/* * GPIO interface for Intel Poulsbo SCH * * Copyright (c) 2010 CompuLab Ltd * Author: Denis Turischev <denis@compulab.co.il> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License 2 as published * by the Free Software Foundation. * * This program is distributed in the hope that 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; see the file COPYING. If not, write to * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/io.h> #include <linux/errno.h> #include <linux/acpi.h> #include <linux/platform_device.h> #include <linux/pci_ids.h> #include <linux/gpio.h> #define GEN 0x00 #define GIO 0x04 #define GLV 0x08 struct sch_gpio { struct gpio_chip chip; spinlock_t lock; unsigned short iobase; unsigned short core_base; unsigned short resume_base; }; static unsigned sch_gpio_offset(struct sch_gpio *sch, unsigned gpio, unsigned reg) { unsigned base = 0; if (gpio >= sch->resume_base) { gpio -= sch->resume_base; base += 0x20; } return base + reg + gpio / 8; } static unsigned sch_gpio_bit(struct sch_gpio *sch, unsigned gpio) { if (gpio >= sch->resume_base) gpio -= sch->resume_base; return gpio % 8; } static int sch_gpio_reg_get(struct sch_gpio *sch, unsigned gpio, unsigned reg) { unsigned short offset, bit; u8 reg_val; offset = sch_gpio_offset(sch, gpio, reg); bit = sch_gpio_bit(sch, gpio); reg_val = !!(inb(sch->iobase + offset) & BIT(bit)); return reg_val; } static void sch_gpio_reg_set(struct sch_gpio *sch, unsigned gpio, unsigned reg, int val) { unsigned short offset, bit; u8 reg_val; offset = sch_gpio_offset(sch, gpio, reg); bit = sch_gpio_bit(sch, gpio); reg_val = inb(sch->iobase + offset); if (val) outb(reg_val | BIT(bit), sch->iobase + offset); else outb((reg_val & ~BIT(bit)), sch->iobase + offset); } static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num) { struct sch_gpio *sch = gpiochip_get_data(gc); spin_lock(&sch->lock); sch_gpio_reg_set(sch, gpio_num, GIO, 1); spin_unlock(&sch->lock); return 0; } static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num) { struct sch_gpio *sch = gpiochip_get_data(gc); return sch_gpio_reg_get(sch, gpio_num, GLV); } static void sch_gpio_set(struct gpio_chip *gc, unsigned gpio_num, int val) { struct sch_gpio *sch = gpiochip_get_data(gc); spin_lock(&sch->lock); sch_gpio_reg_set(sch, gpio_num, GLV, val); spin_unlock(&sch->lock); } static int sch_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num, int val) { struct sch_gpio *sch = gpiochip_get_data(gc); spin_lock(&sch->lock); sch_gpio_reg_set(sch, gpio_num, GIO, 0); spin_unlock(&sch->lock); /* * according to the datasheet, writing to the level register has no * effect when GPIO is programmed as input. * Actually the the level register is read-only when configured as input. * Thus presetting the output level before switching to output is _NOT_ possible. * Hence we set the level after configuring the GPIO as output. * But we cannot prevent a short low pulse if direction is set to high * and an external pull-up is connected. */ sch_gpio_set(gc, gpio_num, val); return 0; } static const struct gpio_chip sch_gpio_chip = { .label = "sch_gpio", .owner = THIS_MODULE, .direction_input = sch_gpio_direction_in, .get = sch_gpio_get, .direction_output = sch_gpio_direction_out, .set = sch_gpio_set, }; static int sch_gpio_probe(struct platform_device *pdev) { struct sch_gpio *sch; struct resource *res; sch = devm_kzalloc(&pdev->dev, sizeof(*sch), GFP_KERNEL); if (!sch) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_IO, 0); if (!res) return -EBUSY; if (!devm_request_region(&pdev->dev, res->start, resource_size(res), pdev->name)) return -EBUSY; spin_lock_init(&sch->lock); sch->iobase = res->start; sch->chip = sch_gpio_chip; sch->chip.label = dev_name(&pdev->dev); sch->chip.parent = &pdev->dev; switch (pdev->id) { case PCI_DEVICE_ID_INTEL_SCH_LPC: sch->core_base = 0; sch->resume_base = 10; sch->chip.ngpio = 14; /* * GPIO[6:0] enabled by default * GPIO7 is configured by the CMC as SLPIOVR * Enable GPIO[9:8] core powered gpios explicitly */ sch_gpio_reg_set(sch, 8, GEN, 1); sch_gpio_reg_set(sch, 9, GEN, 1); /* * SUS_GPIO[2:0] enabled by default * Enable SUS_GPIO3 resume powered gpio explicitly */ sch_gpio_reg_set(sch, 13, GEN, 1); break; case PCI_DEVICE_ID_INTEL_ITC_LPC: sch->core_base = 0; sch->resume_base = 5; sch->chip.ngpio = 14; break; case PCI_DEVICE_ID_INTEL_CENTERTON_ILB: sch->core_base = 0; sch->resume_base = 21; sch->chip.ngpio = 30; break; case PCI_DEVICE_ID_INTEL_QUARK_X1000_ILB: sch->core_base = 0; sch->resume_base = 2; sch->chip.ngpio = 8; break; default: return -ENODEV; } platform_set_drvdata(pdev, sch); return devm_gpiochip_add_data(&pdev->dev, &sch->chip, sch); } static struct platform_driver sch_gpio_driver = { .driver = { .name = "sch_gpio", }, .probe = sch_gpio_probe, }; module_platform_driver(sch_gpio_driver); MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>"); MODULE_DESCRIPTION("GPIO interface for Intel Poulsbo SCH"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:sch_gpio");