Add PCI legacy bridge device driver

PCI legacy bridge is a device connected to PCI bus and
allowing to program the routes from interrupt pins to IRQ
numbers.

Change-Id: I129719d71f958bbf5ad8c5c9949dcea93d94b89d
Signed-off-by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com>
This commit is contained in:
Dmitriy Korovkin 2015-10-01 14:40:23 -04:00 committed by Anas Nashif
commit 13b3e2a127
4 changed files with 256 additions and 0 deletions

View file

@ -52,6 +52,36 @@ config PCI_ENUMERATION
statically set in every relevant driver's configuration, it statically set in every relevant driver's configuration, it
might be wise to disable this option to remove useless code. might be wise to disable this option to remove useless code.
config PCI_LEGACY_BRIDGE
bool
prompt "PCI legacy bridge device support"
depends on PCI
default n
help
This option adds support for PCI legacy bridge device, that
allows direct setup of the PCI interrupt pin to IRQ number
mapping.
config PCI_LEGACY_BRIDGE_BUS
int "PCI Legacy Bridge Bus number"
depends on PCI_LEGACY_BRIDGE
default 0
config PCI_LEGACY_BRIDGE_DEV
int "PCI Legacy Bridge Device number"
depends on PCI_LEGACY_BRIDGE
default 0
config PCI_LEGACY_BRIDGE_VENDOR_ID
hex "PCI Legacy Bridge Vendor ID"
depends on PCI_LEGACY_BRIDGE
default 0
config PCI_LEGACY_BRIDGE_DEVICE_ID
hex "PCI Legacy Bridge Device ID"
depends on PCI_LEGACY_BRIDGE
default 0
config PCI_DEBUG config PCI_DEBUG
bool bool
prompt "Enable PCI debugging" prompt "Enable PCI debugging"

View file

@ -1 +1,2 @@
obj-$(CONFIG_PCI) = pci.o pci_config.o pci_interface.o obj-$(CONFIG_PCI) = pci.o pci_config.o pci_interface.o
obj-$(CONFIG_PCI_LEGACY_BRIDGE) += pci_legacy_bridge.o

View file

@ -0,0 +1,220 @@
/* pci_legacy_bridge.c - PCI legacy bridge device driver */
/*
* Copyright (c) 2015 Wind River Systems, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2) Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3) Neither the name of Wind River Systems nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
DESCRIPTION
Module provides routines for utilizing the PCI legacy bridge, including
detection of the bridge and using the bridge to configure the routing between
PCI interrupt pins and IRQs.
*/
#include <nanokernel.h>
#include <arch/cpu.h>
#include <drivers/pci/pci_mgr.h>
#include <drivers/pci/pci.h>
#include <board.h>
#define PCI_LEGACY_BRIDGE_REG (0xF0 / 4) /* RCBA offset in 32-bit words */
#define PCI_ADDR_IRQAGENT0 0x3140
#define PCI_ADDR_IRQAGENT1 0x3142
#define PCI_ADDR_IRQAGENT2 0x3144
#define PCI_ADDR_IRQAGENT3 0x3146
/**
*
* @brief Return the address mask for the specified root complex
*
* The routine checks for the memory present at the specified register
* and fills in base address mask.
* Routine should be called in single thread mode during the system
* initialization.
*
* @param pci_ctrl_addr PCI device configuration register address
* @param mask Pointer to the base address mask
*
* @return 0 if root complex is implemented, -1 if not.
*/
static int pci_rcba_mask_get(union pci_addr_reg pci_ctrl_addr,
uint32_t *mask)
{
uint32_t old_value;
/* save the current setting */
pci_read(DEFAULT_PCI_CONTROLLER,
pci_ctrl_addr,
sizeof(old_value),
&old_value);
/* write to the RCBA to see how large it is */
pci_write(DEFAULT_PCI_CONTROLLER,
pci_ctrl_addr,
sizeof(uint32_t),
0xffffffff);
pci_read(DEFAULT_PCI_CONTROLLER,
pci_ctrl_addr,
sizeof(*mask),
mask);
/* put back the old configuration */
pci_write(DEFAULT_PCI_CONTROLLER,
pci_ctrl_addr,
sizeof(old_value),
old_value);
/* check if this RCBA is implemented */
if (*mask != 0xffffffff && *mask != 0) {
/* clear the least address unrelated bit */
*mask &= ~0x01;
return 0;
}
/* RCBA not supported */
return -1;
}
/**
*
* @brief Retrieves the device information for the PCI legacy bridge, if present
*
* @param dev_info device information structure that the routine fills in
*
* @return 0 if legacy bridge is detected and -1 otherwise
*/
int pci_legacy_bridge_detect(struct pci_dev_info *dev_info)
{
union pci_addr_reg pci_ctrl_addr;
static union pci_dev pci_dev_header;
uint32_t pci_data; /* temporary data to read */
uint32_t rcba; /* root complex base address */
uint32_t rcba_mask; /* bits set for RCBA */
/* initialise the PCI controller address register value */
pci_ctrl_addr.value = 0;
pci_ctrl_addr.field.bus = CONFIG_PCI_LEGACY_BRIDGE_BUS;
pci_ctrl_addr.field.device = CONFIG_PCI_LEGACY_BRIDGE_DEV;
/* verify first if there is a valid device at this point */
pci_ctrl_addr.field.func = 0;
pci_read(DEFAULT_PCI_CONTROLLER,
pci_ctrl_addr,
sizeof(pci_data),
&pci_data);
if (pci_data == 0xffffffff) {
return -1;
}
/* get the PCI header from the device */
pci_header_get(DEFAULT_PCI_CONTROLLER,
pci_ctrl_addr,
&pci_dev_header);
if (pci_dev_header.field.vendor_id != CONFIG_PCI_LEGACY_BRIDGE_VENDOR_ID ||
pci_dev_header.field.device_id != CONFIG_PCI_LEGACY_BRIDGE_DEVICE_ID) {
return -1;
}
pci_ctrl_addr.field.reg = PCI_LEGACY_BRIDGE_REG;
/* read RCBA PCI register */
pci_read(DEFAULT_PCI_CONTROLLER,
pci_ctrl_addr,
sizeof(rcba),
&rcba);
if (pci_rcba_mask_get(pci_ctrl_addr, &rcba_mask) != 0) {
return -1;
}
dev_info->addr = rcba & rcba_mask;
if (dev_info->addr != 0) {
/* calculate the size of the root complex memory required */
dev_info->size = 1 << (find_lsb_set(rcba_mask) - 1);
}
dev_info->irq = -1;
dev_info->bus = CONFIG_PCI_LEGACY_BRIDGE_BUS;
dev_info->dev = CONFIG_PCI_LEGACY_BRIDGE_DEV;
dev_info->function = 0;
dev_info->mem_type = BAR_SPACE_MEM;
dev_info->class = pci_dev_header.field.class;
dev_info->bar = 0;
dev_info->vendor_id = pci_dev_header.field.vendor_id;
dev_info->device_id = pci_dev_header.field.device_id;
return 0;
}
/**
*
* @brief Configures the route from INTx to IRQx on specified I/O block
*
* I/O block 0 includes devices connected to PCIe, I/O block 1 includes
* UART, SPI, GPIO, I2C
*
* @param dev_info device information structure that the routine fills in
* @param io_block_num number on I/O block
* @param pci_interrupt_pin PCI interrupt pin
* @param irq_number IRQ number that corresponds the PCI interrupt pin
*
* @return N/A
*/
void pci_legacy_bridge_configure(struct pci_dev_info *dev_info,
int io_block_num,
int pci_interrupt_pin,
int irq_number)
{
uint32_t addr = (io_block_num == 0) ? PCI_ADDR_IRQAGENT1 :
PCI_ADDR_IRQAGENT3;
/*
* Each interrupt queue agent register in PCI legacy
* bridge has the following format:
* Bits 15:12 indicates which IRQ is used for INTD. Valid numbers are
* 0-7, which corresponds IRQ 16 - IRQ 23
* Bits 11:8 indicates which IRQ is used for INTC.
* Bits 7:4 indicates which IRQ is used for INTB.
* Bits 3:0 indicates which IRQ is used for INTA.
*/
int offset = (pci_interrupt_pin - 1) * 4;
uint16_t irq_routing = sys_read16(dev_info->addr + addr);
irq_routing &= ~(0x0f << offset);
irq_routing |= (irq_number - NUM_STD_IRQS) << offset;
sys_write16(irq_routing, dev_info->addr + addr);
}

View file

@ -78,6 +78,11 @@ static inline int pci_bus_scan(struct pci_dev_info *dev_info)
#endif /* CONFIG_PCI_ENUMERATION */ #endif /* CONFIG_PCI_ENUMERATION */
void pci_enable_regs(struct pci_dev_info *dev_info); void pci_enable_regs(struct pci_dev_info *dev_info);
int pci_legacy_bridge_detect(struct pci_dev_info *dev_info);
void pci_legacy_bridge_configure(struct pci_dev_info *dev_info,
int io_block_num,
int pci_interrupt_pin,
int irq_number);
#ifdef CONFIG_PCI_DEBUG #ifdef CONFIG_PCI_DEBUG
extern void pci_show(struct pci_dev_info *dev_info); extern void pci_show(struct pci_dev_info *dev_info);