[PATCH v1 4/5] pci: dw: add common functions to support old hw based pci driver

Murali Karicheri
2014-05-15T16:01:31Z

The older version of DW hw has application space registers for MSI
controller and inbound/outbound access configuration. Also the legacy
interrupt has registers in the application space. Drivers such as
keystone pci uses these common functions to implement the driver.
These are re-factored from the original driver to separate files
to allow re-use for the next driver that is based on old dw pci hw such
as that found on keystone.

CC: Santosh Shilimkar <santosh.shilimkar@ti.com>
CC: Mohit Kumar <mohit.kumar@st.com>
CC: Jingoo Han <jg1.han@samsung.com>
CC: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
---
drivers/pci/host/Kconfig | 6 +-
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pci-dw-old-msi.c | 150 +++++++++++++++
drivers/pci/host/pci-dw-old.c | 371 +++++++++++++++++++++++++++++++++++++
drivers/pci/host/pci-dw-old.h | 30 +++
5 files changed, 557 insertions(+), 1 deletion(-)
create mode 100644 drivers/pci/host/pci-dw-old-msi.c
create mode 100644 drivers/pci/host/pci-dw-old.c
create mode 100644 drivers/pci/host/pci-dw-old.h

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index a6f67ec..c4f4732 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -9,6 +9,11 @@ config PCI_MVEBU
config PCIE_DW
bool

+config PCI_DW_OLD
+ bool "Designware Old PCIe h/w"
+ help
+ Say Y here if the DW h/w is old version (3.65)
+
config PCI_EXYNOS
bool "Samsung Exynos PCIe controller"
depends on SOC_EXYNOS5440
@@ -32,5 +37,4 @@ config PCI_RCAR_GEN2
Say Y here if you want internal PCI support on R-Car Gen2 SoC.
There are 3 internal PCI controllers available with a single
built-in EHCI/OHCI host controller present on each one.
-
endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 13fb333..be5d939 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o
obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
+obj-$(CONFIG_PCI_DW_OLD) += pci-dw-old-msi.o pci-dw-old.o
diff --git a/drivers/pci/host/pci-dw-old-msi.c b/drivers/pci/host/pci-dw-old-msi.c
new file mode 100644
index 0000000..450bb2f
--- /dev/null
+++ b/drivers/pci/host/pci-dw-old-msi.c
@@ -0,0 +1,150 @@
+/*
+ * Designware(dw) old MSI controller (v3.65 or similar)
+ *
+ * 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/of_irq.h>
+#include <linux/kernel.h>
+#include <linux/msi.h>
+#include <linux/pci.h>
+
+#include "pcie-designware.h"
+#include "pci-dw-old.h"
+
+#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 IRQ_EOI 0x050
+#define MSI_IRQ_OFFSET 4
+
+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;
+}
+
+inline u32 dw_old_get_msi_data(struct pcie_port *pp)
+{
+ return pp->app_base + MSI_IRQ;
+}
+
+void dw_old_handle_msi_irq(struct pcie_port *pp, int offset)
+{
+ u32 pending, vector;
+ int src, virq;
+
+ pending = readl(pp->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 dw_old_msi_irq_ack(struct irq_data *d)
+{
+ u32 offset, reg_offset, bit_pos;
+ 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);
+ offset = irq - irq_linear_revmap(pp->irq_domain, 0);
+ update_reg_offset_bit_pos(offset, &reg_offset, &bit_pos);
+
+ writel(BIT(bit_pos),
+ pp->va_app_base + MSI0_IRQ_STATUS + (reg_offset << 4));
+ writel(reg_offset + MSI_IRQ_OFFSET, pp->va_app_base + IRQ_EOI);
+}
+
+static void dw_old_msi_irq_mask(struct irq_data *d)
+{
+ u32 offset, reg_offset, bit_pos;
+ 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);
+ offset = irq - irq_linear_revmap(pp->irq_domain, 0);
+ update_reg_offset_bit_pos(offset, &reg_offset, &bit_pos);
+
+ /* mask the end point if PVM implemented */
+ if (IS_ENABLED(CONFIG_PCI_MSI)) {
+ if (msi->msi_attrib.maskbit)
+ mask_msi_irq(d);
+ }
+
+ writel(BIT(bit_pos),
+ pp->va_app_base + MSI0_IRQ_ENABLE_CLR + (reg_offset << 4));
+}
+
+static void dw_old_msi_irq_unmask(struct irq_data *d)
+{
+ u32 offset, reg_offset, bit_pos;
+ 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);
+ offset = irq - irq_linear_revmap(pp->irq_domain, 0);
+ update_reg_offset_bit_pos(offset, &reg_offset, &bit_pos);
+
+ /* mask the end point if PVM implemented */
+ if (IS_ENABLED(CONFIG_PCI_MSI)) {
+ if (msi->msi_attrib.maskbit)
+ unmask_msi_irq(d);
+ }
+
+ writel(BIT(bit_pos),
+ pp->va_app_base + MSI0_IRQ_ENABLE_SET + (reg_offset << 4));
+}
+
+static struct irq_chip dw_old_msi_chip = {
+ .name = "PCI-DW-MSI-OLD",
+ .irq_ack = dw_old_msi_irq_ack,
+ .irq_mask = dw_old_msi_irq_mask,
+ .irq_unmask = dw_old_msi_irq_unmask,
+};
+
+static int dw_old_msi_map(struct irq_domain *domain, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ irq_set_chip_and_handler(irq, &dw_old_msi_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 dw_old_msi_domain_ops = {
+ .map = dw_old_msi_map,
+};
diff --git a/drivers/pci/host/pci-dw-old.c b/drivers/pci/host/pci-dw-old.c
new file mode 100644
index 0000000..b805013
--- /dev/null
+++ b/drivers/pci/host/pci-dw-old.c
@@ -0,0 +1,371 @@
+/*
+ * Designware(dw) old common functions (v3.65 or similar)
+ *
+ * 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_pci.h>
+#include <linux/pci.h>
+
+#include "pcie-designware.h"
+#include "pci-dw-old.h"
+
+/* Application register defines */
+#define LTSSM_EN_VAL BIT(0)
+#define LTSSM_STATE_MASK 0x1f
+#define LTSSM_STATE_L0 0x11
+#define DIR_SPD (1 << 17)
+#define DBI_CS2_EN_VAL BIT(5)
+#define OB_XLAT_EN_VAL BIT(1)
+
+/* 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))
+#define IRQ_EOI 0x050
+#define IRQ_STATUS 0x184
+#define IRQ_ENABLE_SET 0x188
+#define IRQ_ENABLE_CLR 0x18c
+
+/* Config space registers */
+#define DEBUG0 0x728
+#define PL_GEN2 0x80c
+
+static inline struct pcie_port *sys_to_pcie(struct pci_sys_data *sys)
+{
+ return sys->private_data;
+}
+
+void dw_old_enable_legacy_irqs(struct pcie_port *pp)
+{
+ int i;
+
+ for (i = 0; i < MAX_LEGACY_IRQS; i++)
+ writel(0x1, pp->va_app_base + IRQ_ENABLE_SET + (i << 4));
+}
+
+void dw_old_handle_legacy_irq(struct pcie_port *pp, int offset)
+{
+ u32 pending;
+ int virq;
+
+ pending = readl(pp->va_app_base + IRQ_STATUS + (offset << 4));
+
+ if (BIT(0) & pending) {
+ virq = irq_linear_revmap(pp->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, pp->va_app_base + IRQ_EOI);
+}
+
+static void dw_old_ack_irq(struct irq_data *d)
+{
+}
+
+static void dw_old_mask_irq(struct irq_data *d)
+{
+}
+
+static void dw_old_unmask_irq(struct irq_data *d)
+{
+}
+
+struct irq_chip dw_old_legacy_irq_chip = {
+ .name = "PCI-DW-LEGACY-old-irq",
+ .irq_ack = dw_old_ack_irq,
+ .irq_mask = dw_old_mask_irq,
+ .irq_unmask = dw_old_unmask_irq,
+};
+
+static int dw_old_init_legacy_irq_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ irq_set_chip_and_handler(irq, &dw_old_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 dw_old_legacy_irq_domian_ops = {
+ .map = dw_old_init_legacy_irq_map,
+ .xlate = irq_domain_xlate_onetwocell,
+};
+
+/**
+ * dw_old_set_outbound_trans() - Set PHYADDR <-> BUSADDR
+ * mapping for outbound
+ */
+void dw_old_setup_ob_regs(struct pcie_port *pp)
+{
+ u32 start = pp->mem.start, end = pp->mem.end;
+ int i, tr_size;
+
+ dev_dbg(pp->dev, "Setting outbound translation for %#x-%#x\n",
+ start, end);
+
+ /* Set outbound translation size per window division */
+ writel(CFG_PCIM_WIN_SZ_IDX & 0x7, pp->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, pp->va_app_base + OB_OFFSET_INDEX(i));
+ writel(0, pp->va_app_base + OB_OFFSET_HI(i));
+ start += tr_size;
+ }
+
+ /* Enable OB translation */
+ writel(OB_XLAT_EN_VAL | readl(pp->va_app_base + CMD_STATUS),
+ pp->va_app_base + CMD_STATUS);
+}
+
+/**
+ * dw_old_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 inline void dw_old_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));
+}
+
+/**
+ * dw_old_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 inline void dw_old_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 dw_old_disable_bars(struct pcie_port *pp)
+{
+ dw_old_set_dbi_mode(pp->va_app_base);
+ writel(0, pp->dbi_base + PCI_BASE_ADDRESS_0);
+ writel(0, pp->dbi_base + PCI_BASE_ADDRESS_1);
+ dw_old_clear_dbi_mode(pp->va_app_base);
+}
+
+/**
+ * dw_old_setup_config_addr() - Set up configuration space address for a
+ * device
+ *
+ * @pp: ptr to pcie_port structure
+ * @bus: Bus number the device is residing on
+ * @device: Device number
+ * @function: Function number in device
+ *
+ * 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 inline void __iomem *
+dw_old_setup_config_addr(struct pcie_port *pp, u8 bus, u8 device, u8 function)
+{
+ 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, pp->va_app_base + CFG_SETUP);
+
+ return pp->dbi_base + SPACE0_REMOTE_CFG_OFFSET;
+}
+
+int dw_old_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
+ unsigned int devfn, int where, int size, u32 *val)
+{
+ u8 bus_num = bus->number;
+ void __iomem *addr;
+ int ret;
+
+ addr = dw_old_setup_config_addr(pp, bus_num, PCI_SLOT(devfn),
+ PCI_FUNC(devfn));
+
+ ret = dw_pcie_cfg_read(addr + (where & ~0x3), where, size, val);
+
+ return ret;
+}
+
+int dw_old_wr_other_conf(struct pcie_port *pp,
+ struct pci_bus *bus, unsigned int devfn, int where,
+ int size, u32 val)
+{
+ u8 bus_num = bus->number;
+ void __iomem *addr;
+
+ addr = dw_old_setup_config_addr(pp, bus_num, PCI_SLOT(devfn),
+ PCI_FUNC(devfn));
+ return dw_pcie_cfg_write(addr + (where & ~0x3), where, size, val);
+}
+
+/**
+ * dw_old_set_ib_access() - Setup inbound access
+ *
+ * Configure BAR0 for inbound access. BAR0 is set up in h/w to have
+ * access to PCIESS application register space and just needs to set up
+ * inbound address (mainly used for MSI).
+ */
+static void dw_old_set_ib_access(struct pcie_port *pp)
+{
+ /* Configure and set up BAR0 */
+ dw_old_set_dbi_mode(pp->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);
+
+ dw_old_clear_dbi_mode(pp->va_app_base);
+ /*
+ * For BAR0, just setting bus address for inbound writes (MSI) should
+ * be sufficient. Use physical address to avoid any conflicts.
+ */
+ writel(pp->app_base, pp->dbi_base + PCI_BASE_ADDRESS_0);
+}
+
+/**
+ * dw_old_pcie_scan_bus() - common function to scan bus
+ *
+ * common functin to scan old dw based pci bus. This also sets inbound access
+ * after scan.
+ */
+static struct pci_bus *dw_old_pcie_scan_bus(int nr, struct pci_sys_data *sys)
+{
+ struct pcie_port *pp = sys_to_pcie(sys);
+ struct pci_bus *bus;
+
+ bus = dw_pcie_scan_bus(nr, sys);
+ if (bus)
+ dw_old_set_ib_access(pp);
+
+ return bus;
+}
+
+/**
+ * dw_old_pcie_link_up() - Check if link up
+ *
+ * optionally enable link train using link_train option and check if link is up.
+ */
+int dw_old_pcie_link_up(struct pcie_port *pp, int link_train)
+{
+ u32 val;
+
+ if (link_train) {
+ /*
+ * KeyStone devices do not support h/w autonomous
+ * link up-training to GEN2 from GEN1 in either EP/RC modes.
+ * The software needs to initiate speed change.
+ */
+ val = readl(pp->dbi_base + PL_GEN2);
+ writel(val | DIR_SPD, pp->dbi_base + PL_GEN2);
+ /*
+ * Initiate Link Training. We will delay for L0 as specified by
+ * standard, but will still proceed and return success
+ * irrespective of L0 status as this will be handled by explicit
+ * L0 state checks during enumeration.
+ */
+ val = readl(pp->va_app_base + CMD_STATUS);
+ writel(LTSSM_EN_VAL | val, pp->va_app_base + CMD_STATUS);
+
+ }
+
+ val = readl(pp->dbi_base + DEBUG0);
+
+ return (val & LTSSM_STATE_MASK) == LTSSM_STATE_L0;
+}
+
+static struct hw_pci dw_old_pcie_hw = {
+ .nr_controllers = 1,
+ .setup = dw_pcie_setup,
+ .scan = dw_old_pcie_scan_bus,
+ .swizzle = pci_common_swizzle,
+ .add_bus = dw_pcie_add_bus,
+ .map_irq = of_irq_parse_and_map_pci,
+};
+
+
+/**
+ * dw_old_pcie_host_init() - initialize host for old dw hardware
+ *
+ * Parse the pcie resources from DT bindings and then call common
+ * dw function to do host initialization.
+ */
+int __init dw_old_pcie_host_init(struct pcie_port *pp, struct device_node *np)
+{
+ int ret;
+
+ if (!pp->va_app_base)
+ return -EINVAL;
+
+ /* create legacy domain */
+ pp->legacy_irq_domain = irq_domain_add_linear(np,
+ MAX_LEGACY_IRQS,
+ &dw_old_legacy_irq_domian_ops, NULL);
+
+ if (!pp->legacy_irq_domain) {
+ dev_err(pp->dev, "Failed to add irq domain for legacy irqs\n");
+ return -EINVAL;
+ }
+
+ ret = dw_pcie_parse_resource(pp);
+ if (ret)
+ return ret;
+
+ return dw_pcie_common_host_init(pp, &dw_old_pcie_hw,
+ &dw_old_msi_domain_ops);
+}
diff --git a/drivers/pci/host/pci-dw-old.h b/drivers/pci/host/pci-dw-old.h
new file mode 100644
index 0000000..6e1af50
--- /dev/null
+++ b/drivers/pci/host/pci-dw-old.h
@@ -0,0 +1,30 @@
+/*
+ * Designware(dw) old MSI controller (v3.65 or similar) common includes
+ *
+ * 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.
+ */
+
+#define MAX_LEGACY_IRQS 4
+
+extern const struct irq_domain_ops dw_old_msi_domain_ops;
+
+void dw_old_handle_msi_irq(struct pcie_port *pp, int offset);
+u32 dw_old_get_msi_data(struct pcie_port *pp);
+void dw_old_enable_legacy_irqs(struct pcie_port *pp);
+void dw_old_handle_legacy_irq(struct pcie_port *pp, int offset);
+int dw_old_pcie_host_init(struct pcie_port *pp, struct device_node *np);
+int dw_old_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
+ unsigned int devfn, int where, int size, u32 val);
+int dw_old_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
+ unsigned int devfn, int where, int size, u32 *val);
+void dw_old_disable_bars(struct pcie_port *pp);
+void dw_old_setup_ob_regs(struct pcie_port *pp);
+int dw_old_pcie_link_up(struct pcie_port *pp, int link_train);
--
1.7.9.5