diff options
Diffstat (limited to 'drivers/gpio/gpio-xilinx.c')
| -rw-r--r-- | drivers/gpio/gpio-xilinx.c | 246 |
1 files changed, 242 insertions, 4 deletions
diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c index f88db56543c2..62deb755f910 100644 --- a/drivers/gpio/gpio-xilinx.c +++ b/drivers/gpio/gpio-xilinx.c @@ -10,7 +10,9 @@ #include <linux/errno.h> #include <linux/gpio/driver.h> #include <linux/init.h> +#include <linux/interrupt.h> #include <linux/io.h> +#include <linux/irq.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/of_platform.h> @@ -22,6 +24,11 @@ #define XGPIO_CHANNEL_OFFSET 0x8 +#define XGPIO_GIER_OFFSET 0x11c /* Global Interrupt Enable */ +#define XGPIO_GIER_IE BIT(31) +#define XGPIO_IPISR_OFFSET 0x120 /* IP Interrupt Status */ +#define XGPIO_IPIER_OFFSET 0x128 /* IP Interrupt Enable */ + /* Read/Write access to the GPIO registers */ #if defined(CONFIG_ARCH_ZYNQ) || defined(CONFIG_X86) # define xgpio_readreg(offset) readl(offset) @@ -36,9 +43,15 @@ * @gc: GPIO chip * @regs: register block * @gpio_width: GPIO width for every channel - * @gpio_state: GPIO state shadow register + * @gpio_state: GPIO write state shadow register + * @gpio_last_irq_read: GPIO read state register from last interrupt * @gpio_dir: GPIO direction shadow register * @gpio_lock: Lock used for synchronization + * @irq: IRQ used by GPIO device + * @irqchip: IRQ chip + * @irq_enable: GPIO IRQ enable/disable bitfield + * @irq_rising_edge: GPIO IRQ rising edge enable/disable bitfield + * @irq_falling_edge: GPIO IRQ falling edge enable/disable bitfield * @clk: clock resource for this driver */ struct xgpio_instance { @@ -46,8 +59,14 @@ struct xgpio_instance { void __iomem *regs; unsigned int gpio_width[2]; u32 gpio_state[2]; + u32 gpio_last_irq_read[2]; u32 gpio_dir[2]; spinlock_t gpio_lock; /* For serializing operations */ + int irq; + struct irq_chip irqchip; + u32 irq_enable[2]; + u32 irq_rising_edge[2]; + u32 irq_falling_edge[2]; struct clk *clk; }; @@ -277,6 +296,175 @@ static int xgpio_remove(struct platform_device *pdev) } /** + * xgpio_irq_ack - Acknowledge a child GPIO interrupt. + * @irq_data: per IRQ and chip data passed down to chip functions + * This currently does nothing, but irq_ack is unconditionally called by + * handle_edge_irq and therefore must be defined. + */ +static void xgpio_irq_ack(struct irq_data *irq_data) +{ +} + +/** + * xgpio_irq_mask - Write the specified signal of the GPIO device. + * @irq_data: per IRQ and chip data passed down to chip functions + */ +static void xgpio_irq_mask(struct irq_data *irq_data) +{ + unsigned long flags; + struct xgpio_instance *chip = irq_data_get_irq_chip_data(irq_data); + int irq_offset = irqd_to_hwirq(irq_data); + int index = xgpio_index(chip, irq_offset); + int offset = xgpio_offset(chip, irq_offset); + + spin_lock_irqsave(&chip->gpio_lock, flags); + + chip->irq_enable[index] &= ~BIT(offset); + + if (!chip->irq_enable[index]) { + /* Disable per channel interrupt */ + u32 temp = xgpio_readreg(chip->regs + XGPIO_IPIER_OFFSET); + + temp &= ~BIT(index); + xgpio_writereg(chip->regs + XGPIO_IPIER_OFFSET, temp); + } + spin_unlock_irqrestore(&chip->gpio_lock, flags); +} + +/** + * xgpio_irq_unmask - Write the specified signal of the GPIO device. + * @irq_data: per IRQ and chip data passed down to chip functions + */ +static void xgpio_irq_unmask(struct irq_data *irq_data) +{ + unsigned long flags; + struct xgpio_instance *chip = irq_data_get_irq_chip_data(irq_data); + int irq_offset = irqd_to_hwirq(irq_data); + int index = xgpio_index(chip, irq_offset); + int offset = xgpio_offset(chip, irq_offset); + u32 old_enable = chip->irq_enable[index]; + + spin_lock_irqsave(&chip->gpio_lock, flags); + + chip->irq_enable[index] |= BIT(offset); + + if (!old_enable) { + /* Clear any existing per-channel interrupts */ + u32 val = xgpio_readreg(chip->regs + XGPIO_IPISR_OFFSET) & + BIT(index); + + if (val) + xgpio_writereg(chip->regs + XGPIO_IPISR_OFFSET, val); + + /* Update GPIO IRQ read data before enabling interrupt*/ + val = xgpio_readreg(chip->regs + XGPIO_DATA_OFFSET + + index * XGPIO_CHANNEL_OFFSET); + chip->gpio_last_irq_read[index] = val; + + /* Enable per channel interrupt */ + val = xgpio_readreg(chip->regs + XGPIO_IPIER_OFFSET); + val |= BIT(index); + xgpio_writereg(chip->regs + XGPIO_IPIER_OFFSET, val); + } + + spin_unlock_irqrestore(&chip->gpio_lock, flags); +} + +/** + * xgpio_set_irq_type - Write the specified signal of the GPIO device. + * @irq_data: Per IRQ and chip data passed down to chip functions + * @type: Interrupt type that is to be set for the gpio pin + * + * Return: + * 0 if interrupt type is supported otherwise -EINVAL + */ +static int xgpio_set_irq_type(struct irq_data *irq_data, unsigned int type) +{ + struct xgpio_instance *chip = irq_data_get_irq_chip_data(irq_data); + int irq_offset = irqd_to_hwirq(irq_data); + int index = xgpio_index(chip, irq_offset); + int offset = xgpio_offset(chip, irq_offset); + + /* + * The Xilinx GPIO hardware provides a single interrupt status + * indication for any state change in a given GPIO channel (bank). + * Therefore, only rising edge or falling edge triggers are + * supported. + */ + switch (type & IRQ_TYPE_SENSE_MASK) { + case IRQ_TYPE_EDGE_BOTH: + chip->irq_rising_edge[index] |= BIT(offset); + chip->irq_falling_edge[index] |= BIT(offset); + break; + case IRQ_TYPE_EDGE_RISING: + chip->irq_rising_edge[index] |= BIT(offset); + chip->irq_falling_edge[index] &= ~BIT(offset); + break; + case IRQ_TYPE_EDGE_FALLING: + chip->irq_rising_edge[index] &= ~BIT(offset); + chip->irq_falling_edge[index] |= BIT(offset); + break; + default: + return -EINVAL; + } + + irq_set_handler_locked(irq_data, handle_edge_irq); + return 0; +} + +/** + * xgpio_irqhandler - Gpio interrupt service routine + * @desc: Pointer to interrupt description + */ +static void xgpio_irqhandler(struct irq_desc *desc) +{ + struct xgpio_instance *chip = irq_desc_get_handler_data(desc); + struct irq_chip *irqchip = irq_desc_get_chip(desc); + u32 num_channels = chip->gpio_width[1] ? 2 : 1; + u32 offset = 0, index; + u32 status = xgpio_readreg(chip->regs + XGPIO_IPISR_OFFSET); + + xgpio_writereg(chip->regs + XGPIO_IPISR_OFFSET, status); + + chained_irq_enter(irqchip, desc); + for (index = 0; index < num_channels; index++) { + if ((status & BIT(index))) { + unsigned long rising_events, falling_events, all_events; + unsigned long flags; + u32 data, bit; + unsigned int irq; + + spin_lock_irqsave(&chip->gpio_lock, flags); + data = xgpio_readreg(chip->regs + XGPIO_DATA_OFFSET + + index * XGPIO_CHANNEL_OFFSET); + rising_events = data & + ~chip->gpio_last_irq_read[index] & + chip->irq_enable[index] & + chip->irq_rising_edge[index]; + falling_events = ~data & + chip->gpio_last_irq_read[index] & + chip->irq_enable[index] & + chip->irq_falling_edge[index]; + dev_dbg(chip->gc.parent, + "IRQ chan %u rising 0x%lx falling 0x%lx\n", + index, rising_events, falling_events); + all_events = rising_events | falling_events; + chip->gpio_last_irq_read[index] = data; + spin_unlock_irqrestore(&chip->gpio_lock, flags); + + for_each_set_bit(bit, &all_events, 32) { + irq = irq_find_mapping(chip->gc.irq.domain, + offset + bit); + generic_handle_irq(irq); + } + } + offset += chip->gpio_width[index]; + } + + chained_irq_exit(irqchip, desc); +} + +/** * xgpio_of_probe - Probe method for the GPIO device. * @pdev: pointer to the platform device * @@ -289,7 +477,10 @@ static int xgpio_probe(struct platform_device *pdev) struct xgpio_instance *chip; int status = 0; struct device_node *np = pdev->dev.of_node; - u32 is_dual; + u32 is_dual = 0; + u32 cells = 2; + struct gpio_irq_chip *girq; + u32 temp; chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); if (!chip) @@ -305,6 +496,15 @@ static int xgpio_probe(struct platform_device *pdev) if (of_property_read_u32(np, "xlnx,tri-default", &chip->gpio_dir[0])) chip->gpio_dir[0] = 0xFFFFFFFF; + /* Update cells with gpio-cells value */ + if (of_property_read_u32(np, "#gpio-cells", &cells)) + dev_dbg(&pdev->dev, "Missing gpio-cells property\n"); + + if (cells != 2) { + dev_err(&pdev->dev, "#gpio-cells mismatch\n"); + return -EINVAL; + } + /* * Check device node and parent device node for device width * and assume default width of 32 @@ -343,6 +543,7 @@ static int xgpio_probe(struct platform_device *pdev) chip->gc.parent = &pdev->dev; chip->gc.direction_input = xgpio_dir_in; chip->gc.direction_output = xgpio_dir_out; + chip->gc.of_gpio_n_cells = cells; chip->gc.get = xgpio_get; chip->gc.set = xgpio_set; chip->gc.set_multiple = xgpio_set_multiple; @@ -367,14 +568,51 @@ static int xgpio_probe(struct platform_device *pdev) xgpio_save_regs(chip); + chip->irq = platform_get_irq_optional(pdev, 0); + if (chip->irq <= 0) + goto skip_irq; + + chip->irqchip.name = "gpio-xilinx"; + chip->irqchip.irq_ack = xgpio_irq_ack; + chip->irqchip.irq_mask = xgpio_irq_mask; + chip->irqchip.irq_unmask = xgpio_irq_unmask; + chip->irqchip.irq_set_type = xgpio_set_irq_type; + + /* Disable per-channel interrupts */ + xgpio_writereg(chip->regs + XGPIO_IPIER_OFFSET, 0); + /* Clear any existing per-channel interrupts */ + temp = xgpio_readreg(chip->regs + XGPIO_IPISR_OFFSET); + xgpio_writereg(chip->regs + XGPIO_IPISR_OFFSET, temp); + /* Enable global interrupts */ + xgpio_writereg(chip->regs + XGPIO_GIER_OFFSET, XGPIO_GIER_IE); + + girq = &chip->gc.irq; + girq->chip = &chip->irqchip; + girq->parent_handler = xgpio_irqhandler; + girq->num_parents = 1; + girq->parents = devm_kcalloc(&pdev->dev, 1, + sizeof(*girq->parents), + GFP_KERNEL); + if (!girq->parents) { + status = -ENOMEM; + goto err_unprepare_clk; + } + girq->parents[0] = chip->irq; + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_bad_irq; + +skip_irq: status = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip); if (status) { dev_err(&pdev->dev, "failed to add GPIO chip\n"); - clk_disable_unprepare(chip->clk); - return status; + goto err_unprepare_clk; } return 0; + +err_unprepare_clk: + clk_disable_unprepare(chip->clk); + return status; } static const struct of_device_id xgpio_of_match[] = { |