irqchip: Add NXP INTMUX interrupt multiplexer support
authorJoakim Zhang <qiangqing.zhang@nxp.com>
Fri, 17 Jan 2020 06:10:10 +0000 (06:10 +0000)
committerMarc Zyngier <maz@kernel.org>
Mon, 20 Jan 2020 19:10:05 +0000 (19:10 +0000)
The Interrupt Multiplexer (INTMUX) expands the number of peripherals
that can interrupt the core:
* The INTMUX has 8 channels that are assigned to 8 NVIC interrupt slots.
* Each INTMUX channel can receive up to 32 interrupt sources and has 1
  interrupt output.
* The INTMUX routes the interrupt sources to the interrupt outputs.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200117060653.27485-3-qiangqing.zhang@nxp.com
drivers/irqchip/Kconfig
drivers/irqchip/Makefile
drivers/irqchip/irq-imx-intmux.c [new file with mode: 0644]

index 20c62d7..1006c69 100644 (file)
@@ -457,6 +457,12 @@ config IMX_IRQSTEER
        help
          Support for the i.MX IRQSTEER interrupt multiplexer/remapper.
 
+config IMX_INTMUX
+       def_bool y if ARCH_MXC
+       select IRQ_DOMAIN
+       help
+         Support for the i.MX INTMUX interrupt multiplexer.
+
 config LS1X_IRQ
        bool "Loongson-1 Interrupt Controller"
        depends on MACH_LOONGSON32
index 4b1c511..eae0d78 100644 (file)
@@ -100,6 +100,7 @@ obj-$(CONFIG_CSKY_MPINTC)           += irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)            += irq-csky-apb-intc.o
 obj-$(CONFIG_SIFIVE_PLIC)              += irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)             += irq-imx-irqsteer.o
+obj-$(CONFIG_IMX_INTMUX)               += irq-imx-intmux.o
 obj-$(CONFIG_MADERA_IRQ)               += irq-madera.o
 obj-$(CONFIG_LS1X_IRQ)                 += irq-ls1x.o
 obj-$(CONFIG_TI_SCI_INTR_IRQCHIP)      += irq-ti-sci-intr.o
diff --git a/drivers/irqchip/irq-imx-intmux.c b/drivers/irqchip/irq-imx-intmux.c
new file mode 100644 (file)
index 0000000..c27577c
--- /dev/null
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright 2017 NXP
+
+/*                     INTMUX Block Diagram
+ *
+ *                               ________________
+ * interrupt source #  0  +---->|                |
+ *                        |     |                |
+ * interrupt source #  1  +++-->|                |
+ *            ...         | |   |   channel # 0  |--------->interrupt out # 0
+ *            ...         | |   |                |
+ *            ...         | |   |                |
+ * interrupt source # X-1 +++-->|________________|
+ *                        | | |
+ *                        | | |
+ *                        | | |  ________________
+ *                        +---->|                |
+ *                        | | | |                |
+ *                        | +-->|                |
+ *                        | | | |   channel # 1  |--------->interrupt out # 1
+ *                        | | +>|                |
+ *                        | | | |                |
+ *                        | | | |________________|
+ *                        | | |
+ *                        | | |
+ *                        | | |       ...
+ *                        | | |       ...
+ *                        | | |
+ *                        | | |  ________________
+ *                        +---->|                |
+ *                          | | |                |
+ *                          +-->|                |
+ *                            | |   channel # N  |--------->interrupt out # N
+ *                            +>|                |
+ *                              |                |
+ *                              |________________|
+ *
+ *
+ * N: Interrupt Channel Instance Number (N=7)
+ * X: Interrupt Source Number for each channel (X=32)
+ *
+ * The INTMUX interrupt multiplexer has 8 channels, each channel receives 32
+ * interrupt sources and generates 1 interrupt output.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/spinlock.h>
+
+#define CHANIER(n)     (0x10 + (0x40 * n))
+#define CHANIPR(n)     (0x20 + (0x40 * n))
+
+#define CHAN_MAX_NUM           0x8
+
+struct intmux_irqchip_data {
+       int                     chanidx;
+       int                     irq;
+       struct irq_domain       *domain;
+};
+
+struct intmux_data {
+       raw_spinlock_t                  lock;
+       void __iomem                    *regs;
+       struct clk                      *ipg_clk;
+       int                             channum;
+       struct intmux_irqchip_data      irqchip_data[];
+};
+
+static void imx_intmux_irq_mask(struct irq_data *d)
+{
+       struct intmux_irqchip_data *irqchip_data = d->chip_data;
+       int idx = irqchip_data->chanidx;
+       struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
+                                               irqchip_data[idx]);
+       unsigned long flags;
+       void __iomem *reg;
+       u32 val;
+
+       raw_spin_lock_irqsave(&data->lock, flags);
+       reg = data->regs + CHANIER(idx);
+       val = readl_relaxed(reg);
+       /* disable the interrupt source of this channel */
+       val &= ~BIT(d->hwirq);
+       writel_relaxed(val, reg);
+       raw_spin_unlock_irqrestore(&data->lock, flags);
+}
+
+static void imx_intmux_irq_unmask(struct irq_data *d)
+{
+       struct intmux_irqchip_data *irqchip_data = d->chip_data;
+       int idx = irqchip_data->chanidx;
+       struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
+                                               irqchip_data[idx]);
+       unsigned long flags;
+       void __iomem *reg;
+       u32 val;
+
+       raw_spin_lock_irqsave(&data->lock, flags);
+       reg = data->regs + CHANIER(idx);
+       val = readl_relaxed(reg);
+       /* enable the interrupt source of this channel */
+       val |= BIT(d->hwirq);
+       writel_relaxed(val, reg);
+       raw_spin_unlock_irqrestore(&data->lock, flags);
+}
+
+static struct irq_chip imx_intmux_irq_chip = {
+       .name           = "intmux",
+       .irq_mask       = imx_intmux_irq_mask,
+       .irq_unmask     = imx_intmux_irq_unmask,
+};
+
+static int imx_intmux_irq_map(struct irq_domain *h, unsigned int irq,
+                             irq_hw_number_t hwirq)
+{
+       irq_set_chip_data(irq, h->host_data);
+       irq_set_chip_and_handler(irq, &imx_intmux_irq_chip, handle_level_irq);
+
+       return 0;
+}
+
+static int imx_intmux_irq_xlate(struct irq_domain *d, struct device_node *node,
+                               const u32 *intspec, unsigned int intsize,
+                               unsigned long *out_hwirq, unsigned int *out_type)
+{
+       struct intmux_irqchip_data *irqchip_data = d->host_data;
+       int idx = irqchip_data->chanidx;
+       struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
+                                               irqchip_data[idx]);
+
+       /*
+        * two cells needed in interrupt specifier:
+        * the 1st cell: hw interrupt number
+        * the 2nd cell: channel index
+        */
+       if (WARN_ON(intsize != 2))
+               return -EINVAL;
+
+       if (WARN_ON(intspec[1] >= data->channum))
+               return -EINVAL;
+
+       *out_hwirq = intspec[0];
+       *out_type = IRQ_TYPE_LEVEL_HIGH;
+
+       return 0;
+}
+
+static int imx_intmux_irq_select(struct irq_domain *d, struct irq_fwspec *fwspec,
+                                enum irq_domain_bus_token bus_token)
+{
+       struct intmux_irqchip_data *irqchip_data = d->host_data;
+
+       /* Not for us */
+       if (fwspec->fwnode != d->fwnode)
+               return false;
+
+       return irqchip_data->chanidx == fwspec->param[1];
+}
+
+static const struct irq_domain_ops imx_intmux_domain_ops = {
+       .map            = imx_intmux_irq_map,
+       .xlate          = imx_intmux_irq_xlate,
+       .select         = imx_intmux_irq_select,
+};
+
+static void imx_intmux_irq_handler(struct irq_desc *desc)
+{
+       struct intmux_irqchip_data *irqchip_data = irq_desc_get_handler_data(desc);
+       int idx = irqchip_data->chanidx;
+       struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
+                                               irqchip_data[idx]);
+       unsigned long irqstat;
+       int pos, virq;
+
+       chained_irq_enter(irq_desc_get_chip(desc), desc);
+
+       /* read the interrupt source pending status of this channel */
+       irqstat = readl_relaxed(data->regs + CHANIPR(idx));
+
+       for_each_set_bit(pos, &irqstat, 32) {
+               virq = irq_find_mapping(irqchip_data->domain, pos);
+               if (virq)
+                       generic_handle_irq(virq);
+       }
+
+       chained_irq_exit(irq_desc_get_chip(desc), desc);
+}
+
+static int imx_intmux_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       struct irq_domain *domain;
+       struct intmux_data *data;
+       int channum;
+       int i, ret;
+
+       channum = platform_irq_count(pdev);
+       if (channum == -EPROBE_DEFER) {
+               return -EPROBE_DEFER;
+       } else if (channum > CHAN_MAX_NUM) {
+               dev_err(&pdev->dev, "supports up to %d multiplex channels\n",
+                       CHAN_MAX_NUM);
+               return -EINVAL;
+       }
+
+       data = devm_kzalloc(&pdev->dev, sizeof(*data) +
+                           channum * sizeof(data->irqchip_data[0]), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       data->regs = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(data->regs)) {
+               dev_err(&pdev->dev, "failed to initialize reg\n");
+               return PTR_ERR(data->regs);
+       }
+
+       data->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
+       if (IS_ERR(data->ipg_clk)) {
+               ret = PTR_ERR(data->ipg_clk);
+               if (ret != -EPROBE_DEFER)
+                       dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
+               return ret;
+       }
+
+       data->channum = channum;
+       raw_spin_lock_init(&data->lock);
+
+       ret = clk_prepare_enable(data->ipg_clk);
+       if (ret) {
+               dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
+               return ret;
+       }
+
+       for (i = 0; i < channum; i++) {
+               data->irqchip_data[i].chanidx = i;
+
+               data->irqchip_data[i].irq = irq_of_parse_and_map(np, i);
+               if (data->irqchip_data[i].irq <= 0) {
+                       ret = -EINVAL;
+                       dev_err(&pdev->dev, "failed to get irq\n");
+                       goto out;
+               }
+
+               domain = irq_domain_add_linear(np, 32, &imx_intmux_domain_ops,
+                                              &data->irqchip_data[i]);
+               if (!domain) {
+                       ret = -ENOMEM;
+                       dev_err(&pdev->dev, "failed to create IRQ domain\n");
+                       goto out;
+               }
+               data->irqchip_data[i].domain = domain;
+
+               /* disable all interrupt sources of this channel firstly */
+               writel_relaxed(0, data->regs + CHANIER(i));
+
+               irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
+                                                imx_intmux_irq_handler,
+                                                &data->irqchip_data[i]);
+       }
+
+       platform_set_drvdata(pdev, data);
+
+       return 0;
+out:
+       clk_disable_unprepare(data->ipg_clk);
+       return ret;
+}
+
+static int imx_intmux_remove(struct platform_device *pdev)
+{
+       struct intmux_data *data = platform_get_drvdata(pdev);
+       int i;
+
+       for (i = 0; i < data->channum; i++) {
+               /* disable all interrupt sources of this channel */
+               writel_relaxed(0, data->regs + CHANIER(i));
+
+               irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
+                                                NULL, NULL);
+
+               irq_domain_remove(data->irqchip_data[i].domain);
+       }
+
+       clk_disable_unprepare(data->ipg_clk);
+
+       return 0;
+}
+
+static const struct of_device_id imx_intmux_id[] = {
+       { .compatible = "fsl,imx-intmux", },
+       { /* sentinel */ },
+};
+
+static struct platform_driver imx_intmux_driver = {
+       .driver = {
+               .name = "imx-intmux",
+               .of_match_table = imx_intmux_id,
+       },
+       .probe = imx_intmux_probe,
+       .remove = imx_intmux_remove,
+};
+builtin_platform_driver(imx_intmux_driver);