diff options
Diffstat (limited to 'arch/arm/plat-orion/gpio.c')
-rw-r--r-- | arch/arm/plat-orion/gpio.c | 616 |
1 files changed, 616 insertions, 0 deletions
diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c new file mode 100644 index 0000000000..595e9cb33c --- /dev/null +++ b/arch/arm/plat-orion/gpio.c @@ -0,0 +1,616 @@ +/* + * 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/driver.h> +#include <linux/gpio/consumer.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 = gpiochip_get_data(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 = gpiochip_get_data(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 = gpiochip_get_data(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 = gpiochip_get_data(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 = gpiochip_get_data(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 = gpiochip_get_data(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); + gpiod_set_raw_value(desc, 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(struct irq_desc *desc) +{ + struct orion_gpio_chip *ochip = irq_desc_get_handler_data(desc); + 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 = gpiochip_get_data(chip); + u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk; + const char *label; + 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_each_requested_gpio(chip, i, label) { + u32 msk; + bool is_out; + + 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_puts(s, " disabled\n"); + continue; + } + if (edg_msk & msk) + seq_puts(s, " edge "); + if (lvl_msk & msk) + seq_puts(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(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; + 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_data(&ochip->chip, ochip); + + /* + * 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_chained_handler_and_data(irqs[i], + gpio_irq_handler, + 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 = 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(NULL, + 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++; +} |