[U-Boot] [PATCH 1/2] PCI: Add driver for a 'pci-host-ecam-generic' host controller
Tuomas Tynkkynen
tuomas.tynkkynen at iki.fi
Wed Aug 30 08:31:34 UTC 2017
QEMU emulates such a device with '-machine virt,highmem=off' on ARM.
The 'highmem=off' part is required for things to work as the PCI code
in U-Boot doesn't seem to support 64-bit BARs.
This driver is basically a copy-paste of the Xilinx PCIE driver with the
Xilinx-specific bits removed and compatible string changed... The
generic code should probably be extracted into some sort of library
functions instead of duplicating them before committing this driver.
Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
---
drivers/pci/Kconfig | 8 ++
drivers/pci/Makefile | 1 +
drivers/pci/pcie_ecam_generic.c | 193 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 202 insertions(+)
create mode 100644 drivers/pci/pcie_ecam_generic.c
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index e2a1c0a409..745161fb9f 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -33,6 +33,14 @@ config PCI_PNP
help
Enable PCI memory and I/O space resource allocation and assignment.
+config PCIE_ECAM_GENERIC
+ bool "Generic PCI-E ECAM support"
+ default n
+ depends on DM_PCI
+ help
+ Say Y here if you want to enable support for generic ECAM-based
+ PCIe controllers, such as the one emulated by QEMU.
+
config PCIE_DW_MVEBU
bool "Enable Armada-8K PCIe driver (DesignWare core)"
default n
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index ad44e83996..5eb12efbf5 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_PCI) += pci.o pci_auto_old.o
endif
obj-$(CONFIG_PCI) += pci_auto_common.o pci_common.o
+obj-$(CONFIG_PCIE_ECAM_GENERIC) += pcie_ecam_generic.o
obj-$(CONFIG_FSL_PCI_INIT) += fsl_pci_init.o
obj-$(CONFIG_PCI_INDIRECT_BRIDGE) += pci_indirect.o
obj-$(CONFIG_PCI_GT64120) += pci_gt64120.o
diff --git a/drivers/pci/pcie_ecam_generic.c b/drivers/pci/pcie_ecam_generic.c
new file mode 100644
index 0000000000..039e378cb0
--- /dev/null
+++ b/drivers/pci/pcie_ecam_generic.c
@@ -0,0 +1,193 @@
+/*
+ * Generic PCIE host provided by e.g. QEMU
+ *
+ * Heavily based on drivers/pci/pcie_xilinx.c
+ *
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <pci.h>
+
+#include <asm/io.h>
+
+/**
+ * struct generic_ecam_pcie - generic_ecam PCIe controller state
+ * @hose: The parent classes PCI controller state
+ * @cfg_base: The base address of memory mapped configuration space
+ */
+struct generic_ecam_pcie {
+ struct pci_controller hose;
+ void *cfg_base;
+};
+
+/**
+ * pcie_generic_ecam_config_address() - Calculate the address of a config access
+ * @pcie: Pointer to the PCI controller state
+ * @bdf: Identifies the PCIe device to access
+ * @offset: The offset into the device's configuration space
+ * @paddress: Pointer to the pointer to write the calculates address to
+ *
+ * Calculates the address that should be accessed to perform a PCIe
+ * configuration space access for a given device identified by the PCIe
+ * controller device @pcie and the bus, device & function numbers in @bdf. If
+ * access to the device is not valid then the function will return an error
+ * code. Otherwise the address to access will be written to the pointer pointed
+ * to by @paddress.
+ *
+ * Return: 0 on success, else -ENODEV
+ */
+static int pcie_generic_ecam_config_address(struct generic_ecam_pcie *pcie, pci_dev_t bdf,
+ uint offset, void **paddress)
+{
+ unsigned int bus = PCI_BUS(bdf);
+ unsigned int dev = PCI_DEV(bdf);
+ unsigned int func = PCI_FUNC(bdf);
+ void *addr;
+
+ addr = pcie->cfg_base;
+ addr += bus << 20;
+ addr += dev << 15;
+ addr += func << 12;
+ addr += offset;
+ *paddress = addr;
+
+ return 0;
+}
+
+/**
+ * pcie_generic_ecam_read_config() - Read from configuration space
+ * @pcie: Pointer to the PCI controller state
+ * @bdf: Identifies the PCIe device to access
+ * @offset: The offset into the device's configuration space
+ * @valuep: A pointer at which to store the read value
+ * @size: Indicates the size of access to perform
+ *
+ * Read a value of size @size from offset @offset within the configuration
+ * space of the device identified by the bus, device & function numbers in @bdf
+ * on the PCI bus @bus.
+ *
+ * Return: 0 on success, else -ENODEV or -EINVAL
+ */
+static int pcie_generic_ecam_read_config(struct udevice *bus, pci_dev_t bdf,
+ uint offset, ulong *valuep,
+ enum pci_size_t size)
+{
+ struct generic_ecam_pcie *pcie = dev_get_priv(bus);
+ void *address;
+ int err;
+
+ err = pcie_generic_ecam_config_address(pcie, bdf, offset, &address);
+ if (err < 0) {
+ *valuep = pci_get_ff(size);
+ return 0;
+ }
+
+ switch (size) {
+ case PCI_SIZE_8:
+ *valuep = __raw_readb(address);
+ return 0;
+ case PCI_SIZE_16:
+ *valuep = __raw_readw(address);
+ return 0;
+ case PCI_SIZE_32:
+ *valuep = __raw_readl(address);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+/**
+ * pcie_generic_ecam_write_config() - Write to configuration space
+ * @pcie: Pointer to the PCI controller state
+ * @bdf: Identifies the PCIe device to access
+ * @offset: The offset into the device's configuration space
+ * @value: The value to write
+ * @size: Indicates the size of access to perform
+ *
+ * Write the value @value of size @size from offset @offset within the
+ * configuration space of the device identified by the bus, device & function
+ * numbers in @bdf on the PCI bus @bus.
+ *
+ * Return: 0 on success, else -ENODEV or -EINVAL
+ */
+static int pcie_generic_ecam_write_config(struct udevice *bus, pci_dev_t bdf,
+ uint offset, ulong value,
+ enum pci_size_t size)
+{
+ struct generic_ecam_pcie *pcie = dev_get_priv(bus);
+ void *address;
+ int err;
+
+ err = pcie_generic_ecam_config_address(pcie, bdf, offset, &address);
+ if (err < 0)
+ return 0;
+
+ switch (size) {
+ case PCI_SIZE_8:
+ __raw_writeb(value, address);
+ return 0;
+ case PCI_SIZE_16:
+ __raw_writew(value, address);
+ return 0;
+ case PCI_SIZE_32:
+ __raw_writel(value, address);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+/**
+ * pcie_generic_ecam_ofdata_to_platdata() - Translate from DT to device state
+ * @dev: A pointer to the device being operated on
+ *
+ * Translate relevant data from the device tree pertaining to device @dev into
+ * state that the driver will later make use of. This state is stored in the
+ * device's private data structure.
+ *
+ * Return: 0 on success, else -EINVAL
+ */
+static int pcie_generic_ecam_ofdata_to_platdata(struct udevice *dev)
+{
+ struct generic_ecam_pcie *pcie = dev_get_priv(dev);
+ struct fdt_resource reg_res;
+ DECLARE_GLOBAL_DATA_PTR;
+ int err;
+
+ err = fdt_get_resource(gd->fdt_blob, dev_of_offset(dev), "reg",
+ 0, ®_res);
+ if (err < 0) {
+ error("\"reg\" resource not found\n");
+ return err;
+ }
+
+ pcie->cfg_base = map_physmem(reg_res.start,
+ fdt_resource_size(®_res),
+ MAP_NOCACHE);
+
+ return 0;
+}
+
+static const struct dm_pci_ops pcie_generic_ecam_ops = {
+ .read_config = pcie_generic_ecam_read_config,
+ .write_config = pcie_generic_ecam_write_config,
+};
+
+static const struct udevice_id pcie_generic_ecam_ids[] = {
+ { .compatible = "pci-host-ecam-generic" },
+ { }
+};
+
+U_BOOT_DRIVER(pcie_generic_ecam) = {
+ .name = "pcie_generic_ecam",
+ .id = UCLASS_PCI,
+ .of_match = pcie_generic_ecam_ids,
+ .ops = &pcie_generic_ecam_ops,
+ .ofdata_to_platdata = pcie_generic_ecam_ofdata_to_platdata,
+ .priv_auto_alloc_size = sizeof(struct generic_ecam_pcie),
+};
--
2.13.0
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