diff options
Diffstat (limited to 'drivers/gpio/gpio-tqmx86.c')
| -rw-r--r-- | drivers/gpio/gpio-tqmx86.c | 110 |
1 files changed, 80 insertions, 30 deletions
diff --git a/drivers/gpio/gpio-tqmx86.c b/drivers/gpio/gpio-tqmx86.c index 3a28c1f27..f2e7e8754 100644 --- a/drivers/gpio/gpio-tqmx86.c +++ b/drivers/gpio/gpio-tqmx86.c @@ -6,6 +6,7 @@ * Vadim V.Vlasov <vvlasov@dev.rtsoft.ru> */ +#include <linux/bitmap.h> #include <linux/bitops.h> #include <linux/errno.h> #include <linux/gpio/driver.h> @@ -28,16 +29,25 @@ #define TQMX86_GPIIC 3 /* GPI Interrupt Configuration Register */ #define TQMX86_GPIIS 4 /* GPI Interrupt Status Register */ +#define TQMX86_GPII_NONE 0 #define TQMX86_GPII_FALLING BIT(0) #define TQMX86_GPII_RISING BIT(1) +/* Stored in irq_type as a trigger type, but not actually valid as a register + * value, so the name doesn't use "GPII" + */ +#define TQMX86_INT_BOTH (BIT(0) | BIT(1)) #define TQMX86_GPII_MASK (BIT(0) | BIT(1)) #define TQMX86_GPII_BITS 2 +/* Stored in irq_type with GPII bits */ +#define TQMX86_INT_UNMASKED BIT(2) struct tqmx86_gpio_data { struct gpio_chip chip; void __iomem *io_base; int irq; + /* Lock must be held for accessing output and irq_type fields */ raw_spinlock_t spinlock; + DECLARE_BITMAP(output, TQMX86_NGPIO); u8 irq_type[TQMX86_NGPI]; }; @@ -64,15 +74,10 @@ static void tqmx86_gpio_set(struct gpio_chip *chip, unsigned int offset, { struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip); unsigned long flags; - u8 val; raw_spin_lock_irqsave(&gpio->spinlock, flags); - val = tqmx86_gpio_read(gpio, TQMX86_GPIOD); - if (value) - val |= BIT(offset); - else - val &= ~BIT(offset); - tqmx86_gpio_write(gpio, val, TQMX86_GPIOD); + __assign_bit(offset, gpio->output, value); + tqmx86_gpio_write(gpio, bitmap_get_value8(gpio->output, 0), TQMX86_GPIOD); raw_spin_unlock_irqrestore(&gpio->spinlock, flags); } @@ -107,21 +112,38 @@ static int tqmx86_gpio_get_direction(struct gpio_chip *chip, return GPIO_LINE_DIRECTION_OUT; } +static void tqmx86_gpio_irq_config(struct tqmx86_gpio_data *gpio, int offset) + __must_hold(&gpio->spinlock) +{ + u8 type = TQMX86_GPII_NONE, gpiic; + + if (gpio->irq_type[offset] & TQMX86_INT_UNMASKED) { + type = gpio->irq_type[offset] & TQMX86_GPII_MASK; + + if (type == TQMX86_INT_BOTH) + type = tqmx86_gpio_get(&gpio->chip, offset + TQMX86_NGPO) + ? TQMX86_GPII_FALLING + : TQMX86_GPII_RISING; + } + + gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC); + gpiic &= ~(TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS)); + gpiic |= type << (offset * TQMX86_GPII_BITS); + tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC); +} + static void tqmx86_gpio_irq_mask(struct irq_data *data) { unsigned int offset = (data->hwirq - TQMX86_NGPO); struct tqmx86_gpio_data *gpio = gpiochip_get_data( irq_data_get_irq_chip_data(data)); unsigned long flags; - u8 gpiic, mask; - - mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS); raw_spin_lock_irqsave(&gpio->spinlock, flags); - gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC); - gpiic &= ~mask; - tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC); + gpio->irq_type[offset] &= ~TQMX86_INT_UNMASKED; + tqmx86_gpio_irq_config(gpio, offset); raw_spin_unlock_irqrestore(&gpio->spinlock, flags); + gpiochip_disable_irq(&gpio->chip, irqd_to_hwirq(data)); } @@ -131,16 +153,12 @@ static void tqmx86_gpio_irq_unmask(struct irq_data *data) struct tqmx86_gpio_data *gpio = gpiochip_get_data( irq_data_get_irq_chip_data(data)); unsigned long flags; - u8 gpiic, mask; - - mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS); gpiochip_enable_irq(&gpio->chip, irqd_to_hwirq(data)); + raw_spin_lock_irqsave(&gpio->spinlock, flags); - gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC); - gpiic &= ~mask; - gpiic |= gpio->irq_type[offset] << (offset * TQMX86_GPII_BITS); - tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC); + gpio->irq_type[offset] |= TQMX86_INT_UNMASKED; + tqmx86_gpio_irq_config(gpio, offset); raw_spin_unlock_irqrestore(&gpio->spinlock, flags); } @@ -151,7 +169,7 @@ static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type) unsigned int offset = (data->hwirq - TQMX86_NGPO); unsigned int edge_type = type & IRQF_TRIGGER_MASK; unsigned long flags; - u8 new_type, gpiic; + u8 new_type; switch (edge_type) { case IRQ_TYPE_EDGE_RISING: @@ -161,19 +179,16 @@ static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type) new_type = TQMX86_GPII_FALLING; break; case IRQ_TYPE_EDGE_BOTH: - new_type = TQMX86_GPII_FALLING | TQMX86_GPII_RISING; + new_type = TQMX86_INT_BOTH; break; default: return -EINVAL; /* not supported */ } - gpio->irq_type[offset] = new_type; - raw_spin_lock_irqsave(&gpio->spinlock, flags); - gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC); - gpiic &= ~((TQMX86_GPII_MASK) << (offset * TQMX86_GPII_BITS)); - gpiic |= new_type << (offset * TQMX86_GPII_BITS); - tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC); + gpio->irq_type[offset] &= ~TQMX86_GPII_MASK; + gpio->irq_type[offset] |= new_type; + tqmx86_gpio_irq_config(gpio, offset); raw_spin_unlock_irqrestore(&gpio->spinlock, flags); return 0; @@ -184,8 +199,8 @@ static void tqmx86_gpio_irq_handler(struct irq_desc *desc) struct gpio_chip *chip = irq_desc_get_handler_data(desc); struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip); struct irq_chip *irq_chip = irq_desc_get_chip(desc); - unsigned long irq_bits; - int i = 0; + unsigned long irq_bits, flags; + int i; u8 irq_status; chained_irq_enter(irq_chip, desc); @@ -194,6 +209,34 @@ static void tqmx86_gpio_irq_handler(struct irq_desc *desc) tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS); irq_bits = irq_status; + + raw_spin_lock_irqsave(&gpio->spinlock, flags); + for_each_set_bit(i, &irq_bits, TQMX86_NGPI) { + /* + * Edge-both triggers are implemented by flipping the edge + * trigger after each interrupt, as the controller only supports + * either rising or falling edge triggers, but not both. + * + * Internally, the TQMx86 GPIO controller has separate status + * registers for rising and falling edge interrupts. GPIIC + * configures which bits from which register are visible in the + * interrupt status register GPIIS and defines what triggers the + * parent IRQ line. Writing to GPIIS always clears both rising + * and falling interrupt flags internally, regardless of the + * currently configured trigger. + * + * In consequence, we can cleanly implement the edge-both + * trigger in software by first clearing the interrupt and then + * setting the new trigger based on the current GPIO input in + * tqmx86_gpio_irq_config() - even if an edge arrives between + * reading the input and setting the trigger, we will have a new + * interrupt pending. + */ + if ((gpio->irq_type[i] & TQMX86_GPII_MASK) == TQMX86_INT_BOTH) + tqmx86_gpio_irq_config(gpio, i); + } + raw_spin_unlock_irqrestore(&gpio->spinlock, flags); + for_each_set_bit(i, &irq_bits, TQMX86_NGPI) generic_handle_domain_irq(gpio->chip.irq.domain, i + TQMX86_NGPO); @@ -277,6 +320,13 @@ static int tqmx86_gpio_probe(struct platform_device *pdev) tqmx86_gpio_write(gpio, (u8)~TQMX86_DIR_INPUT_MASK, TQMX86_GPIODD); + /* + * Reading the previous output state is not possible with TQMx86 hardware. + * Initialize all outputs to 0 to have a defined state that matches the + * shadow register. + */ + tqmx86_gpio_write(gpio, 0, TQMX86_GPIOD); + chip = &gpio->chip; chip->label = "gpio-tqmx86"; chip->owner = THIS_MODULE; |