openwrt-owl/target/linux/imx6/files-3.10/arch/arm/mach-imx/msi.c

157 lines
3.5 KiB
C

/*
* arch/arm/mach-mx6/msi.c
*
* PCI MSI support for the imx processor
*
* Copyright (c) 2013, Boundary Devices.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <asm/bitops.h>
#include <asm/mach/irq.h>
#include <asm/irq.h>
#include <linux/irqchip/chained_irq.h>
#include "hardware.h"
#include "msi.h"
#define IMX_NUM_MSI_IRQS 128
static DECLARE_BITMAP(msi_irq_in_use, IMX_NUM_MSI_IRQS);
static int irq_base;
static void imx_msi_handler(unsigned int irq, struct irq_desc *desc)
{
int i, j;
unsigned status;
struct irq_chip *chip = irq_get_chip(irq);
irq_base = irq_alloc_descs(-1, 0, IMX_NUM_MSI_IRQS, 0);
if (irq_base < 0) {
printk(KERN_ERR "%s: could not allocate IRQ numbers\n", __func__);
return;
}
chained_irq_enter(chip, desc);
for (i = 0; i < 8; i++) {
status = imx_pcie_msi_pending(i);
while (status) {
j = __fls(status);
generic_handle_irq(irq_base + j);
status &= ~(1 << j);
}
irq_base += 32;
}
chained_irq_exit(chip, desc);
}
/*
* Dynamic irq allocate and deallocation
*/
int create_irq(void)
{
int irq, pos;
do {
pos = find_first_zero_bit(msi_irq_in_use, IMX_NUM_MSI_IRQS);
if ((unsigned)pos >= IMX_NUM_MSI_IRQS)
return -ENOSPC;
/* test_and_set_bit operates on 32-bits at a time */
} while (test_and_set_bit(pos, msi_irq_in_use));
irq = irq_base + pos;
dynamic_irq_init(irq);
return irq;
}
void destroy_irq(unsigned int irq)
{
int pos = irq - irq_base;
dynamic_irq_cleanup(irq);
clear_bit(pos, msi_irq_in_use);
}
void arch_teardown_msi_irq(unsigned int irq)
{
destroy_irq(irq);
}
static void imx_msi_irq_ack(struct irq_data *d)
{
return;
}
static void imx_msi_irq_enable(struct irq_data *d)
{
imx_pcie_enable_irq(d->irq - irq_base, 1);
return unmask_msi_irq(d);
}
static void imx_msi_irq_disable(struct irq_data *d)
{
imx_pcie_enable_irq(d->irq - irq_base, 0);
return mask_msi_irq(d);
}
static void imx_msi_irq_mask(struct irq_data *d)
{
imx_pcie_mask_irq(d->irq - irq_base, 1);
return mask_msi_irq(d);
}
static void imx_msi_irq_unmask(struct irq_data *d)
{
imx_pcie_mask_irq(d->irq - irq_base, 0);
return unmask_msi_irq(d);
}
static struct irq_chip imx_msi_chip = {
.name = "PCIe-MSI",
.irq_ack = imx_msi_irq_ack,
.irq_enable = imx_msi_irq_enable,
.irq_disable = imx_msi_irq_disable,
.irq_mask = imx_msi_irq_mask,
.irq_unmask = imx_msi_irq_unmask,
};
int arch_setup_msi_irq(struct pci_dev *pdev, struct msi_desc *desc)
{
int irq = create_irq();
struct msi_msg msg;
if (irq < 0)
return irq;
irq_set_msi_desc(irq, desc);
msg.address_hi = 0x0;
msg.address_lo = MSI_MATCH_ADDR;
msg.data = (mxc_cpu_type << 15) | ((irq - irq_base) & 0xff);
write_msi_msg(irq, &msg);
irq_set_chip_and_handler(irq, &imx_msi_chip, handle_simple_irq);
set_irq_flags(irq, IRQF_VALID);
pr_info("%s: %d of %d\n", __func__, irq, NR_IRQS);
return 0;
}
void imx_msi_init(void)
{
irq_set_chained_handler(MXC_INT_PCIE_0, imx_msi_handler);
}