diff options
Diffstat (limited to 'drivers/gpio/gpio-bcm-kona.c')
| -rw-r--r-- | drivers/gpio/gpio-bcm-kona.c | 640 |
1 files changed, 640 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-bcm-kona.c b/drivers/gpio/gpio-bcm-kona.c new file mode 100644 index 000000000000..72c927dc3be1 --- /dev/null +++ b/drivers/gpio/gpio-bcm-kona.c @@ -0,0 +1,640 @@ +/* + * Copyright (C) 2012-2013 Broadcom Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/bitops.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/gpio.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> +#include <linux/module.h> +#include <linux/irqdomain.h> +#include <linux/irqchip/chained_irq.h> + +#define BCM_GPIO_PASSWD 0x00a5a501 +#define GPIO_PER_BANK 32 +#define GPIO_MAX_BANK_NUM 8 + +#define GPIO_BANK(gpio) ((gpio) >> 5) +#define GPIO_BIT(gpio) ((gpio) & (GPIO_PER_BANK - 1)) + +#define GPIO_OUT_STATUS(bank) (0x00000000 + ((bank) << 2)) +#define GPIO_IN_STATUS(bank) (0x00000020 + ((bank) << 2)) +#define GPIO_OUT_SET(bank) (0x00000040 + ((bank) << 2)) +#define GPIO_OUT_CLEAR(bank) (0x00000060 + ((bank) << 2)) +#define GPIO_INT_STATUS(bank) (0x00000080 + ((bank) << 2)) +#define GPIO_INT_MASK(bank) (0x000000a0 + ((bank) << 2)) +#define GPIO_INT_MSKCLR(bank) (0x000000c0 + ((bank) << 2)) +#define GPIO_CONTROL(bank) (0x00000100 + ((bank) << 2)) +#define GPIO_PWD_STATUS(bank) (0x00000500 + ((bank) << 2)) + +#define GPIO_GPPWR_OFFSET 0x00000520 + +#define GPIO_GPCTR0_DBR_SHIFT 5 +#define GPIO_GPCTR0_DBR_MASK 0x000001e0 + +#define GPIO_GPCTR0_ITR_SHIFT 3 +#define GPIO_GPCTR0_ITR_MASK 0x00000018 +#define GPIO_GPCTR0_ITR_CMD_RISING_EDGE 0x00000001 +#define GPIO_GPCTR0_ITR_CMD_FALLING_EDGE 0x00000002 +#define GPIO_GPCTR0_ITR_CMD_BOTH_EDGE 0x00000003 + +#define GPIO_GPCTR0_IOTR_MASK 0x00000001 +#define GPIO_GPCTR0_IOTR_CMD_0UTPUT 0x00000000 +#define GPIO_GPCTR0_IOTR_CMD_INPUT 0x00000001 + +#define GPIO_GPCTR0_DB_ENABLE_MASK 0x00000100 + +#define LOCK_CODE 0xffffffff +#define UNLOCK_CODE 0x00000000 + +struct bcm_kona_gpio { + void __iomem *reg_base; + int num_bank; + spinlock_t lock; + struct gpio_chip gpio_chip; + struct irq_domain *irq_domain; + struct bcm_kona_gpio_bank *banks; + struct platform_device *pdev; +}; + +struct bcm_kona_gpio_bank { + int id; + int irq; + /* Used in the interrupt handler */ + struct bcm_kona_gpio *kona_gpio; +}; + +static inline struct bcm_kona_gpio *to_kona_gpio(struct gpio_chip *chip) +{ + return container_of(chip, struct bcm_kona_gpio, gpio_chip); +} + +static void bcm_kona_gpio_set_lockcode_bank(void __iomem *reg_base, + int bank_id, int lockcode) +{ + writel(BCM_GPIO_PASSWD, reg_base + GPIO_GPPWR_OFFSET); + writel(lockcode, reg_base + GPIO_PWD_STATUS(bank_id)); +} + +static inline void bcm_kona_gpio_lock_bank(void __iomem *reg_base, int bank_id) +{ + bcm_kona_gpio_set_lockcode_bank(reg_base, bank_id, LOCK_CODE); +} + +static inline void bcm_kona_gpio_unlock_bank(void __iomem *reg_base, + int bank_id) +{ + bcm_kona_gpio_set_lockcode_bank(reg_base, bank_id, UNLOCK_CODE); +} + +static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value) +{ + struct bcm_kona_gpio *kona_gpio; + void __iomem *reg_base; + int bank_id = GPIO_BANK(gpio); + int bit = GPIO_BIT(gpio); + u32 val, reg_offset; + unsigned long flags; + + kona_gpio = to_kona_gpio(chip); + reg_base = kona_gpio->reg_base; + spin_lock_irqsave(&kona_gpio->lock, flags); + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + /* determine the GPIO pin direction */ + val = readl(reg_base + GPIO_CONTROL(gpio)); + val &= GPIO_GPCTR0_IOTR_MASK; + + /* this function only applies to output pin */ + if (GPIO_GPCTR0_IOTR_CMD_INPUT == val) + goto out; + + reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id); + + val = readl(reg_base + reg_offset); + val |= BIT(bit); + writel(val, reg_base + reg_offset); + +out: + bcm_kona_gpio_lock_bank(reg_base, bank_id); + spin_unlock_irqrestore(&kona_gpio->lock, flags); +} + +static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio) +{ + struct bcm_kona_gpio *kona_gpio; + void __iomem *reg_base; + int bank_id = GPIO_BANK(gpio); + int bit = GPIO_BIT(gpio); + u32 val, reg_offset; + unsigned long flags; + + kona_gpio = to_kona_gpio(chip); + reg_base = kona_gpio->reg_base; + spin_lock_irqsave(&kona_gpio->lock, flags); + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + /* determine the GPIO pin direction */ + val = readl(reg_base + GPIO_CONTROL(gpio)); + val &= GPIO_GPCTR0_IOTR_MASK; + + /* read the GPIO bank status */ + reg_offset = (GPIO_GPCTR0_IOTR_CMD_INPUT == val) ? + GPIO_IN_STATUS(bank_id) : GPIO_OUT_STATUS(bank_id); + val = readl(reg_base + reg_offset); + + bcm_kona_gpio_lock_bank(reg_base, bank_id); + spin_unlock_irqrestore(&kona_gpio->lock, flags); + + /* return the specified bit status */ + return !!(val & bit); +} + +static int bcm_kona_gpio_direction_input(struct gpio_chip *chip, unsigned gpio) +{ + struct bcm_kona_gpio *kona_gpio; + void __iomem *reg_base; + u32 val; + unsigned long flags; + int bank_id = GPIO_BANK(gpio); + + kona_gpio = to_kona_gpio(chip); + reg_base = kona_gpio->reg_base; + spin_lock_irqsave(&kona_gpio->lock, flags); + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + val = readl(reg_base + GPIO_CONTROL(gpio)); + val &= ~GPIO_GPCTR0_IOTR_MASK; + val |= GPIO_GPCTR0_IOTR_CMD_INPUT; + writel(val, reg_base + GPIO_CONTROL(gpio)); + + bcm_kona_gpio_lock_bank(reg_base, bank_id); + spin_unlock_irqrestore(&kona_gpio->lock, flags); + + return 0; +} + +static int bcm_kona_gpio_direction_output(struct gpio_chip *chip, + unsigned gpio, int value) +{ + struct bcm_kona_gpio *kona_gpio; + void __iomem *reg_base; + int bank_id = GPIO_BANK(gpio); + int bit = GPIO_BIT(gpio); + u32 val, reg_offset; + unsigned long flags; + + kona_gpio = to_kona_gpio(chip); + reg_base = kona_gpio->reg_base; + spin_lock_irqsave(&kona_gpio->lock, flags); + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + val = readl(reg_base + GPIO_CONTROL(gpio)); + val &= ~GPIO_GPCTR0_IOTR_MASK; + val |= GPIO_GPCTR0_IOTR_CMD_0UTPUT; + writel(val, reg_base + GPIO_CONTROL(gpio)); + reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id); + + val = readl(reg_base + reg_offset); + val |= BIT(bit); + writel(val, reg_base + reg_offset); + + bcm_kona_gpio_lock_bank(reg_base, bank_id); + spin_unlock_irqrestore(&kona_gpio->lock, flags); + + return 0; +} + +static int bcm_kona_gpio_to_irq(struct gpio_chip *chip, unsigned gpio) +{ + struct bcm_kona_gpio *kona_gpio; + + kona_gpio = to_kona_gpio(chip); + if (gpio >= kona_gpio->gpio_chip.ngpio) + return -ENXIO; + return irq_create_mapping(kona_gpio->irq_domain, gpio); +} + +static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio, + unsigned debounce) +{ + struct bcm_kona_gpio *kona_gpio; + void __iomem *reg_base; + u32 val, res; + unsigned long flags; + int bank_id = GPIO_BANK(gpio); + + kona_gpio = to_kona_gpio(chip); + reg_base = kona_gpio->reg_base; + /* debounce must be 1-128ms (or 0) */ + if ((debounce > 0 && debounce < 1000) || debounce > 128000) { + dev_err(chip->dev, "Debounce value %u not in range\n", + debounce); + return -EINVAL; + } + + /* calculate debounce bit value */ + if (debounce != 0) { + /* Convert to ms */ + debounce /= 1000; + /* find the MSB */ + res = fls(debounce) - 1; + /* Check if MSB-1 is set (round up or down) */ + if (res > 0 && (debounce & BIT(res - 1))) + res++; + } + + /* spin lock for read-modify-write of the GPIO register */ + spin_lock_irqsave(&kona_gpio->lock, flags); + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + val = readl(reg_base + GPIO_CONTROL(gpio)); + val &= ~GPIO_GPCTR0_DBR_MASK; + + if (debounce == 0) { + /* disable debounce */ + val &= ~GPIO_GPCTR0_DB_ENABLE_MASK; + } else { + val |= GPIO_GPCTR0_DB_ENABLE_MASK | + (res << GPIO_GPCTR0_DBR_SHIFT); + } + + writel(val, reg_base + GPIO_CONTROL(gpio)); + + bcm_kona_gpio_lock_bank(reg_base, bank_id); + spin_unlock_irqrestore(&kona_gpio->lock, flags); + + return 0; +} + +static struct gpio_chip template_chip = { + .label = "bcm-kona-gpio", + .owner = THIS_MODULE, + .direction_input = bcm_kona_gpio_direction_input, + .get = bcm_kona_gpio_get, + .direction_output = bcm_kona_gpio_direction_output, + .set = bcm_kona_gpio_set, + .set_debounce = bcm_kona_gpio_set_debounce, + .to_irq = bcm_kona_gpio_to_irq, + .base = 0, +}; + +static void bcm_kona_gpio_irq_ack(struct irq_data *d) +{ + struct bcm_kona_gpio *kona_gpio; + void __iomem *reg_base; + int gpio = d->hwirq; + int bank_id = GPIO_BANK(gpio); + int bit = GPIO_BIT(gpio); + u32 val; + unsigned long flags; + + kona_gpio = irq_data_get_irq_chip_data(d); + reg_base = kona_gpio->reg_base; + spin_lock_irqsave(&kona_gpio->lock, flags); + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + val = readl(reg_base + GPIO_INT_STATUS(bank_id)); + val |= BIT(bit); + writel(val, reg_base + GPIO_INT_STATUS(bank_id)); + + bcm_kona_gpio_lock_bank(reg_base, bank_id); + spin_unlock_irqrestore(&kona_gpio->lock, flags); +} + +static void bcm_kona_gpio_irq_mask(struct irq_data *d) +{ + struct bcm_kona_gpio *kona_gpio; + void __iomem *reg_base; + int gpio = d->hwirq; + int bank_id = GPIO_BANK(gpio); + int bit = GPIO_BIT(gpio); + u32 val; + unsigned long flags; + + kona_gpio = irq_data_get_irq_chip_data(d); + reg_base = kona_gpio->reg_base; + spin_lock_irqsave(&kona_gpio->lock, flags); + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + val = readl(reg_base + GPIO_INT_MASK(bank_id)); + val |= BIT(bit); + writel(val, reg_base + GPIO_INT_MASK(bank_id)); + + bcm_kona_gpio_lock_bank(reg_base, bank_id); + spin_unlock_irqrestore(&kona_gpio->lock, flags); +} + +static void bcm_kona_gpio_irq_unmask(struct irq_data *d) +{ + struct bcm_kona_gpio *kona_gpio; + void __iomem *reg_base; + int gpio = d->hwirq; + int bank_id = GPIO_BANK(gpio); + int bit = GPIO_BIT(gpio); + u32 val; + unsigned long flags; + + kona_gpio = irq_data_get_irq_chip_data(d); + reg_base = kona_gpio->reg_base; + spin_lock_irqsave(&kona_gpio->lock, flags); + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + val = readl(reg_base + GPIO_INT_MSKCLR(bank_id)); + val |= BIT(bit); + writel(val, reg_base + GPIO_INT_MSKCLR(bank_id)); + + bcm_kona_gpio_lock_bank(reg_base, bank_id); + spin_unlock_irqrestore(&kona_gpio->lock, flags); +} + +static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type) +{ + struct bcm_kona_gpio *kona_gpio; + void __iomem *reg_base; + int gpio = d->hwirq; + u32 lvl_type; + u32 val; + unsigned long flags; + int bank_id = GPIO_BANK(gpio); + + kona_gpio = irq_data_get_irq_chip_data(d); + reg_base = kona_gpio->reg_base; + switch (type & IRQ_TYPE_SENSE_MASK) { + case IRQ_TYPE_EDGE_RISING: + lvl_type = GPIO_GPCTR0_ITR_CMD_RISING_EDGE; + break; + + case IRQ_TYPE_EDGE_FALLING: + lvl_type = GPIO_GPCTR0_ITR_CMD_FALLING_EDGE; + break; + + case IRQ_TYPE_EDGE_BOTH: + lvl_type = GPIO_GPCTR0_ITR_CMD_BOTH_EDGE; + break; + + case IRQ_TYPE_LEVEL_HIGH: + case IRQ_TYPE_LEVEL_LOW: + /* BCM GPIO doesn't support level triggering */ + default: + dev_err(kona_gpio->gpio_chip.dev, + "Invalid BCM GPIO irq type 0x%x\n", type); + return -EINVAL; + } + + spin_lock_irqsave(&kona_gpio->lock, flags); + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + val = readl(reg_base + GPIO_CONTROL(gpio)); + val &= ~GPIO_GPCTR0_ITR_MASK; + val |= lvl_type << GPIO_GPCTR0_ITR_SHIFT; + writel(val, reg_base + GPIO_CONTROL(gpio)); + + bcm_kona_gpio_lock_bank(reg_base, bank_id); + spin_unlock_irqrestore(&kona_gpio->lock, flags); + + return 0; +} + +static void bcm_kona_gpio_irq_handler(unsigned int irq, struct irq_desc *desc) +{ + void __iomem *reg_base; + int bit, bank_id; + unsigned long sta; + struct bcm_kona_gpio_bank *bank = irq_get_handler_data(irq); + struct irq_chip *chip = irq_desc_get_chip(desc); + + chained_irq_enter(chip, desc); + + /* + * For bank interrupts, we can't use chip_data to store the kona_gpio + * pointer, since GIC needs it for its own purposes. Therefore, we get + * our pointer from the bank structure. + */ + reg_base = bank->kona_gpio->reg_base; + bank_id = bank->id; + bcm_kona_gpio_unlock_bank(reg_base, bank_id); + + while ((sta = readl(reg_base + GPIO_INT_STATUS(bank_id)) & + (~(readl(reg_base + GPIO_INT_MASK(bank_id)))))) { + for_each_set_bit(bit, &sta, 32) { + int hwirq = GPIO_PER_BANK * bank_id + bit; + int child_irq = + irq_find_mapping(bank->kona_gpio->irq_domain, + hwirq); + /* + * Clear interrupt before handler is called so we don't + * miss any interrupt occurred during executing them. + */ + writel(readl(reg_base + GPIO_INT_STATUS(bank_id)) | + BIT(bit), reg_base + GPIO_INT_STATUS(bank_id)); + /* Invoke interrupt handler */ + generic_handle_irq(child_irq); + } + } + + bcm_kona_gpio_lock_bank(reg_base, bank_id); + + chained_irq_exit(chip, desc); +} + +static struct irq_chip bcm_gpio_irq_chip = { + .name = "bcm-kona-gpio", + .irq_ack = bcm_kona_gpio_irq_ack, + .irq_mask = bcm_kona_gpio_irq_mask, + .irq_unmask = bcm_kona_gpio_irq_unmask, + .irq_set_type = bcm_kona_gpio_irq_set_type, +}; + +static struct __initconst of_device_id bcm_kona_gpio_of_match[] = { + { .compatible = "brcm,kona-gpio" }, + {} +}; + +MODULE_DEVICE_TABLE(of, bcm_kona_gpio_of_match); + +/* + * This lock class tells lockdep that GPIO irqs are in a different + * category than their parents, so it won't report false recursion. + */ +static struct lock_class_key gpio_lock_class; + +static int bcm_kona_gpio_irq_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hwirq) +{ + int ret; + + ret = irq_set_chip_data(irq, d->host_data); + if (ret < 0) + return ret; + irq_set_lockdep_class(irq, &gpio_lock_class); + irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, handle_simple_irq); +#ifdef CONFIG_ARM + set_irq_flags(irq, IRQF_VALID); +#else + irq_set_noprobe(irq); +#endif + + return 0; +} + +static void bcm_kona_gpio_irq_unmap(struct irq_domain *d, unsigned int irq) +{ + irq_set_chip_and_handler(irq, NULL, NULL); + irq_set_chip_data(irq, NULL); +} + +static struct irq_domain_ops bcm_kona_irq_ops = { + .map = bcm_kona_gpio_irq_map, + .unmap = bcm_kona_gpio_irq_unmap, + .xlate = irq_domain_xlate_twocell, +}; + +static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio) +{ + void __iomem *reg_base; + int i; + + reg_base = kona_gpio->reg_base; + /* disable interrupts and clear status */ + for (i = 0; i < kona_gpio->num_bank; i++) { + bcm_kona_gpio_unlock_bank(reg_base, i); + writel(0xffffffff, reg_base + GPIO_INT_MASK(i)); + writel(0xffffffff, reg_base + GPIO_INT_STATUS(i)); + bcm_kona_gpio_lock_bank(reg_base, i); + } +} + +static int bcm_kona_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct of_device_id *match; + struct resource *res; + struct bcm_kona_gpio_bank *bank; + struct bcm_kona_gpio *kona_gpio; + struct gpio_chip *chip; + int ret; + int i; + + match = of_match_device(bcm_kona_gpio_of_match, dev); + if (!match) { + dev_err(dev, "Failed to find gpio controller\n"); + return -ENODEV; + } + + kona_gpio = devm_kzalloc(dev, sizeof(*kona_gpio), GFP_KERNEL); + if (!kona_gpio) + return -ENOMEM; + + kona_gpio->gpio_chip = template_chip; + chip = &kona_gpio->gpio_chip; + kona_gpio->num_bank = of_irq_count(dev->of_node); + if (kona_gpio->num_bank == 0) { + dev_err(dev, "Couldn't determine # GPIO banks\n"); + return -ENOENT; + } + if (kona_gpio->num_bank > GPIO_MAX_BANK_NUM) { + dev_err(dev, "Too many GPIO banks configured (max=%d)\n", + GPIO_MAX_BANK_NUM); + return -ENXIO; + } + kona_gpio->banks = devm_kzalloc(dev, + kona_gpio->num_bank * + sizeof(*kona_gpio->banks), GFP_KERNEL); + if (!kona_gpio->banks) + return -ENOMEM; + + kona_gpio->pdev = pdev; + platform_set_drvdata(pdev, kona_gpio); + chip->of_node = dev->of_node; + chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK; + + kona_gpio->irq_domain = irq_domain_add_linear(dev->of_node, + chip->ngpio, + &bcm_kona_irq_ops, + kona_gpio); + if (!kona_gpio->irq_domain) { + dev_err(dev, "Couldn't allocate IRQ domain\n"); + return -ENXIO; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + kona_gpio->reg_base = devm_ioremap_resource(dev, res); + if (IS_ERR(kona_gpio->reg_base)) { + ret = -ENXIO; + goto err_irq_domain; + } + + for (i = 0; i < kona_gpio->num_bank; i++) { + bank = &kona_gpio->banks[i]; + bank->id = i; + bank->irq = platform_get_irq(pdev, i); + bank->kona_gpio = kona_gpio; + if (bank->irq < 0) { + dev_err(dev, "Couldn't get IRQ for bank %d", i); + ret = -ENOENT; + goto err_irq_domain; + } + } + + dev_info(&pdev->dev, "Setting up Kona GPIO\n"); + + bcm_kona_gpio_reset(kona_gpio); + + ret = gpiochip_add(chip); + if (ret < 0) { + dev_err(dev, "Couldn't add GPIO chip -- %d\n", ret); + goto err_irq_domain; + } + for (i = 0; i < chip->ngpio; i++) { + int irq = bcm_kona_gpio_to_irq(chip, i); + irq_set_lockdep_class(irq, &gpio_lock_class); + irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, + handle_simple_irq); +#ifdef CONFIG_ARM + set_irq_flags(irq, IRQF_VALID); +#else + irq_set_noprobe(irq); +#endif + } + for (i = 0; i < kona_gpio->num_bank; i++) { + bank = &kona_gpio->banks[i]; + irq_set_chained_handler(bank->irq, bcm_kona_gpio_irq_handler); + irq_set_handler_data(bank->irq, bank); + } + + spin_lock_init(&kona_gpio->lock); + + return 0; + +err_irq_domain: + irq_domain_remove(kona_gpio->irq_domain); + + return ret; +} + +static struct platform_driver bcm_kona_gpio_driver = { + .driver = { + .name = "bcm-kona-gpio", + .owner = THIS_MODULE, + .of_match_table = bcm_kona_gpio_of_match, + }, + .probe = bcm_kona_gpio_probe, +}; + +module_platform_driver(bcm_kona_gpio_driver); + +MODULE_AUTHOR("Broadcom"); +MODULE_DESCRIPTION("Broadcom Kona GPIO Driver"); +MODULE_LICENSE("GPL v2"); |