PCI: keystone: Add TI Keystone PCIe driver
The Keystone PCIe controller is based on v3.65 version of the Designware
h/w. Main differences are:
1. No ATU support
2. Legacy and MSI IRQ functions are implemented in application register
space
3. MSI interrupts are multiplexed over 8 IRQ lines to the Host side.
All of the application register space handing code is organized into
pci-keystone-dw.c and the functions are called from pci-keystone.c to
implement PCI controller driver. Also add necessary DT documentation and
update the MAINTAINERS file for the driver.
[bhelgaas: spelling and whitespace fixes]
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Grant Likely <grant.likely@linaro.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: Mohit Kumar <mohit.kumar@st.com>
CC: Pratyush Anand <pratyush.anand@st.com>
CC: Jingoo Han <jg1.han@samsung.com>
CC: Richard Zhu <r65037@freescale.com>
CC: Kishon Vijay Abraham I <kishon@ti.com>
CC: Marek Vasut <marex@denx.de>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Pawel Moll <pawel.moll@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
CC: Ian Campbell <ijc+devicetree@hellion.org.uk>
CC: Kumar Gala <galak@codeaurora.org>
CC: Randy Dunlap <rdunlap@infradead.org>
CC: Grant Likely <grant.likely@linaro.org>diff --git a/drivers/pci/host/pci-keystone-dw.c b/drivers/pci/host/pci-keystone-dw.c
new file mode 100644
index 0000000..2434786
--- /dev/null
+++ b/drivers/pci/host/pci-keystone-dw.c
@@ -0,0 +1,516 @@
+/*
+ * Designware application register space functions for Keystone PCI controller
+ *
+ * Copyright (C) 2013-2014 Texas Instruments., Ltd.
+ * http://www.ti.com
+ *
+ * Author: Murali Karicheri <m-karicheri2@ti.com>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+#include "pcie-designware.h"
+#include "pci-keystone.h"
+
+/* Application register defines */
+#define LTSSM_EN_VAL 1
+#define LTSSM_STATE_MASK 0x1f
+#define LTSSM_STATE_L0 0x11
+#define DBI_CS2_EN_VAL 0x20
+#define OB_XLAT_EN_VAL 2
+
+/* Application registers */
+#define CMD_STATUS 0x004
+#define CFG_SETUP 0x008
+#define OB_SIZE 0x030
+#define CFG_PCIM_WIN_SZ_IDX 3
+#define CFG_PCIM_WIN_CNT 32
+#define SPACE0_REMOTE_CFG_OFFSET 0x1000
+#define OB_OFFSET_INDEX(n) (0x200 + (8 * n))
+#define OB_OFFSET_HI(n) (0x204 + (8 * n))
+
+/* IRQ register defines */
+#define IRQ_EOI 0x050
+#define IRQ_STATUS 0x184
+#define IRQ_ENABLE_SET 0x188
+#define IRQ_ENABLE_CLR 0x18c
+
+#define MSI_IRQ 0x054
+#define MSI0_IRQ_STATUS 0x104
+#define MSI0_IRQ_ENABLE_SET 0x108
+#define MSI0_IRQ_ENABLE_CLR 0x10c
+#define IRQ_STATUS 0x184
+#define MSI_IRQ_OFFSET 4
+
+/* Config space registers */
+#define DEBUG0 0x728
+
+#define to_keystone_pcie(x) container_of(x, struct keystone_pcie, pp)
+
+static inline struct pcie_port *sys_to_pcie(struct pci_sys_data *sys)
+{
+ return sys->private_data;
+}
+
+static inline void update_reg_offset_bit_pos(u32 offset, u32 *reg_offset,
+ u32 *bit_pos)
+{
+ *reg_offset = offset % 8;
+ *bit_pos = offset >> 3;
+}
+
+u32 ks_dw_pcie_get_msi_data(struct pcie_port *pp)
+{
+ struct keystone_pcie *ks_pcie = to_keystone_pcie(pp);
+
+ return ks_pcie->app.start + MSI_IRQ;
+}
+
+void ks_dw_pcie_handle_msi_irq(struct keystone_pcie *ks_pcie, int offset)
+{
+ struct pcie_port *pp = &ks_pcie->pp;
+ u32 pending, vector;
+ int src, virq;
+
+ pending = readl(ks_pcie->va_app_base + MSI0_IRQ_STATUS + (offset << 4));
+
+ /*
+ * MSI0 status bit 0-3 shows vectors 0, 8, 16, 24, MSI1 status bit
+ * shows 1, 9, 17, 25 and so forth
+ */
+ for (src = 0; src < 4; src++) {
+ if (BIT(src) & pending) {
+ vector = offset + (src << 3);
+ virq = irq_linear_revmap(pp->irq_domain, vector);
+ dev_dbg(pp->dev, "irq: bit %d, vector %d, virq %d\n",
+ src, vector, virq);
+ generic_handle_irq(virq);
+ }
+ }
+}
+
+static void ks_dw_pcie_msi_irq_ack(struct irq_data *d)
+{
+ u32 offset, reg_offset, bit_pos;
+ struct keystone_pcie *ks_pcie;
+ unsigned int irq = d->irq;
+ struct msi_desc *msi;
+ struct pcie_port *pp;
+
+ msi = irq_get_msi_desc(irq);
+ pp = sys_to_pcie(msi->dev->bus->sysdata);
+ ks_pcie = to_keystone_pcie(pp);
+ offset = irq - irq_linear_revmap(pp->irq_domain, 0);
+ update_reg_offset_bit_pos(offset, ®_offset, &bit_pos);
+
+ writel(BIT(bit_pos),
+ ks_pcie->va_app_base + MSI0_IRQ_STATUS + (reg_offset << 4));
+ writel(reg_offset + MSI_IRQ_OFFSET, ks_pcie->va_app_base + IRQ_EOI);
+}
+
+void ks_dw_pcie_msi_set_irq(struct pcie_port *pp, int irq)
+{
+ u32 reg_offset, bit_pos;
+ struct keystone_pcie *ks_pcie = to_keystone_pcie(pp);
+
+ update_reg_offset_bit_pos(irq, ®_offset, &bit_pos);
+ writel(BIT(bit_pos),
+ ks_pcie->va_app_base + MSI0_IRQ_ENABLE_SET + (reg_offset << 4));
+}
+
+void ks_dw_pcie_msi_clear_irq(struct pcie_port *pp, int irq)
+{
+ u32 reg_offset, bit_pos;
+ struct keystone_pcie *ks_pcie = to_keystone_pcie(pp);
+
+ update_reg_offset_bit_pos(irq, ®_offset, &bit_pos);
+ writel(BIT(bit_pos),
+ ks_pcie->va_app_base + MSI0_IRQ_ENABLE_CLR + (reg_offset << 4));
+}
+
+static void ks_dw_pcie_msi_irq_mask(struct irq_data *d)
+{
+ struct keystone_pcie *ks_pcie;
+ unsigned int irq = d->irq;
+ struct msi_desc *msi;
+ struct pcie_port *pp;
+ u32 offset;
+
+ msi = irq_get_msi_desc(irq);
+ pp = sys_to_pcie(msi->dev->bus->sysdata);
+ ks_pcie = to_keystone_pcie(pp);
+ offset = irq - irq_linear_revmap(pp->irq_domain, 0);
+
+ /* Mask the end point if PVM implemented */
+ if (IS_ENABLED(CONFIG_PCI_MSI)) {
+ if (msi->msi_attrib.maskbit)
+ mask_msi_irq(d);
+ }
+
+ ks_dw_pcie_msi_clear_irq(pp, offset);
+}
+
+static void ks_dw_pcie_msi_irq_unmask(struct irq_data *d)
+{
+ struct keystone_pcie *ks_pcie;
+ unsigned int irq = d->irq;
+ struct msi_desc *msi;
+ struct pcie_port *pp;
+ u32 offset;
+
+ msi = irq_get_msi_desc(irq);
+ pp = sys_to_pcie(msi->dev->bus->sysdata);
+ ks_pcie = to_keystone_pcie(pp);
+ offset = irq - irq_linear_revmap(pp->irq_domain, 0);
+
+ /* Mask the end point if PVM implemented */
+ if (IS_ENABLED(CONFIG_PCI_MSI)) {
+ if (msi->msi_attrib.maskbit)
+ unmask_msi_irq(d);
+ }
+
+ ks_dw_pcie_msi_set_irq(pp, offset);
+}
+
+static struct irq_chip ks_dw_pcie_msi_irq_chip = {
+ .name = "Keystone-PCIe-MSI-IRQ",
+ .irq_ack = ks_dw_pcie_msi_irq_ack,
+ .irq_mask = ks_dw_pcie_msi_irq_mask,
+ .irq_unmask = ks_dw_pcie_msi_irq_unmask,
+};
+
+static int ks_dw_pcie_msi_map(struct irq_domain *domain, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ irq_set_chip_and_handler(irq, &ks_dw_pcie_msi_irq_chip,
+ handle_level_irq);
+ irq_set_chip_data(irq, domain->host_data);
+ set_irq_flags(irq, IRQF_VALID);
+
+ return 0;
+}
+
+const struct irq_domain_ops ks_dw_pcie_msi_domain_ops = {
+ .map = ks_dw_pcie_msi_map,
+};
+
+int ks_dw_pcie_msi_host_init(struct pcie_port *pp, struct msi_chip *chip)
+{
+ struct keystone_pcie *ks_pcie = to_keystone_pcie(pp);
+ int i;
+
+ pp->irq_domain = irq_domain_add_linear(ks_pcie->msi_intc_np,
+ MAX_MSI_IRQS,
+ &ks_dw_pcie_msi_domain_ops,
+ chip);
+ if (!pp->irq_domain) {
+ dev_err(pp->dev, "irq domain init failed\n");
+ return -ENXIO;
+ }
+
+ for (i = 0; i < MAX_MSI_IRQS; i++)
+ irq_create_mapping(pp->irq_domain, i);
+
+ return 0;
+}
+
+void ks_dw_pcie_enable_legacy_irqs(struct keystone_pcie *ks_pcie)
+{
+ int i;
+
+ for (i = 0; i < MAX_LEGACY_IRQS; i++)
+ writel(0x1, ks_pcie->va_app_base + IRQ_ENABLE_SET + (i << 4));
+}
+
+void ks_dw_pcie_handle_legacy_irq(struct keystone_pcie *ks_pcie, int offset)
+{
+ struct pcie_port *pp = &ks_pcie->pp;
+ u32 pending;
+ int virq;
+
+ pending = readl(ks_pcie->va_app_base + IRQ_STATUS + (offset << 4));
+
+ if (BIT(0) & pending) {
+ virq = irq_linear_revmap(ks_pcie->legacy_irq_domain, offset);
+ dev_dbg(pp->dev, ": irq: irq_offset %d, virq %d\n", offset,
+ virq);
+ generic_handle_irq(virq);
+ }
+
+ /* EOI the INTx interrupt */
+ writel(offset, ks_pcie->va_app_base + IRQ_EOI);
+}
+
+static void ks_dw_pcie_ack_legacy_irq(struct irq_data *d)
+{
+}
+
+static void ks_dw_pcie_mask_legacy_irq(struct irq_data *d)
+{
+}
+
+static void ks_dw_pcie_unmask_legacy_irq(struct irq_data *d)
+{
+}
+
+static struct irq_chip ks_dw_pcie_legacy_irq_chip = {
+ .name = "Keystone-PCI-Legacy-IRQ",
+ .irq_ack = ks_dw_pcie_ack_legacy_irq,
+ .irq_mask = ks_dw_pcie_mask_legacy_irq,
+ .irq_unmask = ks_dw_pcie_unmask_legacy_irq,
+};
+
+static int ks_dw_pcie_init_legacy_irq_map(struct irq_domain *d,
+ unsigned int irq, irq_hw_number_t hw_irq)
+{
+ irq_set_chip_and_handler(irq, &ks_dw_pcie_legacy_irq_chip,
+ handle_level_irq);
+ irq_set_chip_data(irq, d->host_data);
+ set_irq_flags(irq, IRQF_VALID);
+
+ return 0;
+}
+
+static const struct irq_domain_ops ks_dw_pcie_legacy_irq_domain_ops = {
+ .map = ks_dw_pcie_init_legacy_irq_map,
+ .xlate = irq_domain_xlate_onetwocell,
+};
+
+/**
+ * ks_dw_pcie_set_dbi_mode() - Set DBI mode to access overlaid BAR mask
+ * registers
+ *
+ * Since modification of dbi_cs2 involves different clock domain, read the
+ * status back to ensure the transition is complete.
+ */
+static void ks_dw_pcie_set_dbi_mode(void __iomem *reg_virt)
+{
+ u32 val;
+
+ writel(DBI_CS2_EN_VAL | readl(reg_virt + CMD_STATUS),
+ reg_virt + CMD_STATUS);
+
+ do {
+ val = readl(reg_virt + CMD_STATUS);
+ } while (!(val & DBI_CS2_EN_VAL));
+}
+
+/**
+ * ks_dw_pcie_clear_dbi_mode() - Disable DBI mode
+ *
+ * Since modification of dbi_cs2 involves different clock domain, read the
+ * status back to ensure the transition is complete.
+ */
+static void ks_dw_pcie_clear_dbi_mode(void __iomem *reg_virt)
+{
+ u32 val;
+
+ writel(~DBI_CS2_EN_VAL & readl(reg_virt + CMD_STATUS),
+ reg_virt + CMD_STATUS);
+
+ do {
+ val = readl(reg_virt + CMD_STATUS);
+ } while (val & DBI_CS2_EN_VAL);
+}
+
+void ks_dw_pcie_setup_rc_app_regs(struct keystone_pcie *ks_pcie)
+{
+ struct pcie_port *pp = &ks_pcie->pp;
+ u32 start = pp->mem.start, end = pp->mem.end;
+ int i, tr_size;
+
+ /* Disable BARs for inbound access */
+ ks_dw_pcie_set_dbi_mode(ks_pcie->va_app_base);
+ writel(0, pp->dbi_base + PCI_BASE_ADDRESS_0);
+ writel(0, pp->dbi_base + PCI_BASE_ADDRESS_1);
+ ks_dw_pcie_clear_dbi_mode(ks_pcie->va_app_base);
+
+ /* Set outbound translation size per window division */
+ writel(CFG_PCIM_WIN_SZ_IDX & 0x7, ks_pcie->va_app_base + OB_SIZE);
+
+ tr_size = (1 << (CFG_PCIM_WIN_SZ_IDX & 0x7)) * SZ_1M;
+
+ /* Using Direct 1:1 mapping of RC <-> PCI memory space */
+ for (i = 0; (i < CFG_PCIM_WIN_CNT) && (start < end); i++) {
+ writel(start | 1, ks_pcie->va_app_base + OB_OFFSET_INDEX(i));
+ writel(0, ks_pcie->va_app_base + OB_OFFSET_HI(i));
+ start += tr_size;
+ }
+
+ /* Enable OB translation */
+ writel(OB_XLAT_EN_VAL | readl(ks_pcie->va_app_base + CMD_STATUS),
+ ks_pcie->va_app_base + CMD_STATUS);
+}
+
+/**
+ * ks_pcie_cfg_setup() - Set up configuration space address for a device
+ *
+ * @ks_pcie: ptr to keystone_pcie structure
+ * @bus: Bus number the device is residing on
+ * @devfn: device, function number info
+ *
+ * Forms and returns the address of configuration space mapped in PCIESS
+ * address space 0. Also configures CFG_SETUP for remote configuration space
+ * access.
+ *
+ * The address space has two regions to access configuration - local and remote.
+ * We access local region for bus 0 (as RC is attached on bus 0) and remote
+ * region for others with TYPE 1 access when bus > 1. As for device on bus = 1,
+ * we will do TYPE 0 access as it will be on our secondary bus (logical).
+ * CFG_SETUP is needed only for remote configuration access.
+ */
+static void __iomem *ks_pcie_cfg_setup(struct keystone_pcie *ks_pcie, u8 bus,
+ unsigned int devfn)
+{
+ u8 device = PCI_SLOT(devfn), function = PCI_FUNC(devfn);
+ struct pcie_port *pp = &ks_pcie->pp;
+ u32 regval;
+
+ if (bus == 0)
+ return pp->dbi_base;
+
+ regval = (bus << 16) | (device << 8) | function;
+
+ /*
+ * Since Bus#1 will be a virtual bus, we need to have TYPE0
+ * access only.
+ * TYPE 1
+ */
+ if (bus != 1)
+ regval |= BIT(24);
+
+ writel(regval, ks_pcie->va_app_base + CFG_SETUP);
+ return pp->va_cfg0_base;
+}
+
+int ks_dw_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
+ unsigned int devfn, int where, int size, u32 *val)
+{
+ struct keystone_pcie *ks_pcie = to_keystone_pcie(pp);
+ u8 bus_num = bus->number;
+ void __iomem *addr;
+
+ addr = ks_pcie_cfg_setup(ks_pcie, bus_num, devfn);
+
+ return dw_pcie_cfg_read(addr + (where & ~0x3), where, size, val);
+}
+
+int ks_dw_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
+ unsigned int devfn, int where, int size, u32 val)
+{
+ struct keystone_pcie *ks_pcie = to_keystone_pcie(pp);
+ u8 bus_num = bus->number;
+ void __iomem *addr;
+
+ addr = ks_pcie_cfg_setup(ks_pcie, bus_num, devfn);
+
+ return dw_pcie_cfg_write(addr + (where & ~0x3), where, size, val);
+}
+
+/**
+ * ks_dw_pcie_v3_65_scan_bus() - keystone scan_bus post initialization
+ *
+ * This sets BAR0 to enable inbound access for MSI_IRQ register
+ */
+void ks_dw_pcie_v3_65_scan_bus(struct pcie_port *pp)
+{
+ struct keystone_pcie *ks_pcie = to_keystone_pcie(pp);
+
+ /* Configure and set up BAR0 */
+ ks_dw_pcie_set_dbi_mode(ks_pcie->va_app_base);
+
+ /* Enable BAR0 */
+ writel(1, pp->dbi_base + PCI_BASE_ADDRESS_0);
+ writel(SZ_4K - 1, pp->dbi_base + PCI_BASE_ADDRESS_0);
+
+ ks_dw_pcie_clear_dbi_mode(ks_pcie->va_app_base);
+
+ /*
+ * For BAR0, just setting bus address for inbound writes (MSI) should
+ * be sufficient. Use physical address to avoid any conflicts.
+ */
+ writel(ks_pcie->app.start, pp->dbi_base + PCI_BASE_ADDRESS_0);
+}
+
+/**
+ * ks_dw_pcie_link_up() - Check if link up
+ */
+int ks_dw_pcie_link_up(struct pcie_port *pp)
+{
+ u32 val = readl(pp->dbi_base + DEBUG0);
+
+ return (val & LTSSM_STATE_MASK) == LTSSM_STATE_L0;
+}
+
+void ks_dw_pcie_initiate_link_train(struct keystone_pcie *ks_pcie)
+{
+ u32 val;
+
+ /* Disable Link training */
+ val = readl(ks_pcie->va_app_base + CMD_STATUS);
+ val &= ~LTSSM_EN_VAL;
+ writel(LTSSM_EN_VAL | val, ks_pcie->va_app_base + CMD_STATUS);
+
+ /* Initiate Link Training */
+ val = readl(ks_pcie->va_app_base + CMD_STATUS);
+ writel(LTSSM_EN_VAL | val, ks_pcie->va_app_base + CMD_STATUS);
+}
+
+/**
+ * ks_dw_pcie_host_init() - initialize host for v3_65 dw hardware
+ *
+ * Ioremap the register resources, initialize legacy irq domain
+ * and call dw_pcie_v3_65_host_init() API to initialize the Keystone
+ * PCI host controller.
+ */
+int __init ks_dw_pcie_host_init(struct keystone_pcie *ks_pcie,
+ struct device_node *msi_intc_np)
+{
+ struct pcie_port *pp = &ks_pcie->pp;
+ struct platform_device *pdev = to_platform_device(pp->dev);
+ struct resource *res;
+
+ /* Index 0 is the config reg. space address */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pp->dbi_base = devm_ioremap_resource(pp->dev, res);
+ if (IS_ERR(pp->dbi_base))
+ return PTR_ERR(pp->dbi_base);
+
+ /*
+ * We set these same and is used in pcie rd/wr_other_conf
+ * functions
+ */
+ pp->va_cfg0_base = pp->dbi_base + SPACE0_REMOTE_CFG_OFFSET;
+ pp->va_cfg1_base = pp->va_cfg0_base;
+
+ /* Index 1 is the application reg. space address */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ ks_pcie->app = *res;
+ ks_pcie->va_app_base = devm_ioremap_resource(pp->dev, res);
+ if (IS_ERR(ks_pcie->va_app_base))
+ return PTR_ERR(ks_pcie->va_app_base);
+
+ /* Create legacy IRQ domain */
+ ks_pcie->legacy_irq_domain =
+ irq_domain_add_linear(ks_pcie->legacy_intc_np,
+ MAX_LEGACY_IRQS,
+ &ks_dw_pcie_legacy_irq_domain_ops,
+ NULL);
+ if (!ks_pcie->legacy_irq_domain) {
+ dev_err(pp->dev, "Failed to add irq domain for legacy irqs\n");
+ return -EINVAL;
+ }
+
+ return dw_pcie_host_init(pp);
+}