| Message ID | 20231106-refclk_always_on-v1-2-17a7fd8b532b@quicinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | phy: qcom-qmp-pcie: Add support to keep refclk always on | expand |
On Mon, 6 Nov 2023 at 13:53, Krishna chaitanya chundru <quic_krichai@quicinc.com> wrote: > > In PCIe low power states like L1.1 or L1.2 the phy will stop > supplying refclk to endpoint. If endpoint asserts clkreq to bring > back link L0, then RC needs to provide refclk to endpoint. > > If there is some issues in platform with clkreq signal propagation > to host and due to that host will not send refclk which results PCIe link > down. For those platforms phy needs to provide refclk even in low power > states. > > Add a flag which indicates refclk is always supplied to endpoint. > > Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com> > --- > drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 21 +++++++++++++++++---- > 1 file changed, 17 insertions(+), 4 deletions(-) > > diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c > index a63ca7424974..d7e377a7d96e 100644 > --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c > +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c > @@ -43,6 +43,8 @@ > /* QPHY_PCS_STATUS bit */ > #define PHYSTATUS BIT(6) > #define PHYSTATUS_4_20 BIT(7) > +/* PCS_PCIE_ENDPOINT_REFCLK_CNTRL */ > +#define EPCLK_ALWAYS_ON_EN BIT(6) > > #define PHY_INIT_COMPLETE_TIMEOUT 10000 > > @@ -77,6 +79,7 @@ enum qphy_reg_layout { > QPHY_START_CTRL, > QPHY_PCS_STATUS, > QPHY_PCS_POWER_DOWN_CONTROL, > + QPHY_PCS_ENDPOINT_REFCLK_CNTRL, > /* Keep last to ensure regs_layout arrays are properly initialized */ > QPHY_LAYOUT_SIZE > }; > @@ -103,10 +106,11 @@ static const unsigned int sdm845_qhp_pciephy_regs_layout[QPHY_LAYOUT_SIZE] = { > }; > > static const unsigned int pciephy_v4_regs_layout[QPHY_LAYOUT_SIZE] = { > - [QPHY_SW_RESET] = QPHY_V4_PCS_SW_RESET, > - [QPHY_START_CTRL] = QPHY_V4_PCS_START_CONTROL, > - [QPHY_PCS_STATUS] = QPHY_V4_PCS_PCS_STATUS1, > - [QPHY_PCS_POWER_DOWN_CONTROL] = QPHY_V4_PCS_POWER_DOWN_CONTROL, > + [QPHY_SW_RESET] = QPHY_V4_PCS_SW_RESET, > + [QPHY_START_CTRL] = QPHY_V4_PCS_START_CONTROL, > + [QPHY_PCS_STATUS] = QPHY_V4_PCS_PCS_STATUS1, > + [QPHY_PCS_POWER_DOWN_CONTROL] = QPHY_V4_PCS_POWER_DOWN_CONTROL, No unnecessary whitespace changes, please. > + [QPHY_PCS_ENDPOINT_REFCLK_CNTRL] = QPHY_V4_PCS_PCIE_ENDPOINT_REFCLK_CNTRL, Any other platform having this register? > }; > > static const unsigned int pciephy_v5_regs_layout[QPHY_LAYOUT_SIZE] = { > @@ -2244,6 +2248,8 @@ struct qmp_pcie { > struct phy *phy; > int mode; > > + bool refclk_always_on; > + > struct clk_fixed_rate pipe_clk_fixed; > }; > > @@ -3159,6 +3165,10 @@ static void qmp_pcie_init_registers(struct qmp_pcie *qmp, const struct qmp_phy_c > qmp_pcie_configure(pcs, tbls->pcs, tbls->pcs_num); > qmp_pcie_configure(pcs_misc, tbls->pcs_misc, tbls->pcs_misc_num); > > + if (qmp->refclk_always_on && cfg->regs[QPHY_PCS_ENDPOINT_REFCLK_CNTRL]) > + qphy_setbits(pcs_misc, cfg->regs[QPHY_PCS_ENDPOINT_REFCLK_CNTRL], > + EPCLK_ALWAYS_ON_EN); > + > if (cfg->lanes >= 4 && qmp->tcsr_4ln_config) { > qmp_pcie_configure(serdes, cfg->serdes_4ln_tbl, cfg->serdes_4ln_num); > qmp_pcie_init_port_b(qmp, tbls); > @@ -3681,6 +3691,9 @@ static int qmp_pcie_probe(struct platform_device *pdev) > if (ret) > goto err_node_put; > > + qmp->refclk_always_on = of_property_read_bool(dev->of_node, > + "qcom,refclk-always-on"); Error out if !cfg->regs[QPHY_PCS_ENDPOINT_REFCLK_CNTRL]). Otherwise your DT value can be silently ignored. > + > ret = phy_pipe_clk_register(qmp, np); > if (ret) > goto err_node_put; > > -- > 2.42.0 >
On Mon, Nov 06, 2023 at 05:22:35PM +0530, Krishna chaitanya chundru wrote: > In PCIe low power states like L1.1 or L1.2 the phy will stop > supplying refclk to endpoint. If endpoint asserts clkreq to bring > back link L0, then RC needs to provide refclk to endpoint. > > If there is some issues in platform with clkreq signal propagation > to host and due to that host will not send refclk which results PCIe link > down. For those platforms phy needs to provide refclk even in low power Double <space> ------------^^ > states. > > Add a flag which indicates refclk is always supplied to endpoint. > The patch itself look good, the problem description looks good, but if you have an indication that the refclk "is always supplied to the endpoint", then you don't have a problem with refclk and I don't think you need this patch. Something to the tune of "keep refclk always supplied to endpoint" seems to more appropriately describe what this flag is doing. > Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com> > --- > drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 21 +++++++++++++++++---- > 1 file changed, 17 insertions(+), 4 deletions(-) > > diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c > index a63ca7424974..d7e377a7d96e 100644 > --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c > +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c > @@ -43,6 +43,8 @@ > /* QPHY_PCS_STATUS bit */ > #define PHYSTATUS BIT(6) > #define PHYSTATUS_4_20 BIT(7) > +/* PCS_PCIE_ENDPOINT_REFCLK_CNTRL */ > +#define EPCLK_ALWAYS_ON_EN BIT(6) > > #define PHY_INIT_COMPLETE_TIMEOUT 10000 > > @@ -77,6 +79,7 @@ enum qphy_reg_layout { > QPHY_START_CTRL, > QPHY_PCS_STATUS, > QPHY_PCS_POWER_DOWN_CONTROL, > + QPHY_PCS_ENDPOINT_REFCLK_CNTRL, > /* Keep last to ensure regs_layout arrays are properly initialized */ > QPHY_LAYOUT_SIZE > }; > @@ -103,10 +106,11 @@ static const unsigned int sdm845_qhp_pciephy_regs_layout[QPHY_LAYOUT_SIZE] = { > }; > > static const unsigned int pciephy_v4_regs_layout[QPHY_LAYOUT_SIZE] = { > - [QPHY_SW_RESET] = QPHY_V4_PCS_SW_RESET, > - [QPHY_START_CTRL] = QPHY_V4_PCS_START_CONTROL, > - [QPHY_PCS_STATUS] = QPHY_V4_PCS_PCS_STATUS1, > - [QPHY_PCS_POWER_DOWN_CONTROL] = QPHY_V4_PCS_POWER_DOWN_CONTROL, > + [QPHY_SW_RESET] = QPHY_V4_PCS_SW_RESET, > + [QPHY_START_CTRL] = QPHY_V4_PCS_START_CONTROL, > + [QPHY_PCS_STATUS] = QPHY_V4_PCS_PCS_STATUS1, > + [QPHY_PCS_POWER_DOWN_CONTROL] = QPHY_V4_PCS_POWER_DOWN_CONTROL, > + [QPHY_PCS_ENDPOINT_REFCLK_CNTRL] = QPHY_V4_PCS_PCIE_ENDPOINT_REFCLK_CNTRL, > }; > > static const unsigned int pciephy_v5_regs_layout[QPHY_LAYOUT_SIZE] = { > @@ -2244,6 +2248,8 @@ struct qmp_pcie { > struct phy *phy; > int mode; > > + bool refclk_always_on; > + > struct clk_fixed_rate pipe_clk_fixed; > }; > > @@ -3159,6 +3165,10 @@ static void qmp_pcie_init_registers(struct qmp_pcie *qmp, const struct qmp_phy_c > qmp_pcie_configure(pcs, tbls->pcs, tbls->pcs_num); > qmp_pcie_configure(pcs_misc, tbls->pcs_misc, tbls->pcs_misc_num); > > + if (qmp->refclk_always_on && cfg->regs[QPHY_PCS_ENDPOINT_REFCLK_CNTRL]) > + qphy_setbits(pcs_misc, cfg->regs[QPHY_PCS_ENDPOINT_REFCLK_CNTRL], > + EPCLK_ALWAYS_ON_EN); > + > if (cfg->lanes >= 4 && qmp->tcsr_4ln_config) { > qmp_pcie_configure(serdes, cfg->serdes_4ln_tbl, cfg->serdes_4ln_num); > qmp_pcie_init_port_b(qmp, tbls); > @@ -3681,6 +3691,9 @@ static int qmp_pcie_probe(struct platform_device *pdev) > if (ret) > goto err_node_put; > > + qmp->refclk_always_on = of_property_read_bool(dev->of_node, > + "qcom,refclk-always-on"); Leave this line unwrapped, for readability. Regards, Bjorn > + > ret = phy_pipe_clk_register(qmp, np); > if (ret) > goto err_node_put; > > -- > 2.42.0 >
diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c index a63ca7424974..d7e377a7d96e 100644 --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c @@ -43,6 +43,8 @@ /* QPHY_PCS_STATUS bit */ #define PHYSTATUS BIT(6) #define PHYSTATUS_4_20 BIT(7) +/* PCS_PCIE_ENDPOINT_REFCLK_CNTRL */ +#define EPCLK_ALWAYS_ON_EN BIT(6) #define PHY_INIT_COMPLETE_TIMEOUT 10000 @@ -77,6 +79,7 @@ enum qphy_reg_layout { QPHY_START_CTRL, QPHY_PCS_STATUS, QPHY_PCS_POWER_DOWN_CONTROL, + QPHY_PCS_ENDPOINT_REFCLK_CNTRL, /* Keep last to ensure regs_layout arrays are properly initialized */ QPHY_LAYOUT_SIZE }; @@ -103,10 +106,11 @@ static const unsigned int sdm845_qhp_pciephy_regs_layout[QPHY_LAYOUT_SIZE] = { }; static const unsigned int pciephy_v4_regs_layout[QPHY_LAYOUT_SIZE] = { - [QPHY_SW_RESET] = QPHY_V4_PCS_SW_RESET, - [QPHY_START_CTRL] = QPHY_V4_PCS_START_CONTROL, - [QPHY_PCS_STATUS] = QPHY_V4_PCS_PCS_STATUS1, - [QPHY_PCS_POWER_DOWN_CONTROL] = QPHY_V4_PCS_POWER_DOWN_CONTROL, + [QPHY_SW_RESET] = QPHY_V4_PCS_SW_RESET, + [QPHY_START_CTRL] = QPHY_V4_PCS_START_CONTROL, + [QPHY_PCS_STATUS] = QPHY_V4_PCS_PCS_STATUS1, + [QPHY_PCS_POWER_DOWN_CONTROL] = QPHY_V4_PCS_POWER_DOWN_CONTROL, + [QPHY_PCS_ENDPOINT_REFCLK_CNTRL] = QPHY_V4_PCS_PCIE_ENDPOINT_REFCLK_CNTRL, }; static const unsigned int pciephy_v5_regs_layout[QPHY_LAYOUT_SIZE] = { @@ -2244,6 +2248,8 @@ struct qmp_pcie { struct phy *phy; int mode; + bool refclk_always_on; + struct clk_fixed_rate pipe_clk_fixed; }; @@ -3159,6 +3165,10 @@ static void qmp_pcie_init_registers(struct qmp_pcie *qmp, const struct qmp_phy_c qmp_pcie_configure(pcs, tbls->pcs, tbls->pcs_num); qmp_pcie_configure(pcs_misc, tbls->pcs_misc, tbls->pcs_misc_num); + if (qmp->refclk_always_on && cfg->regs[QPHY_PCS_ENDPOINT_REFCLK_CNTRL]) + qphy_setbits(pcs_misc, cfg->regs[QPHY_PCS_ENDPOINT_REFCLK_CNTRL], + EPCLK_ALWAYS_ON_EN); + if (cfg->lanes >= 4 && qmp->tcsr_4ln_config) { qmp_pcie_configure(serdes, cfg->serdes_4ln_tbl, cfg->serdes_4ln_num); qmp_pcie_init_port_b(qmp, tbls); @@ -3681,6 +3691,9 @@ static int qmp_pcie_probe(struct platform_device *pdev) if (ret) goto err_node_put; + qmp->refclk_always_on = of_property_read_bool(dev->of_node, + "qcom,refclk-always-on"); + ret = phy_pipe_clk_register(qmp, np); if (ret) goto err_node_put;
In PCIe low power states like L1.1 or L1.2 the phy will stop supplying refclk to endpoint. If endpoint asserts clkreq to bring back link L0, then RC needs to provide refclk to endpoint. If there is some issues in platform with clkreq signal propagation to host and due to that host will not send refclk which results PCIe link down. For those platforms phy needs to provide refclk even in low power states. Add a flag which indicates refclk is always supplied to endpoint. Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com> --- drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-)