--- /dev/null
+/*
+ * Copyright (c) 2015 Endless Mobile, Inc.
+ * Author: Carlo Caione <carlo@endlessm.com>
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Jerome Brunet <jbrunet@baylibre.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ * The full GNU General Public License is included in this distribution
+ * in the file called COPYING.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#define NUM_CHANNEL 8
+#define MAX_INPUT_MUX 256
+
+#define REG_EDGE_POL 0x00
+#define REG_PIN_03_SEL 0x04
+#define REG_PIN_47_SEL 0x08
+#define REG_FILTER_SEL 0x0c
+
+#define REG_EDGE_POL_MASK(x) (BIT(x) | BIT(16 + (x)))
+#define REG_EDGE_POL_EDGE(x) BIT(x)
+#define REG_EDGE_POL_LOW(x) BIT(16 + (x))
+#define REG_PIN_SEL_SHIFT(x) (((x) % 4) * 8)
+#define REG_FILTER_SEL_SHIFT(x) ((x) * 4)
+
+struct meson_gpio_irq_params {
+ unsigned int nr_hwirq;
+};
+
+static const struct meson_gpio_irq_params meson8b_params = {
+ .nr_hwirq = 119,
+};
+
+static const struct meson_gpio_irq_params gxbb_params = {
+ .nr_hwirq = 133,
+};
+
+static const struct meson_gpio_irq_params gxl_params = {
+ .nr_hwirq = 110,
+};
+
+static const struct of_device_id meson_irq_gpio_matches[] = {
+ { .compatible = "amlogic,meson8b-gpio-intc", .data = &meson8b_params },
+ { .compatible = "amlogic,meson-gxbb-gpio-intc", .data = &gxbb_params },
+ { .compatible = "amlogic,meson-gxl-gpio-intc", .data = &gxl_params },
+ { }
+};
+
+struct meson_gpio_irq_controller {
+ unsigned int nr_hwirq;
+ void __iomem *base;
+ u32 channel_irqs[NUM_CHANNEL];
+ DECLARE_BITMAP(channel_map, NUM_CHANNEL);
+ spinlock_t lock;
+};
+
+static void meson_gpio_irq_update_bits(struct meson_gpio_irq_controller *ctl,
+ unsigned int reg, u32 mask, u32 val)
+{
+ u32 tmp;
+
+ tmp = readl_relaxed(ctl->base + reg);
+ tmp &= ~mask;
+ tmp |= val;
+ writel_relaxed(tmp, ctl->base + reg);
+}
+
+static unsigned int meson_gpio_irq_channel_to_reg(unsigned int channel)
+{
+ return (channel < 4) ? REG_PIN_03_SEL : REG_PIN_47_SEL;
+}
+
+static int
+meson_gpio_irq_request_channel(struct meson_gpio_irq_controller *ctl,
+ unsigned long hwirq,
+ u32 **channel_hwirq)
+{
+ unsigned int reg, idx;
+
+ spin_lock(&ctl->lock);
+
+ /* Find a free channel */
+ idx = find_first_zero_bit(ctl->channel_map, NUM_CHANNEL);
+ if (idx >= NUM_CHANNEL) {
+ spin_unlock(&ctl->lock);
+ pr_err("No channel available\n");
+ return -ENOSPC;
+ }
+
+ /* Mark the channel as used */
+ set_bit(idx, ctl->channel_map);
+
+ /*
+ * Setup the mux of the channel to route the signal of the pad
+ * to the appropriate input of the GIC
+ */
+ reg = meson_gpio_irq_channel_to_reg(idx);
+ meson_gpio_irq_update_bits(ctl, reg,
+ 0xff << REG_PIN_SEL_SHIFT(idx),
+ hwirq << REG_PIN_SEL_SHIFT(idx));
+
+ /*
+ * Get the hwirq number assigned to this channel through
+ * a pointer the channel_irq table. The added benifit of this
+ * method is that we can also retrieve the channel index with
+ * it, using the table base.
+ */
+ *channel_hwirq = &(ctl->channel_irqs[idx]);
+
+ spin_unlock(&ctl->lock);
+
+ pr_debug("hwirq %lu assigned to channel %d - irq %u\n",
+ hwirq, idx, **channel_hwirq);
+
+ return 0;
+}
+
+static unsigned int
+meson_gpio_irq_get_channel_idx(struct meson_gpio_irq_controller *ctl,
+ u32 *channel_hwirq)
+{
+ return channel_hwirq - ctl->channel_irqs;
+}
+
+static void
+meson_gpio_irq_release_channel(struct meson_gpio_irq_controller *ctl,
+ u32 *channel_hwirq)
+{
+ unsigned int idx;
+
+ idx = meson_gpio_irq_get_channel_idx(ctl, channel_hwirq);
+ clear_bit(idx, ctl->channel_map);
+}
+
+static int meson_gpio_irq_type_setup(struct meson_gpio_irq_controller *ctl,
+ unsigned int type,
+ u32 *channel_hwirq)
+{
+ u32 val = 0;
+ unsigned int idx;
+
+ idx = meson_gpio_irq_get_channel_idx(ctl, channel_hwirq);
+
+ /*
+ * The controller has a filter block to operate in either LEVEL or
+ * EDGE mode, then signal is sent to the GIC. To enable LEVEL_LOW and
+ * EDGE_FALLING support (which the GIC does not support), the filter
+ * block is also able to invert the input signal it gets before
+ * providing it to the GIC.
+ */
+ type &= IRQ_TYPE_SENSE_MASK;
+
+ if (type == IRQ_TYPE_EDGE_BOTH)
+ return -EINVAL;
+
+ if (type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))
+ val |= REG_EDGE_POL_EDGE(idx);
+
+ if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_EDGE_FALLING))
+ val |= REG_EDGE_POL_LOW(idx);
+
+ spin_lock(&ctl->lock);
+
+ meson_gpio_irq_update_bits(ctl, REG_EDGE_POL,
+ REG_EDGE_POL_MASK(idx), val);
+
+ spin_unlock(&ctl->lock);
+
+ return 0;
+}
+
+static unsigned int meson_gpio_irq_type_output(unsigned int type)
+{
+ unsigned int sense = type & IRQ_TYPE_SENSE_MASK;
+
+ type &= ~IRQ_TYPE_SENSE_MASK;
+
+ /*
+ * The polarity of the signal provided to the GIC should always
+ * be high.
+ */
+ if (sense & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
+ type |= IRQ_TYPE_LEVEL_HIGH;
+ else if (sense & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING))
+ type |= IRQ_TYPE_EDGE_RISING;
+
+ return type;
+}
+
+static int meson_gpio_irq_set_type(struct irq_data *data, unsigned int type)
+{
+ struct meson_gpio_irq_controller *ctl = data->domain->host_data;
+ u32 *channel_hwirq = irq_data_get_irq_chip_data(data);
+ int ret;
+
+ ret = meson_gpio_irq_type_setup(ctl, type, channel_hwirq);
+ if (ret)
+ return ret;
+
+ return irq_chip_set_type_parent(data,
+ meson_gpio_irq_type_output(type));
+}
+
+static struct irq_chip meson_gpio_irq_chip = {
+ .name = "meson-gpio-irqchip",
+ .irq_mask = irq_chip_mask_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_set_type = meson_gpio_irq_set_type,
+ .irq_retrigger = irq_chip_retrigger_hierarchy,
+#ifdef CONFIG_SMP
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+#endif
+ .flags = IRQCHIP_SET_TYPE_MASKED,
+};
+
+static int meson_gpio_irq_domain_translate(struct irq_domain *domain,
+ struct irq_fwspec *fwspec,
+ unsigned long *hwirq,
+ unsigned int *type)
+{
+ if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
+ *hwirq = fwspec->param[0];
+ *type = fwspec->param[1];
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int meson_gpio_irq_allocate_gic_irq(struct irq_domain *domain,
+ unsigned int virq,
+ u32 hwirq,
+ unsigned int type)
+{
+ struct irq_fwspec fwspec;
+
+ fwspec.fwnode = domain->parent->fwnode;
+ fwspec.param_count = 3;
+ fwspec.param[0] = 0; /* SPI */
+ fwspec.param[1] = hwirq;
+ fwspec.param[2] = meson_gpio_irq_type_output(type);
+
+ return irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
+}
+
+static int meson_gpio_irq_domain_alloc(struct irq_domain *domain,
+ unsigned int virq,
+ unsigned int nr_irqs,
+ void *data)
+{
+ struct irq_fwspec *fwspec = data;
+ struct meson_gpio_irq_controller *ctl = domain->host_data;
+ unsigned long hwirq;
+ u32 *channel_hwirq;
+ unsigned int type;
+ int ret;
+
+ if (WARN_ON(nr_irqs != 1))
+ return -EINVAL;
+
+ ret = meson_gpio_irq_domain_translate(domain, fwspec, &hwirq, &type);
+ if (ret)
+ return ret;
+
+ ret = meson_gpio_irq_request_channel(ctl, hwirq, &channel_hwirq);
+ if (ret)
+ return ret;
+
+ ret = meson_gpio_irq_allocate_gic_irq(domain, virq,
+ *channel_hwirq, type);
+ if (ret < 0) {
+ pr_err("failed to allocate gic irq %u\n", *channel_hwirq);
+ meson_gpio_irq_release_channel(ctl, channel_hwirq);
+ return ret;
+ }
+
+ irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
+ &meson_gpio_irq_chip, channel_hwirq);
+
+ return 0;
+}
+
+static void meson_gpio_irq_domain_free(struct irq_domain *domain,
+ unsigned int virq,
+ unsigned int nr_irqs)
+{
+ struct meson_gpio_irq_controller *ctl = domain->host_data;
+ struct irq_data *irq_data;
+ u32 *channel_hwirq;
+
+ if (WARN_ON(nr_irqs != 1))
+ return;
+
+ irq_domain_free_irqs_parent(domain, virq, 1);
+
+ irq_data = irq_domain_get_irq_data(domain, virq);
+ channel_hwirq = irq_data_get_irq_chip_data(irq_data);
+
+ meson_gpio_irq_release_channel(ctl, channel_hwirq);
+}
+
+static const struct irq_domain_ops meson_gpio_irq_domain_ops = {
+ .alloc = meson_gpio_irq_domain_alloc,
+ .free = meson_gpio_irq_domain_free,
+ .translate = meson_gpio_irq_domain_translate,
+};
+
+static int __init meson_gpio_irq_parse_dt(struct device_node *node,
+ struct meson_gpio_irq_controller *ctl)
+{
+ const struct of_device_id *match;
+ const struct meson_gpio_irq_params *params;
+ int ret;
+
+ match = of_match_node(meson_irq_gpio_matches, node);
+ if (!match)
+ return -ENODEV;
+
+ params = match->data;
+ ctl->nr_hwirq = params->nr_hwirq;
+
+ ret = of_property_read_variable_u32_array(node,
+ "amlogic,channel-interrupts",
+ ctl->channel_irqs,
+ NUM_CHANNEL,
+ NUM_CHANNEL);
+ if (ret < 0) {
+ pr_err("can't get %d channel interrupts\n", NUM_CHANNEL);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int __init meson_gpio_irq_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct irq_domain *domain, *parent_domain;
+ struct meson_gpio_irq_controller *ctl;
+ int ret;
+
+ if (!parent) {
+ pr_err("missing parent interrupt node\n");
+ return -ENODEV;
+ }
+
+ parent_domain = irq_find_host(parent);
+ if (!parent_domain) {
+ pr_err("unable to obtain parent domain\n");
+ return -ENXIO;
+ }
+
+ ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
+ if (!ctl)
+ return -ENOMEM;
+
+ spin_lock_init(&ctl->lock);
+
+ ctl->base = of_iomap(node, 0);
+ if (!ctl->base) {
+ ret = -ENOMEM;
+ goto free_ctl;
+ }
+
+ ret = meson_gpio_irq_parse_dt(node, ctl);
+ if (ret)
+ goto free_channel_irqs;
+
+ domain = irq_domain_create_hierarchy(parent_domain, 0, ctl->nr_hwirq,
+ of_node_to_fwnode(node),
+ &meson_gpio_irq_domain_ops,
+ ctl);
+ if (!domain) {
+ pr_err("failed to add domain\n");
+ ret = -ENODEV;
+ goto free_channel_irqs;
+ }
+
+ pr_info("%d to %d gpio interrupt mux initialized\n",
+ ctl->nr_hwirq, NUM_CHANNEL);
+
+ return 0;
+
+free_channel_irqs:
+ iounmap(ctl->base);
+free_ctl:
+ kfree(ctl);
+
+ return ret;
+}
+
+IRQCHIP_DECLARE(meson_gpio_intc, "amlogic,meson-gpio-intc",
+ meson_gpio_irq_of_init);
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