Re: [PATCH net-next v2 8/9] net: stmmac: qcom-ethqos: add per-platform NOC clock voting
From: Lorenzo Bianconi <hidden>
Date: 2026-09-09 18:48:01
Also in:
linux-arm-kernel, linux-arm-msm, linux-devicetree, lkml
Some SoCs gate the EMAC's path to the System NOC behind dedicated clocks that must be enabled before the DMA can reach memory. Add ethqos_noc_clk_cfg and the corresponding fields in the driver-data and runtime structs so each compatible can declare its own set with per-clock rates. The clocks are acquired during probe and enabled/disabled alongside the existing link clock in ethqos_clks_config(). No functional change for existing compatibles. This will help us when we add support for Shikra. Signed-off-by: Mohd Ayaan Anwar <mohd.anwar@oss.qualcomm.com> --- .../ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c | 106 +++++++++++++++++++++ 1 file changed, 106 insertions(+)
[...]
quoted hunk ↗ jump to hunk
static u32 rgmii_readl(struct qcom_ethqos *ethqos, unsigned int offset)@@ -689,15 +703,51 @@ static int ethqos_mac_finish_serdes(struct net_device *ndev, void *priv, static int ethqos_clks_config(void *priv, bool enabled) { struct qcom_ethqos *ethqos = priv; + unsigned int i; int ret = 0; if (enabled) { + if (ethqos->num_noc_clks) { + ret = dev_pm_opp_set_rate(ðqos->pdev->dev, + ethqos->noc_clk_rates[0]);
assuming the first clock is always an OPP device seems a bit fragile to me. Can we find a way to enforce it? (e.g. have a dedicated clk_bulk_data struct for it).
quoted hunk ↗ jump to hunk
+ if (ret) { + dev_err(ðqos->pdev->dev, + "NOC OPP rate set failed: %d\n", ret); + return ret; + } + + for (i = 1; i < ethqos->num_noc_clks; i++) { + ret = clk_set_rate(ethqos->noc_clks[i].clk, + ethqos->noc_clk_rates[i]); + if (ret) { + dev_err(ðqos->pdev->dev, + "NOC clock rate set failed: %d\n", ret); + dev_pm_opp_set_rate(ðqos->pdev->dev, 0); + return ret; + } + } + } + ret = clk_prepare_enable(ethqos->link_clk); if (ret) { dev_err(ðqos->pdev->dev, "link_clk enable failed\n"); + if (ethqos->num_noc_clks) + dev_pm_opp_set_rate(ðqos->pdev->dev, 0); return ret; } + if (ethqos->num_noc_clks) { + ret = clk_bulk_prepare_enable(ethqos->num_noc_clks, + ethqos->noc_clks); + if (ret) { + dev_err(ðqos->pdev->dev, + "NOC clocks enable failed: %d\n", ret); + clk_disable_unprepare(ethqos->link_clk); + dev_pm_opp_set_rate(ðqos->pdev->dev, 0); + return ret; + } + } + /* Enable functional clock to prevent DMA reset to timeout due * to lacking PHY clock after the hardware block has been power * cycled. The actual configuration will be adjusted once@@ -706,7 +756,12 @@ static int ethqos_clks_config(void *priv, bool enabled) qcom_ethqos_set_sgmii_loopback(ethqos, true); ethqos_set_func_clk_en(ethqos); } else { + if (ethqos->num_noc_clks) + clk_bulk_disable_unprepare(ethqos->num_noc_clks, + ethqos->noc_clks); clk_disable_unprepare(ethqos->link_clk); + if (ethqos->num_noc_clks) + dev_pm_opp_set_rate(ðqos->pdev->dev, 0); } return ret;@@ -734,6 +789,51 @@ static void ethqos_ptp_clk_freq_config(struct stmmac_priv *priv) netdev_dbg(priv->dev, "PTP rate %lu\n", plat_dat->clk_ptp_rate); } +static void qcom_ethqos_noc_opp_cleanup(void *dev) +{ + dev_pm_opp_set_rate(dev, 0); +} + +/* Some SoCs gate NOC access behind dedicated clocks. Acquire them here + * so ethqos_clks_config() can enable/disable them at runtime. The OPP + * table is used to propagate the required VDD_CX performance state via + * dev_pm_opp_set_rate(). + */ +static int qcom_ethqos_init_noc_clks(struct qcom_ethqos *ethqos, + const struct ethqos_emac_driver_data *data) +{ + struct device *dev = ðqos->pdev->dev; + unsigned int i; + int ret; + + if (!data->num_noc_clks) + return 0; + + for (i = 0; i < data->num_noc_clks; i++) { + ethqos->noc_clks[i].id = data->noc_clk_cfg[i].id; + ethqos->noc_clk_rates[i] = data->noc_clk_cfg[i].rate; + } + ethqos->num_noc_clks = data->num_noc_clks; + + ret = devm_clk_bulk_get(dev, ethqos->num_noc_clks, ethqos->noc_clks); + if (ret) + return dev_err_probe(dev, ret, "Failed to get NOC clocks\n"); + + ret = devm_pm_opp_set_clkname(dev, data->noc_clk_cfg[0].id); + if (ret) + return dev_err_probe(dev, ret, "Failed to set OPP clock name\n"); + + ret = devm_pm_opp_of_add_table(dev); + if (ret) + return dev_err_probe(dev, ret, "Failed to add OPP table\n"); + + ret = dev_pm_opp_set_rate(dev, data->noc_clk_cfg[0].rate); + if (ret) + return dev_err_probe(dev, ret, "Failed to set initial NOC OPP rate\n"); + + return devm_add_action_or_reset(dev, qcom_ethqos_noc_opp_cleanup, dev); +} + static int qcom_ethqos_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node;@@ -795,6 +895,12 @@ static int qcom_ethqos_probe(struct platform_device *pdev) ethqos->has_emac_ge_3 = data->has_emac_ge_3; ethqos->needs_sgmii_loopback = data->needs_sgmii_loopback; + if (data->num_noc_clks) {
I guess you can drop this check since it is already done in qcom_ethqos_init_noc_clks(), right? Regards, Lorenzo
+ ret = qcom_ethqos_init_noc_clks(ethqos, data); + if (ret) + return ret; + } + ethqos->link_clk = devm_clk_get(dev, data->link_clk_name ?: "rgmii"); if (IS_ERR(ethqos->link_clk)) return dev_err_probe(dev, PTR_ERR(ethqos->link_clk), -- 2.34.1
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