[PATCH RESEND v10 05/11] PCI: brcmstb: Add bcm7278 PERST# support

From: Jim Quinlan
Date: Mon Aug 17 2020 - 17:55:07 EST


From: Jim Quinlan <jquinlan@xxxxxxxxxxxx>

The PERST# bit was moved to a different register in 7278-type STB chips.
In addition, the polarity of the bit was also changed; for other chips
writing a 1 specified assert; for 7278-type chips, writing a 0 specifies
assert.

Of course, PERST# is a PCIe asserted-low signal.

Signed-off-by: Jim Quinlan <jquinlan@xxxxxxxxxxxx>
Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
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 7c148eb65170..e5e7f7d82eda 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -83,6 +83,7 @@

#define PCIE_MISC_PCIE_CTRL 0x4064
#define PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK 0x1
+#define PCIE_MISC_PCIE_CTRL_PCIE_PERSTB_MASK 0x4

#define PCIE_MISC_PCIE_STATUS 0x4068
#define PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK 0x80
@@ -685,9 +686,16 @@ static inline void brcm_pcie_perst_set(struct brcm_pcie *pcie, u32 val)
{
u32 tmp;

- tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
- u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
- writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
+ if (pcie->type == BCM7278) {
+ /* Perst bit has moved and assert value is 0 */
+ tmp = readl(pcie->base + PCIE_MISC_PCIE_CTRL);
+ u32p_replace_bits(&tmp, !val, PCIE_MISC_PCIE_CTRL_PCIE_PERSTB_MASK);
+ writel(tmp, pcie->base + PCIE_MISC_PCIE_CTRL);
+ } else {
+ tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
+ u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
+ writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1(pcie));
+ }
}

static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
@@ -772,7 +780,10 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)

/* Reset the bridge */
brcm_pcie_bridge_sw_init_set(pcie, 1);
- brcm_pcie_perst_set(pcie, 1);
+
+ /* BCM7278 fails when PERST# is set here */
+ if (pcie->type != BCM7278)
+ brcm_pcie_perst_set(pcie, 1);

usleep_range(100, 200);

--
2.17.1