diff options
Diffstat (limited to 'drivers/gpio/gpio-em.c')
| -rw-r--r-- | drivers/gpio/gpio-em.c | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-em.c b/drivers/gpio/gpio-em.c new file mode 100644 index 0000000000..858e6ebbb5 --- /dev/null +++ b/drivers/gpio/gpio-em.c @@ -0,0 +1,390 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Emma Mobile GPIO Support - GIO + * + * Copyright (C) 2012 Magnus Damm + */ + +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/bitops.h> +#include <linux/err.h> +#include <linux/gpio/driver.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/pinctrl/consumer.h> + +struct em_gio_priv { + void __iomem *base0; + void __iomem *base1; + spinlock_t sense_lock; + struct platform_device *pdev; + struct gpio_chip gpio_chip; + struct irq_chip irq_chip; + struct irq_domain *irq_domain; +}; + +#define GIO_E1 0x00 +#define GIO_E0 0x04 +#define GIO_EM 0x04 +#define GIO_OL 0x08 +#define GIO_OH 0x0c +#define GIO_I 0x10 +#define GIO_IIA 0x14 +#define GIO_IEN 0x18 +#define GIO_IDS 0x1c +#define GIO_IIM 0x1c +#define GIO_RAW 0x20 +#define GIO_MST 0x24 +#define GIO_IIR 0x28 + +#define GIO_IDT0 0x40 +#define GIO_IDT1 0x44 +#define GIO_IDT2 0x48 +#define GIO_IDT3 0x4c +#define GIO_RAWBL 0x50 +#define GIO_RAWBH 0x54 +#define GIO_IRBL 0x58 +#define GIO_IRBH 0x5c + +#define GIO_IDT(n) (GIO_IDT0 + ((n) * 4)) + +static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs) +{ + if (offs < GIO_IDT0) + return ioread32(p->base0 + offs); + else + return ioread32(p->base1 + (offs - GIO_IDT0)); +} + +static inline void em_gio_write(struct em_gio_priv *p, int offs, + unsigned long value) +{ + if (offs < GIO_IDT0) + iowrite32(value, p->base0 + offs); + else + iowrite32(value, p->base1 + (offs - GIO_IDT0)); +} + +static void em_gio_irq_disable(struct irq_data *d) +{ + struct em_gio_priv *p = irq_data_get_irq_chip_data(d); + + em_gio_write(p, GIO_IDS, BIT(irqd_to_hwirq(d))); +} + +static void em_gio_irq_enable(struct irq_data *d) +{ + struct em_gio_priv *p = irq_data_get_irq_chip_data(d); + + em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d))); +} + +static int em_gio_irq_reqres(struct irq_data *d) +{ + struct em_gio_priv *p = irq_data_get_irq_chip_data(d); + int ret; + + ret = gpiochip_lock_as_irq(&p->gpio_chip, irqd_to_hwirq(d)); + if (ret) { + dev_err(p->gpio_chip.parent, + "unable to lock HW IRQ %lu for IRQ\n", + irqd_to_hwirq(d)); + return ret; + } + return 0; +} + +static void em_gio_irq_relres(struct irq_data *d) +{ + struct em_gio_priv *p = irq_data_get_irq_chip_data(d); + + gpiochip_unlock_as_irq(&p->gpio_chip, irqd_to_hwirq(d)); +} + + +#define GIO_ASYNC(x) (x + 8) + +static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = { + [IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00), + [IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01), + [IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02), + [IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03), + [IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04), +}; + +static int em_gio_irq_set_type(struct irq_data *d, unsigned int type) +{ + unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK]; + struct em_gio_priv *p = irq_data_get_irq_chip_data(d); + unsigned int reg, offset, shift; + unsigned long flags; + unsigned long tmp; + + if (!value) + return -EINVAL; + + offset = irqd_to_hwirq(d); + + pr_debug("gio: sense irq = %d, mode = %d\n", offset, value); + + /* 8 x 4 bit fields in 4 IDT registers */ + reg = GIO_IDT(offset >> 3); + shift = (offset & 0x07) << 4; + + spin_lock_irqsave(&p->sense_lock, flags); + + /* disable the interrupt in IIA */ + tmp = em_gio_read(p, GIO_IIA); + tmp &= ~BIT(offset); + em_gio_write(p, GIO_IIA, tmp); + + /* change the sense setting in IDT */ + tmp = em_gio_read(p, reg); + tmp &= ~(0xf << shift); + tmp |= value << shift; + em_gio_write(p, reg, tmp); + + /* clear pending interrupts */ + em_gio_write(p, GIO_IIR, BIT(offset)); + + /* enable the interrupt in IIA */ + tmp = em_gio_read(p, GIO_IIA); + tmp |= BIT(offset); + em_gio_write(p, GIO_IIA, tmp); + + spin_unlock_irqrestore(&p->sense_lock, flags); + + return 0; +} + +static irqreturn_t em_gio_irq_handler(int irq, void *dev_id) +{ + struct em_gio_priv *p = dev_id; + unsigned long pending; + unsigned int offset, irqs_handled = 0; + + while ((pending = em_gio_read(p, GIO_MST))) { + offset = __ffs(pending); + em_gio_write(p, GIO_IIR, BIT(offset)); + generic_handle_domain_irq(p->irq_domain, offset); + irqs_handled++; + } + + return irqs_handled ? IRQ_HANDLED : IRQ_NONE; +} + +static inline struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip) +{ + return gpiochip_get_data(chip); +} + +static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + em_gio_write(gpio_to_priv(chip), GIO_E0, BIT(offset)); + return 0; +} + +static int em_gio_get(struct gpio_chip *chip, unsigned offset) +{ + return !!(em_gio_read(gpio_to_priv(chip), GIO_I) & BIT(offset)); +} + +static void __em_gio_set(struct gpio_chip *chip, unsigned int reg, + unsigned shift, int value) +{ + /* upper 16 bits contains mask and lower 16 actual value */ + em_gio_write(gpio_to_priv(chip), reg, + (BIT(shift + 16)) | (value << shift)); +} + +static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + /* output is split into two registers */ + if (offset < 16) + __em_gio_set(chip, GIO_OL, offset, value); + else + __em_gio_set(chip, GIO_OH, offset - 16, value); +} + +static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset, + int value) +{ + /* write GPIO value to output before selecting output mode of pin */ + em_gio_set(chip, offset, value); + em_gio_write(gpio_to_priv(chip), GIO_E1, BIT(offset)); + return 0; +} + +static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset) +{ + return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset); +} + +static int em_gio_request(struct gpio_chip *chip, unsigned offset) +{ + return pinctrl_gpio_request(chip->base + offset); +} + +static void em_gio_free(struct gpio_chip *chip, unsigned offset) +{ + pinctrl_gpio_free(chip->base + offset); + + /* Set the GPIO as an input to ensure that the next GPIO request won't + * drive the GPIO pin as an output. + */ + em_gio_direction_input(chip, offset); +} + +static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int irq, + irq_hw_number_t hwirq) +{ + struct em_gio_priv *p = h->host_data; + + pr_debug("gio: map hw irq = %d, irq = %d\n", (int)hwirq, irq); + + irq_set_chip_data(irq, h->host_data); + irq_set_chip_and_handler(irq, &p->irq_chip, handle_level_irq); + return 0; +} + +static const struct irq_domain_ops em_gio_irq_domain_ops = { + .map = em_gio_irq_domain_map, + .xlate = irq_domain_xlate_twocell, +}; + +static void em_gio_irq_domain_remove(void *data) +{ + struct irq_domain *domain = data; + + irq_domain_remove(domain); +} + +static int em_gio_probe(struct platform_device *pdev) +{ + struct em_gio_priv *p; + struct gpio_chip *gpio_chip; + struct irq_chip *irq_chip; + struct device *dev = &pdev->dev; + const char *name = dev_name(dev); + unsigned int ngpios; + int irq[2], ret; + + p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL); + if (!p) + return -ENOMEM; + + p->pdev = pdev; + platform_set_drvdata(pdev, p); + spin_lock_init(&p->sense_lock); + + irq[0] = platform_get_irq(pdev, 0); + if (irq[0] < 0) + return irq[0]; + + irq[1] = platform_get_irq(pdev, 1); + if (irq[1] < 0) + return irq[1]; + + p->base0 = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(p->base0)) + return PTR_ERR(p->base0); + + p->base1 = devm_platform_ioremap_resource(pdev, 1); + if (IS_ERR(p->base1)) + return PTR_ERR(p->base1); + + if (of_property_read_u32(dev->of_node, "ngpios", &ngpios)) { + dev_err(dev, "Missing ngpios OF property\n"); + return -EINVAL; + } + + gpio_chip = &p->gpio_chip; + gpio_chip->direction_input = em_gio_direction_input; + gpio_chip->get = em_gio_get; + gpio_chip->direction_output = em_gio_direction_output; + gpio_chip->set = em_gio_set; + gpio_chip->to_irq = em_gio_to_irq; + gpio_chip->request = em_gio_request; + gpio_chip->free = em_gio_free; + gpio_chip->label = name; + gpio_chip->parent = dev; + gpio_chip->owner = THIS_MODULE; + gpio_chip->base = -1; + gpio_chip->ngpio = ngpios; + + irq_chip = &p->irq_chip; + irq_chip->name = "gpio-em"; + irq_chip->irq_mask = em_gio_irq_disable; + irq_chip->irq_unmask = em_gio_irq_enable; + irq_chip->irq_set_type = em_gio_irq_set_type; + irq_chip->irq_request_resources = em_gio_irq_reqres; + irq_chip->irq_release_resources = em_gio_irq_relres; + irq_chip->flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND; + + p->irq_domain = irq_domain_add_simple(dev->of_node, ngpios, 0, + &em_gio_irq_domain_ops, p); + if (!p->irq_domain) { + dev_err(dev, "cannot initialize irq domain\n"); + return -ENXIO; + } + + ret = devm_add_action_or_reset(dev, em_gio_irq_domain_remove, + p->irq_domain); + if (ret) + return ret; + + if (devm_request_irq(dev, irq[0], em_gio_irq_handler, 0, name, p)) { + dev_err(dev, "failed to request low IRQ\n"); + return -ENOENT; + } + + if (devm_request_irq(dev, irq[1], em_gio_irq_handler, 0, name, p)) { + dev_err(dev, "failed to request high IRQ\n"); + return -ENOENT; + } + + ret = devm_gpiochip_add_data(dev, gpio_chip, p); + if (ret) { + dev_err(dev, "failed to add GPIO controller\n"); + return ret; + } + + return 0; +} + +static const struct of_device_id em_gio_dt_ids[] = { + { .compatible = "renesas,em-gio", }, + {}, +}; +MODULE_DEVICE_TABLE(of, em_gio_dt_ids); + +static struct platform_driver em_gio_device_driver = { + .probe = em_gio_probe, + .driver = { + .name = "em_gio", + .of_match_table = em_gio_dt_ids, + } +}; + +static int __init em_gio_init(void) +{ + return platform_driver_register(&em_gio_device_driver); +} +postcore_initcall(em_gio_init); + +static void __exit em_gio_exit(void) +{ + platform_driver_unregister(&em_gio_device_driver); +} +module_exit(em_gio_exit); + +MODULE_AUTHOR("Magnus Damm"); +MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver"); +MODULE_LICENSE("GPL v2"); |