@@ -690,6 +690,9 @@ config GPIO_XGENE_SB
config GPIO_XILINX
tristate "Xilinx GPIO support"
+ select GPIOLIB_IRQCHIP
+ select IRQ_DOMAIN_HIERARCHY
+ depends on OF_GPIO
help
Say yes here to support the Xilinx FPGA GPIO device
@@ -10,9 +10,12 @@
#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_gpio.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
@@ -22,6 +25,11 @@
#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 +44,14 @@
* @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
+ * @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 +59,13 @@ 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;
+ u32 irq_enable[2];
+ u32 irq_rising_edge[2];
+ u32 irq_falling_edge[2];
struct clk *clk;
};
@@ -277,6 +295,183 @@ 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;
+}
+
+static struct irq_chip xgpio_irqchip = {
+ .name = "gpio-xilinx",
+ .irq_ack = xgpio_irq_ack,
+ .irq_mask = xgpio_irq_mask,
+ .irq_unmask = xgpio_irq_unmask,
+ .irq_set_type = xgpio_set_irq_type,
+};
+
+/**
+ * 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 +484,10 @@ 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 +503,10 @@ 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");
+
/*
* Check device node and parent device node for device width
* and assume default width of 32
@@ -343,6 +545,7 @@ 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 +570,45 @@ 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;
+
+ /* 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 = &xgpio_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[] = {