diff options
Diffstat (limited to 'drivers/pci/controller/pcie-mediatek-gen3.c')
| -rw-r--r-- | drivers/pci/controller/pcie-mediatek-gen3.c | 117 |
1 files changed, 76 insertions, 41 deletions
diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c index be52e3a123ab..aa24ac9aaecc 100644 --- a/drivers/pci/controller/pcie-mediatek-gen3.c +++ b/drivers/pci/controller/pcie-mediatek-gen3.c @@ -125,6 +125,8 @@ #define MAX_NUM_PHY_RESETS 3 +#define PCIE_MTK_RESET_TIME_US 10 + /* Time in ms needed to complete PCIe reset on EN7581 SoC */ #define PCIE_EN7581_RESET_TIME_MS 100 @@ -133,10 +135,18 @@ struct mtk_gen3_pcie; #define PCIE_CONF_LINK2_CTL_STS (PCIE_CFG_OFFSET_ADDR + 0xb0) #define PCIE_CONF_LINK2_LCR2_LINK_SPEED GENMASK(3, 0) +enum mtk_gen3_pcie_flags { + SKIP_PCIE_RSTB = BIT(0), /* Skip PERST# assertion during device + * probing or suspend/resume phase to + * avoid hw bugs/issues. + */ +}; + /** * struct mtk_gen3_pcie_pdata - differentiate between host generations * @power_up: pcie power_up callback * @phy_resets: phy reset lines SoC data. + * @flags: pcie device flags. */ struct mtk_gen3_pcie_pdata { int (*power_up)(struct mtk_gen3_pcie *pcie); @@ -144,6 +154,7 @@ struct mtk_gen3_pcie_pdata { const char *id[MAX_NUM_PHY_RESETS]; int num_resets; } phy_resets; + u32 flags; }; /** @@ -438,22 +449,33 @@ static int mtk_pcie_startup_port(struct mtk_gen3_pcie *pcie) val |= PCIE_DISABLE_DVFSRC_VLT_REQ; writel_relaxed(val, pcie->base + PCIE_MISC_CTRL_REG); - /* Assert all reset signals */ - val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG); - val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB; - writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG); - /* - * Described in PCIe CEM specification sections 2.2 (PERST# Signal) - * and 2.2.1 (Initial Power-Up (G3 to S0)). - * The deassertion of PERST# should be delayed 100ms (TPVPERL) - * for the power and clock to become stable. + * Airoha EN7581 has a hw bug asserting/releasing PCIE_PE_RSTB signal + * causing occasional PCIe link down. In order to overcome the issue, + * PCIE_RSTB signals are not asserted/released at this stage and the + * PCIe block is reset using en7523_reset_assert() and + * en7581_pci_enable(). */ - msleep(100); - - /* De-assert reset signals */ - val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | PCIE_PE_RSTB); - writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG); + if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) { + /* Assert all reset signals */ + val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG); + val |= PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | + PCIE_PE_RSTB; + writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG); + + /* + * Described in PCIe CEM specification revision 6.0. + * + * The deassertion of PERST# should be delayed 100ms (TPVPERL) + * for the power and clock to become stable. + */ + msleep(PCIE_T_PVPERL_MS); + + /* De-assert reset signals */ + val &= ~(PCIE_MAC_RSTB | PCIE_PHY_RSTB | PCIE_BRG_RSTB | + PCIE_PE_RSTB); + writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG); + } /* Check if the link is up or not */ err = readl_poll_timeout(pcie->base + PCIE_LINK_STATUS_REG, val, @@ -913,11 +935,20 @@ static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie) u32 val; /* - * Wait for the time needed to complete the bulk assert in - * mtk_pcie_setup for EN7581 SoC. + * The controller may have been left out of reset by the bootloader + * so make sure that we get a clean start by asserting resets here. */ - mdelay(PCIE_EN7581_RESET_TIME_MS); + reset_control_bulk_assert(pcie->soc->phy_resets.num_resets, + pcie->phy_resets); + reset_control_assert(pcie->mac_reset); + /* Wait for the time needed to complete the reset lines assert. */ + msleep(PCIE_EN7581_RESET_TIME_MS); + + /* + * Unlike the other MediaTek Gen3 controllers, the Airoha EN7581 + * requires PHY initialization and power-on before PHY reset deassert. + */ err = phy_init(pcie->phy); if (err) { dev_err(dev, "failed to initialize PHY\n"); @@ -940,17 +971,11 @@ static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie) * Wait for the time needed to complete the bulk de-assert above. * This time is specific for EN7581 SoC. */ - mdelay(PCIE_EN7581_RESET_TIME_MS); + msleep(PCIE_EN7581_RESET_TIME_MS); pm_runtime_enable(dev); pm_runtime_get_sync(dev); - err = clk_bulk_prepare(pcie->num_clks, pcie->clks); - if (err) { - dev_err(dev, "failed to prepare clock\n"); - goto err_clk_prepare; - } - val = FIELD_PREP(PCIE_VAL_LN0_DOWNSTREAM, 0x47) | FIELD_PREP(PCIE_VAL_LN1_DOWNSTREAM, 0x47) | FIELD_PREP(PCIE_VAL_LN0_UPSTREAM, 0x41) | @@ -963,17 +988,22 @@ static int mtk_pcie_en7581_power_up(struct mtk_gen3_pcie *pcie) FIELD_PREP(PCIE_K_FINETUNE_MAX, 0xf); writel_relaxed(val, pcie->base + PCIE_PIPE4_PIE8_REG); - err = clk_bulk_enable(pcie->num_clks, pcie->clks); + err = clk_bulk_prepare_enable(pcie->num_clks, pcie->clks); if (err) { dev_err(dev, "failed to prepare clock\n"); - goto err_clk_enable; + goto err_clk_prepare_enable; } + /* + * Airoha EN7581 performs PCIe reset via clk callbacks since it has a + * hw issue with PCIE_PE_RSTB signal. Add wait for the time needed to + * complete the PCIe reset. + */ + msleep(PCIE_T_PVPERL_MS); + return 0; -err_clk_enable: - clk_bulk_unprepare(pcie->num_clks, pcie->clks); -err_clk_prepare: +err_clk_prepare_enable: pm_runtime_put_sync(dev); pm_runtime_disable(dev); reset_control_bulk_assert(pcie->soc->phy_resets.num_resets, pcie->phy_resets); @@ -990,6 +1020,15 @@ static int mtk_pcie_power_up(struct mtk_gen3_pcie *pcie) struct device *dev = pcie->dev; int err; + /* + * The controller may have been left out of reset by the bootloader + * so make sure that we get a clean start by asserting resets here. + */ + reset_control_bulk_assert(pcie->soc->phy_resets.num_resets, + pcie->phy_resets); + reset_control_assert(pcie->mac_reset); + usleep_range(PCIE_MTK_RESET_TIME_US, 2 * PCIE_MTK_RESET_TIME_US); + /* PHY power on and enable pipe clock */ err = reset_control_bulk_deassert(pcie->soc->phy_resets.num_resets, pcie->phy_resets); if (err) { @@ -1074,14 +1113,6 @@ static int mtk_pcie_setup(struct mtk_gen3_pcie *pcie) * counter since the bulk is shared. */ reset_control_bulk_deassert(pcie->soc->phy_resets.num_resets, pcie->phy_resets); - /* - * The controller may have been left out of reset by the bootloader - * so make sure that we get a clean start by asserting resets here. - */ - reset_control_bulk_assert(pcie->soc->phy_resets.num_resets, pcie->phy_resets); - - reset_control_assert(pcie->mac_reset); - usleep_range(10, 20); /* Don't touch the hardware registers before power up */ err = pcie->soc->power_up(pcie); @@ -1231,10 +1262,12 @@ static int mtk_pcie_suspend_noirq(struct device *dev) return err; } - /* Pull down the PERST# pin */ - val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG); - val |= PCIE_PE_RSTB; - writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG); + if (!(pcie->soc->flags & SKIP_PCIE_RSTB)) { + /* Assert the PERST# pin */ + val = readl_relaxed(pcie->base + PCIE_RST_CTRL_REG); + val |= PCIE_PE_RSTB; + writel_relaxed(val, pcie->base + PCIE_RST_CTRL_REG); + } dev_dbg(pcie->dev, "entered L2 states successfully"); @@ -1285,6 +1318,7 @@ static const struct mtk_gen3_pcie_pdata mtk_pcie_soc_en7581 = { .id[2] = "phy-lane2", .num_resets = 3, }, + .flags = SKIP_PCIE_RSTB, }; static const struct of_device_id mtk_pcie_of_match[] = { @@ -1301,6 +1335,7 @@ static struct platform_driver mtk_pcie_driver = { .name = "mtk-pcie-gen3", .of_match_table = mtk_pcie_of_match, .pm = &mtk_pcie_pm_ops, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, }, }; |