[RFC PATCH 2/2] PCI: apple: Add driver for the Apple M1
From: Alyssa Rosenzweig
Date: Sun Aug 15 2021 - 00:26:09 EST
Add a driver for the PCIe controller found in Apple system-on-chips,
particularly the Apple M1. This driver exposes the internal bus used for
the USB type-A ports, Ethernet, Wi-Fi, and Bluetooth. This patch brings
up the USB type-A ports and Ethernet. Bringing up the radios requires
interfacing with the System Management Coprocessor via Apple's
mailboxes, so that's left to a future patch.
In this state, the driver consists of two major parts: hardware
initialization and MSI handling. The hardware initialization is derived
from Mark Kettenis's U-Boot patches which in turn is derived from
Corellium's patches for the hardware. The rest of the driver is derived
from Marc Zyngier's driver for the hardware.
Co-developed-by: Stan Skowronek <stan@xxxxxxxxxxxxx>
Signed-off-by: Stan Skowronek <stan@xxxxxxxxxxxxx>
Co-developed-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/pci/controller/Kconfig | 13 +
drivers/pci/controller/Makefile | 1 +
drivers/pci/controller/pcie-apple.c | 466 ++++++++++++++++++++++++++++
4 files changed, 481 insertions(+)
create mode 100644 drivers/pci/controller/pcie-apple.c
diff --git a/MAINTAINERS b/MAINTAINERS
index d7d2e1d1e2f2..f13f65a844f7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1274,6 +1274,7 @@ M: Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx>
L: linux-pci@xxxxxxxxxxxxxxx
S: Maintained
F: Documentation/devicetree/bindings/pci/apple,pcie.yaml
+F: drivers/pci/controller/pcie-apple.c
APPLE SMC DRIVER
M: Henrik Rydberg <rydberg@xxxxxxxxxxx>
diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index 326f7d13024f..881a6a81f3e2 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -312,6 +312,19 @@ config PCIE_HISI_ERR
Say Y here if you want error handling support
for the PCIe controller's errors on HiSilicon HIP SoCs
+config PCIE_APPLE
+ tristate "Apple PCIe controller"
+ depends on ARCH_APPLE || COMPILE_TEST
+ depends on OF
+ depends on PCI_MSI_IRQ_DOMAIN
+ depends on GPIOLIB
+ help
+ Say Y here if you want to enable PCIe controller support on Apple
+ system-on-chips, like the Apple M1. This is required for the USB
+ type-A ports, Ethernet, Wi-Fi, and Bluetooth.
+
+ If unsure, say Y if you have an Apple Silicon system.
+
source "drivers/pci/controller/dwc/Kconfig"
source "drivers/pci/controller/mobiveil/Kconfig"
source "drivers/pci/controller/cadence/Kconfig"
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index aaf30b3dcc14..f9d40bad932c 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_VMD) += vmd.o
obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
obj-$(CONFIG_PCI_LOONGSON) += pci-loongson.o
obj-$(CONFIG_PCIE_HISI_ERR) += pcie-hisi-error.o
+obj-$(CONFIG_PCIE_APPLE) += pcie-apple.o
# pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
obj-y += dwc/
obj-y += mobiveil/
diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
new file mode 100644
index 000000000000..08088e06460f
--- /dev/null
+++ b/drivers/pci/controller/pcie-apple.c
@@ -0,0 +1,466 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host bridge driver for Apple system-on-chips.
+ *
+ * The HW is ECAM compliant, so once the controller is initialized, the driver
+ * mostly only needs MSI handling. Initialization requires enabling power and
+ * clocks, along with a number of register pokes.
+ *
+ * Copyright (C) 2021 Google LLC
+ * Copyright (C) 2021 Corellium LLC
+ * Copyright (C) 2021 Mark Kettenis <kettenis@xxxxxxxxxxx>
+ * Copyright (C) 2021 Alyssa Rosenzweig <alyssa@xxxxxxxxxxxxx>
+ * Author: Marc Zyngier <maz@xxxxxxxxxx>
+ */
+
+#include <linux/kernel.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/pci-ecam.h>
+#include <linux/iopoll.h>
+#include <linux/gpio/consumer.h>
+
+#define CORE_RC_PHYIF_CTL 0x00024
+#define CORE_RC_PHYIF_CTL_RUN BIT(0)
+#define CORE_RC_PHYIF_STAT 0x00028
+#define CORE_RC_PHYIF_STAT_REFCLK BIT(4)
+#define CORE_RC_CTL 0x00050
+#define CORE_RC_CTL_RUN BIT(0)
+#define CORE_RC_STAT 0x00058
+#define CORE_RC_STAT_READY BIT(0)
+#define CORE_FABRIC_STAT 0x04000
+#define CORE_FABRIC_STAT_MASK 0x001F001F
+#define CORE_PHY_CTL 0x80000
+#define CORE_PHY_CTL_CLK0REQ BIT(0)
+#define CORE_PHY_CTL_CLK1REQ BIT(1)
+#define CORE_PHY_CTL_CLK0ACK BIT(2)
+#define CORE_PHY_CTL_CLK1ACK BIT(3)
+#define CORE_PHY_CTL_RESET BIT(7)
+#define CORE_LANE_CFG(port) (0x84000 + 0x4000 * (port))
+#define CORE_LANE_CFG_REFCLK0REQ BIT(0)
+#define CORE_LANE_CFG_REFCLK1 BIT(1)
+#define CORE_LANE_CFG_REFCLK0ACK BIT(2)
+#define CORE_LANE_CFG_REFCLKEN (BIT(9) | BIT(10))
+#define CORE_LANE_CTL(port) (0x84004 + 0x4000 * (port))
+#define CORE_LANE_CTL_CFGACC BIT(15)
+
+#define PORT_LTSSMCTL 0x00080
+#define PORT_LTSSMCTL_START BIT(0)
+#define PORT_INTSTAT 0x00100
+#define PORT_INT_TUNNEL_ERR BIT(31)
+#define PORT_INT_CPL_TIMEOUT BIT(23)
+#define PORT_INT_RID2SID_MAPERR BIT(22)
+#define PORT_INT_CPL_ABORT BIT(21)
+#define PORT_INT_MSI_BAD_DATA BIT(19)
+#define PORT_INT_MSI_ERR BIT(18)
+#define PORT_INT_REQADDR_GT32 BIT(17)
+#define PORT_INT_AF_TIMEOUT BIT(15)
+#define PORT_INT_LINK_DOWN BIT(14)
+#define PORT_INT_LINK_UP BIT(12)
+#define PORT_INT_LINK_BWMGMT BIT(11)
+#define PORT_INT_AER_MASK (15 << 4)
+#define PORT_INT_PORT_ERR BIT(4)
+#define PORT_INT_INTx(i) BIT(i)
+#define PORT_INT_INTxALL 15
+#define PORT_INTMSK 0x00104
+#define PORT_INTMSKSET 0x00108
+#define PORT_INTMSKCLR 0x0010c
+#define PORT_MSICFG 0x00124
+#define PORT_MSICFG_EN BIT(0)
+#define PORT_MSICFG_L2MSINUM_SHIFT 4
+#define PORT_MSIBASE 0x00128
+#define PORT_MSIBASE_1_SHIFT 16
+#define PORT_MSIADDR 0x00168
+#define PORT_LINKSTS 0x00208
+#define PORT_LINKSTS_UP BIT(0)
+#define PORT_LINKSTS_BUSY BIT(2)
+#define PORT_LINKCMDSTS 0x00210
+#define PORT_OUTS_NPREQS 0x00284
+#define PORT_OUTS_NPREQS_REQ BIT(24)
+#define PORT_OUTS_NPREQS_CPL BIT(16)
+#define PORT_RXWR_FIFO 0x00288
+#define PORT_RXWR_FIFO_HDR GENMASK(15, 10)
+#define PORT_RXWR_FIFO_DATA GENMASK(9, 0)
+#define PORT_RXRD_FIFO 0x0028C
+#define PORT_RXRD_FIFO_REQ GENMASK(6, 0)
+#define PORT_OUTS_CPLS 0x00290
+#define PORT_OUTS_CPLS_SHRD GENMASK(14, 8)
+#define PORT_OUTS_CPLS_WAIT GENMASK(6, 0)
+#define PORT_APPCLK 0x00800
+#define PORT_APPCLK_EN BIT(0)
+#define PORT_APPCLK_CGDIS BIT(8)
+#define PORT_STATUS 0x00804
+#define PORT_STATUS_READY BIT(0)
+#define PORT_REFCLK 0x00810
+#define PORT_REFCLK_EN BIT(0)
+#define PORT_REFCLK_CGDIS BIT(8)
+#define PORT_PERST 0x00814
+#define PORT_PERST_OFF BIT(0)
+#define PORT_RID2SID(i16) (0x00828 + 4 * (i16))
+#define PORT_RID2SID_VALID BIT(31)
+#define PORT_RID2SID_SID_SHIFT 16
+#define PORT_RID2SID_BUS_SHIFT 8
+#define PORT_RID2SID_DEV_SHIFT 3
+#define PORT_RID2SID_FUNC_SHIFT 0
+#define PORT_OUTS_PREQS_HDR 0x00980
+#define PORT_OUTS_PREQS_HDR_MASK GENMASK(9, 0)
+#define PORT_OUTS_PREQS_DATA 0x00984
+#define PORT_OUTS_PREQS_DATA_MASK GENMASK(15, 0)
+#define PORT_TUNCTRL 0x00988
+#define PORT_TUNCTRL_PERST_ON BIT(0)
+#define PORT_TUNCTRL_PERST_ACK_REQ BIT(1)
+#define PORT_TUNSTAT 0x0098c
+#define PORT_TUNSTAT_PERST_ON BIT(0)
+#define PORT_TUNSTAT_PERST_ACK_PEND BIT(1)
+#define PORT_PREFMEM_ENABLE 0x00994
+
+/* The doorbell address is "well known" */
+#define DOORBELL_ADDR 0xfffff000
+
+/* The hardware exposes 3 ports. Port 0 (WiFi and Bluetooth) is special, as it
+ * is power-gated by SMC to facilitate rfkill.
+ */
+enum apple_pcie_port {
+ APPLE_PCIE_PORT_RADIO = 0,
+ APPLE_PCIE_PORT_USB = 1,
+ APPLE_PCIE_PORT_ETHERNET = 2,
+ APPLE_PCIE_NUM_PORTS
+};
+
+struct apple_pcie {
+ u32 msi_base;
+ u32 nvecs;
+ struct mutex lock;
+ struct device *dev;
+ struct irq_domain *domain;
+ unsigned long *bitmap;
+ void __iomem *rc;
+};
+
+static inline void rmwl(u32 clr, u32 set, void __iomem *addr)
+{
+ writel((readl(addr) & ~clr) | set, addr);
+}
+
+static void apple_msi_top_irq_mask(struct irq_data *d)
+{
+ pci_msi_mask_irq(d);
+ irq_chip_mask_parent(d);
+}
+
+static void apple_msi_top_irq_unmask(struct irq_data *d)
+{
+ pci_msi_unmask_irq(d);
+ irq_chip_unmask_parent(d);
+}
+
+static void apple_msi_top_irq_eoi(struct irq_data *d)
+{
+ irq_chip_eoi_parent(d);
+}
+
+static struct irq_chip apple_msi_top_chip = {
+ .name = "PCIe MSI",
+ .irq_mask = apple_msi_top_irq_mask,
+ .irq_unmask = apple_msi_top_irq_unmask,
+ .irq_eoi = apple_msi_top_irq_eoi,
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+ .irq_set_type = irq_chip_set_type_parent,
+};
+
+static void apple_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
+{
+ msg->address_hi = 0;
+ msg->address_lo = DOORBELL_ADDR;
+ msg->data = data->hwirq;
+}
+
+static struct irq_chip apple_msi_bottom_chip = {
+ .name = "MSI",
+ .irq_mask = irq_chip_mask_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+ .irq_set_type = irq_chip_set_type_parent,
+ .irq_compose_msi_msg = apple_msi_compose_msg,
+};
+
+static int apple_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *args)
+{
+ struct apple_pcie *pcie = domain->host_data;
+ struct irq_fwspec fwspec;
+ unsigned int i;
+ int ret, hwirq;
+
+ mutex_lock(&pcie->lock);
+
+ hwirq = bitmap_find_free_region(pcie->bitmap, pcie->nvecs,
+ order_base_2(nr_irqs));
+
+ mutex_unlock(&pcie->lock);
+
+ if (hwirq < 0)
+ return -ENOSPC;
+
+ fwspec.fwnode = domain->parent->fwnode;
+ fwspec.param_count = 3;
+ fwspec.param[0] = 0;
+ fwspec.param[1] = hwirq + pcie->msi_base;
+ fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
+
+ ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, &fwspec);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < nr_irqs; i++) {
+ irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+ &apple_msi_bottom_chip,
+ domain->host_data);
+ }
+
+ return 0;
+}
+
+static void apple_msi_domain_free(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs)
+{
+ struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+ struct apple_pcie *pcie = domain->host_data;
+
+ mutex_lock(&pcie->lock);
+
+ bitmap_release_region(pcie->bitmap, d->hwirq, order_base_2(nr_irqs));
+
+ mutex_unlock(&pcie->lock);
+}
+
+static const struct irq_domain_ops apple_msi_domain_ops = {
+ .alloc = apple_msi_domain_alloc,
+ .free = apple_msi_domain_free,
+};
+
+static struct msi_domain_info apple_msi_info = {
+ .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
+ .chip = &apple_msi_top_chip,
+};
+
+static int apple_pcie_setup_refclk(void __iomem *rc,
+ void __iomem *port,
+ unsigned int idx)
+{
+ u32 stat;
+ int res;
+
+ res = readl_poll_timeout(rc + CORE_RC_PHYIF_STAT, stat,
+ stat & CORE_RC_PHYIF_STAT_REFCLK, 100, 50000);
+ if (res < 0)
+ return res;
+
+ rmwl(0, CORE_LANE_CTL_CFGACC, rc + CORE_LANE_CTL(idx));
+ rmwl(0, CORE_LANE_CFG_REFCLK0REQ, rc + CORE_LANE_CFG(idx));
+
+ res = readl_poll_timeout(rc + CORE_LANE_CFG(idx), stat,
+ stat & CORE_LANE_CFG_REFCLK0ACK, 100, 50000);
+ if (res < 0)
+ return res;
+
+ rmwl(0, CORE_LANE_CFG_REFCLK1, rc + CORE_LANE_CFG(idx));
+ res = readl_poll_timeout(rc + CORE_LANE_CFG(idx), stat,
+ stat & CORE_LANE_CFG_REFCLK1, 100, 50000);
+
+ if (res < 0)
+ return res;
+
+ rmwl(CORE_LANE_CTL_CFGACC, 0, rc + CORE_LANE_CTL(idx));
+ udelay(1);
+ rmwl(0, CORE_LANE_CFG_REFCLKEN, rc + CORE_LANE_CFG(idx));
+
+ rmwl(0, PORT_REFCLK_EN, port + PORT_REFCLK);
+
+ return 0;
+}
+
+static int apple_pcie_setup_port(struct apple_pcie *pcie, unsigned int i)
+{
+ struct fwnode_handle *fwnode = dev_fwnode(pcie->dev);
+ void __iomem *port;
+ struct gpio_desc *reset;
+ uint32_t stat;
+ int ret;
+
+ port = devm_of_iomap(pcie->dev, to_of_node(fwnode), i + 3, NULL);
+
+ if (IS_ERR(port))
+ return -ENODEV;
+
+ reset = devm_gpiod_get_index(pcie->dev, "reset", i, 0);
+ if (IS_ERR(reset))
+ return PTR_ERR(reset);
+
+ gpiod_direction_output(reset, 0);
+
+ rmwl(0, PORT_APPCLK_EN, port + PORT_APPCLK);
+
+ ret = apple_pcie_setup_refclk(pcie->rc, port, i);
+ if (ret < 0)
+ return ret;
+
+ rmwl(0, PORT_PERST_OFF, port + PORT_PERST);
+ gpiod_set_value(reset, 1);
+
+ ret = readl_poll_timeout(port + PORT_STATUS, stat,
+ stat & PORT_STATUS_READY, 100, 250000);
+ if (ret < 0) {
+ dev_err(pcie->dev, "port %u ready wait timeout\n", i);
+ return ret;
+ }
+
+ rmwl(PORT_REFCLK_CGDIS, 0, port + PORT_REFCLK);
+ rmwl(PORT_APPCLK_CGDIS, 0, port + PORT_APPCLK);
+
+ ret = readl_poll_timeout(port + PORT_LINKSTS, stat,
+ !(stat & PORT_LINKSTS_BUSY), 100, 250000);
+ if (ret < 0) {
+ dev_err(pcie->dev, "port %u link not busy timeout\n", i);
+ return ret;
+ }
+
+ writel(0xfb512fff, port + PORT_INTMSKSET);
+
+ writel(PORT_INT_LINK_UP | PORT_INT_LINK_DOWN | PORT_INT_AF_TIMEOUT |
+ PORT_INT_REQADDR_GT32 | PORT_INT_MSI_ERR |
+ PORT_INT_MSI_BAD_DATA | PORT_INT_CPL_ABORT |
+ PORT_INT_CPL_TIMEOUT | (1 << 26), port + PORT_INTSTAT);
+
+ usleep_range(5000, 10000);
+
+ rmwl(0, PORT_LTSSMCTL_START, port + PORT_LTSSMCTL);
+
+ ret = readl_poll_timeout(port + PORT_LINKSTS, stat,
+ stat & PORT_LINKSTS_UP, 100, 500000);
+ if (ret < 0) {
+ dev_err(pcie->dev, "port %u link up wait timeout\n", i);
+ return ret;
+ }
+
+ writel(DOORBELL_ADDR, port + PORT_MSIADDR);
+ writel(0, port + PORT_MSIBASE);
+ writel((5 << PORT_MSICFG_L2MSINUM_SHIFT) | PORT_MSICFG_EN,
+ port + PORT_MSICFG);
+
+ return 0;
+}
+
+static int apple_msi_init(struct apple_pcie *pcie)
+{
+ struct fwnode_handle *fwnode = dev_fwnode(pcie->dev);
+ struct device_node *parent_intc;
+ struct irq_domain *parent;
+ int ret, i;
+
+ pcie->rc = devm_of_iomap(pcie->dev, to_of_node(fwnode), 1, NULL);
+
+ if (IS_ERR(pcie->rc))
+ return -ENODEV;
+
+ for (i = 0; i < APPLE_PCIE_NUM_PORTS; ++i) {
+ /* Bringing up the radios requires SMC. Skip for now. */
+ if (i == APPLE_PCIE_PORT_RADIO)
+ continue;
+
+ ret = apple_pcie_setup_port(pcie, i);
+
+ if (ret) {
+ dev_err(pcie->dev, "Port %u setup fail: %d\n", i, ret);
+ return ret;
+ }
+ }
+
+ ret = of_property_read_u32_index(to_of_node(fwnode), "msi-interrupts",
+ 0, &pcie->msi_base);
+ if (ret)
+ return ret;
+
+ ret = of_property_read_u32_index(to_of_node(fwnode), "msi-interrupts",
+ 1, &pcie->nvecs);
+ if (ret)
+ return ret;
+
+ pcie->bitmap = devm_kcalloc(pcie->dev, BITS_TO_LONGS(pcie->nvecs),
+ sizeof(long), GFP_KERNEL);
+ if (!pcie->bitmap)
+ return -ENOMEM;
+
+ parent_intc = of_irq_find_parent(to_of_node(fwnode));
+ parent = irq_find_host(parent_intc);
+ if (!parent_intc || !parent) {
+ dev_err(pcie->dev, "failed to find parent domain\n");
+ return -ENXIO;
+ }
+
+ parent = irq_domain_create_hierarchy(parent, 0, pcie->nvecs, fwnode,
+ &apple_msi_domain_ops, pcie);
+ if (!parent) {
+ dev_err(pcie->dev, "failed to create IRQ domain\n");
+ return -ENOMEM;
+ }
+ irq_domain_update_bus_token(parent, DOMAIN_BUS_NEXUS);
+
+ pcie->domain = pci_msi_create_irq_domain(fwnode, &apple_msi_info,
+ parent);
+ if (!pcie->domain) {
+ dev_err(pcie->dev, "failed to create MSI domain\n");
+ irq_domain_remove(parent);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int apple_m1_pci_init(struct pci_config_window *cfg)
+{
+ struct device *dev = cfg->parent;
+ struct apple_pcie *pcie;
+
+ pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+ if (!pcie)
+ return -ENOMEM;
+
+ pcie->dev = dev;
+
+ mutex_init(&pcie->lock);
+
+ return apple_msi_init(pcie);
+}
+
+static const struct pci_ecam_ops apple_m1_cfg_ecam_ops = {
+ .init = apple_m1_pci_init,
+ .pci_ops = {
+ .map_bus = pci_ecam_map_bus,
+ .read = pci_generic_config_read,
+ .write = pci_generic_config_write,
+ }
+};
+
+static const struct of_device_id apple_pci_of_match[] = {
+ { .compatible = "apple,pcie", .data = &apple_m1_cfg_ecam_ops },
+ { },
+};
+MODULE_DEVICE_TABLE(of, gen_pci_of_match);
+
+static struct platform_driver apple_pci_driver = {
+ .driver = {
+ .name = "pcie-apple",
+ .of_match_table = apple_pci_of_match,
+ },
+ .probe = pci_host_common_probe,
+ .remove = pci_host_common_remove,
+};
+module_platform_driver(apple_pci_driver);
+
+MODULE_LICENSE("GPL v2");
--
2.30.2