initial_commit

1 files changed, 477 insertions, 0 deletions

diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c
new file mode 100644
index 00000000..41ab97eb
--- /dev/null
+++ b/arch/arm/plat-orion/gpio.c
@@ -0,0 +1,477 @@
+/*
+ * arch/arm/plat-orion/gpio.c
+ *
+ * Marvell Orion SoC GPIO handling.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+
+/*
+ * GPIO unit register offsets.
+ */
+#define GPIO_OUT_OFF		0x0000
+#define GPIO_IO_CONF_OFF	0x0004
+#define GPIO_BLINK_EN_OFF	0x0008
+#define GPIO_IN_POL_OFF		0x000c
+#define GPIO_DATA_IN_OFF	0x0010
+#define GPIO_EDGE_CAUSE_OFF	0x0014
+#define GPIO_EDGE_MASK_OFF	0x0018
+#define GPIO_LEVEL_MASK_OFF	0x001c
+
+struct orion_gpio_chip {
+	struct gpio_chip	chip;
+	spinlock_t		lock;
+	void __iomem		*base;
+	unsigned long		valid_input;
+	unsigned long		valid_output;
+	int			mask_offset;
+	int			secondary_irq_base;
+};
+
+static void __iomem *GPIO_OUT(struct orion_gpio_chip *ochip)
+{
+	return ochip->base + GPIO_OUT_OFF;
+}
+
+static void __iomem *GPIO_IO_CONF(struct orion_gpio_chip *ochip)
+{
+	return ochip->base + GPIO_IO_CONF_OFF;
+}
+
+static void __iomem *GPIO_BLINK_EN(struct orion_gpio_chip *ochip)
+{
+	return ochip->base + GPIO_BLINK_EN_OFF;
+}
+
+static void __iomem *GPIO_IN_POL(struct orion_gpio_chip *ochip)
+{
+	return ochip->base + GPIO_IN_POL_OFF;
+}
+
+static void __iomem *GPIO_DATA_IN(struct orion_gpio_chip *ochip)
+{
+	return ochip->base + GPIO_DATA_IN_OFF;
+}
+
+static void __iomem *GPIO_EDGE_CAUSE(struct orion_gpio_chip *ochip)
+{
+	return ochip->base + GPIO_EDGE_CAUSE_OFF;
+}
+
+static void __iomem *GPIO_EDGE_MASK(struct orion_gpio_chip *ochip)
+{
+	return ochip->base + ochip->mask_offset + GPIO_EDGE_MASK_OFF;
+}
+
+static void __iomem *GPIO_LEVEL_MASK(struct orion_gpio_chip *ochip)
+{
+	return ochip->base + ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
+}
+
+
+static struct orion_gpio_chip orion_gpio_chips[2];
+static int orion_gpio_chip_count;
+
+static inline void
+__set_direction(struct orion_gpio_chip *ochip, unsigned pin, int input)
+{
+	u32 u;
+
+	u = readl(GPIO_IO_CONF(ochip));
+	if (input)
+		u |= 1 << pin;
+	else
+		u &= ~(1 << pin);
+	writel(u, GPIO_IO_CONF(ochip));
+}
+
+static void __set_level(struct orion_gpio_chip *ochip, unsigned pin, int high)
+{
+	u32 u;
+
+	u = readl(GPIO_OUT(ochip));
+	if (high)
+		u |= 1 << pin;
+	else
+		u &= ~(1 << pin);
+	writel(u, GPIO_OUT(ochip));
+}
+
+static inline void
+__set_blinking(struct orion_gpio_chip *ochip, unsigned pin, int blink)
+{
+	u32 u;
+
+	u = readl(GPIO_BLINK_EN(ochip));
+	if (blink)
+		u |= 1 << pin;
+	else
+		u &= ~(1 << pin);
+	writel(u, GPIO_BLINK_EN(ochip));
+}
+
+static inline int
+orion_gpio_is_valid(struct orion_gpio_chip *ochip, unsigned pin, int mode)
+{
+	if (pin >= ochip->chip.ngpio)
+		goto err_out;
+
+	if ((mode & GPIO_INPUT_OK) && !test_bit(pin, &ochip->valid_input))
+		goto err_out;
+
+	if ((mode & GPIO_OUTPUT_OK) && !test_bit(pin, &ochip->valid_output))
+		goto err_out;
+
+	return 1;
+
+err_out:
+	pr_debug("%s: invalid GPIO %d\n", __func__, pin);
+	return false;
+}
+
+/*
+ * GENERIC_GPIO primitives.
+ */
+static int orion_gpio_request(struct gpio_chip *chip, unsigned pin)
+{
+	struct orion_gpio_chip *ochip =
+		container_of(chip, struct orion_gpio_chip, chip);
+
+	if (orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK) ||
+	    orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
+		return 0;
+
+	return -EINVAL;
+}
+
+static int orion_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
+{
+	struct orion_gpio_chip *ochip =
+		container_of(chip, struct orion_gpio_chip, chip);
+	unsigned long flags;
+
+	if (!orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK))
+		return -EINVAL;
+
+	spin_lock_irqsave(&ochip->lock, flags);
+	__set_direction(ochip, pin, 1);
+	spin_unlock_irqrestore(&ochip->lock, flags);
+
+	return 0;
+}
+
+static int orion_gpio_get(struct gpio_chip *chip, unsigned pin)
+{
+	struct orion_gpio_chip *ochip =
+		container_of(chip, struct orion_gpio_chip, chip);
+	int val;
+
+	if (readl(GPIO_IO_CONF(ochip)) & (1 << pin)) {
+		val = readl(GPIO_DATA_IN(ochip)) ^ readl(GPIO_IN_POL(ochip));
+	} else {
+		val = readl(GPIO_OUT(ochip));
+	}
+
+	return (val >> pin) & 1;
+}
+
+static int
+orion_gpio_direction_output(struct gpio_chip *chip, unsigned pin, int value)
+{
+	struct orion_gpio_chip *ochip =
+		container_of(chip, struct orion_gpio_chip, chip);
+	unsigned long flags;
+
+	if (!orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
+		return -EINVAL;
+
+	spin_lock_irqsave(&ochip->lock, flags);
+	__set_blinking(ochip, pin, 0);
+	__set_level(ochip, pin, value);
+	__set_direction(ochip, pin, 0);
+	spin_unlock_irqrestore(&ochip->lock, flags);
+
+	return 0;
+}
+
+static void orion_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
+{
+	struct orion_gpio_chip *ochip =
+		container_of(chip, struct orion_gpio_chip, chip);
+	unsigned long flags;
+
+	spin_lock_irqsave(&ochip->lock, flags);
+	__set_level(ochip, pin, value);
+	spin_unlock_irqrestore(&ochip->lock, flags);
+}
+
+static int orion_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
+{
+	struct orion_gpio_chip *ochip =
+		container_of(chip, struct orion_gpio_chip, chip);
+
+	return ochip->secondary_irq_base + pin;
+}
+
+
+/*
+ * Orion-specific GPIO API extensions.
+ */
+static struct orion_gpio_chip *orion_gpio_chip_find(int pin)
+{
+	int i;
+
+	for (i = 0; i < orion_gpio_chip_count; i++) {
+		struct orion_gpio_chip *ochip = orion_gpio_chips + i;
+		struct gpio_chip *chip = &ochip->chip;
+
+		if (pin >= chip->base && pin < chip->base + chip->ngpio)
+			return ochip;
+	}
+
+	return NULL;
+}
+
+void __init orion_gpio_set_unused(unsigned pin)
+{
+	struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
+
+	if (ochip == NULL)
+		return;
+
+	pin -= ochip->chip.base;
+
+	/* Configure as output, drive low. */
+	__set_level(ochip, pin, 0);
+	__set_direction(ochip, pin, 0);
+}
+
+void __init orion_gpio_set_valid(unsigned pin, int mode)
+{
+	struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
+
+	if (ochip == NULL)
+		return;
+
+	pin -= ochip->chip.base;
+
+	if (mode == 1)
+		mode = GPIO_INPUT_OK | GPIO_OUTPUT_OK;
+
+	if (mode & GPIO_INPUT_OK)
+		__set_bit(pin, &ochip->valid_input);
+	else
+		__clear_bit(pin, &ochip->valid_input);
+
+	if (mode & GPIO_OUTPUT_OK)
+		__set_bit(pin, &ochip->valid_output);
+	else
+		__clear_bit(pin, &ochip->valid_output);
+}
+
+void orion_gpio_set_blink(unsigned pin, int blink)
+{
+	struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
+	unsigned long flags;
+
+	if (ochip == NULL)
+		return;
+
+	spin_lock_irqsave(&ochip->lock, flags);
+	__set_level(ochip, pin, 0);
+	__set_blinking(ochip, pin, blink);
+	spin_unlock_irqrestore(&ochip->lock, flags);
+}
+EXPORT_SYMBOL(orion_gpio_set_blink);
+
+
+/*****************************************************************************
+ * Orion GPIO IRQ
+ *
+ * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
+ * value of the line or the opposite value.
+ *
+ * Level IRQ handlers: DATA_IN is used directly as cause register.
+ *                     Interrupt are masked by LEVEL_MASK registers.
+ * Edge IRQ handlers:  Change in DATA_IN are latched in EDGE_CAUSE.
+ *                     Interrupt are masked by EDGE_MASK registers.
+ * Both-edge handlers: Similar to regular Edge handlers, but also swaps
+ *                     the polarity to catch the next line transaction.
+ *                     This is a race condition that might not perfectly
+ *                     work on some use cases.
+ *
+ * Every eight GPIO lines are grouped (OR'ed) before going up to main
+ * cause register.
+ *
+ *                    EDGE  cause    mask
+ *        data-in   /--------| |-----| |----\
+ *     -----| |-----                         ---- to main cause reg
+ *           X      \----------------| |----/
+ *        polarity    LEVEL          mask
+ *
+ ****************************************************************************/
+
+static int gpio_irq_set_type(struct irq_data *d, u32 type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct irq_chip_type *ct = irq_data_get_chip_type(d);
+	struct orion_gpio_chip *ochip = gc->private;
+	int pin;
+	u32 u;
+
+	pin = d->irq - gc->irq_base;
+
+	u = readl(GPIO_IO_CONF(ochip)) & (1 << pin);
+	if (!u) {
+		printk(KERN_ERR "orion gpio_irq_set_type failed "
+				"(irq %d, pin %d).\n", d->irq, pin);
+		return -EINVAL;
+	}
+
+	type &= IRQ_TYPE_SENSE_MASK;
+	if (type == IRQ_TYPE_NONE)
+		return -EINVAL;
+
+	/* Check if we need to change chip and handler */
+	if (!(ct->type & type))
+		if (irq_setup_alt_chip(d, type))
+			return -EINVAL;
+
+	/*
+	 * Configure interrupt polarity.
+	 */
+	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
+		u = readl(GPIO_IN_POL(ochip));
+		u &= ~(1 << pin);
+		writel(u, GPIO_IN_POL(ochip));
+	} else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
+		u = readl(GPIO_IN_POL(ochip));
+		u |= 1 << pin;
+		writel(u, GPIO_IN_POL(ochip));
+	} else if (type == IRQ_TYPE_EDGE_BOTH) {
+		u32 v;
+
+		v = readl(GPIO_IN_POL(ochip)) ^ readl(GPIO_DATA_IN(ochip));
+
+		/*
+		 * set initial polarity based on current input level
+		 */
+		u = readl(GPIO_IN_POL(ochip));
+		if (v & (1 << pin))
+			u |= 1 << pin;		/* falling */
+		else
+			u &= ~(1 << pin);	/* rising */
+		writel(u, GPIO_IN_POL(ochip));
+	}
+
+	return 0;
+}
+
+void __init orion_gpio_init(int gpio_base, int ngpio,
+			    u32 base, int mask_offset, int secondary_irq_base)
+{
+	struct orion_gpio_chip *ochip;
+	struct irq_chip_generic *gc;
+	struct irq_chip_type *ct;
+
+	if (orion_gpio_chip_count == ARRAY_SIZE(orion_gpio_chips))
+		return;
+
+	ochip = orion_gpio_chips + orion_gpio_chip_count;
+	ochip->chip.label = "orion_gpio";
+	ochip->chip.request = orion_gpio_request;
+	ochip->chip.direction_input = orion_gpio_direction_input;
+	ochip->chip.get = orion_gpio_get;
+	ochip->chip.direction_output = orion_gpio_direction_output;
+	ochip->chip.set = orion_gpio_set;
+	ochip->chip.to_irq = orion_gpio_to_irq;
+	ochip->chip.base = gpio_base;
+	ochip->chip.ngpio = ngpio;
+	ochip->chip.can_sleep = 0;
+	spin_lock_init(&ochip->lock);
+	ochip->base = (void __iomem *)base;
+	ochip->valid_input = 0;
+	ochip->valid_output = 0;
+	ochip->mask_offset = mask_offset;
+	ochip->secondary_irq_base = secondary_irq_base;
+
+	gpiochip_add(&ochip->chip);
+
+	orion_gpio_chip_count++;
+
+	/*
+	 * Mask and clear GPIO interrupts.
+	 */
+	writel(0, GPIO_EDGE_CAUSE(ochip));
+	writel(0, GPIO_EDGE_MASK(ochip));
+	writel(0, GPIO_LEVEL_MASK(ochip));
+
+	gc = irq_alloc_generic_chip("orion_gpio_irq", 2, secondary_irq_base,
+				    ochip->base, handle_level_irq);
+	gc->private = ochip;
+
+	ct = gc->chip_types;
+	ct->regs.mask = ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
+	ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
+	ct->chip.irq_mask = irq_gc_mask_clr_bit;
+	ct->chip.irq_unmask = irq_gc_mask_set_bit;
+	ct->chip.irq_set_type = gpio_irq_set_type;
+
+	ct++;
+	ct->regs.mask = ochip->mask_offset + GPIO_EDGE_MASK_OFF;
+	ct->regs.ack = GPIO_EDGE_CAUSE_OFF;
+	ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
+	ct->chip.irq_ack = irq_gc_ack_clr_bit;
+	ct->chip.irq_mask = irq_gc_mask_clr_bit;
+	ct->chip.irq_unmask = irq_gc_mask_set_bit;
+	ct->chip.irq_set_type = gpio_irq_set_type;
+	ct->handler = handle_edge_irq;
+
+	irq_setup_generic_chip(gc, IRQ_MSK(ngpio), IRQ_GC_INIT_MASK_CACHE,
+			       IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
+}
+
+void orion_gpio_irq_handler(int pinoff)
+{
+	struct orion_gpio_chip *ochip;
+	u32 cause, type;
+	int i;
+
+	ochip = orion_gpio_chip_find(pinoff);
+	if (ochip == NULL)
+		return;
+
+	cause = readl(GPIO_DATA_IN(ochip)) & readl(GPIO_LEVEL_MASK(ochip));
+	cause |= readl(GPIO_EDGE_CAUSE(ochip)) & readl(GPIO_EDGE_MASK(ochip));
+
+	for (i = 0; i < ochip->chip.ngpio; i++) {
+		int irq;
+
+		irq = ochip->secondary_irq_base + i;
+
+		if (!(cause & (1 << i)))
+			continue;
+
+		type = irqd_get_trigger_type(irq_get_irq_data(irq));
+		if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
+			/* Swap polarity (race with GPIO line) */
+			u32 polarity;
+
+			polarity = readl(GPIO_IN_POL(ochip));
+			polarity ^= 1 << i;
+			writel(polarity, GPIO_IN_POL(ochip));
+		}
+		generic_handle_irq(irq);
+	}
+}