[PATCH v1 4/4] PCI: brcmstb: Augment driver for MIPs SOCs

Jim Quinlan
2021-12-09T20:47:47Z

The current brcmstb driver works for Arm and Arm64. A few things are
modified here for us to support MIPs as well.

o There are four outbound range register groups and each directs a window
of up to 128MB. Even though there are four 128MB DT "ranges" in the
bmips PCIe DT node, these ranges are contiguous and are collapsed into
a single range by the OF range parser. Now the driver assumes a single
range -- for MIPs only -- and splits it back into 128MB sizes.

o For bcm7425, the config space accesses must be 32-bit reads or
writes. In addition, the 4k config space register array is missing
and not used.

o The registers for the upper 32-bits of the outbound window address do
not exist.

o Burst size must be set to 256 (this refers to an internal bus).

Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
---
drivers/pci/controller/Kconfig | 2 +-
drivers/pci/controller/pcie-brcmstb.c | 82 +++++++++++++++++++++++++--
2 files changed, 79 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index 93b141110537..4ac474d4a956 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -274,7 +274,7 @@ config PCIE_BRCMSTB
BMIPS_GENERIC || COMPILE_TEST
depends on OF
depends on PCI_MSI_IRQ_DOMAIN
- default ARCH_BRCMSTB
+ default ARCH_BRCMSTB || BMIPS_GENERIC
help
Say Y here to enable PCIe host controller support for
Broadcom STB based SoCs, like the Raspberry Pi 4.
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 1fc7bd49a7ad..a267cd5b3233 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -118,6 +118,7 @@
#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_SERDES_IDDQ_MASK 0x08000000
+#define PCIE_BMIPS_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK 0x00800000

#define PCIE_INTR2_CPU_BASE 0x4300
@@ -205,6 +206,8 @@ enum {

enum pcie_type {
GENERIC,
+ BCM7425,
+ BCM7435,
BCM4908,
BCM7278,
BCM2711,
@@ -223,6 +226,12 @@ static const int pcie_offsets[] = {
[EXT_CFG_DATA] = 0x9004,
};

+static const int pcie_offsets_bmips_7425[] = {
+ [RGR1_SW_INIT_1] = 0x8010,
+ [EXT_CFG_INDEX] = 0x8300,
+ [EXT_CFG_DATA] = 0x8304,
+};
+
static const struct pcie_cfg_data generic_cfg = {
.offsets = pcie_offsets,
.type = GENERIC,
@@ -230,6 +239,20 @@ static const struct pcie_cfg_data generic_cfg = {
.bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic,
};

+static const struct pcie_cfg_data bcm7425_cfg = {
+ .offsets = pcie_offsets_bmips_7425,
+ .type = BCM7425,
+ .perst_set = brcm_pcie_perst_set_generic,
+ .bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic,
+};
+
+static const struct pcie_cfg_data bcm7435_cfg = {
+ .offsets = pcie_offsets,
+ .type = BCM7435,
+ .perst_set = brcm_pcie_perst_set_generic,
+ .bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic,
+};
+
static const struct pcie_cfg_data bcm4908_cfg = {
.offsets = pcie_offsets,
.type = BCM4908,
@@ -297,6 +320,11 @@ struct brcm_pcie {
void (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val);
};

+static inline bool is_bmips(const struct brcm_pcie *pcie)
+{
+ return pcie->type == BCM7435 || pcie->type == BCM7425;
+}
+
/*
* This is to convert the size of the inbound "BAR" region to the
* non-linear values of PCIE_X_MISC_RC_BAR[123]_CONFIG_LO.SIZE
@@ -443,6 +471,9 @@ static void brcm_pcie_set_outbound_win(struct brcm_pcie *pcie,
PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK);
writel(tmp, pcie->base + PCIE_MEM_WIN0_BASE_LIMIT(win));

+ if (is_bmips(pcie))
+ return;
+
/* Write the cpu & limit addr upper bits */
high_addr_shift =
HWEIGHT32(PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK);
@@ -718,12 +749,35 @@ static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
return base + PCIE_EXT_CFG_DATA + where;
}

+static void __iomem *brcm_pcie_map_conf32(struct pci_bus *bus, unsigned int devfn,
+ int where)
+{
+ struct brcm_pcie *pcie = bus->sysdata;
+ void __iomem *base = pcie->base;
+ int idx;
+
+ /* Accesses to the RC go right to the RC registers if slot==0 */
+ if (pci_is_root_bus(bus))
+ return PCI_SLOT(devfn) ? NULL : base + (where & ~0x3);
+
+ /* For devices, write to the config space index register */
+ idx = PCIE_ECAM_OFFSET(bus->number, devfn, (where & ~3));
+ writel(idx, base + IDX_ADDR(pcie));
+ return base + DATA_ADDR(pcie);
+}
+
static struct pci_ops brcm_pcie_ops = {
.map_bus = brcm_pcie_map_conf,
.read = pci_generic_config_read,
.write = pci_generic_config_write,
};

+static struct pci_ops brcm_pcie_ops32 = {
+ .map_bus = brcm_pcie_map_conf32,
+ .read = pci_generic_config_read32,
+ .write = pci_generic_config_write32,
+};
+
static inline void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie *pcie, u32 val)
{
u32 tmp, mask = RGR1_SW_INIT_1_INIT_GENERIC_MASK;
@@ -883,7 +937,10 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
pcie->bridge_sw_init_set(pcie, 0);

tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
- tmp &= ~PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK;
+ if (is_bmips(pcie))
+ tmp &= ~PCIE_BMIPS_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK;
+ else
+ tmp &= ~PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK;
writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
/* Wait for SerDes to be stable */
usleep_range(100, 200);
@@ -893,8 +950,10 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
* 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 */
+ if (is_bmips(pcie))
+ burst = 0x1; /* 256 bytes */
+ else if (pcie->type == BCM2711)
+ burst = 0x0; /* 128 bytes */
else if (pcie->type == BCM7278)
burst = 0x3; /* 512 bytes */
else
@@ -988,6 +1047,19 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
return -EINVAL;
}

+ if (is_bmips(pcie)) {
+ u64 start = res->start;
+ unsigned int j, nwins = resource_size(res) / SZ_128M;
+
+ /* bmips PCIe outbound windows have a 128MB max size */
+ if (nwins > BRCM_NUM_PCIE_OUT_WINS)
+ nwins = BRCM_NUM_PCIE_OUT_WINS;
+ for (j = 0; j < nwins; j++, start += SZ_128M)
+ brcm_pcie_set_outbound_win(pcie, j, start,
+ start - entry->offset,
+ SZ_128M);
+ break;
+ }
brcm_pcie_set_outbound_win(pcie, num_out_wins, res->start,
res->start - entry->offset,
resource_size(res));
@@ -1226,6 +1298,8 @@ static const struct of_device_id brcm_pcie_match[] = {
{ .compatible = "brcm,bcm7278-pcie", .data = &bcm7278_cfg },
{ .compatible = "brcm,bcm7216-pcie", .data = &bcm7278_cfg },
{ .compatible = "brcm,bcm7445-pcie", .data = &generic_cfg },
+ { .compatible = "brcm,bcm7435-pcie", .data = &bcm7435_cfg },
+ { .compatible = "brcm,bcm7425-pcie", .data = &bcm7425_cfg },
{},
};

@@ -1315,7 +1389,7 @@ static int brcm_pcie_probe(struct platform_device *pdev)
}
}

- bridge->ops = &brcm_pcie_ops;
+ bridge->ops = pcie->type == BCM7425 ? &brcm_pcie_ops32 : &brcm_pcie_ops;
bridge->sysdata = pcie;

platform_set_drvdata(pdev, pcie);
--
2.17.1