diff options
Diffstat (limited to 'drivers/gpio/gpio-tb10x.c')
| -rw-r--r-- | drivers/gpio/gpio-tb10x.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-tb10x.c b/drivers/gpio/gpio-tb10x.c new file mode 100644 index 0000000..0502b9a --- /dev/null +++ b/drivers/gpio/gpio-tb10x.c @@ -0,0 +1,328 @@ +/* Abilis Systems MODULE DESCRIPTION + * + * Copyright (C) Abilis Systems 2013 + * + * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com> + * Christian Ruppert <christian.ruppert@abilis.com> + * + * 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/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> +#include <linux/slab.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/of_gpio.h> +#include <linux/spinlock.h> +#include <linux/bitops.h> +#include <linux/pinctrl/consumer.h> + +#define TB10X_GPIO_DIR_IN (0x00000000) +#define TB10X_GPIO_DIR_OUT (0x00000001) +#define OFFSET_TO_REG_DDR (0x00) +#define OFFSET_TO_REG_DATA (0x04) +#define OFFSET_TO_REG_INT_EN (0x08) +#define OFFSET_TO_REG_CHANGE (0x0C) +#define OFFSET_TO_REG_WRMASK (0x10) +#define OFFSET_TO_REG_INT_TYPE (0x14) + + +/** + * @spinlock: used for atomic read/modify/write of registers + * @base: register base address + * @domain: IRQ domain of GPIO generated interrupts managed by this controller + * @irq: Interrupt line of parent interrupt controller + * @gc: gpio_chip structure associated to this GPIO controller + */ +struct tb10x_gpio { + spinlock_t spinlock; + void __iomem *base; + struct irq_domain *domain; + int irq; + struct gpio_chip gc; +}; + +static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs) +{ + return ioread32(gpio->base + offs); +} + +static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs, + u32 val) +{ + iowrite32(val, gpio->base + offs); +} + +static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs, + u32 mask, u32 val) +{ + u32 r; + unsigned long flags; + + spin_lock_irqsave(&gpio->spinlock, flags); + + r = tb10x_reg_read(gpio, offs); + r = (r & ~mask) | (val & mask); + + tb10x_reg_write(gpio, offs, r); + + spin_unlock_irqrestore(&gpio->spinlock, flags); +} + +static inline struct tb10x_gpio *to_tb10x_gpio(struct gpio_chip *chip) +{ + return container_of(chip, struct tb10x_gpio, gc); +} + +static int tb10x_gpio_direction_in(struct gpio_chip *chip, unsigned offset) +{ + struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); + int mask = BIT(offset); + int val = TB10X_GPIO_DIR_IN << offset; + + tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val); + + return 0; +} + +static int tb10x_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); + int val; + + val = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_DATA); + + if (val & BIT(offset)) + return 1; + else + return 0; +} + +static void tb10x_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); + int mask = BIT(offset); + int val = value << offset; + + tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DATA, mask, val); +} + +static int tb10x_gpio_direction_out(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); + int mask = BIT(offset); + int val = TB10X_GPIO_DIR_OUT << offset; + + tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val); + + return 0; +} + +static int tb10x_gpio_request(struct gpio_chip *chip, unsigned offset) +{ + return pinctrl_request_gpio(chip->base + offset); +} + +static void tb10x_gpio_free(struct gpio_chip *chip, unsigned offset) +{ + pinctrl_free_gpio(chip->base + offset); +} + +static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset) +{ + struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip); + + return irq_create_mapping(tb10x_gpio->domain, offset); +} + +static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type) +{ + if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) { + pr_err("Only (both) edge triggered interrupts supported.\n"); + return -EINVAL; + } + + irqd_set_trigger_type(data, type); + + return IRQ_SET_MASK_OK; +} + +static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data) +{ + struct tb10x_gpio *tb10x_gpio = data; + u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE); + u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN); + const unsigned long bits = r & m; + int i; + + for_each_set_bit(i, &bits, 32) + generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i)); + + return IRQ_HANDLED; +} + +static int tb10x_gpio_probe(struct platform_device *pdev) +{ + struct tb10x_gpio *tb10x_gpio; + struct resource *mem; + struct device_node *dn = pdev->dev.of_node; + int ret = -EBUSY; + u32 ngpio; + + if (!dn) + return -EINVAL; + + if (of_property_read_u32(dn, "abilis,ngpio", &ngpio)) + return -EINVAL; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem) { + dev_err(&pdev->dev, "No memory resource defined.\n"); + return -EINVAL; + } + + tb10x_gpio = devm_kzalloc(&pdev->dev, sizeof(*tb10x_gpio), GFP_KERNEL); + if (tb10x_gpio == NULL) + return -ENOMEM; + + spin_lock_init(&tb10x_gpio->spinlock); + + tb10x_gpio->base = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(tb10x_gpio->base)) + return PTR_ERR(tb10x_gpio->base); + + tb10x_gpio->gc.label = of_node_full_name(dn); + tb10x_gpio->gc.dev = &pdev->dev; + tb10x_gpio->gc.owner = THIS_MODULE; + tb10x_gpio->gc.direction_input = tb10x_gpio_direction_in; + tb10x_gpio->gc.get = tb10x_gpio_get; + tb10x_gpio->gc.direction_output = tb10x_gpio_direction_out; + tb10x_gpio->gc.set = tb10x_gpio_set; + tb10x_gpio->gc.request = tb10x_gpio_request; + tb10x_gpio->gc.free = tb10x_gpio_free; + tb10x_gpio->gc.base = -1; + tb10x_gpio->gc.ngpio = ngpio; + tb10x_gpio->gc.can_sleep = 0; + + + ret = gpiochip_add(&tb10x_gpio->gc); + if (ret < 0) { + dev_err(&pdev->dev, "Could not add gpiochip.\n"); + goto fail_gpiochip_registration; + } + + platform_set_drvdata(pdev, tb10x_gpio); + + if (of_find_property(dn, "interrupt-controller", NULL)) { + struct irq_chip_generic *gc; + + ret = platform_get_irq(pdev, 0); + if (ret < 0) { + dev_err(&pdev->dev, "No interrupt specified.\n"); + goto fail_get_irq; + } + + tb10x_gpio->gc.to_irq = tb10x_gpio_to_irq; + tb10x_gpio->irq = ret; + + ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade, + IRQF_TRIGGER_NONE | IRQF_SHARED, + dev_name(&pdev->dev), tb10x_gpio); + if (ret != 0) + goto fail_request_irq; + + tb10x_gpio->domain = irq_domain_add_linear(dn, + tb10x_gpio->gc.ngpio, + &irq_generic_chip_ops, NULL); + if (!tb10x_gpio->domain) { + ret = -ENOMEM; + goto fail_irq_domain; + } + + ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain, + tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label, + handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE, + IRQ_GC_INIT_MASK_CACHE); + if (ret) + goto fail_irq_domain; + + gc = tb10x_gpio->domain->gc->gc[0]; + gc->reg_base = tb10x_gpio->base; + gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH; + gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit; + gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit; + gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit; + gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type; + gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE; + gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN; + } + + return 0; + +fail_irq_domain: +fail_request_irq: +fail_get_irq: + gpiochip_remove(&tb10x_gpio->gc); +fail_gpiochip_registration: +fail_ioremap: + return ret; +} + +static int __exit tb10x_gpio_remove(struct platform_device *pdev) +{ + struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev); + int ret; + + if (tb10x_gpio->gc.to_irq) { + irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0], + BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0); + kfree(tb10x_gpio->domain->gc); + irq_domain_remove(tb10x_gpio->domain); + free_irq(tb10x_gpio->irq, tb10x_gpio); + } + ret = gpiochip_remove(&tb10x_gpio->gc); + if (ret) + return ret; + + return 0; +} + +static const struct of_device_id tb10x_gpio_dt_ids[] = { + { .compatible = "abilis,tb10x-gpio" }, + { } +}; +MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids); + +static struct platform_driver tb10x_gpio_driver = { + .probe = tb10x_gpio_probe, + .remove = tb10x_gpio_remove, + .driver = { + .name = "tb10x-gpio", + .of_match_table = of_match_ptr(tb10x_gpio_dt_ids), + .owner = THIS_MODULE, + } +}; + +module_platform_driver(tb10x_gpio_driver); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("tb10x gpio."); +MODULE_VERSION("0.0.1"); |