diff options
Diffstat (limited to 'kernel/drivers/gpio/gpio-sta2x11.c')
| -rw-r--r-- | kernel/drivers/gpio/gpio-sta2x11.c | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/kernel/drivers/gpio/gpio-sta2x11.c b/kernel/drivers/gpio/gpio-sta2x11.c new file mode 100644 index 000000000..18579ac65 --- /dev/null +++ b/kernel/drivers/gpio/gpio-sta2x11.c @@ -0,0 +1,439 @@ +/* + * 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 = container_of(gpio, struct gsta_gpio, 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 = container_of(gpio, struct gsta_gpio, 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 = container_of(gpio, struct gsta_gpio, 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 = container_of(gpio, struct gsta_gpio, 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 = container_of(gpio, struct gsta_gpio, 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_modify_status(i, IRQ_NOREQUEST | IRQ_NOPROBE, 0); + } + 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 = gpiochip_add(&chip->gpio); + 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"); |