[PATCH v9 11/12] PCI: brcmstb: Set bus max burst size by chip type

Jim Quinlan
2020-07-24T20:46:11Z

The proper value of the parameter SCB_MAX_BURST_SIZE varies per chip. The
2711 family requires 128B whereas other devices can employ 512. The
assignment is complicated by the fact that the values for this two-bit
field have different meanings;

Value Type_Generic Type_7278

00 Reserved 128B
01 128B 256B
10 256B 512B
11 512B Reserved

Signed-off-by: Jim Quinlan <jquinlan@broadcom.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
---
drivers/pci/controller/pcie-brcmstb.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index a2e02b2fbd36..87a6f51d821a 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -55,7 +55,7 @@
#define PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK 0x1000
#define PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK 0x2000
#define PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK 0x300000
-#define PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128 0x0
+
#define PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK 0xf8000000
#define PCIE_MISC_MISC_CTRL_SCB1_SIZE_MASK 0x07c00000
#define PCIE_MISC_MISC_CTRL_SCB2_SIZE_MASK 0x0000001f
@@ -847,7 +847,7 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
int num_out_wins = 0;
u16 nlw, cls, lnksta;
int i, ret, memc;
- u32 tmp, aspm_support;
+ u32 tmp, burst, aspm_support;

/* Reset the bridge */
brcm_pcie_bridge_sw_init_set(pcie, 1);
@@ -867,11 +867,22 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
/* Wait for SerDes to be stable */
usleep_range(100, 200);

+ /*
+ * SCB_MAX_BURST_SIZE is a two bit field. For GENERIC chips it
+ * is encoded as 0=128, 1=256, 2=512, 3=Rsvd, for BCM7278 it
+ * is encoded as 0=Rsvd, 1=128, 2=256, 3=512.
+ */
+ if (pcie->type == BCM2711)
+ burst = 0x0; /* 128B */
+ else if (pcie->type == BCM7278)
+ burst = 0x3; /* 512 bytes */
+ else
+ burst = 0x2; /* 512 bytes */
+
/* Set SCB_MAX_BURST_SIZE, CFG_READ_UR_MODE, SCB_ACCESS_EN */
u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK);
u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK);
- u32p_replace_bits(&tmp, PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128,
- PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK);
+ u32p_replace_bits(&tmp, burst, PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK);
writel(tmp, base + PCIE_MISC_MISC_CTRL);

ret = brcm_pcie_get_rc_bar2_size_and_offset(pcie, &rc_bar2_size,
--
2.17.1