[PATCH] i2c: amd-mp2: use msix/msi if the hardware supports

Raju Rangoju
2022-10-25T18:11:59Z

Use msix or msi interrupts if the hardware supports it. Else, fallback to
legacy interrupts.

Fixes: 529766e0a011 ("i2c: Add drivers for the AMD PCIe MP2 I2C controller")
Co-developed-by: Basavaraj Natikar <basavaraj.natikar@amd.com>
Signed-off-by: Basavaraj Natikar <basavaraj.natikar@amd.com>
Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
---
drivers/i2c/busses/i2c-amd-mp2-pci.c | 30 +++++++++++++++++++---------
drivers/i2c/busses/i2c-amd-mp2.h | 1 +
2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/drivers/i2c/busses/i2c-amd-mp2-pci.c b/drivers/i2c/busses/i2c-amd-mp2-pci.c
index f57077a7448d..143165300949 100644
--- a/drivers/i2c/busses/i2c-amd-mp2-pci.c
+++ b/drivers/i2c/busses/i2c-amd-mp2-pci.c
@@ -288,7 +288,7 @@ static void amd_mp2_clear_reg(struct amd_mp2_dev *privdata)
static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,
struct pci_dev *pci_dev)
{
- int rc;
+ int irq_flag = 0, rc;

pci_set_drvdata(pci_dev, privdata);

@@ -311,17 +311,29 @@ static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,
if (rc)
goto err_dma_mask;

- /* Set up intx irq */
+ /* request and enable interrupt */
writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
- pci_intx(pci_dev, 1);
- rc = devm_request_irq(&pci_dev->dev, pci_dev->irq, amd_mp2_irq_isr,
- IRQF_SHARED, dev_name(&pci_dev->dev), privdata);
- if (rc)
- pci_err(pci_dev, "Failure requesting irq %i: %d\n",
- pci_dev->irq, rc);
+ rc = pci_alloc_irq_vectors(pci_dev, 1, 1, PCI_IRQ_ALL_TYPES);
+ if (rc < 0) {
+ dev_err(&pci_dev->dev, "Failed to allocate single IRQ err=%d\n", rc);
+ goto err_dma_mask;
+ }
+
+ privdata->dev_irq = pci_irq_vector(pci_dev, 0);
+ if (!pci_dev->msix_enabled && !pci_dev->msi_enabled)
+ irq_flag = IRQF_SHARED;
+
+ rc = devm_request_irq(&pci_dev->dev, privdata->dev_irq,
+ amd_mp2_irq_isr, irq_flag, dev_name(&pci_dev->dev), privdata);
+ if (rc) {
+ pci_err(pci_dev, "Failure requesting irq %i: %d\n", privdata->dev_irq, rc);
+ goto free_irq_vectors;
+ }

return rc;

+free_irq_vectors:
+ free_irq(privdata->dev_irq, privdata);
err_dma_mask:
pci_clear_master(pci_dev);
err_pci_enable:
@@ -364,7 +376,7 @@ static void amd_mp2_pci_remove(struct pci_dev *pci_dev)
pm_runtime_forbid(&pci_dev->dev);
pm_runtime_get_noresume(&pci_dev->dev);

- pci_intx(pci_dev, 0);
+ free_irq(privdata->dev_irq, privdata);
pci_clear_master(pci_dev);

amd_mp2_clear_reg(privdata);
diff --git a/drivers/i2c/busses/i2c-amd-mp2.h b/drivers/i2c/busses/i2c-amd-mp2.h
index ddecd0c88656..018a42de8b1e 100644
--- a/drivers/i2c/busses/i2c-amd-mp2.h
+++ b/drivers/i2c/busses/i2c-amd-mp2.h
@@ -183,6 +183,7 @@ struct amd_mp2_dev {
struct mutex c2p_lock;
u8 c2p_lock_busid;
unsigned int probed;
+ int dev_irq;
};

/* PCIe communication driver */
--
2.25.1