Re: [PATCH v2 net-next 04/13] net: enetc: add initial netc-blk-ctrl driver support

From: Frank Li
Date: Tue Oct 15 2024 - 12:16:03 EST


On Tue, Oct 15, 2024 at 08:58:32PM +0800, Wei Fang wrote:
> The netc-blk-ctrl driver is used to configure Integrated Endpoint
> Register Block (IERB) and Privileged Register Block (PRB) of NETC.
> For i.MX platforms, it is also used to configure the NETCMIX block.
>
> The IERB contains registers that are used for pre-boot initialization,
> debug, and non-customer configuration. The PRB controls global reset
> and global error handling for NETC. The NETCMIX block is mainly used
> to set MII protocol and PCS protocol of the links, it also contains
> settings for some other functions.
>
> Note the IERB configuration registers can only be written after being
> unlocked by PRB, otherwise, all write operations are inhibited. A warm
> reset is performed when the IERB is unlocked, and it results in an FLR
> to all NETC devices. Therefore, all NETC device drivers must be probed
> or initialized after the warm reset is finished.
>
> Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
> ---
> v2 changes:
> 1. Add linux/bits.h
> 2. Remove the useless check at the beginning of netc_blk_ctrl_probe().
> 3. Use dev_err_probe() in netc_blk_ctrl_probe().
> ---
> drivers/net/ethernet/freescale/enetc/Kconfig | 14 +
> drivers/net/ethernet/freescale/enetc/Makefile | 3 +
> .../ethernet/freescale/enetc/netc_blk_ctrl.c | 472 ++++++++++++++++++
> include/linux/fsl/netc_global.h | 39 ++
> 4 files changed, 528 insertions(+)
> create mode 100644 drivers/net/ethernet/freescale/enetc/netc_blk_ctrl.c
> create mode 100644 include/linux/fsl/netc_global.h
>
> diff --git a/drivers/net/ethernet/freescale/enetc/Kconfig b/drivers/net/ethernet/freescale/enetc/Kconfig
> index 4d75e6807e92..51d80ea959d4 100644
> --- a/drivers/net/ethernet/freescale/enetc/Kconfig
> +++ b/drivers/net/ethernet/freescale/enetc/Kconfig
> @@ -75,3 +75,17 @@ config FSL_ENETC_QOS
> enable/disable from user space via Qos commands(tc). In the kernel
> side, it can be loaded by Qos driver. Currently, it is only support
> taprio(802.1Qbv) and Credit Based Shaper(802.1Qbu).
> +
> +config NXP_NETC_BLK_CTRL
> + tristate "NETC blocks control driver"
> + help
> + This driver configures Integrated Endpoint Register Block (IERB) and
> + Privileged Register Block (PRB) of NETC. For i.MX platforms, it also
> + includes the configuration of NETCMIX block.
> + The IERB contains registers that are used for pre-boot initialization,
> + debug, and non-customer configuration. The PRB controls global reset
> + and global error handling for NETC. The NETCMIX block is mainly used
> + to set MII protocol and PCS protocol of the links, it also contains
> + settings for some other functions.
> +
> + If compiled as module (M), the module name is nxp-netc-blk-ctrl.
> diff --git a/drivers/net/ethernet/freescale/enetc/Makefile b/drivers/net/ethernet/freescale/enetc/Makefile
> index b13cbbabb2ea..5c277910d538 100644
> --- a/drivers/net/ethernet/freescale/enetc/Makefile
> +++ b/drivers/net/ethernet/freescale/enetc/Makefile
> @@ -19,3 +19,6 @@ fsl-enetc-mdio-y := enetc_pci_mdio.o enetc_mdio.o
>
> obj-$(CONFIG_FSL_ENETC_PTP_CLOCK) += fsl-enetc-ptp.o
> fsl-enetc-ptp-y := enetc_ptp.o
> +
> +obj-$(CONFIG_NXP_NETC_BLK_CTRL) += nxp-netc-blk-ctrl.o
> +nxp-netc-blk-ctrl-y := netc_blk_ctrl.o
> \ No newline at end of file
> diff --git a/drivers/net/ethernet/freescale/enetc/netc_blk_ctrl.c b/drivers/net/ethernet/freescale/enetc/netc_blk_ctrl.c
> new file mode 100644
> index 000000000000..62c912aeeb5d
> --- /dev/null
> +++ b/drivers/net/ethernet/freescale/enetc/netc_blk_ctrl.c
> @@ -0,0 +1,472 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
> +/*
> + * NXP NETC Blocks Control Driver
> + *
> + * Copyright 2024 NXP
> + */
> +#include <linux/bits.h>
> +#include <linux/clk.h>
> +#include <linux/debugfs.h>
> +#include <linux/delay.h>
> +#include <linux/fsl/netc_global.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_net.h>
> +#include <linux/of_platform.h>
> +#include <linux/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/seq_file.h>
> +
> +/* NETCMIX registers */
> +#define IMX95_CFG_LINK_IO_VAR 0x0
> +#define IO_VAR_16FF_16G_SERDES 0x1
> +#define IO_VAR(port, var) (((var) & 0xf) << ((port) << 2))
> +
> +#define IMX95_CFG_LINK_MII_PROT 0x4
> +#define CFG_LINK_MII_PORT_0 GENMASK(3, 0)
> +#define CFG_LINK_MII_PORT_1 GENMASK(7, 4)
> +#define MII_PROT_MII 0x0
> +#define MII_PROT_RMII 0x1
> +#define MII_PROT_RGMII 0x2
> +#define MII_PROT_SERIAL 0x3
> +#define MII_PROT(port, prot) (((prot) & 0xf) << ((port) << 2))
> +
> +#define IMX95_CFG_LINK_PCS_PROT(a) (0x8 + (a) * 4)
> +#define PCS_PROT_1G_SGMII BIT(0)
> +#define PCS_PROT_2500M_SGMII BIT(1)
> +#define PCS_PROT_XFI BIT(3)
> +#define PCS_PROT_SFI BIT(4)
> +#define PCS_PROT_10G_SXGMII BIT(6)
> +
> +/* NETC privileged register block register */
> +#define PRB_NETCRR 0x100
> +#define NETCRR_SR BIT(0)
> +#define NETCRR_LOCK BIT(1)
> +
> +#define PRB_NETCSR 0x104
> +#define NETCSR_ERROR BIT(0)
> +#define NETCSR_STATE BIT(1)
> +
> +/* NETC integrated endpoint register block register */
> +#define IERB_EMDIOFAUXR 0x344
> +#define IERB_T0FAUXR 0x444
> +#define IERB_EFAUXR(a) (0x3044 + 0x100 * (a))
> +#define IERB_VFAUXR(a) (0x4004 + 0x40 * (a))
> +#define FAUXR_LDID GENMASK(3, 0)
> +
> +/* Platform information */
> +#define IMX95_ENETC0_BUS_DEVFN 0x0
> +#define IMX95_ENETC1_BUS_DEVFN 0x40
> +#define IMX95_ENETC2_BUS_DEVFN 0x80
> +
> +/* Flags for different platforms */
> +#define NETC_HAS_NETCMIX BIT(0)
> +
> +struct netc_devinfo {
> + u32 flags;
> + int (*netcmix_init)(struct platform_device *pdev);
> + int (*ierb_init)(struct platform_device *pdev);
> +};
> +
> +struct netc_blk_ctrl {
> + void __iomem *prb;
> + void __iomem *ierb;
> + void __iomem *netcmix;
> + struct clk *ipg_clk;
> +
> + const struct netc_devinfo *devinfo;
> + struct platform_device *pdev;
> + struct dentry *debugfs_root;
> +};
> +
> +static void netc_reg_write(void __iomem *base, u32 offset, u32 val)
> +{
> + netc_write(base + offset, val);
> +}
> +
> +static u32 netc_reg_read(void __iomem *base, u32 offset)
> +{
> + return netc_read(base + offset);
> +}
> +
> +static int netc_of_pci_get_bus_devfn(struct device_node *np)
> +{
> + u32 reg[5];
> + int error;
> +
> + error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
> + if (error)
> + return error;
> +
> + return (reg[0] >> 8) & 0xffff;
> +}
> +
> +static int netc_get_link_mii_protocol(phy_interface_t interface)
> +{
> + switch (interface) {
> + case PHY_INTERFACE_MODE_MII:
> + return MII_PROT_MII;
> + case PHY_INTERFACE_MODE_RMII:
> + return MII_PROT_RMII;
> + case PHY_INTERFACE_MODE_RGMII:
> + case PHY_INTERFACE_MODE_RGMII_ID:
> + case PHY_INTERFACE_MODE_RGMII_RXID:
> + case PHY_INTERFACE_MODE_RGMII_TXID:
> + return MII_PROT_RGMII;
> + case PHY_INTERFACE_MODE_SGMII:
> + case PHY_INTERFACE_MODE_2500BASEX:
> + case PHY_INTERFACE_MODE_10GBASER:
> + case PHY_INTERFACE_MODE_XGMII:
> + case PHY_INTERFACE_MODE_USXGMII:
> + return MII_PROT_SERIAL;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int imx95_netcmix_init(struct platform_device *pdev)
> +{
> + struct netc_blk_ctrl *priv = platform_get_drvdata(pdev);
> + struct device_node *np = pdev->dev.of_node;
> + phy_interface_t interface;
> + int bus_devfn, mii_proto;
> + u32 val;
> + int err;
> +
> + /* Default setting of MII protocol */
> + val = MII_PROT(0, MII_PROT_RGMII) | MII_PROT(1, MII_PROT_RGMII) |
> + MII_PROT(2, MII_PROT_SERIAL);
> +
> + /* Update the link MII protocol through parsing phy-mode */
> + for_each_available_child_of_node_scoped(np, child) {
> + for_each_available_child_of_node_scoped(child, gchild) {
> + if (!of_device_is_compatible(gchild, "nxp,imx95-enetc"))
> + continue;
> +
> + bus_devfn = netc_of_pci_get_bus_devfn(gchild);
> + if (bus_devfn < 0)
> + return -EINVAL;
> +
> + if (bus_devfn == IMX95_ENETC2_BUS_DEVFN)
> + continue;
> +
> + err = of_get_phy_mode(gchild, &interface);
> + if (err)
> + continue;
> +
> + mii_proto = netc_get_link_mii_protocol(interface);
> + if (mii_proto < 0)
> + return -EINVAL;
> +
> + switch (bus_devfn) {
> + case IMX95_ENETC0_BUS_DEVFN:
> + val = u32_replace_bits(val, mii_proto,
> + CFG_LINK_MII_PORT_0);
> + break;
> + case IMX95_ENETC1_BUS_DEVFN:
> + val = u32_replace_bits(val, mii_proto,
> + CFG_LINK_MII_PORT_1);
> + break;
> + default:
> + return -EINVAL;
> + }
> + }
> + }
> +
> + /* Configure Link I/O variant */
> + netc_reg_write(priv->netcmix, IMX95_CFG_LINK_IO_VAR,
> + IO_VAR(2, IO_VAR_16FF_16G_SERDES));
> + /* Configure Link 2 PCS protocol */
> + netc_reg_write(priv->netcmix, IMX95_CFG_LINK_PCS_PROT(2),
> + PCS_PROT_10G_SXGMII);
> + netc_reg_write(priv->netcmix, IMX95_CFG_LINK_MII_PROT, val);
> +
> + return 0;
> +}
> +
> +static bool netc_ierb_is_locked(struct netc_blk_ctrl *priv)
> +{
> + return !!(netc_reg_read(priv->prb, PRB_NETCRR) & NETCRR_LOCK);
> +}
> +
> +static int netc_lock_ierb(struct netc_blk_ctrl *priv)
> +{
> + u32 val;
> +
> + netc_reg_write(priv->prb, PRB_NETCRR, NETCRR_LOCK);
> +
> + return read_poll_timeout(netc_reg_read, val, !(val & NETCSR_STATE),
> + 100, 2000, false, priv->prb, PRB_NETCSR);
> +}
> +
> +static int netc_unlock_ierb_with_warm_reset(struct netc_blk_ctrl *priv)
> +{
> + u32 val;
> +
> + netc_reg_write(priv->prb, PRB_NETCRR, 0);
> +
> + return read_poll_timeout(netc_reg_read, val, !(val & NETCRR_LOCK),
> + 1000, 100000, true, priv->prb, PRB_NETCRR);
> +}
> +
> +static int imx95_ierb_init(struct platform_device *pdev)
> +{
> + struct netc_blk_ctrl *priv = platform_get_drvdata(pdev);
> +
> + /* EMDIO : No MSI-X intterupt */
> + netc_reg_write(priv->ierb, IERB_EMDIOFAUXR, 0);
> + /* ENETC0 PF */
> + netc_reg_write(priv->ierb, IERB_EFAUXR(0), 0);
> + /* ENETC0 VF0 */
> + netc_reg_write(priv->ierb, IERB_VFAUXR(0), 1);
> + /* ENETC0 VF1 */
> + netc_reg_write(priv->ierb, IERB_VFAUXR(1), 2);
> + /* ENETC1 PF */
> + netc_reg_write(priv->ierb, IERB_EFAUXR(1), 3);
> + /* ENETC1 VF0 */
> + netc_reg_write(priv->ierb, IERB_VFAUXR(2), 5);
> + /* ENETC1 VF1 */
> + netc_reg_write(priv->ierb, IERB_VFAUXR(3), 6);
> + /* ENETC2 PF */
> + netc_reg_write(priv->ierb, IERB_EFAUXR(2), 4);
> + /* ENETC2 VF0 */
> + netc_reg_write(priv->ierb, IERB_VFAUXR(4), 5);
> + /* ENETC2 VF1 */
> + netc_reg_write(priv->ierb, IERB_VFAUXR(5), 6);
> + /* NETC TIMER */
> + netc_reg_write(priv->ierb, IERB_T0FAUXR, 7);
> +
> + return 0;
> +}
> +
> +static int netc_ierb_init(struct platform_device *pdev)
> +{
> + struct netc_blk_ctrl *priv = platform_get_drvdata(pdev);
> + const struct netc_devinfo *devinfo = priv->devinfo;
> + int err;
> +
> + if (netc_ierb_is_locked(priv)) {
> + err = netc_unlock_ierb_with_warm_reset(priv);
> + if (err) {
> + dev_err(&pdev->dev, "Unlock IERB failed.\n");
> + return err;
> + }
> + }
> +
> + if (devinfo->ierb_init) {
> + err = devinfo->ierb_init(pdev);
> + if (err)
> + return err;
> + }
> +
> + err = netc_lock_ierb(priv);
> + if (err) {
> + dev_err(&pdev->dev, "Lock IERB failed.\n");
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +#if IS_ENABLED(CONFIG_DEBUG_FS)
> +static int netc_prb_show(struct seq_file *s, void *data)
> +{
> + struct netc_blk_ctrl *priv = s->private;
> + u32 val;
> +
> + val = netc_reg_read(priv->prb, PRB_NETCRR);
> + seq_printf(s, "[PRB NETCRR] Lock:%d SR:%d\n",
> + (val & NETCRR_LOCK) ? 1 : 0,
> + (val & NETCRR_SR) ? 1 : 0);
> +
> + val = netc_reg_read(priv->prb, PRB_NETCSR);
> + seq_printf(s, "[PRB NETCSR] State:%d Error:%d\n",
> + (val & NETCSR_STATE) ? 1 : 0,
> + (val & NETCSR_ERROR) ? 1 : 0);
> +
> + return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(netc_prb);
> +
> +static void netc_blk_ctrl_create_debugfs(struct netc_blk_ctrl *priv)
> +{
> + struct dentry *root;
> +
> + root = debugfs_create_dir("netc_blk_ctrl", NULL);
> + if (IS_ERR(root))
> + return;
> +
> + priv->debugfs_root = root;
> +
> + debugfs_create_file("prb", 0444, root, priv, &netc_prb_fops);
> +}
> +
> +static void netc_blk_ctrl_remove_debugfs(struct netc_blk_ctrl *priv)
> +{
> + debugfs_remove_recursive(priv->debugfs_root);
> + priv->debugfs_root = NULL;
> +}
> +
> +#else
> +
> +static void netc_blk_ctrl_create_debugfs(struct netc_blk_ctrl *priv)
> +{
> +}
> +
> +static void netc_blk_ctrl_remove_debugfs(struct netc_blk_ctrl *priv)
> +{
> +}
> +#endif
> +
> +static int netc_prb_check_error(struct netc_blk_ctrl *priv)
> +{
> + u32 val;
> +
> + val = netc_reg_read(priv->prb, PRB_NETCSR);
> + if (val & NETCSR_ERROR)
> + return -1;
> +
> + return 0;
> +}
> +
> +static const struct netc_devinfo imx95_devinfo = {
> + .flags = NETC_HAS_NETCMIX,

did you meet platform without NETC_HAS_NETCMIX? Add it only when it is
really used.

> + .netcmix_init = imx95_netcmix_init,
> + .ierb_init = imx95_ierb_init,
> +};
> +
> +static const struct of_device_id netc_blk_ctrl_match[] = {
> + { .compatible = "nxp,imx95-netc-blk-ctrl", .data = &imx95_devinfo },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, netc_blk_ctrl_match);
> +
> +static int netc_blk_ctrl_probe(struct platform_device *pdev)
> +{
> + struct device_node *node = pdev->dev.of_node;
> + const struct netc_devinfo *devinfo;
> + struct device *dev = &pdev->dev;
> + const struct of_device_id *id;
> + struct netc_blk_ctrl *priv;
> + void __iomem *regs;
> + int err;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->pdev = pdev;
> + priv->ipg_clk = devm_clk_get_optional(dev, "ipg_clk");
> + if (IS_ERR(priv->ipg_clk)) {
> + err = PTR_ERR(priv->ipg_clk);
> + dev_err_probe(dev, err, "Get ipg_clk failed\n");
> + return err;
> + }

simple
return dev_err_probe(dev, PTR_ERR(priv->ipg_clk), "Get ipg_clk failed\n");

> +
> + err = clk_prepare_enable(priv->ipg_clk);
> + if (err) {
> + dev_err_probe(dev, err, "Enable ipg_clk failed\n");
> + goto disable_ipg_clk;
> + }


You can use devm_clk_get_optional_enabled(dev, "ipg_clk") instead of
devm_clk_get_optional(), above tunk can be removed.

> +
> + id = of_match_device(netc_blk_ctrl_match, dev);
> + if (!id) {
> + err = -EINVAL;
> + dev_err_probe(dev, err, "Cannot match device\n");
> + goto disable_ipg_clk;
> + }
> +
> + devinfo = (struct netc_devinfo *)id->data;
> + if (!devinfo) {
> + err = -EINVAL;
> + dev_err_probe(dev, err, "No device information\n");
> + goto disable_ipg_clk;
> + }

because use devm_clk_get_optional_enabled()
simple

return dev_err_probe(dev, -ENVAL, "No device information\n");

same for below error check code.

> + priv->devinfo = devinfo;
> +
> + regs = devm_platform_ioremap_resource_byname(pdev, "ierb");
> + if (IS_ERR(regs)) {
> + err = PTR_ERR(regs);
> + dev_err_probe(dev, err, "Missing IERB resource\n");
> + goto disable_ipg_clk;
> + }
> + priv->ierb = regs;
> +
> + regs = devm_platform_ioremap_resource_byname(pdev, "prb");
> + if (IS_ERR(regs)) {
> + err = PTR_ERR(regs);
> + dev_err_probe(dev, err, "Missing PRB resource\n");
> + goto disable_ipg_clk;
> + }
> + priv->prb = regs;
> +
> + if (devinfo->flags & NETC_HAS_NETCMIX) {
> + regs = devm_platform_ioremap_resource_byname(pdev, "netcmix");
> + if (IS_ERR(regs)) {
> + err = PTR_ERR(regs);
> + dev_err_probe(dev, err, "Missing NETCMIX resource\n");
> + goto disable_ipg_clk;
> + }
> + priv->netcmix = regs;
> + }
> +
> + platform_set_drvdata(pdev, priv);
> +
> + if (devinfo->netcmix_init) {
> + err = devinfo->netcmix_init(pdev);
> + if (err) {
> + dev_err_probe(dev, err, "Initializing NETCMIX failed\n");
> + goto disable_ipg_clk;
> + }
> + }
> +
> + err = netc_ierb_init(pdev);
> + if (err) {
> + dev_err_probe(dev, err, "Initializing IERB failed\n");
> + goto disable_ipg_clk;
> + }
> +
> + if (netc_prb_check_error(priv) < 0)
> + dev_warn(dev, "The current IERB configuration is invalid\n");
> +
> + netc_blk_ctrl_create_debugfs(priv);
> +
> + err = of_platform_populate(node, NULL, NULL, dev);
> + if (err) {
> + dev_err_probe(dev, err, "of_platform_populate failed\n");
> + goto remove_debugfs;
> + }
> +
> + return 0;
> +
> +remove_debugfs:
> + netc_blk_ctrl_remove_debugfs(priv);
> +disable_ipg_clk:
> + clk_disable_unprepare(priv->ipg_clk);
> +
> + return err;
> +}
> +
> +static void netc_blk_ctrl_remove(struct platform_device *pdev)
> +{
> + struct netc_blk_ctrl *priv = platform_get_drvdata(pdev);
> +
> + of_platform_depopulate(&pdev->dev);
> + netc_blk_ctrl_remove_debugfs(priv);
> + clk_disable_unprepare(priv->ipg_clk);
> +}
> +
> +static struct platform_driver netc_blk_ctrl_driver = {
> + .driver = {
> + .name = "nxp-netc-blk-ctrl",
> + .of_match_table = netc_blk_ctrl_match,
> + },
> + .probe = netc_blk_ctrl_probe,
> + .remove = netc_blk_ctrl_remove,
> +};
> +
> +module_platform_driver(netc_blk_ctrl_driver);
> +
> +MODULE_DESCRIPTION("NXP NETC Blocks Control Driver");
> +MODULE_LICENSE("Dual BSD/GPL");
> diff --git a/include/linux/fsl/netc_global.h b/include/linux/fsl/netc_global.h
> new file mode 100644
> index 000000000000..f26b1b6f8813
> --- /dev/null
> +++ b/include/linux/fsl/netc_global.h
> @@ -0,0 +1,39 @@
> +/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */
> +/* Copyright 2024 NXP
> + */
> +#ifndef __NETC_GLOBAL_H
> +#define __NETC_GLOBAL_H
> +
> +#include <linux/io.h>
> +
> +static inline u32 netc_read(void __iomem *reg)
> +{
> + return ioread32(reg);
> +}
> +
> +#ifdef ioread64
> +static inline u64 netc_read64(void __iomem *reg)
> +{
> + return ioread64(reg);
> +}
> +#else
> +static inline u64 netc_read64(void __iomem *reg)
> +{
> + u32 low, high;
> + u64 val;
> +
> + low = ioread32(reg);
> + high = ioread32(reg + 4);
> +
> + val = (u64)high << 32 | low;
> +
> + return val;
> +}
> +#endif

netc_read64 is not used at this patch. Add it when use it.

> +
> +static inline void netc_write(void __iomem *reg, u32 val)
> +{
> + iowrite32(val, reg);
> +}
> +
> +#endif
> --
> 2.34.1
>