Re: [PATCH v1 4/4] PCI: brcmstb: Augment driver for MIPs SOCs
flat view
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2022-07-06 21:42:16
Also in:
linux-mips, linux-pci, lkml
On Thu, Dec 09, 2021 at 03:47:25PM -0500, Jim Quinlan wrote:
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).
...quoted hunk ↗ jump to hunk
@@ -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
quoted hunk ↗ jump to hunk
@@ -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);
brcm_pcie_resume() has similar code that updates PCIE_MISC_HARD_PCIE_HARD_DEBUG [1]: tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG); u32p_replace_bits(&tmp, 0, PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK); writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG); /* wait for serdes to be stable */ udelay(100); This patch didn't change brcm_pcie_resume() to check is_bmips(). Should it? If so, it would be nice to use the same method for updating the value (either u32p_replace_bits or plain C bitops) in both places. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/controller/pcie-brcmstb.c?id=v5.18#n1452 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel