/* * STMicroelectronics ConneXt (STA2X11) GPIO driver * * Copyright 2012 ST Microelectronics (Alessandro Rubini) * Based on gpio-ml-ioh.c, Copyright 2010 OKI Semiconductors Ltd. * Also based on previous sta2x11 work, Copyright 2011 Wind River Systems, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 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; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/gpio.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/pci.h> #include <linux/platform_device.h> #include <linux/mfd/sta2x11-mfd.h> struct gsta_regs { u32 dat; /* 0x00 */ u32 dats; u32 datc; u32 pdis; u32 dir; /* 0x10 */ u32 dirs; u32 dirc; u32 unused_1c; u32 afsela; /* 0x20 */ u32 unused_24[7]; u32 rimsc; /* 0x40 */ u32 fimsc; u32 is; u32 ic; }; struct gsta_gpio { spinlock_t lock; struct device *dev; void __iomem *reg_base; struct gsta_regs __iomem *regs[GSTA_NR_BLOCKS]; struct gpio_chip gpio; int irq_base; /* FIXME: save the whole config here (AF, ...) */ unsigned irq_type[GSTA_NR_GPIO]; }; static inline struct gsta_regs __iomem *__regs(struct gsta_gpio *chip, int nr) { return chip->regs[nr / GSTA_GPIO_PER_BLOCK]; } static inline u32 __bit(int nr) { return 1U << (nr % GSTA_GPIO_PER_BLOCK); } /* * gpio methods */ static void gsta_gpio_set(struct gpio_chip *gpio, unsigned nr, int val) { struct gsta_gpio *chip = gpiochip_get_data(gpio); struct gsta_regs __iomem *regs = __regs(chip, nr); u32 bit = __bit(nr); if (val) writel(bit, ®s->dats); else writel(bit, ®s->datc); } static int gsta_gpio_get(struct gpio_chip *gpio, unsigned nr) { struct gsta_gpio *chip = gpiochip_get_data(gpio); struct gsta_regs __iomem *regs = __regs(chip, nr); u32 bit = __bit(nr); return !!(readl(®s->dat) & bit); } static int gsta_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, int val) { struct gsta_gpio *chip = gpiochip_get_data(gpio); struct gsta_regs __iomem *regs = __regs(chip, nr); u32 bit = __bit(nr); writel(bit, ®s->dirs); /* Data register after direction, otherwise pullup/down is selected */ if (val) writel(bit, ®s->dats); else writel(bit, ®s->datc); return 0; } static int gsta_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) { struct gsta_gpio *chip = gpiochip_get_data(gpio); struct gsta_regs __iomem *regs = __regs(chip, nr); u32 bit = __bit(nr); writel(bit, ®s->dirc); return 0; } static int gsta_gpio_to_irq(struct gpio_chip *gpio, unsigned offset) { struct gsta_gpio *chip = gpiochip_get_data(gpio); return chip->irq_base + offset; } static void gsta_gpio_setup(struct gsta_gpio *chip) /* called from probe */ { struct gpio_chip *gpio = &chip->gpio; /* * ARCH_NR_GPIOS is currently 256 and dynamic allocation starts * from the end. However, for compatibility, we need the first * ConneXt device to start from gpio 0: it's the main chipset * on most boards so documents and drivers assume gpio0..gpio127 */ static int gpio_base; gpio->label = dev_name(chip->dev); gpio->owner = THIS_MODULE; gpio->direction_input = gsta_gpio_direction_input; gpio->get = gsta_gpio_get; gpio->direction_output = gsta_gpio_direction_output; gpio->set = gsta_gpio_set; gpio->dbg_show = NULL; gpio->base = gpio_base; gpio->ngpio = GSTA_NR_GPIO; gpio->can_sleep = false; gpio->to_irq = gsta_gpio_to_irq; /* * After the first device, turn to dynamic gpio numbers. * For example, with ARCH_NR_GPIOS = 256 we can fit two cards */ if (!gpio_base) gpio_base = -1; } /* * Special method: alternate functions and pullup/pulldown. This is only * invoked on startup to configure gpio's according to platform data. * FIXME : this functionality shall be managed (and exported to other drivers) * via the pin control subsystem. */ static void gsta_set_config(struct gsta_gpio *chip, int nr, unsigned cfg) { struct gsta_regs __iomem *regs = __regs(chip, nr); unsigned long flags; u32 bit = __bit(nr); u32 val; int err = 0; pr_info("%s: %p %i %i\n", __func__, chip, nr, cfg); if (cfg == PINMUX_TYPE_NONE) return; /* Alternate function or not? */ spin_lock_irqsave(&chip->lock, flags); val = readl(®s->afsela); if (cfg == PINMUX_TYPE_FUNCTION) val |= bit; else val &= ~bit; writel(val | bit, ®s->afsela); if (cfg == PINMUX_TYPE_FUNCTION) { spin_unlock_irqrestore(&chip->lock, flags); return; } /* not alternate function: set details */ switch (cfg) { case PINMUX_TYPE_OUTPUT_LOW: writel(bit, ®s->dirs); writel(bit, ®s->datc); break; case PINMUX_TYPE_OUTPUT_HIGH: writel(bit, ®s->dirs); writel(bit, ®s->dats); break; case PINMUX_TYPE_INPUT: writel(bit, ®s->dirc); val = readl(®s->pdis) | bit; writel(val, ®s->pdis); break; case PINMUX_TYPE_INPUT_PULLUP: writel(bit, ®s->dirc); val = readl(®s->pdis) & ~bit; writel(val, ®s->pdis); writel(bit, ®s->dats); break; case PINMUX_TYPE_INPUT_PULLDOWN: writel(bit, ®s->dirc); val = readl(®s->pdis) & ~bit; writel(val, ®s->pdis); writel(bit, ®s->datc); break; default: err = 1; } spin_unlock_irqrestore(&chip->lock, flags); if (err) pr_err("%s: chip %p, pin %i, cfg %i is invalid\n", __func__, chip, nr, cfg); } /* * Irq methods */ static void gsta_irq_disable(struct irq_data *data) { struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data); struct gsta_gpio *chip = gc->private; int nr = data->irq - chip->irq_base; struct gsta_regs __iomem *regs = __regs(chip, nr); u32 bit = __bit(nr); u32 val; unsigned long flags; spin_lock_irqsave(&chip->lock, flags); if (chip->irq_type[nr] & IRQ_TYPE_EDGE_RISING) { val = readl(®s->rimsc) & ~bit; writel(val, ®s->rimsc); } if (chip->irq_type[nr] & IRQ_TYPE_EDGE_FALLING) { val = readl(®s->fimsc) & ~bit; writel(val, ®s->fimsc); } spin_unlock_irqrestore(&chip->lock, flags); return; } static void gsta_irq_enable(struct irq_data *data) { struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data); struct gsta_gpio *chip = gc->private; int nr = data->irq - chip->irq_base; struct gsta_regs __iomem *regs = __regs(chip, nr); u32 bit = __bit(nr); u32 val; int type; unsigned long flags; type = chip->irq_type[nr]; spin_lock_irqsave(&chip->lock, flags); val = readl(®s->rimsc); if (type & IRQ_TYPE_EDGE_RISING) writel(val | bit, ®s->rimsc); else writel(val & ~bit, ®s->rimsc); val = readl(®s->rimsc); if (type & IRQ_TYPE_EDGE_FALLING) writel(val | bit, ®s->fimsc); else writel(val & ~bit, ®s->fimsc); spin_unlock_irqrestore(&chip->lock, flags); return; } static int gsta_irq_type(struct irq_data *d, unsigned int type) { struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); struct gsta_gpio *chip = gc->private; int nr = d->irq - chip->irq_base; /* We only support edge interrupts */ if (!(type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))) { pr_debug("%s: unsupported type 0x%x\n", __func__, type); return -EINVAL; } chip->irq_type[nr] = type; /* used for enable/disable */ gsta_irq_enable(d); return 0; } static irqreturn_t gsta_gpio_handler(int irq, void *dev_id) { struct gsta_gpio *chip = dev_id; struct gsta_regs __iomem *regs; u32 is; int i, nr, base; irqreturn_t ret = IRQ_NONE; for (i = 0; i < GSTA_NR_BLOCKS; i++) { regs = chip->regs[i]; base = chip->irq_base + i * GSTA_GPIO_PER_BLOCK; while ((is = readl(®s->is))) { nr = __ffs(is); irq = base + nr; generic_handle_irq(irq); writel(1 << nr, ®s->ic); ret = IRQ_HANDLED; } } return ret; } static void gsta_alloc_irq_chip(struct gsta_gpio *chip) { struct irq_chip_generic *gc; struct irq_chip_type *ct; gc = irq_alloc_generic_chip(KBUILD_MODNAME, 1, chip->irq_base, chip->reg_base, handle_simple_irq); gc->private = chip; ct = gc->chip_types; ct->chip.irq_set_type = gsta_irq_type; ct->chip.irq_disable = gsta_irq_disable; ct->chip.irq_enable = gsta_irq_enable; /* FIXME: this makes at most 32 interrupts. Request 0 by now */ irq_setup_generic_chip(gc, 0 /* IRQ_MSK(GSTA_GPIO_PER_BLOCK) */, 0, IRQ_NOREQUEST | IRQ_NOPROBE, 0); /* Set up all all 128 interrupts: code from setup_generic_chip */ { struct irq_chip_type *ct = gc->chip_types; int i, j; for (j = 0; j < GSTA_NR_GPIO; j++) { i = chip->irq_base + j; irq_set_chip_and_handler(i, &ct->chip, ct->handler); irq_set_chip_data(i, gc); irq_clear_status_flags(i, IRQ_NOREQUEST | IRQ_NOPROBE); } gc->irq_cnt = i - gc->irq_base; } } /* The platform device used here is instantiated by the MFD device */ static int gsta_probe(struct platform_device *dev) { int i, err; struct pci_dev *pdev; struct sta2x11_gpio_pdata *gpio_pdata; struct gsta_gpio *chip; struct resource *res; pdev = *(struct pci_dev **)dev_get_platdata(&dev->dev); gpio_pdata = dev_get_platdata(&pdev->dev); if (gpio_pdata == NULL) dev_err(&dev->dev, "no gpio config\n"); pr_debug("gpio config: %p\n", gpio_pdata); res = platform_get_resource(dev, IORESOURCE_MEM, 0); chip = devm_kzalloc(&dev->dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; chip->dev = &dev->dev; chip->reg_base = devm_ioremap_resource(&dev->dev, res); if (IS_ERR(chip->reg_base)) return PTR_ERR(chip->reg_base); for (i = 0; i < GSTA_NR_BLOCKS; i++) { chip->regs[i] = chip->reg_base + i * 4096; /* disable all irqs */ writel(0, &chip->regs[i]->rimsc); writel(0, &chip->regs[i]->fimsc); writel(~0, &chip->regs[i]->ic); } spin_lock_init(&chip->lock); gsta_gpio_setup(chip); if (gpio_pdata) for (i = 0; i < GSTA_NR_GPIO; i++) gsta_set_config(chip, i, gpio_pdata->pinconfig[i]); /* 384 was used in previous code: be compatible for other drivers */ err = irq_alloc_descs(-1, 384, GSTA_NR_GPIO, NUMA_NO_NODE); if (err < 0) { dev_warn(&dev->dev, "sta2x11 gpio: Can't get irq base (%i)\n", -err); return err; } chip->irq_base = err; gsta_alloc_irq_chip(chip); err = request_irq(pdev->irq, gsta_gpio_handler, IRQF_SHARED, KBUILD_MODNAME, chip); if (err < 0) { dev_err(&dev->dev, "sta2x11 gpio: Can't request irq (%i)\n", -err); goto err_free_descs; } err = devm_gpiochip_add_data(&dev->dev, &chip->gpio, chip); if (err < 0) { dev_err(&dev->dev, "sta2x11 gpio: Can't register (%i)\n", -err); goto err_free_irq; } platform_set_drvdata(dev, chip); return 0; err_free_irq: free_irq(pdev->irq, chip); err_free_descs: irq_free_descs(chip->irq_base, GSTA_NR_GPIO); return err; } static struct platform_driver sta2x11_gpio_platform_driver = { .driver = { .name = "sta2x11-gpio", }, .probe = gsta_probe, }; module_platform_driver(sta2x11_gpio_platform_driver); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("sta2x11_gpio GPIO driver");