[PATCH net-next v2 3/5] net: pcs: qcom-ipq9574: Add PCS instantiation and phylink operations

Lei Wei
2024-12-04T14:53:15Z

This patch adds the following PCS functionality for the PCS driver
for IPQ9574 SoC:

a.) Parses PCS MII DT nodes and instantiate each MII PCS instance.
b.) Exports PCS instance get and put APIs. The network driver calls
the PCS get API to get and associate the PCS instance with the port
MAC.
c.) PCS phylink operations for SGMII/QSGMII interface modes.

Signed-off-by: Lei Wei <quic_leiwei@quicinc.com>
---
drivers/net/pcs/pcs-qcom-ipq9574.c | 462 +++++++++++++++++++++++++++++++++++
include/linux/pcs/pcs-qcom-ipq9574.h | 16 ++
2 files changed, 478 insertions(+)

diff --git a/drivers/net/pcs/pcs-qcom-ipq9574.c b/drivers/net/pcs/pcs-qcom-ipq9574.c
index ea90c1902b61..3608f5506477 100644
--- a/drivers/net/pcs/pcs-qcom-ipq9574.c
+++ b/drivers/net/pcs/pcs-qcom-ipq9574.c
@@ -6,12 +6,46 @@
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/pcs/pcs-qcom-ipq9574.h>
#include <linux/phy.h>
+#include <linux/phylink.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#include <dt-bindings/net/qcom,ipq9574-pcs.h>

+/* Maximum number of MIIs per PCS instance. There are 5 MIIs for PSGMII. */
+#define PCS_MAX_MII_NRS 5
+
+#define PCS_CALIBRATION 0x1e0
+#define PCS_CALIBRATION_DONE BIT(7)
+
+#define PCS_MODE_CTRL 0x46c
+#define PCS_MODE_SEL_MASK GENMASK(12, 8)
+#define PCS_MODE_SGMII FIELD_PREP(PCS_MODE_SEL_MASK, 0x4)
+#define PCS_MODE_QSGMII FIELD_PREP(PCS_MODE_SEL_MASK, 0x1)
+
+#define PCS_MII_CTRL(x) (0x480 + 0x18 * (x))
+#define PCS_MII_ADPT_RESET BIT(11)
+#define PCS_MII_FORCE_MODE BIT(3)
+#define PCS_MII_SPEED_MASK GENMASK(2, 1)
+#define PCS_MII_SPEED_1000 FIELD_PREP(PCS_MII_SPEED_MASK, 0x2)
+#define PCS_MII_SPEED_100 FIELD_PREP(PCS_MII_SPEED_MASK, 0x1)
+#define PCS_MII_SPEED_10 FIELD_PREP(PCS_MII_SPEED_MASK, 0x0)
+
+#define PCS_MII_STS(x) (0x488 + 0x18 * (x))
+#define PCS_MII_LINK_STS BIT(7)
+#define PCS_MII_STS_DUPLEX_FULL BIT(6)
+#define PCS_MII_STS_SPEED_MASK GENMASK(5, 4)
+#define PCS_MII_STS_SPEED_10 0
+#define PCS_MII_STS_SPEED_100 1
+#define PCS_MII_STS_SPEED_1000 2
+
+#define PCS_PLL_RESET 0x780
+#define PCS_ANA_SW_RESET BIT(6)
+
#define XPCS_INDIRECT_ADDR 0x8000
#define XPCS_INDIRECT_AHB_ADDR 0x83fc
#define XPCS_INDIRECT_ADDR_H GENMASK(20, 8)
@@ -20,6 +54,18 @@
FIELD_PREP(GENMASK(9, 2), \
FIELD_GET(XPCS_INDIRECT_ADDR_L, reg)))

+/* Per PCS MII private data */
+struct ipq_pcs_mii {
+ struct ipq_pcs *qpcs;
+ struct phylink_pcs pcs;
+ int index;
+
+ /* RX clock from NSSCC to PCS MII */
+ struct clk *rx_clk;
+ /* TX clock from NSSCC to PCS MII */
+ struct clk *tx_clk;
+};
+
/* PCS private data */
struct ipq_pcs {
struct device *dev;
@@ -27,12 +73,422 @@ struct ipq_pcs {
struct regmap *regmap;
phy_interface_t interface;

+ /* Lock to protect PCS configurations shared by multiple MII ports */
+ struct mutex config_lock;
+
/* RX clock supplied to NSSCC */
struct clk_hw rx_hw;
/* TX clock supplied to NSSCC */
struct clk_hw tx_hw;
+
+ struct ipq_pcs_mii *qpcs_mii[PCS_MAX_MII_NRS];
};

+#define phylink_pcs_to_qpcs_mii(_pcs) \
+ container_of(_pcs, struct ipq_pcs_mii, pcs)
+
+static void ipq_pcs_get_state_sgmii(struct ipq_pcs *qpcs,
+ int index,
+ struct phylink_link_state *state)
+{
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(qpcs->regmap, PCS_MII_STS(index), &val);
+ if (ret) {
+ state->link = 0;
+ return;
+ }
+
+ state->link = !!(val & PCS_MII_LINK_STS);
+
+ if (!state->link)
+ return;
+
+ switch (FIELD_GET(PCS_MII_STS_SPEED_MASK, val)) {
+ case PCS_MII_STS_SPEED_1000:
+ state->speed = SPEED_1000;
+ break;
+ case PCS_MII_STS_SPEED_100:
+ state->speed = SPEED_100;
+ break;
+ case PCS_MII_STS_SPEED_10:
+ state->speed = SPEED_10;
+ break;
+ default:
+ state->link = false;
+ return;
+ }
+
+ if (val & PCS_MII_STS_DUPLEX_FULL)
+ state->duplex = DUPLEX_FULL;
+ else
+ state->duplex = DUPLEX_HALF;
+}
+
+static int ipq_pcs_config_mode(struct ipq_pcs *qpcs,
+ phy_interface_t interface)
+{
+ unsigned int val;
+ int ret;
+
+ /* Configure PCS interface mode */
+ switch (interface) {
+ case PHY_INTERFACE_MODE_SGMII:
+ val = PCS_MODE_SGMII;
+ break;
+ case PHY_INTERFACE_MODE_QSGMII:
+ val = PCS_MODE_QSGMII;
+ break;
+ default:
+ dev_err(qpcs->dev,
+ "Unsupported interface %s\n", phy_modes(interface));
+ return -EOPNOTSUPP;
+ }
+
+ ret = regmap_update_bits(qpcs->regmap, PCS_MODE_CTRL,
+ PCS_MODE_SEL_MASK, val);
+ if (ret)
+ return ret;
+
+ /* PCS PLL reset */
+ ret = regmap_update_bits(qpcs->regmap, PCS_PLL_RESET,
+ PCS_ANA_SW_RESET, 0);
+ if (ret)
+ return ret;
+
+ fsleep(1000);
+ ret = regmap_update_bits(qpcs->regmap, PCS_PLL_RESET,
+ PCS_ANA_SW_RESET, PCS_ANA_SW_RESET);
+ if (ret)
+ return ret;
+
+ /* Wait for calibration completion */
+ ret = regmap_read_poll_timeout(qpcs->regmap, PCS_CALIBRATION,
+ val, val & PCS_CALIBRATION_DONE,
+ 1000, 100000);
+ if (ret) {
+ dev_err(qpcs->dev, "PCS calibration timed-out\n");
+ return ret;
+ }
+
+ qpcs->interface = interface;
+
+ return 0;
+}
+
+static int ipq_pcs_config_sgmii(struct ipq_pcs *qpcs,
+ int index,
+ unsigned int neg_mode,
+ phy_interface_t interface)
+{
+ int ret;
+
+ /* Access to PCS registers such as PCS_MODE_CTRL which are
+ * common to all MIIs, is lock protected and configured
+ * only once.
+ */
+ mutex_lock(&qpcs->config_lock);
+
+ if (qpcs->interface != interface) {
+ ret = ipq_pcs_config_mode(qpcs, interface);
+ if (ret) {
+ mutex_unlock(&qpcs->config_lock);
+ return ret;
+ }
+ }
+
+ mutex_unlock(&qpcs->config_lock);
+
+ /* Nothing to do here as in-band autoneg mode is enabled
+ * by default for each PCS MII port.
+ */
+ if (neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED)
+ return 0;
+
+ /* Set force speed mode */
+ return regmap_update_bits(qpcs->regmap, PCS_MII_CTRL(index),
+ PCS_MII_FORCE_MODE, PCS_MII_FORCE_MODE);
+}
+
+static int ipq_pcs_link_up_config_sgmii(struct ipq_pcs *qpcs,
+ int index,
+ unsigned int neg_mode,
+ int speed)
+{
+ unsigned int val;
+ int ret;
+
+ /* PCS speed need not be configured if in-band autoneg is enabled */
+ if (neg_mode != PHYLINK_PCS_NEG_INBAND_ENABLED) {
+ /* PCS speed set for force mode */
+ switch (speed) {
+ case SPEED_1000:
+ val = PCS_MII_SPEED_1000;
+ break;
+ case SPEED_100:
+ val = PCS_MII_SPEED_100;
+ break;
+ case SPEED_10:
+ val = PCS_MII_SPEED_10;
+ break;
+ default:
+ dev_err(qpcs->dev, "Invalid SGMII speed %d\n", speed);
+ return -EINVAL;
+ }
+
+ ret = regmap_update_bits(qpcs->regmap, PCS_MII_CTRL(index),
+ PCS_MII_SPEED_MASK, val);
+ if (ret)
+ return ret;
+ }
+
+ /* PCS adapter reset */
+ ret = regmap_update_bits(qpcs->regmap, PCS_MII_CTRL(index),
+ PCS_MII_ADPT_RESET, 0);
+ if (ret)
+ return ret;
+
+ return regmap_update_bits(qpcs->regmap, PCS_MII_CTRL(index),
+ PCS_MII_ADPT_RESET, PCS_MII_ADPT_RESET);
+}
+
+static int ipq_pcs_enable(struct phylink_pcs *pcs)
+{
+ struct ipq_pcs_mii *qpcs_mii = phylink_pcs_to_qpcs_mii(pcs);
+ struct ipq_pcs *qpcs = qpcs_mii->qpcs;
+ int index = qpcs_mii->index;
+ int ret;
+
+ ret = clk_prepare_enable(qpcs_mii->rx_clk);
+ if (ret) {
+ dev_err(qpcs->dev, "Failed to enable MII %d RX clock\n", index);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(qpcs_mii->tx_clk);
+ if (ret) {
+ dev_err(qpcs->dev, "Failed to enable MII %d TX clock\n", index);
+ clk_disable_unprepare(qpcs_mii->rx_clk);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void ipq_pcs_disable(struct phylink_pcs *pcs)
+{
+ struct ipq_pcs_mii *qpcs_mii = phylink_pcs_to_qpcs_mii(pcs);
+
+ if (__clk_is_enabled(qpcs_mii->rx_clk))
+ clk_disable_unprepare(qpcs_mii->rx_clk);
+
+ if (__clk_is_enabled(qpcs_mii->tx_clk))
+ clk_disable_unprepare(qpcs_mii->tx_clk);
+}
+
+static void ipq_pcs_get_state(struct phylink_pcs *pcs,
+ struct phylink_link_state *state)
+{
+ struct ipq_pcs_mii *qpcs_mii = phylink_pcs_to_qpcs_mii(pcs);
+ struct ipq_pcs *qpcs = qpcs_mii->qpcs;
+ int index = qpcs_mii->index;
+
+ switch (state->interface) {
+ case PHY_INTERFACE_MODE_SGMII:
+ case PHY_INTERFACE_MODE_QSGMII:
+ ipq_pcs_get_state_sgmii(qpcs, index, state);
+ break;
+ default:
+ break;
+ }
+
+ dev_dbg_ratelimited(qpcs->dev,
+ "mode=%s/%s/%s link=%u\n",
+ phy_modes(state->interface),
+ phy_speed_to_str(state->speed),
+ phy_duplex_to_str(state->duplex),
+ state->link);
+}
+
+static int ipq_pcs_config(struct phylink_pcs *pcs,
+ unsigned int neg_mode,
+ phy_interface_t interface,
+ const unsigned long *advertising,
+ bool permit)
+{
+ struct ipq_pcs_mii *qpcs_mii = phylink_pcs_to_qpcs_mii(pcs);
+ struct ipq_pcs *qpcs = qpcs_mii->qpcs;
+ int index = qpcs_mii->index;
+
+ switch (interface) {
+ case PHY_INTERFACE_MODE_SGMII:
+ case PHY_INTERFACE_MODE_QSGMII:
+ return ipq_pcs_config_sgmii(qpcs, index, neg_mode, interface);
+ default:
+ dev_err(qpcs->dev,
+ "Unsupported interface %s\n", phy_modes(interface));
+ return -EOPNOTSUPP;
+ };
+}
+
+static void ipq_pcs_link_up(struct phylink_pcs *pcs,
+ unsigned int neg_mode,
+ phy_interface_t interface,
+ int speed, int duplex)
+{
+ struct ipq_pcs_mii *qpcs_mii = phylink_pcs_to_qpcs_mii(pcs);
+ struct ipq_pcs *qpcs = qpcs_mii->qpcs;
+ int index = qpcs_mii->index;
+ int ret;
+
+ switch (interface) {
+ case PHY_INTERFACE_MODE_SGMII:
+ case PHY_INTERFACE_MODE_QSGMII:
+ ret = ipq_pcs_link_up_config_sgmii(qpcs, index,
+ neg_mode, speed);
+ break;
+ default:
+ dev_err(qpcs->dev,
+ "Unsupported interface %s\n", phy_modes(interface));
+ return;
+ }
+
+ if (ret)
+ dev_err(qpcs->dev, "PCS link up fail for interface %s\n",
+ phy_modes(interface));
+}
+
+static const struct phylink_pcs_ops ipq_pcs_phylink_ops = {
+ .pcs_enable = ipq_pcs_enable,
+ .pcs_disable = ipq_pcs_disable,
+ .pcs_get_state = ipq_pcs_get_state,
+ .pcs_config = ipq_pcs_config,
+ .pcs_link_up = ipq_pcs_link_up,
+};
+
+/**
+ * ipq_pcs_get() - Get the IPQ PCS MII instance
+ * @np: Device tree node to the PCS MII
+ *
+ * Description: Get the phylink PCS instance for the given PCS MII node @np.
+ * This instance is associated with the specific MII of the PCS and the
+ * corresponding Ethernet netdevice.
+ *
+ * Return: A pointer to the phylink PCS instance or an error-pointer value.
+ */
+struct phylink_pcs *ipq_pcs_get(struct device_node *np)
+{
+ struct platform_device *pdev;
+ struct ipq_pcs_mii *qpcs_mii;
+ struct ipq_pcs *qpcs;
+ u32 index;
+
+ if (of_property_read_u32(np, "reg", &index))
+ return ERR_PTR(-EINVAL);
+
+ if (index >= PCS_MAX_MII_NRS)
+ return ERR_PTR(-EINVAL);
+
+ /* Get the parent device */
+ pdev = of_find_device_by_node(np->parent);
+ if (!pdev)
+ return ERR_PTR(-ENODEV);
+
+ qpcs = platform_get_drvdata(pdev);
+ if (!qpcs) {
+ put_device(&pdev->dev);
+
+ /* If probe is not yet completed, return DEFER to
+ * the dependent driver.
+ */
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ qpcs_mii = qpcs->qpcs_mii[index];
+ if (!qpcs_mii) {
+ put_device(&pdev->dev);
+ return ERR_PTR(-ENOENT);
+ }
+
+ return &qpcs_mii->pcs;
+}
+EXPORT_SYMBOL(ipq_pcs_get);
+
+/**
+ * ipq_pcs_put() - Release the IPQ PCS MII instance
+ * @pcs: PCS instance
+ *
+ * Description: Release a phylink PCS instance.
+ */
+void ipq_pcs_put(struct phylink_pcs *pcs)
+{
+ struct ipq_pcs_mii *qpcs_mii = phylink_pcs_to_qpcs_mii(pcs);
+
+ /* Put reference taken by of_find_device_by_node() in
+ * ipq_pcs_get().
+ */
+ put_device(qpcs_mii->qpcs->dev);
+}
+EXPORT_SYMBOL(ipq_pcs_put);
+
+/* Parse the PCS MII DT nodes which are child nodes of the PCS node,
+ * and instantiate each MII PCS instance.
+ */
+static int ipq_pcs_create_miis(struct ipq_pcs *qpcs)
+{
+ struct device *dev = qpcs->dev;
+ struct ipq_pcs_mii *qpcs_mii;
+ struct device_node *mii_np;
+ u32 index;
+ int ret;
+
+ for_each_available_child_of_node(dev->of_node, mii_np) {
+ ret = of_property_read_u32(mii_np, "reg", &index);
+ if (ret) {
+ dev_err(dev, "Failed to read MII index\n");
+ of_node_put(mii_np);
+ return ret;
+ }
+
+ if (index >= PCS_MAX_MII_NRS) {
+ dev_err(dev, "Invalid MII index\n");
+ of_node_put(mii_np);
+ return -EINVAL;
+ }
+
+ qpcs_mii = devm_kzalloc(dev, sizeof(*qpcs_mii), GFP_KERNEL);
+ if (!qpcs_mii) {
+ of_node_put(mii_np);
+ return -ENOMEM;
+ }
+
+ qpcs_mii->qpcs = qpcs;
+ qpcs_mii->index = index;
+ qpcs_mii->pcs.ops = &ipq_pcs_phylink_ops;
+ qpcs_mii->pcs.neg_mode = true;
+ qpcs_mii->pcs.poll = true;
+
+ qpcs_mii->rx_clk = devm_get_clk_from_child(dev, mii_np, "rx");
+ if (IS_ERR(qpcs_mii->rx_clk)) {
+ dev_err(dev, "Failed to get MII %d RX clock\n", index);
+ of_node_put(mii_np);
+ return PTR_ERR(qpcs_mii->rx_clk);
+ }
+
+ qpcs_mii->tx_clk = devm_get_clk_from_child(dev, mii_np, "tx");
+ if (IS_ERR(qpcs_mii->tx_clk)) {
+ dev_err(dev, "Failed to get MII %d TX clock\n", index);
+ of_node_put(mii_np);
+ return PTR_ERR(qpcs_mii->tx_clk);
+ }
+
+ qpcs->qpcs_mii[index] = qpcs_mii;
+ }
+
+ return 0;
+}
+
static unsigned long ipq_pcs_clk_rate_get(struct ipq_pcs *qpcs)
{
switch (qpcs->interface) {
@@ -219,6 +675,12 @@ static int ipq9574_pcs_probe(struct platform_device *pdev)
if (ret)
return ret;

+ ret = ipq_pcs_create_miis(qpcs);
+ if (ret)
+ return ret;
+
+ mutex_init(&qpcs->config_lock);
+
platform_set_drvdata(pdev, qpcs);

return 0;
diff --git a/include/linux/pcs/pcs-qcom-ipq9574.h b/include/linux/pcs/pcs-qcom-ipq9574.h
new file mode 100644
index 000000000000..5469a81b4482
--- /dev/null
+++ b/include/linux/pcs/pcs-qcom-ipq9574.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ *
+ */
+
+#ifndef __LINUX_PCS_QCOM_IPQ9574_H
+#define __LINUX_PCS_QCOM_IPQ9574_H
+
+struct device_node;
+struct phylink_pcs;
+
+struct phylink_pcs *ipq_pcs_get(struct device_node *np);
+void ipq_pcs_put(struct phylink_pcs *pcs);
+
+#endif /* __LINUX_PCS_QCOM_IPQ9574_H */

--
2.34.1