/* * 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 registers. * * 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(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");