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-rw-r--r--arch/arm/plat-orion/gpio.c628
1 files changed, 628 insertions, 0 deletions
diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c
new file mode 100644
index 000000000..5168a52a1
--- /dev/null
+++ b/arch/arm/plat-orion/gpio.c
@@ -0,0 +1,628 @@
+/*
+ * 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.
+ */
+
+#define DEBUG
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/leds.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <plat/orion-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;
+ struct irq_domain *domain;
+};
+
+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;
+}
+
+/*
+ * 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 irq_create_mapping(ochip->domain,
+ 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 & 31, 0);
+ __set_blinking(ochip, pin & 31, blink);
+ spin_unlock_irqrestore(&ochip->lock, flags);
+}
+EXPORT_SYMBOL(orion_gpio_set_blink);
+
+#define ORION_BLINK_HALF_PERIOD 100 /* ms */
+
+int orion_gpio_led_blink_set(struct gpio_desc *desc, int state,
+ unsigned long *delay_on, unsigned long *delay_off)
+{
+ unsigned gpio = desc_to_gpio(desc);
+
+ if (delay_on && delay_off && !*delay_on && !*delay_off)
+ *delay_on = *delay_off = ORION_BLINK_HALF_PERIOD;
+
+ switch (state) {
+ case GPIO_LED_NO_BLINK_LOW:
+ case GPIO_LED_NO_BLINK_HIGH:
+ orion_gpio_set_blink(gpio, 0);
+ gpio_set_value(gpio, state);
+ break;
+ case GPIO_LED_BLINK:
+ orion_gpio_set_blink(gpio, 1);
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(orion_gpio_led_blink_set);
+
+
+/*****************************************************************************
+ * 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->hwirq - ochip->secondary_irq_base;
+
+ u = readl(GPIO_IO_CONF(ochip)) & (1 << pin);
+ if (!u) {
+ 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;
+}
+
+static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
+{
+ struct orion_gpio_chip *ochip = irq_get_handler_data(irq);
+ u32 cause, type;
+ int i;
+
+ 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 = irq_get_trigger_type(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);
+ }
+}
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/seq_file.h>
+
+static void orion_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
+{
+ struct orion_gpio_chip *ochip =
+ container_of(chip, struct orion_gpio_chip, chip);
+ u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
+ int i;
+
+ out = readl_relaxed(GPIO_OUT(ochip));
+ io_conf = readl_relaxed(GPIO_IO_CONF(ochip));
+ blink = readl_relaxed(GPIO_BLINK_EN(ochip));
+ in_pol = readl_relaxed(GPIO_IN_POL(ochip));
+ data_in = readl_relaxed(GPIO_DATA_IN(ochip));
+ cause = readl_relaxed(GPIO_EDGE_CAUSE(ochip));
+ edg_msk = readl_relaxed(GPIO_EDGE_MASK(ochip));
+ lvl_msk = readl_relaxed(GPIO_LEVEL_MASK(ochip));
+
+ for (i = 0; i < chip->ngpio; i++) {
+ const char *label;
+ u32 msk;
+ bool is_out;
+
+ label = gpiochip_is_requested(chip, i);
+ if (!label)
+ continue;
+
+ msk = 1 << i;
+ is_out = !(io_conf & msk);
+
+ seq_printf(s, " gpio-%-3d (%-20.20s)", chip->base + i, label);
+
+ if (is_out) {
+ seq_printf(s, " out %s %s\n",
+ out & msk ? "hi" : "lo",
+ blink & msk ? "(blink )" : "");
+ continue;
+ }
+
+ seq_printf(s, " in %s (act %s) - IRQ",
+ (data_in ^ in_pol) & msk ? "hi" : "lo",
+ in_pol & msk ? "lo" : "hi");
+ if (!((edg_msk | lvl_msk) & msk)) {
+ seq_printf(s, " disabled\n");
+ continue;
+ }
+ if (edg_msk & msk)
+ seq_printf(s, " edge ");
+ if (lvl_msk & msk)
+ seq_printf(s, " level");
+ seq_printf(s, " (%s)\n", cause & msk ? "pending" : "clear ");
+ }
+}
+#else
+#define orion_gpio_dbg_show NULL
+#endif
+
+static void orion_gpio_unmask_irq(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct irq_chip_type *ct = irq_data_get_chip_type(d);
+ u32 reg_val;
+ u32 mask = d->mask;
+
+ irq_gc_lock(gc);
+ reg_val = irq_reg_readl(gc, ct->regs.mask);
+ reg_val |= mask;
+ irq_reg_writel(gc, reg_val, ct->regs.mask);
+ irq_gc_unlock(gc);
+}
+
+static void orion_gpio_mask_irq(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct irq_chip_type *ct = irq_data_get_chip_type(d);
+ u32 mask = d->mask;
+ u32 reg_val;
+
+ irq_gc_lock(gc);
+ reg_val = irq_reg_readl(gc, ct->regs.mask);
+ reg_val &= ~mask;
+ irq_reg_writel(gc, reg_val, ct->regs.mask);
+ irq_gc_unlock(gc);
+}
+
+void __init orion_gpio_init(struct device_node *np,
+ int gpio_base, int ngpio,
+ void __iomem *base, int mask_offset,
+ int secondary_irq_base,
+ int irqs[4])
+{
+ struct orion_gpio_chip *ochip;
+ struct irq_chip_generic *gc;
+ struct irq_chip_type *ct;
+ char gc_label[16];
+ int i;
+
+ if (orion_gpio_chip_count == ARRAY_SIZE(orion_gpio_chips))
+ return;
+
+ snprintf(gc_label, sizeof(gc_label), "orion_gpio%d",
+ orion_gpio_chip_count);
+
+ ochip = orion_gpio_chips + orion_gpio_chip_count;
+ ochip->chip.label = kstrdup(gc_label, GFP_KERNEL);
+ 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;
+#ifdef CONFIG_OF
+ ochip->chip.of_node = np;
+#endif
+ ochip->chip.dbg_show = orion_gpio_dbg_show;
+
+ 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);
+
+ /*
+ * Mask and clear GPIO interrupts.
+ */
+ writel(0, GPIO_EDGE_CAUSE(ochip));
+ writel(0, GPIO_EDGE_MASK(ochip));
+ writel(0, GPIO_LEVEL_MASK(ochip));
+
+ /* Setup the interrupt handlers. Each chip can have up to 4
+ * interrupt handlers, with each handler dealing with 8 GPIO
+ * pins. */
+
+ for (i = 0; i < 4; i++) {
+ if (irqs[i]) {
+ irq_set_handler_data(irqs[i], ochip);
+ irq_set_chained_handler(irqs[i], gpio_irq_handler);
+ }
+ }
+
+ 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 = orion_gpio_mask_irq;
+ ct->chip.irq_unmask = orion_gpio_unmask_irq;
+ ct->chip.irq_set_type = gpio_irq_set_type;
+ ct->chip.name = ochip->chip.label;
+
+ 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 = orion_gpio_mask_irq;
+ ct->chip.irq_unmask = orion_gpio_unmask_irq;
+ ct->chip.irq_set_type = gpio_irq_set_type;
+ ct->handler = handle_edge_irq;
+ ct->chip.name = ochip->chip.label;
+
+ irq_setup_generic_chip(gc, IRQ_MSK(ngpio), IRQ_GC_INIT_MASK_CACHE,
+ IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
+
+ /* Setup irq domain on top of the generic chip. */
+ ochip->domain = irq_domain_add_legacy(np,
+ ochip->chip.ngpio,
+ ochip->secondary_irq_base,
+ ochip->secondary_irq_base,
+ &irq_domain_simple_ops,
+ ochip);
+ if (!ochip->domain)
+ panic("%s: couldn't allocate irq domain (DT).\n",
+ ochip->chip.label);
+
+ orion_gpio_chip_count++;
+}