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PCI: rcar: Add MSI support for PCIe

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Add MSI support to the R-Car PCIe driver.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
This commit is contained in:
Phil Edworthy 2014-05-12 11:57:49 +01:00 committed by Bjorn Helgaas
parent c25da47788
commit 290c1fb358
1 changed files with 241 additions and 1 deletions
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242
drivers/pci/host/pcie-rcar.c
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@ -15,8 +15,11 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/msi.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
@ -35,6 +38,7 @@
#define PCIECDR 0x000020
#define PCIEMSR 0x000028
#define PCIEINTXR 0x000400
#define PCIEMSITXR 0x000840
/* Transfer control */
#define PCIETCTLR 0x02000
@ -43,6 +47,11 @@
#define DATA_LINK_ACTIVE 1
#define PCIEERRFR 0x02020
#define UNSUPPORTED_REQUEST (1 << 4)
#define PCIEMSIFR 0x02044
#define PCIEMSIALR 0x02048
#define MSIFE 1
#define PCIEMSIAUR 0x0204c
#define PCIEMSIIER 0x02050
/* root port address */
#define PCIEPRAR(x) (0x02080 + ((x) * 0x4))
@ -85,6 +94,8 @@
#define H1_PCIEPHYDOUTR 0x040014
#define H1_PCIEPHYSR 0x040018
#define INT_PCI_MSI_NR 32
#define RCONF(x) (PCICONF(0)+(x))
#define RPMCAP(x) (PMCAP(0)+(x))
#define REXPCAP(x) (EXPCAP(0)+(x))
@ -97,6 +108,21 @@
#define PCI_MAX_RESOURCES 4
#define MAX_NR_INBOUND_MAPS 6
struct rcar_msi {
DECLARE_BITMAP(used, INT_PCI_MSI_NR);
struct irq_domain *domain;
struct msi_chip chip;
unsigned long pages;
struct mutex lock;
int irq1;
int irq2;
};
static inline struct rcar_msi *to_rcar_msi(struct msi_chip *chip)
{
return container_of(chip, struct rcar_msi, chip);
}
/* Structure representing the PCIe interface */
struct rcar_pcie {
struct device *dev;
@ -106,6 +132,7 @@ struct rcar_pcie {
int root_bus_nr;
struct clk *clk;
struct clk *bus_clk;
struct rcar_msi msi;
};
static inline struct rcar_pcie *sys_to_pcie(struct pci_sys_data *sys)
@ -356,10 +383,20 @@ static int rcar_pcie_setup(int nr, struct pci_sys_data *sys)
return 1;
}
static void rcar_pcie_add_bus(struct pci_bus *bus)
{
if (IS_ENABLED(CONFIG_PCI_MSI)) {
struct rcar_pcie *pcie = sys_to_pcie(bus->sysdata);
bus->msi = &pcie->msi.chip;
}
}
struct hw_pci rcar_pci = {
.setup = rcar_pcie_setup,
.map_irq = of_irq_parse_and_map_pci,
.ops = &rcar_pcie_ops,
.add_bus = rcar_pcie_add_bus,
};
static void rcar_pcie_enable(struct rcar_pcie *pcie)
@ -477,6 +514,10 @@ static int rcar_pcie_hw_init(struct rcar_pcie *pcie)
/* Enable MAC data scrambling. */
rcar_rmw32(pcie, MACCTLR, SCRAMBLE_DISABLE, 0);
/* Enable MSI */
if (IS_ENABLED(CONFIG_PCI_MSI))
pci_write_reg(pcie, 0x101f0000, PCIEMSITXR);
/* Finish initialization - establish a PCI Express link */
pci_write_reg(pcie, CFINIT, PCIETCTLR);
@ -530,11 +571,184 @@ static int rcar_pcie_hw_init_h1(struct rcar_pcie *pcie)
return -ETIMEDOUT;
}
static int rcar_msi_alloc(struct rcar_msi *chip)
{
int msi;
mutex_lock(&chip->lock);
msi = find_first_zero_bit(chip->used, INT_PCI_MSI_NR);
if (msi < INT_PCI_MSI_NR)
set_bit(msi, chip->used);
else
msi = -ENOSPC;
mutex_unlock(&chip->lock);
return msi;
}
static void rcar_msi_free(struct rcar_msi *chip, unsigned long irq)
{
mutex_lock(&chip->lock);
clear_bit(irq, chip->used);
mutex_unlock(&chip->lock);
}
static irqreturn_t rcar_pcie_msi_irq(int irq, void *data)
{
struct rcar_pcie *pcie = data;
struct rcar_msi *msi = &pcie->msi;
unsigned long reg;
reg = pci_read_reg(pcie, PCIEMSIFR);
/* MSI & INTx share an interrupt - we only handle MSI here */
if (!reg)
return IRQ_NONE;
while (reg) {
unsigned int index = find_first_bit(&reg, 32);
unsigned int irq;
/* clear the interrupt */
pci_write_reg(pcie, 1 << index, PCIEMSIFR);
irq = irq_find_mapping(msi->domain, index);
if (irq) {
if (test_bit(index, msi->used))
generic_handle_irq(irq);
else
dev_info(pcie->dev, "unhandled MSI\n");
} else {
/* Unknown MSI, just clear it */
dev_dbg(pcie->dev, "unexpected MSI\n");
}
/* see if there's any more pending in this vector */
reg = pci_read_reg(pcie, PCIEMSIFR);
}
return IRQ_HANDLED;
}
static int rcar_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev,
struct msi_desc *desc)
{
struct rcar_msi *msi = to_rcar_msi(chip);
struct rcar_pcie *pcie = container_of(chip, struct rcar_pcie, msi.chip);
struct msi_msg msg;
unsigned int irq;
int hwirq;
hwirq = rcar_msi_alloc(msi);
if (hwirq < 0)
return hwirq;
irq = irq_create_mapping(msi->domain, hwirq);
if (!irq) {
rcar_msi_free(msi, hwirq);
return -EINVAL;
}
irq_set_msi_desc(irq, desc);
msg.address_lo = pci_read_reg(pcie, PCIEMSIALR) & ~MSIFE;
msg.address_hi = pci_read_reg(pcie, PCIEMSIAUR);
msg.data = hwirq;
write_msi_msg(irq, &msg);
return 0;
}
static void rcar_msi_teardown_irq(struct msi_chip *chip, unsigned int irq)
{
struct rcar_msi *msi = to_rcar_msi(chip);
struct irq_data *d = irq_get_irq_data(irq);
rcar_msi_free(msi, d->hwirq);
}
static struct irq_chip rcar_msi_irq_chip = {
.name = "R-Car PCIe MSI",
.irq_enable = unmask_msi_irq,
.irq_disable = mask_msi_irq,
.irq_mask = mask_msi_irq,
.irq_unmask = unmask_msi_irq,
};
static int rcar_msi_map(struct irq_domain *domain, unsigned int irq,
irq_hw_number_t hwirq)
{
irq_set_chip_and_handler(irq, &rcar_msi_irq_chip, handle_simple_irq);
irq_set_chip_data(irq, domain->host_data);
set_irq_flags(irq, IRQF_VALID);
return 0;
}
static const struct irq_domain_ops msi_domain_ops = {
.map = rcar_msi_map,
};
static int rcar_pcie_enable_msi(struct rcar_pcie *pcie)
{
struct platform_device *pdev = to_platform_device(pcie->dev);
struct rcar_msi *msi = &pcie->msi;
unsigned long base;
int err;
mutex_init(&msi->lock);
msi->chip.dev = pcie->dev;
msi->chip.setup_irq = rcar_msi_setup_irq;
msi->chip.teardown_irq = rcar_msi_teardown_irq;
msi->domain = irq_domain_add_linear(pcie->dev->of_node, INT_PCI_MSI_NR,
&msi_domain_ops, &msi->chip);
if (!msi->domain) {
dev_err(&pdev->dev, "failed to create IRQ domain\n");
return -ENOMEM;
}
/* Two irqs are for MSI, but they are also used for non-MSI irqs */
err = devm_request_irq(&pdev->dev, msi->irq1, rcar_pcie_msi_irq,
IRQF_SHARED, rcar_msi_irq_chip.name, pcie);
if (err < 0) {
dev_err(&pdev->dev, "failed to request IRQ: %d\n", err);
goto err;
}
err = devm_request_irq(&pdev->dev, msi->irq2, rcar_pcie_msi_irq,
IRQF_SHARED, rcar_msi_irq_chip.name, pcie);
if (err < 0) {
dev_err(&pdev->dev, "failed to request IRQ: %d\n", err);
goto err;
}
/* setup MSI data target */
msi->pages = __get_free_pages(GFP_KERNEL, 0);
base = virt_to_phys((void *)msi->pages);
pci_write_reg(pcie, base | MSIFE, PCIEMSIALR);
pci_write_reg(pcie, 0, PCIEMSIAUR);
/* enable all MSI interrupts */
pci_write_reg(pcie, 0xffffffff, PCIEMSIIER);
return 0;
err:
irq_domain_remove(msi->domain);
return err;
}
static int rcar_pcie_get_resources(struct platform_device *pdev,
struct rcar_pcie *pcie)
{
struct resource res;
int err;
int err, i;
err = of_address_to_resource(pdev->dev.of_node, 0, &res);
if (err)
@ -559,6 +773,22 @@ static int rcar_pcie_get_resources(struct platform_device *pdev,
if (err)
goto err_map_reg;
i = irq_of_parse_and_map(pdev->dev.of_node, 0);
if (i < 0) {
dev_err(pcie->dev, "cannot get platform resources for msi interrupt\n");
err = -ENOENT;
goto err_map_reg;
}
pcie->msi.irq1 = i;
i = irq_of_parse_and_map(pdev->dev.of_node, 1);
if (i < 0) {
dev_err(pcie->dev, "cannot get platform resources for msi interrupt\n");
err = -ENOENT;
goto err_map_reg;
}
pcie->msi.irq2 = i;
pcie->base = devm_ioremap_resource(&pdev->dev, &res);
if (IS_ERR(pcie->base)) {
err = PTR_ERR(pcie->base);
@ -732,6 +962,16 @@ static int rcar_pcie_probe(struct platform_device *pdev)
if (err)
return err;
if (IS_ENABLED(CONFIG_PCI_MSI)) {
err = rcar_pcie_enable_msi(pcie);
if (err < 0) {
dev_err(&pdev->dev,
"failed to enable MSI support: %d\n",
err);
return err;
}
}
of_id = of_match_device(rcar_pcie_of_match, pcie->dev);
if (!of_id || !of_id->data)
return -EINVAL;