[PATCH v12 3/6] irqchip: Add IMX MU MSI controller driver

Frank Li
2022-09-22T16:15:15Z

The MU block found in a number of Freescale/NXP SoCs supports generating
IRQs by writing data to a register.

This enables the MU block to be used as a MSI controller, by leveraging
the platform-MSI API.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
drivers/irqchip/Kconfig | 14 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-imx-mu-msi.c | 455 +++++++++++++++++++++++++++++++
3 files changed, 470 insertions(+)
create mode 100644 drivers/irqchip/irq-imx-mu-msi.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 5e4e50122777d..b9adc698ef0fc 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -470,6 +470,20 @@ config IMX_INTMUX
help
Support for the i.MX INTMUX interrupt multiplexer.

+config IMX_MU_MSI
+ tristate "i.MX MU used as MSI controller"
+ depends on OF && HAS_IOMEM
+ default m if ARCH_MXC
+ select IRQ_DOMAIN
+ select IRQ_DOMAIN_HIERARCHY
+ select GENERIC_MSI_IRQ_DOMAIN
+ help
+ Provide a driver for the MU block used as a CPU-to-CPU MSI
+ controller. This requires a specially crafted DT to make use
+ of this driver.
+
+ If unsure, say N
+
config LS1X_IRQ
bool "Loongson-1 Interrupt Controller"
depends on MACH_LOONGSON32
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 5d8e21d3dc6d8..870423746c783 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -98,6 +98,7 @@ obj-$(CONFIG_RISCV_INTC) += irq-riscv-intc.o
obj-$(CONFIG_SIFIVE_PLIC) += irq-sifive-plic.o
obj-$(CONFIG_IMX_IRQSTEER) += irq-imx-irqsteer.o
obj-$(CONFIG_IMX_INTMUX) += irq-imx-intmux.o
+obj-$(CONFIG_IMX_MU_MSI) += irq-imx-mu-msi.o
obj-$(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-mu-msi.c b/drivers/irqchip/irq-imx-mu-msi.c
new file mode 100644
index 0000000000000..4bb9456ba4820
--- /dev/null
+++ b/drivers/irqchip/irq-imx-mu-msi.c
@@ -0,0 +1,455 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Freescale MU used as MSI controller
+ *
+ * Copyright (c) 2018 Pengutronix, Oleksij Rempel <o.rempel@pengutronix.de>
+ * Copyright 2022 NXP
+ * Frank Li <Frank.Li@nxp.com>
+ * Peng Fan <peng.fan@nxp.com>
+ *
+ * Based on drivers/mailbox/imx-mailbox.c
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-iommu.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
+#include <linux/spinlock.h>
+
+#define IMX_MU_CHANS 4
+
+enum imx_mu_xcr {
+ IMX_MU_GIER,
+ IMX_MU_GCR,
+ IMX_MU_TCR,
+ IMX_MU_RCR,
+ IMX_MU_xCR_MAX,
+};
+
+enum imx_mu_xsr {
+ IMX_MU_SR,
+ IMX_MU_GSR,
+ IMX_MU_TSR,
+ IMX_MU_RSR,
+ IMX_MU_xSR_MAX
+};
+
+enum imx_mu_type {
+ IMX_MU_V2 = BIT(1),
+};
+
+/* Receive Interrupt Enable */
+#define IMX_MU_xCR_RIEn(data, x) ((data->cfg->type) & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
+#define IMX_MU_xSR_RFn(data, x) ((data->cfg->type) & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
+
+struct imx_mu_dcfg {
+ enum imx_mu_type type;
+ u32 xTR; /* Transmit Register0 */
+ u32 xRR; /* Receive Register0 */
+ u32 xSR[IMX_MU_xSR_MAX]; /* Status Registers */
+ u32 xCR[IMX_MU_xCR_MAX]; /* Control Registers */
+};
+
+struct imx_mu_msi {
+ raw_spinlock_t lock;
+ struct irq_domain *msi_domain;
+ void __iomem *regs;
+ phys_addr_t msiir_addr;
+ const struct imx_mu_dcfg *cfg;
+ unsigned long used;
+ struct clk *clk;
+};
+
+static void imx_mu_write(struct imx_mu_msi *msi_data, u32 val, u32 offs)
+{
+ iowrite32(val, msi_data->regs + offs);
+}
+
+static u32 imx_mu_read(struct imx_mu_msi *msi_data, u32 offs)
+{
+ return ioread32(msi_data->regs + offs);
+}
+
+static u32 imx_mu_xcr_rmw(struct imx_mu_msi *msi_data, enum imx_mu_xcr type, u32 set, u32 clr)
+{
+ unsigned long flags;
+ u32 val;
+
+ raw_spin_lock_irqsave(&msi_data->lock, flags);
+ val = imx_mu_read(msi_data, msi_data->cfg->xCR[type]);
+ val &= ~clr;
+ val |= set;
+ imx_mu_write(msi_data, val, msi_data->cfg->xCR[type]);
+ raw_spin_unlock_irqrestore(&msi_data->lock, flags);
+
+ return val;
+}
+
+static void imx_mu_msi_parent_mask_irq(struct irq_data *data)
+{
+ struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(data);
+
+ imx_mu_xcr_rmw(msi_data, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(msi_data, data->hwirq));
+}
+
+static void imx_mu_msi_parent_unmask_irq(struct irq_data *data)
+{
+ struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(data);
+
+ imx_mu_xcr_rmw(msi_data, IMX_MU_RCR, IMX_MU_xCR_RIEn(msi_data, data->hwirq), 0);
+}
+
+static void imx_mu_msi_parent_ack_irq(struct irq_data *data)
+{
+ struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(data);
+
+ imx_mu_read(msi_data, msi_data->cfg->xRR + data->hwirq * 4);
+}
+
+static struct irq_chip imx_mu_msi_irq_chip = {
+ .name = "MU-MSI",
+ .irq_ack = irq_chip_ack_parent,
+};
+
+static struct msi_domain_ops imx_mu_msi_irq_ops = {
+};
+
+static struct msi_domain_info imx_mu_msi_domain_info = {
+ .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
+ .ops = &imx_mu_msi_irq_ops,
+ .chip = &imx_mu_msi_irq_chip,
+};
+
+static void imx_mu_msi_parent_compose_msg(struct irq_data *data,
+ struct msi_msg *msg)
+{
+ struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(data);
+ u64 addr = msi_data->msiir_addr + 4 * data->hwirq;
+
+ msg->address_hi = upper_32_bits(addr);
+ msg->address_lo = lower_32_bits(addr);
+ msg->data = data->hwirq;
+}
+
+static int imx_mu_msi_parent_set_affinity(struct irq_data *irq_data,
+ const struct cpumask *mask, bool force)
+{
+ return -EINVAL;
+}
+
+static struct irq_chip imx_mu_msi_parent_chip = {
+ .name = "MU",
+ .irq_mask = imx_mu_msi_parent_mask_irq,
+ .irq_unmask = imx_mu_msi_parent_unmask_irq,
+ .irq_ack = imx_mu_msi_parent_ack_irq,
+ .irq_compose_msi_msg = imx_mu_msi_parent_compose_msg,
+ .irq_set_affinity = imx_mu_msi_parent_set_affinity,
+};
+
+static int imx_mu_msi_domain_irq_alloc(struct irq_domain *domain,
+ unsigned int virq,
+ unsigned int nr_irqs,
+ void *args)
+{
+ struct imx_mu_msi *msi_data = domain->host_data;
+ unsigned long flags;
+ int pos, err = 0;
+
+ WARN_ON(nr_irqs != 1);
+
+ raw_spin_lock_irqsave(&msi_data->lock, flags);
+ pos = find_first_zero_bit(&msi_data->used, IMX_MU_CHANS);
+ if (pos < IMX_MU_CHANS)
+ __set_bit(pos, &msi_data->used);
+ else
+ err = -ENOSPC;
+ raw_spin_unlock_irqrestore(&msi_data->lock, flags);
+
+ if (err)
+ return err;
+
+ irq_domain_set_info(domain, virq, pos,
+ &imx_mu_msi_parent_chip, msi_data,
+ handle_edge_irq, NULL, NULL);
+ return 0;
+}
+
+static void imx_mu_msi_domain_irq_free(struct irq_domain *domain,
+ unsigned int virq, unsigned int nr_irqs)
+{
+ struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+ struct imx_mu_msi *msi_data = irq_data_get_irq_chip_data(d);
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&msi_data->lock, flags);
+ __clear_bit(d->hwirq, &msi_data->used);
+ raw_spin_unlock_irqrestore(&msi_data->lock, flags);
+}
+
+static const struct irq_domain_ops imx_mu_msi_domain_ops = {
+ .alloc = imx_mu_msi_domain_irq_alloc,
+ .free = imx_mu_msi_domain_irq_free,
+};
+
+static void imx_mu_msi_irq_handler(struct irq_desc *desc)
+{
+ struct imx_mu_msi *msi_data = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ u32 status;
+ int i;
+
+ status = imx_mu_read(msi_data, msi_data->cfg->xSR[IMX_MU_RSR]);
+
+ chained_irq_enter(chip, desc);
+ for (i = 0; i < IMX_MU_CHANS; i++) {
+ if (status & IMX_MU_xSR_RFn(msi_data, i))
+ generic_handle_domain_irq(msi_data->msi_domain, i);
+ }
+ chained_irq_exit(chip, desc);
+}
+
+static int imx_mu_msi_domains_init(struct imx_mu_msi *msi_data, struct device *dev)
+{
+ struct fwnode_handle *fwnodes = dev_fwnode(dev);
+ struct irq_domain *parent;
+
+ /* Initialize MSI domain parent */
+ parent = irq_domain_create_linear(fwnodes,
+ IMX_MU_CHANS,
+ &imx_mu_msi_domain_ops,
+ msi_data);
+ if (!parent) {
+ dev_err(dev, "failed to create IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ irq_domain_update_bus_token(parent, DOMAIN_BUS_NEXUS);
+
+ msi_data->msi_domain = platform_msi_create_irq_domain(fwnodes,
+ &imx_mu_msi_domain_info,
+ parent);
+
+ if (!msi_data->msi_domain) {
+ dev_err(dev, "failed to create MSI domain\n");
+ irq_domain_remove(parent);
+ return -ENOMEM;
+ }
+
+ irq_domain_set_pm_device(msi_data->msi_domain, dev);
+
+ return 0;
+}
+
+/* Register offset of different version MU IP */
+static const struct imx_mu_dcfg imx_mu_cfg_imx6sx = {
+ .type = 0,
+ .xTR = 0x0,
+ .xRR = 0x10,
+ .xSR = {
+ [IMX_MU_SR] = 0x20,
+ [IMX_MU_GSR] = 0x20,
+ [IMX_MU_TSR] = 0x20,
+ [IMX_MU_RSR] = 0x20,
+ },
+ .xCR = {
+ [IMX_MU_GIER] = 0x24,
+ [IMX_MU_GCR] = 0x24,
+ [IMX_MU_TCR] = 0x24,
+ [IMX_MU_RCR] = 0x24,
+ },
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx7ulp = {
+ .type = 0,
+ .xTR = 0x20,
+ .xRR = 0x40,
+ .xSR = {
+ [IMX_MU_SR] = 0x60,
+ [IMX_MU_GSR] = 0x60,
+ [IMX_MU_TSR] = 0x60,
+ [IMX_MU_RSR] = 0x60,
+ },
+ .xCR = {
+ [IMX_MU_GIER] = 0x64,
+ [IMX_MU_GCR] = 0x64,
+ [IMX_MU_TCR] = 0x64,
+ [IMX_MU_RCR] = 0x64,
+ },
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp = {
+ .type = IMX_MU_V2,
+ .xTR = 0x200,
+ .xRR = 0x280,
+ .xSR = {
+ [IMX_MU_SR] = 0xC,
+ [IMX_MU_GSR] = 0x118,
+ [IMX_MU_GSR] = 0x124,
+ [IMX_MU_RSR] = 0x12C,
+ },
+ .xCR = {
+ [IMX_MU_GIER] = 0x110,
+ [IMX_MU_GCR] = 0x114,
+ [IMX_MU_TCR] = 0x120,
+ [IMX_MU_RCR] = 0x128
+ },
+};
+
+static int __init imx_mu_of_init(struct device_node *dn,
+ struct device_node *parent,
+ const struct imx_mu_dcfg *cfg)
+{
+ struct platform_device *pdev = of_find_device_by_node(dn);
+ struct device_link *pd_link_a;
+ struct device_link *pd_link_b;
+ struct imx_mu_msi *msi_data;
+ struct resource *res;
+ struct device *pd_a;
+ struct device *pd_b;
+ struct device *dev;
+ int ret;
+ int irq;
+
+ dev = &pdev->dev;
+
+ msi_data = devm_kzalloc(&pdev->dev, sizeof(*msi_data), GFP_KERNEL);
+ if (!msi_data)
+ return -ENOMEM;
+
+ msi_data->cfg = cfg;
+
+ msi_data->regs = devm_platform_ioremap_resource_byname(pdev, "processor-a-side");
+ if (IS_ERR(msi_data->regs)) {
+ dev_err(&pdev->dev, "failed to initialize 'regs'\n");
+ return PTR_ERR(msi_data->regs);
+ }
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "processor-b-side");
+ if (!res)
+ return -EIO;
+
+ msi_data->msiir_addr = res->start + msi_data->cfg->xTR;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq <= 0)
+ return -ENODEV;
+
+ platform_set_drvdata(pdev, msi_data);
+
+ msi_data->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(msi_data->clk))
+ return PTR_ERR(msi_data->clk);
+
+ pd_a = dev_pm_domain_attach_by_name(dev, "processor-a-side");
+ if (IS_ERR(pd_a))
+ return PTR_ERR(pd_a);
+
+ pd_b = dev_pm_domain_attach_by_name(dev, "processor-b-side");
+ if (IS_ERR(pd_b))
+ return PTR_ERR(pd_b);
+
+ pd_link_a = device_link_add(dev, pd_a,
+ DL_FLAG_STATELESS |
+ DL_FLAG_PM_RUNTIME |
+ DL_FLAG_RPM_ACTIVE);
+
+ if (!pd_link_a) {
+ dev_err(dev, "Failed to add device_link to mu a.\n");
+ goto err_pd_a;
+ }
+
+ pd_link_b = device_link_add(dev, pd_b,
+ DL_FLAG_STATELESS |
+ DL_FLAG_PM_RUNTIME |
+ DL_FLAG_RPM_ACTIVE);
+
+
+ if (!pd_link_b) {
+ dev_err(dev, "Failed to add device_link to mu a.\n");
+ goto err_pd_b;
+ }
+
+ ret = imx_mu_msi_domains_init(msi_data, dev);
+ if (ret)
+ goto err_dm_init;
+
+ pm_runtime_enable(dev);
+
+ irq_set_chained_handler_and_data(irq,
+ imx_mu_msi_irq_handler,
+ msi_data);
+
+ return 0;
+
+err_dm_init:
+ device_link_remove(dev, pd_b);
+err_pd_b:
+ device_link_remove(dev, pd_a);
+err_pd_a:
+ return -EINVAL;
+}
+
+static int __maybe_unused imx_mu_runtime_suspend(struct device *dev)
+{
+ struct imx_mu_msi *priv = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(priv->clk);
+
+ return 0;
+}
+
+static int __maybe_unused imx_mu_runtime_resume(struct device *dev)
+{
+ struct imx_mu_msi *priv = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(priv->clk);
+ if (ret)
+ dev_err(dev, "failed to enable clock\n");
+
+ return ret;
+}
+
+static const struct dev_pm_ops imx_mu_pm_ops = {
+ SET_RUNTIME_PM_OPS(imx_mu_runtime_suspend,
+ imx_mu_runtime_resume, NULL)
+};
+
+static int __init imx_mu_imx7ulp_of_init(struct device_node *dn,
+ struct device_node *parent)
+{
+ return imx_mu_of_init(dn, parent, &imx_mu_cfg_imx7ulp);
+}
+
+static int __init imx_mu_imx6sx_of_init(struct device_node *dn,
+ struct device_node *parent)
+{
+ return imx_mu_of_init(dn, parent, &imx_mu_cfg_imx6sx);
+}
+
+static int __init imx_mu_imx8ulp_of_init(struct device_node *dn,
+ struct device_node *parent)
+{
+ return imx_mu_of_init(dn, parent, &imx_mu_cfg_imx8ulp);
+}
+
+IRQCHIP_PLATFORM_DRIVER_BEGIN(imx_mu_msi)
+IRQCHIP_MATCH("fsl,imx7ulp-mu-msi", imx_mu_imx7ulp_of_init)
+IRQCHIP_MATCH("fsl,imx6sx-mu-msi", imx_mu_imx6sx_of_init)
+IRQCHIP_MATCH("fsl,imx8ulp-mu-msi", imx_mu_imx8ulp_of_init)
+IRQCHIP_PLATFORM_DRIVER_END(imx_mu_msi, .pm = &imx_mu_pm_ops)
+
+
+MODULE_AUTHOR("Frank Li <Frank.Li@nxp.com>");
+MODULE_DESCRIPTION("Freescale MU MSI controller driver");
+MODULE_LICENSE("GPL");