@@ -48,10 +48,17 @@
#define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY 0x04dc
#define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK 0xc00
+#define PCIE_RC_CFG_PRIV1_ROOT_CAP 0x4f8
+#define PCIE_RC_CFG_PRIV1_ROOT_CAP_L1SS_MODE_MASK 0xf8
+
#define PCIE_RC_DL_MDIO_ADDR 0x1100
#define PCIE_RC_DL_MDIO_WR_DATA 0x1104
#define PCIE_RC_DL_MDIO_RD_DATA 0x1108
+#define PCIE_0_RC_PL_PHY_DBG_CLKREQ2_0 0x1e30
+#define CLKREQ2_0_CLKREQ_IN_CNT_MASK 0x3f000000
+#define CLKREQ2_0_CLKREQ_IN_MASK 0x40000000
+
#define PCIE_MISC_MISC_CTRL 0x4008
#define PCIE_MISC_MISC_CTRL_PCIE_RCB_64B_MODE_MASK 0x80
#define PCIE_MISC_MISC_CTRL_PCIE_RCB_MPS_MODE_MASK 0x400
@@ -121,9 +128,12 @@
#define PCIE_MISC_HARD_PCIE_HARD_DEBUG 0x4204
#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK 0x2
+#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_L1SS_ENABLE_MASK 0x200000
#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK 0x08000000
#define PCIE_BMIPS_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK 0x00800000
-
+#define PCIE_CLKREQ_MASK \
+ (PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK | \
+ PCIE_MISC_HARD_PCIE_HARD_DEBUG_L1SS_ENABLE_MASK)
#define PCIE_INTR2_CPU_BASE 0x4300
#define PCIE_MSI_INTR2_BASE 0x4500
@@ -1024,13 +1034,58 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
return 0;
}
+static void brcm_config_clkreq(struct brcm_pcie *pcie)
+{
+ bool l1ss = of_property_read_bool(pcie->np, "brcm,enable-l1ss");
+ void __iomem *base = pcie->base;
+ u32 clkreq_set, tmp = readl(base + PCIE_0_RC_PL_PHY_DBG_CLKREQ2_0);
+ bool clkreq_in_seen;
+
+ /*
+ * We have "seen" CLKREQ# if it is asserted or has been in the past.
+ * Note that the CLKREQ_IN_MASK is 1 if CLKREQ# is asserted.
+ */
+ clkreq_in_seen = !!(tmp & CLKREQ2_0_CLKREQ_IN_MASK) ||
+ !!FIELD_GET(CLKREQ2_0_CLKREQ_IN_CNT_MASK, tmp);
+
+ /* Start with safest setting where we provide refclk regardless */
+ clkreq_set = readl(pcie->base + PCIE_MISC_HARD_PCIE_HARD_DEBUG) &
+ ~PCIE_CLKREQ_MASK;
+
+ if (l1ss && IS_ENABLED(CONFIG_PCIEASPM)) {
+ /*
+ * Note: For boards using a mini-card connector, this mode
+ * (L1SS CLKREQ# mode) may not meet the TCRLon maximum time
+ * of 400ns, as specified in 3.2.5.2.2 of the PCI Express
+ * Mini CEM 2.0 specification.
+ */
+ clkreq_set |= PCIE_MISC_HARD_PCIE_HARD_DEBUG_L1SS_ENABLE_MASK;
+ dev_info(pcie->dev, "bi-dir CLKREQ# for L1SS power savings");
+ } else {
+ if (clkreq_in_seen && IS_ENABLED(CONFIG_PCIEASPM)) {
+ clkreq_set |= PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK;
+ dev_info(pcie->dev, "uni-dir CLKREQ# for L0s, L1 ASPM\n");
+ } else {
+ dev_info(pcie->dev, "CLKREQ# ignored; no ASPM\n");
+ /* Might as well unadvertise ASPM */
+ tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY) &
+ ~PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK;
+ writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY);
+ }
+ /* Setting the field to 2 unadvertises L1SS support */
+ tmp = readl(base + PCIE_RC_CFG_PRIV1_ROOT_CAP);
+ u32p_replace_bits(&tmp, 2, PCIE_RC_CFG_PRIV1_ROOT_CAP_L1SS_MODE_MASK);
+ writel(tmp, base + PCIE_RC_CFG_PRIV1_ROOT_CAP);
+ }
+ writel(clkreq_set, pcie->base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+}
+
static int brcm_pcie_start_link(struct brcm_pcie *pcie)
{
struct device *dev = pcie->dev;
void __iomem *base = pcie->base;
u16 nlw, cls, lnksta;
bool ssc_good = false;
- u32 tmp;
int ret, i;
/* Unassert the fundamental reset */
@@ -1055,6 +1110,8 @@ static int brcm_pcie_start_link(struct brcm_pcie *pcie)
return -ENODEV;
}
+ brcm_config_clkreq(pcie);
+
if (pcie->gen)
brcm_pcie_set_gen(pcie, pcie->gen);
@@ -1073,14 +1130,6 @@ static int brcm_pcie_start_link(struct brcm_pcie *pcie)
pci_speed_string(pcie_link_speed[cls]), nlw,
ssc_good ? "(SSC)" : "(!SSC)");
- /*
- * Refclk from RC should be gated with CLKREQ# input when ASPM L0s,L1
- * is enabled => setting the CLKREQ_DEBUG_ENABLE field to 1.
- */
- tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
- tmp |= PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK;
- writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
-
return 0;
}