From f942a7de047d8c599cc1a9a26293c8c7400450ea Mon Sep 17 00:00:00 2001 From: Dmitry Eremin-Solenikov Date: Fri, 1 Jun 2012 17:36:31 +0400 Subject: [PATCH] gpio: add a driver for GPIO pins found on AMD-8111 south bridge chips Add a driver to use GPIO pins available on several AMD south bridges (currently only AMD 8111 is supported). Signed-off-by: Dmitry Eremin-Solenikov Signed-off-by: Linus Walleij --- drivers/gpio/Kconfig | 12 +++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-amd8111.c | 246 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 259 insertions(+) create mode 100644 drivers/gpio/gpio-amd8111.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index c4067d0..c2dfa9f 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -466,6 +466,18 @@ config GPIO_BT8XX If unsure, say N. +config GPIO_AMD8111 + tristate "AMD 8111 GPIO driver" + depends on PCI + help + The AMD 8111 south bridge contains 32 GPIO pins which can be used. + + Note, that usually system firmware/ACPI handles GPIO pins on their + own and users might easily break their systems with uncarefull usage + of this driver! + + If unsure, say N + config GPIO_LANGWELL bool "Intel Langwell/Penwell GPIO support" depends on PCI && X86 diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 0f55662..3a95b17 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_GPIO_74X164) += gpio-74x164.o obj-$(CONFIG_GPIO_AB8500) += gpio-ab8500.o obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o obj-$(CONFIG_GPIO_ADP5588) += gpio-adp5588.o +obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o obj-$(CONFIG_GPIO_CS5535) += gpio-cs5535.o obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o diff --git a/drivers/gpio/gpio-amd8111.c b/drivers/gpio/gpio-amd8111.c new file mode 100644 index 0000000..710fafc --- /dev/null +++ b/drivers/gpio/gpio-amd8111.c @@ -0,0 +1,246 @@ +/* + * 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 + * + * 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 + * Copyright 2000,2001 Philipp Rumpf + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ +#include +#include +#include +#include +#include + +#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 DEFINE_PCI_DEVICE_TABLE(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]; +}; + +#define to_agp(chip) container_of(chip, struct amd_gpio, chip) + +static int amd_gpio_request(struct gpio_chip *chip, unsigned offset) +{ + struct amd_gpio *agp = to_agp(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 = to_agp(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 = to_agp(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 = to_agp(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 = to_agp(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 = to_agp(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 (!request_region(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); + gp.pdev = pdev; + gp.chip.dev = &pdev->dev; + + spin_lock_init(&gp.lock); + + printk(KERN_INFO "AMD-8111 GPIO detected\n"); + err = gpiochip_add(&gp.chip); + if (err) { + printk(KERN_ERR "GPIO registering failed (%d)\n", + err); + release_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE); + goto out; + } +out: + return err; +} + +static void __exit amd_gpio_exit(void) +{ + int err = gpiochip_remove(&gp.chip); + WARN_ON(err); + ioport_unmap(gp.pm); + release_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE); +} + +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"); -- 2.7.4