@@ -24,6 +24,7 @@
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/of_pci.h>
+#include <linux/timer.h>
#include "../pci.h"
#include "../pci-bridge-emul.h"
@@ -99,6 +100,7 @@
#define PCIE_MSG_PM_PME_MASK BIT(7)
#define PCIE_ISR0_MASK_REG (CONTROL_BASE_ADDR + 0x44)
#define PCIE_ISR0_MSI_INT_PENDING BIT(24)
+#define PCIE_ISR0_LINK_DOWN BIT(1)
#define PCIE_ISR0_CORR_ERR BIT(11)
#define PCIE_ISR0_NFAT_ERR BIT(12)
#define PCIE_ISR0_FAT_ERR BIT(13)
@@ -284,6 +286,8 @@ struct advk_pcie {
DECLARE_BITMAP(msi_used, MSI_IRQ_NUM);
struct mutex msi_used_lock;
int link_gen;
+ bool link_was_up;
+ struct timer_list link_irq_timer;
struct pci_bridge_emul bridge;
struct gpio_desc *reset_gpio;
struct phy *phy;
@@ -313,7 +317,24 @@ static inline bool advk_pcie_link_up(struct advk_pcie *pcie)
{
/* check if LTSSM is in normal operation - some L* state */
u8 ltssm_state = advk_pcie_ltssm_state(pcie);
- return ltssm_state >= LTSSM_L0 && ltssm_state < LTSSM_DISABLED;
+ bool link_is_up;
+ u16 slotsta;
+
+ link_is_up = ltssm_state >= LTSSM_L0 && ltssm_state < LTSSM_DISABLED;
+
+ if (link_is_up && !pcie->link_was_up) {
+ dev_info(&pcie->pdev->dev, "link up\n");
+
+ pcie->link_was_up = true;
+
+ slotsta = le16_to_cpu(pcie->bridge.pcie_conf.slotsta);
+ slotsta |= PCI_EXP_SLTSTA_DLLSC;
+ pcie->bridge.pcie_conf.slotsta = cpu_to_le16(slotsta);
+
+ mod_timer(&pcie->link_irq_timer, jiffies + 1);
+ }
+
+ return link_is_up;
}
static inline bool advk_pcie_link_active(struct advk_pcie *pcie)
@@ -442,8 +463,6 @@ static void advk_pcie_train_link(struct advk_pcie *pcie)
ret = advk_pcie_wait_for_link(pcie);
if (ret < 0)
dev_err(dev, "link never came up\n");
- else
- dev_info(dev, "link up\n");
}
/*
@@ -592,6 +611,11 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie)
reg &= ~PCIE_ISR0_MSI_INT_PENDING;
advk_writel(pcie, reg, PCIE_ISR0_MASK_REG);
+ /* Unmask Link Down interrupt */
+ reg = advk_readl(pcie, PCIE_ISR0_MASK_REG);
+ reg &= ~PCIE_ISR0_LINK_DOWN;
+ advk_writel(pcie, reg, PCIE_ISR0_MASK_REG);
+
/* Unmask PME interrupt for processing of PME requester */
reg = advk_readl(pcie, PCIE_ISR0_MASK_REG);
reg &= ~PCIE_MSG_PM_PME_MASK;
@@ -918,6 +942,14 @@ advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
advk_pcie_wait_for_retrain(pcie);
break;
+ case PCI_EXP_SLTCTL: {
+ u16 slotctl = le16_to_cpu(bridge->pcie_conf.slotctl);
+ /* Only emulation of HPIE and DLLSCE bits is provided */
+ slotctl &= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_DLLSCE;
+ bridge->pcie_conf.slotctl = cpu_to_le16(slotctl);
+ break;
+ }
+
case PCI_EXP_RTCTL: {
u16 rootctl = le16_to_cpu(bridge->pcie_conf.rootctl);
/* Only emulation of PMEIE and CRSSVE bits is provided */
@@ -1033,6 +1065,7 @@ static const struct pci_bridge_emul_ops advk_pci_bridge_emul_ops = {
static int advk_sw_pci_bridge_init(struct advk_pcie *pcie)
{
struct pci_bridge_emul *bridge = &pcie->bridge;
+ u32 slotcap;
bridge->conf.vendor =
cpu_to_le16(advk_readl(pcie, PCIE_CORE_DEV_ID_REG) & 0xffff);
@@ -1059,6 +1092,13 @@ static int advk_sw_pci_bridge_init(struct advk_pcie *pcie)
bridge->pcie_conf.cap = cpu_to_le16(2 | PCI_EXP_FLAGS_SLOT);
/*
+ * Mark bridge as Hot Plug Capable since this is the way how to enable
+ * delivering of Data Link Layer State Change interrupts.
+ *
+ * Set No Command Completed Support because bridge does not support
+ * Command Completed Interrupt. Every command is executed immediately
+ * without any delay.
+ *
* Set Presence Detect State bit permanently since there is no support
* for unplugging the card nor detecting whether it is plugged. (If a
* platform exists in the future that supports it, via a GPIO for
@@ -1068,7 +1108,9 @@ static int advk_sw_pci_bridge_init(struct advk_pcie *pcie)
* value is reserved for ports within the same silicon as Root Port
* which is not our case.
*/
- bridge->pcie_conf.slotcap = cpu_to_le32(1 << PCI_EXP_SLTCAP_PSN_SHIFT);
+ slotcap = PCI_EXP_SLTCAP_NCCS | PCI_EXP_SLTCAP_HPC |
+ (1 << PCI_EXP_SLTCAP_PSN_SHIFT);
+ bridge->pcie_conf.slotcap = cpu_to_le32(slotcap);
bridge->pcie_conf.slotsta = cpu_to_le16(PCI_EXP_SLTSTA_PDS);
/* Indicates supports for Completion Retry Status */
@@ -1565,6 +1607,24 @@ static void advk_pcie_remove_rp_irq_domain(struct advk_pcie *pcie)
irq_domain_remove(pcie->rp_irq_domain);
}
+static void advk_pcie_link_irq_handler(struct timer_list *timer)
+{
+ struct advk_pcie *pcie = from_timer(pcie, timer, link_irq_timer);
+ u16 slotctl;
+
+ slotctl = le16_to_cpu(pcie->bridge.pcie_conf.slotctl);
+ if (!(slotctl & PCI_EXP_SLTCTL_DLLSCE) ||
+ !(slotctl & PCI_EXP_SLTCTL_HPIE))
+ return;
+
+ /*
+ * Aardvark HW returns zero for PCI_EXP_FLAGS_IRQ, so use PCIe
+ * interrupt 0
+ */
+ if (generic_handle_domain_irq(pcie->rp_irq_domain, 0) == -EINVAL)
+ dev_err_ratelimited(&pcie->pdev->dev, "unhandled HP IRQ\n");
+}
+
static void advk_pcie_handle_pme(struct advk_pcie *pcie)
{
u32 requester = advk_readl(pcie, PCIE_MSG_LOG_REG) >> 16;
@@ -1616,6 +1676,7 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie)
{
u32 isr0_val, isr0_mask, isr0_status;
u32 isr1_val, isr1_mask, isr1_status;
+ u16 slotsta;
int i;
isr0_val = advk_readl(pcie, PCIE_ISR0_REG);
@@ -1642,6 +1703,26 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie)
dev_err_ratelimited(&pcie->pdev->dev, "unhandled ERR IRQ\n");
}
+ /* Process Link Down interrupt as HP IRQ */
+ if (isr0_status & PCIE_ISR0_LINK_DOWN) {
+ advk_writel(pcie, PCIE_ISR0_LINK_DOWN, PCIE_ISR0_REG);
+
+ dev_info(&pcie->pdev->dev, "link down\n");
+
+ pcie->link_was_up = false;
+
+ slotsta = le16_to_cpu(pcie->bridge.pcie_conf.slotsta);
+ slotsta |= PCI_EXP_SLTSTA_DLLSC;
+ pcie->bridge.pcie_conf.slotsta = cpu_to_le16(slotsta);
+
+ /*
+ * Deactivate timer and call advk_pcie_link_irq_handler()
+ * function directly as we are in the interrupt context.
+ */
+ del_timer_sync(&pcie->link_irq_timer);
+ advk_pcie_link_irq_handler(&pcie->link_irq_timer);
+ }
+
/* Process MSI interrupts */
if (isr0_status & PCIE_ISR0_MSI_INT_PENDING)
advk_pcie_handle_msi(pcie);
@@ -1877,6 +1958,14 @@ static int advk_pcie_probe(struct platform_device *pdev)
if (ret)
return ret;
+ /*
+ * generic_handle_domain_irq() expects local IRQs to be disabled since
+ * normally it is called from interrupt context, so use TIMER_IRQSAFE
+ * flag for this link_irq_timer.
+ */
+ timer_setup(&pcie->link_irq_timer, advk_pcie_link_irq_handler,
+ TIMER_IRQSAFE);
+
advk_pcie_setup_hw(pcie);
ret = advk_sw_pci_bridge_init(pcie);
@@ -1971,6 +2060,9 @@ static int advk_pcie_remove(struct platform_device *pdev)
advk_pcie_remove_msi_irq_domain(pcie);
advk_pcie_remove_irq_domain(pcie);
+ /* Deactivate link event timer */
+ del_timer_sync(&pcie->link_irq_timer);
+
/* Free config space for emulated root bridge */
pci_bridge_emul_cleanup(&pcie->bridge);