From 37dc57c2400b2998868a5c103756f36b8dc53a17 Mon Sep 17 00:00:00 2001 From: Rafa? Mi?ecki Date: Thu, 12 Dec 2013 13:46:03 +0100 Subject: [PATCH 088/110] bcma: gpio: add own IRQ domain Input GPIO changes can generate interrupts, but we need kind of ACK for them by changing IRQ polarity. This is required to stop hardware from keep generating interrupts and generate another one on the next GPIO state change. This code allows using GPIOs with standard interrupts and add for example GPIO buttons support. Signed-off-by: Rafa? Mi?ecki Acked-by: Hauke Mehrtens Acked-by: John Crispin Patchwork: http://patchwork.linux-mips.org/patch/6216/ --- drivers/bcma/Kconfig | 1 + drivers/bcma/driver_gpio.c | 135 ++++++++++++++++++++++++++- include/linux/bcma/bcma_driver_chipcommon.h | 1 + 3 files changed, 134 insertions(+), 3 deletions(-) --- a/drivers/bcma/Kconfig +++ b/drivers/bcma/Kconfig @@ -76,6 +76,7 @@ config BCMA_DRIVER_GMAC_CMN config BCMA_DRIVER_GPIO bool "BCMA GPIO driver" depends on BCMA && GPIOLIB + select IRQ_DOMAIN if BCMA_HOST_SOC help Driver to provide access to the GPIO pins of the bcma bus. --- a/drivers/bcma/driver_gpio.c +++ b/drivers/bcma/driver_gpio.c @@ -9,6 +9,9 @@ */ #include +#include +#include +#include #include #include @@ -73,19 +76,133 @@ static void bcma_gpio_free(struct gpio_c bcma_chipco_gpio_pullup(cc, 1 << gpio, 0); } +#if IS_BUILTIN(CONFIG_BCMA_HOST_SOC) static int bcma_gpio_to_irq(struct gpio_chip *chip, unsigned gpio) { struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip); if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC) - return bcma_core_irq(cc->core); + return irq_find_mapping(cc->irq_domain, gpio); else return -EINVAL; } +static void bcma_gpio_irq_unmask(struct irq_data *d) +{ + struct bcma_drv_cc *cc = irq_data_get_irq_chip_data(d); + int gpio = irqd_to_hwirq(d); + + bcma_chipco_gpio_intmask(cc, BIT(gpio), BIT(gpio)); +} + +static void bcma_gpio_irq_mask(struct irq_data *d) +{ + struct bcma_drv_cc *cc = irq_data_get_irq_chip_data(d); + int gpio = irqd_to_hwirq(d); + + bcma_chipco_gpio_intmask(cc, BIT(gpio), 0); +} + +static struct irq_chip bcma_gpio_irq_chip = { + .name = "BCMA-GPIO", + .irq_mask = bcma_gpio_irq_mask, + .irq_unmask = bcma_gpio_irq_unmask, +}; + +static irqreturn_t bcma_gpio_irq_handler(int irq, void *dev_id) +{ + struct bcma_drv_cc *cc = dev_id; + u32 val = bcma_cc_read32(cc, BCMA_CC_GPIOIN); + u32 mask = bcma_cc_read32(cc, BCMA_CC_GPIOIRQ); + u32 pol = bcma_cc_read32(cc, BCMA_CC_GPIOPOL); + u32 irqs = (val ^ pol) & mask; + int gpio; + + if (!irqs) + return IRQ_NONE; + + for_each_set_bit(gpio, (unsigned long *)&irqs, cc->gpio.ngpio) + generic_handle_irq(bcma_gpio_to_irq(&cc->gpio, gpio)); + bcma_chipco_gpio_polarity(cc, irqs, val & irqs); + + return IRQ_HANDLED; +} + +static int bcma_gpio_irq_domain_init(struct bcma_drv_cc *cc) +{ + struct gpio_chip *chip = &cc->gpio; + int gpio, hwirq, err; + + if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC) + return 0; + + cc->irq_domain = irq_domain_add_linear(NULL, chip->ngpio, + &irq_domain_simple_ops, cc); + if (!cc->irq_domain) { + err = -ENODEV; + goto err_irq_domain; + } + for (gpio = 0; gpio < chip->ngpio; gpio++) { + int irq = irq_create_mapping(cc->irq_domain, gpio); + + irq_set_chip_data(irq, cc); + irq_set_chip_and_handler(irq, &bcma_gpio_irq_chip, + handle_simple_irq); + } + + hwirq = bcma_core_irq(cc->core); + err = request_irq(hwirq, bcma_gpio_irq_handler, IRQF_SHARED, "gpio", + cc); + if (err) + goto err_req_irq; + + bcma_cc_set32(cc, BCMA_CC_IRQMASK, BCMA_CC_IRQ_GPIO); + + return 0; + +err_req_irq: + for (gpio = 0; gpio < chip->ngpio; gpio++) { + int irq = irq_find_mapping(cc->irq_domain, gpio); + + irq_dispose_mapping(irq); + } + irq_domain_remove(cc->irq_domain); +err_irq_domain: + return err; +} + +static void bcma_gpio_irq_domain_exit(struct bcma_drv_cc *cc) +{ + struct gpio_chip *chip = &cc->gpio; + int gpio; + + if (cc->core->bus->hosttype != BCMA_HOSTTYPE_SOC) + return; + + bcma_cc_mask32(cc, BCMA_CC_IRQMASK, ~BCMA_CC_IRQ_GPIO); + free_irq(bcma_core_irq(cc->core), cc); + for (gpio = 0; gpio < chip->ngpio; gpio++) { + int irq = irq_find_mapping(cc->irq_domain, gpio); + + irq_dispose_mapping(irq); + } + irq_domain_remove(cc->irq_domain); +} +#else +static int bcma_gpio_irq_domain_init(struct bcma_drv_cc *cc) +{ + return 0; +} + +static void bcma_gpio_irq_domain_exit(struct bcma_drv_cc *cc) +{ +} +#endif + int bcma_gpio_init(struct bcma_drv_cc *cc) { struct gpio_chip *chip = &cc->gpio; + int err; chip->label = "bcma_gpio"; chip->owner = THIS_MODULE; @@ -95,7 +212,8 @@ int bcma_gpio_init(struct bcma_drv_cc *c chip->set = bcma_gpio_set_value; chip->direction_input = bcma_gpio_direction_input; chip->direction_output = bcma_gpio_direction_output; - chip->to_irq = bcma_gpio_to_irq; + if (IS_BUILTIN(CONFIG_BCMA_HOST_SOC)) + chip->to_irq = bcma_gpio_to_irq; chip->ngpio = 16; /* There is just one SoC in one device and its GPIO addresses should be * deterministic to address them more easily. The other buses could get @@ -105,10 +223,21 @@ int bcma_gpio_init(struct bcma_drv_cc *c else chip->base = -1; - return gpiochip_add(chip); + err = bcma_gpio_irq_domain_init(cc); + if (err) + return err; + + err = gpiochip_add(chip); + if (err) { + bcma_gpio_irq_domain_exit(cc); + return err; + } + + return 0; } int bcma_gpio_unregister(struct bcma_drv_cc *cc) { + bcma_gpio_irq_domain_exit(cc); return gpiochip_remove(&cc->gpio); } --- a/include/linux/bcma/bcma_driver_chipcommon.h +++ b/include/linux/bcma/bcma_driver_chipcommon.h @@ -640,6 +640,7 @@ struct bcma_drv_cc { spinlock_t gpio_lock; #ifdef CONFIG_BCMA_DRIVER_GPIO struct gpio_chip gpio; + struct irq_domain *irq_domain; #endif };