From 6ef00f8b825a5fb5dc2942e467ed251b84dea4eb Mon Sep 17 00:00:00 2001 From: Stanimir Varbanov Date: Mon, 20 Jan 2025 15:01:15 +0200 Subject: [PATCH] PCI: brcmstb: Adjust PHY PLL setup to use a 54MHz input refclk The default input reference clock for the PHY PLL is 100Mhz, except for some devices where it is 54Mhz like bcm2712C1 and bcm2712D0. To implement this adjustments introduce a new .post_setup op in pcie_cfg_data and call it at the end of brcm_pcie_setup function. The bcm2712 .post_setup callback implements the required MDIO writes that switch the PLL refclk and also change PHY PM clock period. Without this RPi5 PCIex1 is unable to enumerate endpoint devices on the expansion connector. Signed-off-by: Stanimir Varbanov Reviewed-by: Florian Fainelli --- drivers/pci/controller/pcie-brcmstb.c | 44 +++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -55,6 +55,10 @@ #define PCIE_RC_DL_MDIO_WR_DATA 0x1104 #define PCIE_RC_DL_MDIO_RD_DATA 0x1108 +#define PCIE_RC_PL_PHY_CTL_15 0x184c +#define PCIE_RC_PL_PHY_CTL_15_DIS_PLL_PD_MASK 0x400000 +#define PCIE_RC_PL_PHY_CTL_15_PM_CLK_PERIOD_MASK 0xff + #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 @@ -251,6 +255,7 @@ struct pcie_cfg_data { u8 num_inbound_wins; int (*perst_set)(struct brcm_pcie *pcie, u32 val); int (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val); + int (*post_setup)(struct brcm_pcie *pcie); }; struct subdev_regulators { @@ -826,6 +831,38 @@ static int brcm_pcie_perst_set_generic(s return 0; } +static int brcm_pcie_post_setup_bcm2712(struct brcm_pcie *pcie) +{ + const u16 data[] = { 0x50b9, 0xbda1, 0x0094, 0x97b4, 0x5030, 0x5030, 0x0007 }; + const u8 regs[] = { 0x16, 0x17, 0x18, 0x19, 0x1b, 0x1c, 0x1e }; + int ret, i; + u32 tmp; + + /* Allow a 54MHz (xosc) refclk source */ + ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0, SET_ADDR_OFFSET, 0x1600); + if (ret < 0) + return ret; + + for (i = 0; i < ARRAY_SIZE(regs); i++) { + ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0, regs[i], data[i]); + if (ret < 0) + return ret; + } + + usleep_range(100, 200); + + /* + * Set L1SS sub-state timers to avoid lengthy state transitions, + * PM clock period is 18.52ns (1/54MHz, round down). + */ + tmp = readl(pcie->base + PCIE_RC_PL_PHY_CTL_15); + tmp &= ~PCIE_RC_PL_PHY_CTL_15_PM_CLK_PERIOD_MASK; + tmp |= 0x12; + writel(tmp, pcie->base + PCIE_RC_PL_PHY_CTL_15); + + return 0; +} + static void add_inbound_win(struct inbound_win *b, u8 *count, u64 size, u64 cpu_addr, u64 pci_offset) { @@ -1189,6 +1226,12 @@ static int brcm_pcie_setup(struct brcm_p PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK); writel(tmp, base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1); + if (pcie->cfg->post_setup) { + ret = pcie->cfg->post_setup(pcie); + if (ret < 0) + return ret; + } + return 0; } @@ -1717,6 +1760,7 @@ static const struct pcie_cfg_data bcm271 .soc_base = BCM7712, .perst_set = brcm_pcie_perst_set_7278, .bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic, + .post_setup = brcm_pcie_post_setup_bcm2712, .quirks = CFG_QUIRK_AVOID_BRIDGE_SHUTDOWN, .num_inbound_wins = 10, };