diff options
Diffstat (limited to 'kernel/drivers/gpio/gpio-lynxpoint.c')
| -rw-r--r-- | kernel/drivers/gpio/gpio-lynxpoint.c | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/kernel/drivers/gpio/gpio-lynxpoint.c b/kernel/drivers/gpio/gpio-lynxpoint.c new file mode 100644 index 000000000..127c755b3 --- /dev/null +++ b/kernel/drivers/gpio/gpio-lynxpoint.c @@ -0,0 +1,474 @@ +/* + * GPIO controller driver for Intel Lynxpoint PCH chipset> + * Copyright (c) 2012, Intel Corporation. + * + * Author: Mathias Nyman <mathias.nyman@linux.intel.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/bitops.h> +#include <linux/interrupt.h> +#include <linux/gpio.h> +#include <linux/slab.h> +#include <linux/acpi.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/io.h> + +/* LynxPoint chipset has support for 94 gpio pins */ + +#define LP_NUM_GPIO 94 + +/* Bitmapped register offsets */ +#define LP_ACPI_OWNED 0x00 /* Bitmap, set by bios, 0: pin reserved for ACPI */ +#define LP_GC 0x7C /* set APIC IRQ to IRQ14 or IRQ15 for all pins */ +#define LP_INT_STAT 0x80 +#define LP_INT_ENABLE 0x90 + +/* Each pin has two 32 bit config registers, starting at 0x100 */ +#define LP_CONFIG1 0x100 +#define LP_CONFIG2 0x104 + +/* LP_CONFIG1 reg bits */ +#define OUT_LVL_BIT BIT(31) +#define IN_LVL_BIT BIT(30) +#define TRIG_SEL_BIT BIT(4) /* 0: Edge, 1: Level */ +#define INT_INV_BIT BIT(3) /* Invert interrupt triggering */ +#define DIR_BIT BIT(2) /* 0: Output, 1: Input */ +#define USE_SEL_BIT BIT(0) /* 0: Native, 1: GPIO */ + +/* LP_CONFIG2 reg bits */ +#define GPINDIS_BIT BIT(2) /* disable input sensing */ +#define GPIWP_BIT (BIT(0) | BIT(1)) /* weak pull options */ + +struct lp_gpio { + struct gpio_chip chip; + struct platform_device *pdev; + spinlock_t lock; + unsigned long reg_base; +}; + +/* + * Lynxpoint gpios are controlled through both bitmapped registers and + * per gpio specific registers. The bitmapped registers are in chunks of + * 3 x 32bit registers to cover all 94 gpios + * + * per gpio specific registers consist of two 32bit registers per gpio + * (LP_CONFIG1 and LP_CONFIG2), with 94 gpios there's a total of + * 188 config registes. + * + * A simplified view of the register layout look like this: + * + * LP_ACPI_OWNED[31:0] gpio ownerships for gpios 0-31 (bitmapped registers) + * LP_ACPI_OWNED[63:32] gpio ownerships for gpios 32-63 + * LP_ACPI_OWNED[94:64] gpio ownerships for gpios 63-94 + * ... + * LP_INT_ENABLE[31:0] ... + * LP_INT_ENABLE[63:31] ... + * LP_INT_ENABLE[94:64] ... + * LP0_CONFIG1 (gpio 0) config1 reg for gpio 0 (per gpio registers) + * LP0_CONFIG2 (gpio 0) config2 reg for gpio 0 + * LP1_CONFIG1 (gpio 1) config1 reg for gpio 1 + * LP1_CONFIG2 (gpio 1) config2 reg for gpio 1 + * LP2_CONFIG1 (gpio 2) ... + * LP2_CONFIG2 (gpio 2) ... + * ... + * LP94_CONFIG1 (gpio 94) ... + * LP94_CONFIG2 (gpio 94) ... + */ + +static unsigned long lp_gpio_reg(struct gpio_chip *chip, unsigned offset, + int reg) +{ + struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip); + int reg_offset; + + if (reg == LP_CONFIG1 || reg == LP_CONFIG2) + /* per gpio specific config registers */ + reg_offset = offset * 8; + else + /* bitmapped registers */ + reg_offset = (offset / 32) * 4; + + return lg->reg_base + reg + reg_offset; +} + +static int lp_gpio_request(struct gpio_chip *chip, unsigned offset) +{ + struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip); + unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); + unsigned long conf2 = lp_gpio_reg(chip, offset, LP_CONFIG2); + unsigned long acpi_use = lp_gpio_reg(chip, offset, LP_ACPI_OWNED); + + pm_runtime_get(&lg->pdev->dev); /* should we put if failed */ + + /* Fail if BIOS reserved pin for ACPI use */ + if (!(inl(acpi_use) & BIT(offset % 32))) { + dev_err(&lg->pdev->dev, "gpio %d reserved for ACPI\n", offset); + return -EBUSY; + } + /* Fail if pin is in alternate function mode (not GPIO mode) */ + if (!(inl(reg) & USE_SEL_BIT)) + return -ENODEV; + + /* enable input sensing */ + outl(inl(conf2) & ~GPINDIS_BIT, conf2); + + + return 0; +} + +static void lp_gpio_free(struct gpio_chip *chip, unsigned offset) +{ + struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip); + unsigned long conf2 = lp_gpio_reg(chip, offset, LP_CONFIG2); + + /* disable input sensing */ + outl(inl(conf2) | GPINDIS_BIT, conf2); + + pm_runtime_put(&lg->pdev->dev); +} + +static int lp_irq_type(struct irq_data *d, unsigned type) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct lp_gpio *lg = container_of(gc, struct lp_gpio, chip); + u32 hwirq = irqd_to_hwirq(d); + unsigned long flags; + u32 value; + unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_CONFIG1); + + if (hwirq >= lg->chip.ngpio) + return -EINVAL; + + spin_lock_irqsave(&lg->lock, flags); + value = inl(reg); + + /* set both TRIG_SEL and INV bits to 0 for rising edge */ + if (type & IRQ_TYPE_EDGE_RISING) + value &= ~(TRIG_SEL_BIT | INT_INV_BIT); + + /* TRIG_SEL bit 0, INV bit 1 for falling edge */ + if (type & IRQ_TYPE_EDGE_FALLING) + value = (value | INT_INV_BIT) & ~TRIG_SEL_BIT; + + /* TRIG_SEL bit 1, INV bit 0 for level low */ + if (type & IRQ_TYPE_LEVEL_LOW) + value = (value | TRIG_SEL_BIT) & ~INT_INV_BIT; + + /* TRIG_SEL bit 1, INV bit 1 for level high */ + if (type & IRQ_TYPE_LEVEL_HIGH) + value |= TRIG_SEL_BIT | INT_INV_BIT; + + outl(value, reg); + spin_unlock_irqrestore(&lg->lock, flags); + + return 0; +} + +static int lp_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); + return !!(inl(reg) & IN_LVL_BIT); +} + +static void lp_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip); + unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); + unsigned long flags; + + spin_lock_irqsave(&lg->lock, flags); + + if (value) + outl(inl(reg) | OUT_LVL_BIT, reg); + else + outl(inl(reg) & ~OUT_LVL_BIT, reg); + + spin_unlock_irqrestore(&lg->lock, flags); +} + +static int lp_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip); + unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); + unsigned long flags; + + spin_lock_irqsave(&lg->lock, flags); + outl(inl(reg) | DIR_BIT, reg); + spin_unlock_irqrestore(&lg->lock, flags); + + return 0; +} + +static int lp_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip); + unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); + unsigned long flags; + + lp_gpio_set(chip, offset, value); + + spin_lock_irqsave(&lg->lock, flags); + outl(inl(reg) & ~DIR_BIT, reg); + spin_unlock_irqrestore(&lg->lock, flags); + + return 0; +} + +static void lp_gpio_irq_handler(unsigned hwirq, struct irq_desc *desc) +{ + struct irq_data *data = irq_desc_get_irq_data(desc); + struct gpio_chip *gc = irq_desc_get_handler_data(desc); + struct lp_gpio *lg = container_of(gc, struct lp_gpio, chip); + struct irq_chip *chip = irq_data_get_irq_chip(data); + u32 base, pin, mask; + unsigned long reg, ena, pending; + + /* check from GPIO controller which pin triggered the interrupt */ + for (base = 0; base < lg->chip.ngpio; base += 32) { + reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT); + ena = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE); + + while ((pending = (inl(reg) & inl(ena)))) { + unsigned irq; + + pin = __ffs(pending); + mask = BIT(pin); + /* Clear before handling so we don't lose an edge */ + outl(mask, reg); + irq = irq_find_mapping(lg->chip.irqdomain, base + pin); + generic_handle_irq(irq); + } + } + chip->irq_eoi(data); +} + +static void lp_irq_unmask(struct irq_data *d) +{ +} + +static void lp_irq_mask(struct irq_data *d) +{ +} + +static void lp_irq_enable(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct lp_gpio *lg = container_of(gc, struct lp_gpio, chip); + u32 hwirq = irqd_to_hwirq(d); + unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE); + unsigned long flags; + + spin_lock_irqsave(&lg->lock, flags); + outl(inl(reg) | BIT(hwirq % 32), reg); + spin_unlock_irqrestore(&lg->lock, flags); +} + +static void lp_irq_disable(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct lp_gpio *lg = container_of(gc, struct lp_gpio, chip); + u32 hwirq = irqd_to_hwirq(d); + unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE); + unsigned long flags; + + spin_lock_irqsave(&lg->lock, flags); + outl(inl(reg) & ~BIT(hwirq % 32), reg); + spin_unlock_irqrestore(&lg->lock, flags); +} + +static struct irq_chip lp_irqchip = { + .name = "LP-GPIO", + .irq_mask = lp_irq_mask, + .irq_unmask = lp_irq_unmask, + .irq_enable = lp_irq_enable, + .irq_disable = lp_irq_disable, + .irq_set_type = lp_irq_type, + .flags = IRQCHIP_SKIP_SET_WAKE, +}; + +static void lp_gpio_irq_init_hw(struct lp_gpio *lg) +{ + unsigned long reg; + unsigned base; + + for (base = 0; base < lg->chip.ngpio; base += 32) { + /* disable gpio pin interrupts */ + reg = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE); + outl(0, reg); + /* Clear interrupt status register */ + reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT); + outl(0xffffffff, reg); + } +} + +static int lp_gpio_probe(struct platform_device *pdev) +{ + struct lp_gpio *lg; + struct gpio_chip *gc; + struct resource *io_rc, *irq_rc; + struct device *dev = &pdev->dev; + unsigned long reg_len; + int ret = -ENODEV; + + lg = devm_kzalloc(dev, sizeof(struct lp_gpio), GFP_KERNEL); + if (!lg) + return -ENOMEM; + + lg->pdev = pdev; + platform_set_drvdata(pdev, lg); + + io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0); + irq_rc = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + + if (!io_rc) { + dev_err(dev, "missing IO resources\n"); + return -EINVAL; + } + + lg->reg_base = io_rc->start; + reg_len = resource_size(io_rc); + + if (!devm_request_region(dev, lg->reg_base, reg_len, "lp-gpio")) { + dev_err(dev, "failed requesting IO region 0x%x\n", + (unsigned int)lg->reg_base); + return -EBUSY; + } + + spin_lock_init(&lg->lock); + + gc = &lg->chip; + gc->label = dev_name(dev); + gc->owner = THIS_MODULE; + gc->request = lp_gpio_request; + gc->free = lp_gpio_free; + gc->direction_input = lp_gpio_direction_input; + gc->direction_output = lp_gpio_direction_output; + gc->get = lp_gpio_get; + gc->set = lp_gpio_set; + gc->base = -1; + gc->ngpio = LP_NUM_GPIO; + gc->can_sleep = false; + gc->dev = dev; + + ret = gpiochip_add(gc); + if (ret) { + dev_err(dev, "failed adding lp-gpio chip\n"); + return ret; + } + + /* set up interrupts */ + if (irq_rc && irq_rc->start) { + lp_gpio_irq_init_hw(lg); + ret = gpiochip_irqchip_add(gc, &lp_irqchip, 0, + handle_simple_irq, IRQ_TYPE_NONE); + if (ret) { + dev_err(dev, "failed to add irqchip\n"); + gpiochip_remove(gc); + return ret; + } + + gpiochip_set_chained_irqchip(gc, &lp_irqchip, + (unsigned)irq_rc->start, + lp_gpio_irq_handler); + } + + pm_runtime_enable(dev); + + return 0; +} + +static int lp_gpio_runtime_suspend(struct device *dev) +{ + return 0; +} + +static int lp_gpio_runtime_resume(struct device *dev) +{ + return 0; +} + +static int lp_gpio_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct lp_gpio *lg = platform_get_drvdata(pdev); + unsigned long reg; + int i; + + /* on some hardware suspend clears input sensing, re-enable it here */ + for (i = 0; i < lg->chip.ngpio; i++) { + if (gpiochip_is_requested(&lg->chip, i) != NULL) { + reg = lp_gpio_reg(&lg->chip, i, LP_CONFIG2); + outl(inl(reg) & ~GPINDIS_BIT, reg); + } + } + return 0; +} + +static const struct dev_pm_ops lp_gpio_pm_ops = { + .runtime_suspend = lp_gpio_runtime_suspend, + .runtime_resume = lp_gpio_runtime_resume, + .resume = lp_gpio_resume, +}; + +static const struct acpi_device_id lynxpoint_gpio_acpi_match[] = { + { "INT33C7", 0 }, + { "INT3437", 0 }, + { } +}; +MODULE_DEVICE_TABLE(acpi, lynxpoint_gpio_acpi_match); + +static int lp_gpio_remove(struct platform_device *pdev) +{ + struct lp_gpio *lg = platform_get_drvdata(pdev); + pm_runtime_disable(&pdev->dev); + gpiochip_remove(&lg->chip); + return 0; +} + +static struct platform_driver lp_gpio_driver = { + .probe = lp_gpio_probe, + .remove = lp_gpio_remove, + .driver = { + .name = "lp_gpio", + .pm = &lp_gpio_pm_ops, + .acpi_match_table = ACPI_PTR(lynxpoint_gpio_acpi_match), + }, +}; + +static int __init lp_gpio_init(void) +{ + return platform_driver_register(&lp_gpio_driver); +} + +static void __exit lp_gpio_exit(void) +{ + platform_driver_unregister(&lp_gpio_driver); +} + +subsys_initcall(lp_gpio_init); +module_exit(lp_gpio_exit); + +MODULE_AUTHOR("Mathias Nyman (Intel)"); +MODULE_DESCRIPTION("GPIO interface for Intel Lynxpoint"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:lp_gpio"); |