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    Subject[PATCH v4 01/10] irqchip: Add driver for Loongson I/O Local Interrupt Controller
    Date
    This controller appeared on Loongson family of chips as the primary
    package interrupt source.

    Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
    ---
    drivers/irqchip/Kconfig | 9 +
    drivers/irqchip/Makefile | 1 +
    drivers/irqchip/irq-loongson-liointc.c | 338 +++++++++++++++++++++++++
    3 files changed, 348 insertions(+)
    create mode 100644 drivers/irqchip/irq-loongson-liointc.c

    diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
    index 6d397732138d..c609eaa319d2 100644
    --- a/drivers/irqchip/Kconfig
    +++ b/drivers/irqchip/Kconfig
    @@ -513,4 +513,13 @@ config EXYNOS_IRQ_COMBINER
    Say yes here to add support for the IRQ combiner devices embedded
    in Samsung Exynos chips.

    +config LOONGSON_LIOINTC
    + bool "Loongson Local I/O Interrupt Controller"
    + depends on MACH_LOONGSON64
    + default y
    + select IRQ_DOMAIN
    + select GENERIC_IRQ_CHIP
    + help
    + Support for the Loongson Local I/O Interrupt Controller.
    +
    endmenu
    diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
    index eae0d78cbf22..5e7678efdfe6 100644
    --- a/drivers/irqchip/Makefile
    +++ b/drivers/irqchip/Makefile
    @@ -105,3 +105,4 @@ obj-$(CONFIG_MADERA_IRQ) += irq-madera.o
    obj-$(CONFIG_LS1X_IRQ) += irq-ls1x.o
    obj-$(CONFIG_TI_SCI_INTR_IRQCHIP) += irq-ti-sci-intr.o
    obj-$(CONFIG_TI_SCI_INTA_IRQCHIP) += irq-ti-sci-inta.o
    +obj-$(CONFIG_LOONGSON_LIOINTC) += irq-loongson-liointc.o
    diff --git a/drivers/irqchip/irq-loongson-liointc.c b/drivers/irqchip/irq-loongson-liointc.c
    new file mode 100644
    index 000000000000..d7efab9f4ee7
    --- /dev/null
    +++ b/drivers/irqchip/irq-loongson-liointc.c
    @@ -0,0 +1,338 @@
    +// SPDX-License-Identifier: GPL-2.0
    +/*
    + * Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
    + * Loongson Local IO Interrupt Controller support
    + */
    +
    +#include <linux/errno.h>
    +#include <linux/init.h>
    +#include <linux/types.h>
    +#include <linux/interrupt.h>
    +#include <linux/ioport.h>
    +#include <linux/irqchip.h>
    +#include <linux/of_address.h>
    +#include <linux/of_irq.h>
    +#include <linux/io.h>
    +#include <linux/smp.h>
    +#include <linux/irqchip/chained_irq.h>
    +
    +#include <boot_param.h>
    +
    +#define LIOINTC_CHIP_IRQ 32
    +#define LIOINTC_NUM_PARENT 4
    +
    +#define LIOINTC_REG_INTx_MAP(x) (x * 0x1)
    +#define LIOINTC_INTC_CHIP_START 0x20
    +
    +#define LIOINTC_REG_INTC_STATUS (LIOINTC_INTC_CHIP_START + 0x20)
    +#define LIOINTC_REG_INTC_EN_STATUS (LIOINTC_INTC_CHIP_START + 0x04)
    +#define LIOINTC_REG_INTC_ENABLE (LIOINTC_INTC_CHIP_START + 0x08)
    +#define LIOINTC_REG_INTC_DISABLE (LIOINTC_INTC_CHIP_START + 0x0c)
    +#define LIOINTC_REG_INTC_POL (LIOINTC_INTC_CHIP_START + 0x10)
    +#define LIOINTC_REG_INTC_EDGE (LIOINTC_INTC_CHIP_START + 0x14)
    +
    +#define BUGGY_LPC_IRQ 10
    +
    +#define LIOINTC_SHIFT_INTx 4
    +
    +struct liointc_handler_data {
    + struct liointc_priv *priv;
    + u32 parent_int_map;
    +};
    +
    +struct liointc_priv {
    + void __iomem *base;
    + struct irq_chip_generic *gc;
    + u8 map_cache[LIOINTC_CHIP_IRQ];
    + struct liointc_handler_data handler[LIOINTC_NUM_PARENT];
    + u8 possible_parent_mask;
    + bool have_lpc_irq_bug;
    +};
    +
    +static void liointc_chained_handle_irq(struct irq_desc *desc)
    +{
    + struct liointc_handler_data *handler = irq_desc_get_handler_data(desc);
    + struct irq_chip *chip = irq_desc_get_chip(desc);
    + struct irq_chip_generic *gc = handler->priv->gc;
    + u32 pending;
    +
    + chained_irq_enter(chip, desc);
    +
    + pending = readl(gc->reg_base + LIOINTC_REG_INTC_STATUS);
    +
    + if (!pending) {
    + /* Always blame LPC IRQ if we have that Bug with LPC interrupt enabled */
    + if (handler->priv->have_lpc_irq_bug &&
    + (handler->parent_int_map & ~gc->mask_cache & BIT(BUGGY_LPC_IRQ)))
    + generic_handle_irq(irq_find_mapping(gc->domain, BUGGY_LPC_IRQ));
    + else
    + spurious_interrupt();
    + }
    +
    + while (pending) {
    + int bit = __ffs(pending);
    +
    + generic_handle_irq(irq_find_mapping(gc->domain, bit));
    + pending &= ~BIT(bit);
    + }
    +
    + chained_irq_exit(chip, desc);
    +}
    +
    +static void map_cache_set_core(struct liointc_priv *priv, int irq, int core)
    +{
    + priv->map_cache[irq] &= ~GENMASK(3, 0);
    + priv->map_cache[irq] |= BIT(core);
    +}
    +
    +static void write_map_cache(struct liointc_priv *priv, int irq)
    +{
    + writeb(priv->map_cache[irq],
    + priv->base + LIOINTC_REG_INTx_MAP(irq));
    +}
    +
    +static void liointc_set_bit(struct irq_chip_generic *gc,
    + unsigned int offset,
    + u32 mask, bool set)
    +{
    + if (set)
    + writel(readl(gc->reg_base + offset) | mask,
    + gc->reg_base + offset);
    + else
    + writel(readl(gc->reg_base + offset) & ~mask,
    + gc->reg_base + offset);
    +}
    +
    +static int liointc_set_type(struct irq_data *data, unsigned int type)
    +{
    + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
    + u32 mask = data->mask;
    + unsigned long flags;
    +
    + irq_gc_lock_irqsave(gc, flags);
    + switch (type) {
    + case IRQ_TYPE_LEVEL_HIGH:
    + liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, false);
    + liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, true);
    + break;
    + case IRQ_TYPE_LEVEL_LOW:
    + liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, false);
    + liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, false);
    + break;
    + case IRQ_TYPE_EDGE_RISING:
    + liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, true);
    + liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, true);
    + break;
    + case IRQ_TYPE_EDGE_FALLING:
    + liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, true);
    + liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, false);
    + break;
    + default:
    + return -EINVAL;
    + }
    + irq_gc_unlock_irqrestore(gc, flags);
    +
    + irqd_set_trigger_type(data, type);
    + return 0;
    +}
    +
    +static int liointc_set_affinity(struct irq_data *idata,
    + const cpumask_t *cpu_mask, bool force)
    +{
    + return -ENAVAIL;
    +}
    +
    +static void liointc_resume(struct irq_chip_generic *gc)
    +{
    + struct liointc_priv *priv = gc->private;
    + unsigned long flags;
    + int i;
    +
    + irq_gc_lock_irqsave(gc, flags);
    + /* Revert map cache */
    + for (i = 0; i < LIOINTC_CHIP_IRQ; i++)
    + write_map_cache(priv, i);
    +
    + /* Revert mask cache again */
    + writel(gc->mask_cache, gc->reg_base + LIOINTC_REG_INTC_DISABLE);
    + writel(~gc->mask_cache, gc->reg_base + LIOINTC_REG_INTC_ENABLE);
    + irq_gc_unlock_irqrestore(gc, flags);
    +}
    +
    +static void validate_parent_mask(struct liointc_priv *priv, u32 of_parent_int_map[])
    +{
    + u32 proceed_mask = 0x0, duplicated_mask = 0x0;
    + int i;
    + int fallback_parent = __ffs(priv->possible_parent_mask);
    +
    + for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
    + /* Try if the parent is avilable */
    + if (!(priv->possible_parent_mask & BIT(i)))
    + continue;
    +
    + priv->handler[i].parent_int_map = of_parent_int_map[i];
    +
    + /* Detect if the IRQ have previously proceed */
    + duplicated_mask |= (priv->handler[i].parent_int_map & proceed_mask);
    + proceed_mask |= priv->handler[i].parent_int_map;
    + }
    +
    + /* Fallback IRQs with no map bit set */
    + while (~proceed_mask) {
    + int bit = __ffs(~proceed_mask);
    +
    + pr_warn("loongson-liointc: Found homeless IRQ %d, map to INT%d\n",
    + bit, fallback_parent);
    + priv->handler[fallback_parent].parent_int_map |= BIT(bit);
    + proceed_mask |= BIT(bit);
    + }
    +
    + /* Fallback IRQs with multiple map bit set */
    + while (duplicated_mask) {
    + int bit = __ffs(duplicated_mask);
    +
    + pr_warn("loongson-liointc: IRQ %d have multiple parents, map to INT%d\n",
    + bit, fallback_parent);
    + /* Clear the bit in all parent bits */
    + for (i = 0; i < LIOINTC_NUM_PARENT; i++)
    + priv->handler[i].parent_int_map &= ~BIT(bit);
    +
    + priv->handler[fallback_parent].parent_int_map |= BIT(bit);
    + duplicated_mask &= ~BIT(bit);
    + }
    +
    + /* Generate parent INT part of map Cache */
    + for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
    + u32 pending = priv->handler[i].parent_int_map;
    +
    + while (pending) {
    + int bit = __ffs(pending);
    +
    + priv->map_cache[bit] = BIT(i) << LIOINTC_SHIFT_INTx;
    + pending &= ~BIT(bit);
    + }
    + }
    +}
    +
    +static const char *parent_names[] = {"int0", "int1", "int2", "int3"};
    +
    +int __init liointc_of_init(struct device_node *node,
    + struct device_node *parent)
    +{
    + struct irq_chip_generic *gc;
    + struct irq_domain *domain;
    + struct irq_chip_type *ct;
    + struct liointc_priv *priv;
    + u32 of_parent_int_map[LIOINTC_NUM_PARENT];
    + int parent_irq[LIOINTC_NUM_PARENT];
    + int core = loongson_sysconf.boot_cpu_id;
    + int i, err = 0;
    + int sz;
    +
    + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
    + if (!priv)
    + return -ENOMEM;
    +
    + priv->base = of_iomap(node, 0);
    + if (!priv->base) {
    + err = -ENODEV;
    + goto out_free_priv;
    + }
    +
    + if (of_device_is_compatible(node, "loongson,liointc-1.0"))
    + priv->have_lpc_irq_bug = true;
    +
    + for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
    + parent_irq[i] = of_irq_get_byname(node, parent_names[i]);
    + if (parent_irq[i] >= 0)
    + priv->possible_parent_mask |= BIT(i);
    + }
    +
    +
    + if (!priv->possible_parent_mask) {
    + pr_err("loongson-liointc: No parent\n");
    + err = -ENOMEM;
    + goto out_iounmap;
    + }
    +
    + sz = of_property_read_variable_u32_array(node, "loongson,parent_int_map",
    + &of_parent_int_map[0], LIOINTC_NUM_PARENT,
    + LIOINTC_NUM_PARENT);
    + if (sz < 4) {
    + pr_err("loongson-liointc: No parent_int_map\n");
    + err = -ENODEV;
    + goto out_iounmap;
    + }
    +
    + /* Setup IRQ domain */
    + domain = irq_domain_add_linear(node, 32,
    + &irq_generic_chip_ops, priv);
    + if (!domain) {
    + pr_err("loongson-liointc: cannot add IRQ domain\n");
    + err = -ENOMEM;
    + goto out_iounmap;
    + }
    +
    + err = irq_alloc_domain_generic_chips(domain, 32, 1,
    + node->full_name, handle_level_irq,
    + IRQ_NOPROBE, 0, 0);
    + if (err) {
    + pr_err("loongson-liointc: unable to register IRQ domain\n");
    + err = -ENOMEM;
    + goto out_free_domain;
    + }
    +
    +
    + /* Disable all IRQs */
    + writel(0xffffffff, priv->base + LIOINTC_REG_INTC_DISABLE);
    + /* Set to level triggered */
    + writel(0x0, priv->base + LIOINTC_REG_INTC_EDGE);
    +
    + validate_parent_mask(priv, &of_parent_int_map[0]);
    +
    + for (i = 0; i < LIOINTC_CHIP_IRQ; i++) {
    + map_cache_set_core(priv, i, core);
    + write_map_cache(priv, i);
    + }
    +
    + gc = irq_get_domain_generic_chip(domain, 0);
    + gc->private = priv;
    + gc->reg_base = priv->base;
    + gc->domain = domain;
    + gc->resume = liointc_resume;
    +
    + ct = gc->chip_types;
    + ct->regs.enable = LIOINTC_REG_INTC_ENABLE;
    + ct->regs.disable = LIOINTC_REG_INTC_DISABLE;
    + ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
    + ct->chip.irq_mask = irq_gc_mask_disable_reg;
    + ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
    + ct->chip.irq_set_type = liointc_set_type;
    + ct->chip.irq_set_affinity = liointc_set_affinity;
    +
    + gc->mask_cache = 0xffffffff;
    + priv->gc = gc;
    +
    + for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
    + if (parent_irq[i] < 0)
    + continue;
    +
    + priv->handler[i].priv = priv;
    + irq_set_chained_handler_and_data(parent_irq[i],
    + liointc_chained_handle_irq, &priv->handler[i]);
    + }
    +
    + return 0;
    +
    +out_free_domain:
    + irq_domain_remove(domain);
    +out_iounmap:
    + iounmap(priv->base);
    +out_free_priv:
    + kfree(priv);
    +
    + return err;
    +}
    +
    +IRQCHIP_DECLARE(loongson_liointc_1_0, "loongson,liointc-1.0", liointc_of_init);
    +IRQCHIP_DECLARE(loongson_liointc_1_0a, "loongson,liointc-1.0a", liointc_of_init);
    --
    2.25.0

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