struct amd_gpio { + struct gpio_chip chip; + u32 pmbase; + void __iomem *pm; + struct pci_dev *pdev; + spinlock_t lock; /* guards hw registers and orig table */ + u8 orig[32]; +}; + +static int amd_gpio_request(struct gpio_chip *chip, unsigned offset) +{ + struct amd_gpio *agp = gpiochip_get_data(chip); + + agp->orig[offset] = ioread8(agp->pm + AMD_REG_GPIO(offset)) & + (AMD_GPIO_DEBOUNCE | AMD_GPIO_MODE_MASK | AMD_GPIO_X_MASK); + + dev_dbg(&agp->pdev->dev, "Requested gpio %d, data %x\n", offset, agp->orig[offset]); + + return 0; +} + +static void amd_gpio_free(struct gpio_chip *chip, unsigned offset) +{ + struct amd_gpio *agp = gpiochip_get_data(chip); + + dev_dbg(&agp->pdev->dev, "Freed gpio %d, data %x\n", offset, agp->orig[offset]); + + iowrite8(agp->orig[offset], agp->pm + AMD_REG_GPIO(offset)); +} + +static void amd_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct amd_gpio *agp = gpiochip_get_data(chip); + u8 temp; + unsigned long flags; + + spin_lock_irqsave(&agp->lock, flags); + temp = ioread8(agp->pm + AMD_REG_GPIO(offset)); + temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW); + iowrite8(temp, agp->pm + AMD_REG_GPIO(offset)); + spin_unlock_irqrestore(&agp->lock, flags); + + dev_dbg(&agp->pdev->dev, "Setting gpio %d, value %d, reg=%02x\n", offset, !!value, temp); +} + +static int amd_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct amd_gpio *agp = gpiochip_get_data(chip); + u8 temp; + + temp = ioread8(agp->pm + AMD_REG_GPIO(offset)); + + dev_dbg(&agp->pdev->dev, "Getting gpio %d, reg=%02x\n", offset, temp); + + return (temp & AMD_GPIO_RTIN) ? 1 : 0; +} + +static int amd_gpio_dirout(struct gpio_chip *chip, unsigned offset, int value) +{ + struct amd_gpio *agp = gpiochip_get_data(chip); + u8 temp; + unsigned long flags; + + spin_lock_irqsave(&agp->lock, flags); + temp = ioread8(agp->pm + AMD_REG_GPIO(offset)); + temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW); + iowrite8(temp, agp->pm + AMD_REG_GPIO(offset)); + spin_unlock_irqrestore(&agp->lock, flags); + + dev_dbg(&agp->pdev->dev, "Dirout gpio %d, value %d, reg=%02x\n", offset, !!value, temp); + + return 0; +} + +static int amd_gpio_dirin(struct gpio_chip *chip, unsigned offset) +{ + struct amd_gpio *agp = gpiochip_get_data(chip); + u8 temp; + unsigned long flags; + + spin_lock_irqsave(&agp->lock, flags); + temp = ioread8(agp->pm + AMD_REG_GPIO(offset)); + temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_IN; + iowrite8(temp, agp->pm + AMD_REG_GPIO(offset)); + spin_unlock_irqrestore(&agp->lock, flags); + + dev_dbg(&agp->pdev->dev, "Dirin gpio %d, reg=%02x\n", offset, temp); + + return 0; +} + +static struct amd_gpio gp = { + .chip = { + .label = "AMD GPIO", + .owner = THIS_MODULE, + .base = -1, + .ngpio = 32, + .request = amd_gpio_request, + .free = amd_gpio_free, + .set = amd_gpio_set, + .get = amd_gpio_get, + .direction_output = amd_gpio_dirout, + .direction_input = amd_gpio_dirin, + }, +}; + +static int __init amd_gpio_init(void) +{ + int err = -ENODEV; + struct pci_dev *pdev = NULL; + const struct pci_device_id *ent; + + /* We look for our device - AMD South Bridge + * I don't know about a system with two such bridges, + * so we can assume that there is max. one device. + * + * We can't use plain pci_driver mechanism, + * as the device is really a multiple function device, + * main driver that binds to the pci_device is an smbus + * driver and have to find & bind to the device this way. + */ + for_each_pci_dev(pdev) { + ent = pci_match_id(pci_tbl, pdev); + if (ent) + goto found; + } + /* Device not found. */ + goto out; + +found: + err = pci_read_config_dword(pdev, 0x58, &gp.pmbase); + if (err) + goto out; + err = -EIO; + gp.pmbase &= 0x0000FF00; + if (gp.pmbase == 0) + goto out; + if (!devm_request_region(&pdev->dev, gp.pmbase + PMBASE_OFFSET, + PMBASE_SIZE, "AMD GPIO")) { + dev_err(&pdev->dev, "AMD GPIO region 0x%x already in use!\n", + gp.pmbase + PMBASE_OFFSET); + err = -EBUSY; + goto out; + } + gp.pm = ioport_map(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE); + if (!gp.pm) { + dev_err(&pdev->dev, "Couldn't map io port into io memory\n"); + err = -ENOMEM; + goto out; + } + gp.pdev = pdev; + gp.chip.parent = &pdev->dev; + + spin_lock_init(&gp.lock); + + dev_info(&pdev->dev, "AMD-8111 GPIO detected\n"); + err = gpiochip_add_data(&gp.chip, &gp); + if (err) { + dev_err(&pdev->dev, "GPIO registering failed (%d)\n", err); + ioport_unmap(gp.pm); + goto out; + } + return 0; + +out: + pci_dev_put(pdev); + return err; +} + +static void __exit amd_gpio_exit(void) +{ + gpiochip_remove(&gp.chip); + ioport_unmap(gp.pm); + pci_dev_put(gp.pdev); +} + +module_init(amd_gpio_init); +module_exit(amd_gpio_exit); + +MODULE_AUTHOR("The Linux Kernel team"); +MODULE_DESCRIPTION("GPIO driver for AMD chipsets"); +MODULE_LICENSE("GPL"); |