[PATCH net-next v5 05/13] net: pcs: add Renesas MII converter driver

Clément Léger
2022-05-19T15:32:52Z

Add a PCS driver for the MII converter that is present on the Renesas
RZ/N1 SoC. This MII converter is reponsible for converting MII to
RMII/RGMII or act as a MII pass-trough. Exposing it as a PCS allows to
reuse it in both the switch driver and the stmmac driver. Currently,
this driver only allows the PCS to be used by the dual Cortex-A7
subsystem since the register locking system is not used.

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
---
drivers/net/pcs/Kconfig | 8 +
drivers/net/pcs/Makefile | 1 +
drivers/net/pcs/pcs-rzn1-miic.c | 516 ++++++++++++++++++++++++++++++++
include/linux/pcs-rzn1-miic.h | 18 ++
4 files changed, 543 insertions(+)
create mode 100644 drivers/net/pcs/pcs-rzn1-miic.c
create mode 100644 include/linux/pcs-rzn1-miic.h

diff --git a/drivers/net/pcs/Kconfig b/drivers/net/pcs/Kconfig
index 22ba7b0b476d..6a500d30ca4c 100644
--- a/drivers/net/pcs/Kconfig
+++ b/drivers/net/pcs/Kconfig
@@ -18,4 +18,12 @@ config PCS_LYNX
This module provides helpers to phylink for managing the Lynx PCS
which is part of the Layerscape and QorIQ Ethernet SERDES.

+config PCS_RZN1_MIIC
+ tristate "Renesas RZ/N1 MII converter"
+ depends on ARCH_RZN1 || COMPILE_TEST
+ help
+ This module provides a driver for the MII converter that is available
+ on RZ/N1 SoCs. This PCS converts MII to RMII/RGMII or can be set in
+ pass-through mode for MII.
+
endmenu
diff --git a/drivers/net/pcs/Makefile b/drivers/net/pcs/Makefile
index 0603d469bd57..0ff5388fcdea 100644
--- a/drivers/net/pcs/Makefile
+++ b/drivers/net/pcs/Makefile
@@ -5,3 +5,4 @@ pcs_xpcs-$(CONFIG_PCS_XPCS) := pcs-xpcs.o pcs-xpcs-nxp.o

obj-$(CONFIG_PCS_XPCS) += pcs_xpcs.o
obj-$(CONFIG_PCS_LYNX) += pcs-lynx.o
+obj-$(CONFIG_PCS_RZN1_MIIC) += pcs-rzn1-miic.o
diff --git a/drivers/net/pcs/pcs-rzn1-miic.c b/drivers/net/pcs/pcs-rzn1-miic.c
new file mode 100644
index 000000000000..e8962058283c
--- /dev/null
+++ b/drivers/net/pcs/pcs-rzn1-miic.c
@@ -0,0 +1,516 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 Schneider Electric
+ *
+ * Clément Léger <clement.leger@bootlin.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/mdio.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/pcs-rzn1-miic.h>
+#include <linux/phylink.h>
+#include <linux/pm_runtime.h>
+#include <dt-bindings/net/pcs-rzn1-miic.h>
+
+#define MIIC_PRCMD 0x0
+#define MIIC_ESID_CODE 0x4
+
+#define MIIC_MODCTRL 0x20
+#define MIIC_MODCTRL_SW_MODE GENMASK(4, 0)
+
+#define MIIC_CONVCTRL(port) (0x100 + (port) * 4)
+
+#define MIIC_CONVCTRL_CONV_SPEED GENMASK(1, 0)
+#define CONV_MODE_10MBPS 0
+#define CONV_MODE_100MBPS 1
+#define CONV_MODE_1000MBPS 2
+
+#define MIIC_CONVCTRL_CONV_MODE GENMASK(3, 2)
+#define CONV_MODE_MII 0
+#define CONV_MODE_RMII 1
+#define CONV_MODE_RGMII 2
+
+#define MIIC_CONVCTRL_FULLD BIT(8)
+#define MIIC_CONVCTRL_RGMII_LINK BIT(12)
+#define MIIC_CONVCTRL_RGMII_DUPLEX BIT(13)
+#define MIIC_CONVCTRL_RGMII_SPEED GENMASK(15, 14)
+
+#define MIIC_CONVRST 0x114
+#define MIIC_CONVRST_PHYIF_RST(port) BIT(port)
+#define MIIC_CONVRST_PHYIF_RST_MASK GENMASK(4, 0)
+
+#define MIIC_SWCTRL 0x304
+#define MIIC_SWDUPC 0x308
+
+#define MIIC_MAX_NR_PORTS 5
+
+#define MIIC_MODCTRL_CONF_CONV_NUM 6
+#define MIIC_MODCTRL_CONF_NONE -1
+
+/**
+ * struct modctrl_match - Matching table entry for convctrl configuration
+ * See section 8.2.1 of manual.
+ * @mode_cfg: Configuration value for convctrl
+ * @conv: Configuration of ethernet port muxes. First index is SWITCH_PORTIN,
+ * then index 1 - 5 are CONV1 - CONV5.
+ */
+struct modctrl_match {
+ u32 mode_cfg;
+ u8 conv[MIIC_MODCTRL_CONF_CONV_NUM];
+};
+
+static struct modctrl_match modctrl_match_table[] = {
+ {0x0, {MIIC_RTOS_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_SWITCH_PORTC, MIIC_SERCOS_PORTB, MIIC_SERCOS_PORTA}},
+ {0x1, {MIIC_RTOS_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_SWITCH_PORTC, MIIC_ETHERCAT_PORTB, MIIC_ETHERCAT_PORTA}},
+ {0x2, {MIIC_RTOS_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_ETHERCAT_PORTC, MIIC_ETHERCAT_PORTB, MIIC_ETHERCAT_PORTA}},
+ {0x3, {MIIC_RTOS_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_SWITCH_PORTC, MIIC_SWITCH_PORTB, MIIC_SWITCH_PORTA}},
+
+ {0x8, {MIIC_RTOS_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_SWITCH_PORTC, MIIC_SERCOS_PORTB, MIIC_SERCOS_PORTA}},
+ {0x9, {MIIC_RTOS_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_SWITCH_PORTC, MIIC_ETHERCAT_PORTB, MIIC_ETHERCAT_PORTA}},
+ {0xA, {MIIC_RTOS_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_ETHERCAT_PORTC, MIIC_ETHERCAT_PORTB, MIIC_ETHERCAT_PORTA}},
+ {0xB, {MIIC_RTOS_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_SWITCH_PORTC, MIIC_SWITCH_PORTB, MIIC_SWITCH_PORTA}},
+
+ {0x10, {MIIC_GMAC2_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_SWITCH_PORTC, MIIC_SERCOS_PORTB, MIIC_SERCOS_PORTA}},
+ {0x11, {MIIC_GMAC2_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_SWITCH_PORTC, MIIC_ETHERCAT_PORTB, MIIC_ETHERCAT_PORTA}},
+ {0x12, {MIIC_GMAC2_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_ETHERCAT_PORTC, MIIC_ETHERCAT_PORTB, MIIC_ETHERCAT_PORTA}},
+ {0x13, {MIIC_GMAC2_PORT, MIIC_GMAC1_PORT, MIIC_SWITCH_PORTD,
+ MIIC_SWITCH_PORTC, MIIC_SWITCH_PORTB, MIIC_SWITCH_PORTA}}
+};
+
+static const char * const conf_to_string[] = {
+ [MIIC_GMAC1_PORT] = "GMAC1_PORT",
+ [MIIC_GMAC2_PORT] = "GMAC2_PORT",
+ [MIIC_RTOS_PORT] = "RTOS_PORT",
+ [MIIC_SERCOS_PORTA] = "SERCOS_PORTA",
+ [MIIC_SERCOS_PORTB] = "SERCOS_PORTB",
+ [MIIC_ETHERCAT_PORTA] = "ETHERCAT_PORTA",
+ [MIIC_ETHERCAT_PORTB] = "ETHERCAT_PORTB",
+ [MIIC_ETHERCAT_PORTC] = "ETHERCAT_PORTC",
+ [MIIC_SWITCH_PORTA] = "SWITCH_PORTA",
+ [MIIC_SWITCH_PORTB] = "SWITCH_PORTB",
+ [MIIC_SWITCH_PORTC] = "SWITCH_PORTC",
+ [MIIC_SWITCH_PORTD] = "SWITCH_PORTD",
+ [MIIC_HSR_PORTA] = "HSR_PORTA",
+ [MIIC_HSR_PORTB] = "HSR_PORTB",
+};
+
+static const char *index_to_string[MIIC_MODCTRL_CONF_CONV_NUM] = {
+ "SWITCH_PORTIN",
+ "CONV1",
+ "CONV2",
+ "CONV3",
+ "CONV4",
+ "CONV5",
+};
+
+/**
+ * struct miic - MII converter structure
+ * @base: base address of the MII converter
+ * @dev: Device associated to the MII converter
+ * @clks: Clocks used for this device
+ * @nclk: Number of clocks
+ * @lock: Lock used for read-modify-write access
+ */
+struct miic {
+ void __iomem *base;
+ struct device *dev;
+ struct clk_bulk_data *clks;
+ int nclk;
+ spinlock_t lock;
+};
+
+/**
+ * struct miic_port - Per port MII converter struct
+ * @miic: backiling to MII converter structure
+ * @pcs: PCS structure associated to the port
+ * @port: port number
+ */
+struct miic_port {
+ struct miic *miic;
+ struct phylink_pcs pcs;
+ int port;
+};
+
+static struct miic_port *phylink_pcs_to_miic_port(struct phylink_pcs *pcs)
+{
+ return container_of(pcs, struct miic_port, pcs);
+}
+
+static void miic_reg_writel(struct miic *miic, int offset, u32 value)
+{
+ writel(value, miic->base + offset);
+}
+
+static u32 miic_reg_readl(struct miic *miic, int offset)
+{
+ return readl(miic->base + offset);
+}
+
+static void miic_reg_rmw(struct miic *miic, int offset, u32 mask, u32 val)
+{
+ u32 reg;
+
+ spin_lock(&miic->lock);
+
+ reg = miic_reg_readl(miic, offset);
+ reg &= ~mask;
+ reg |= val;
+ miic_reg_writel(miic, offset, reg);
+
+ spin_unlock(&miic->lock);
+}
+
+static void miic_converter_enable(struct miic *miic, int port, int enable)
+{
+ u32 val = 0;
+
+ if (enable)
+ val = MIIC_CONVRST_PHYIF_RST(port);
+
+ miic_reg_rmw(miic, MIIC_CONVRST, MIIC_CONVRST_PHYIF_RST(port), val);
+}
+
+static int miic_config(struct phylink_pcs *pcs, unsigned int mode,
+ phy_interface_t interface,
+ const unsigned long *advertising, bool permit)
+{
+ struct miic_port *miic_port = phylink_pcs_to_miic_port(pcs);
+ struct miic *miic = miic_port->miic;
+ int port = miic_port->port;
+ u32 speed, conv_mode, val;
+
+ switch (interface) {
+ case PHY_INTERFACE_MODE_RMII:
+ conv_mode = CONV_MODE_RMII;
+ speed = CONV_MODE_100MBPS;
+ break;
+ case PHY_INTERFACE_MODE_RGMII:
+ case PHY_INTERFACE_MODE_RGMII_ID:
+ case PHY_INTERFACE_MODE_RGMII_TXID:
+ case PHY_INTERFACE_MODE_RGMII_RXID:
+ conv_mode = CONV_MODE_RGMII;
+ speed = CONV_MODE_1000MBPS;
+ break;
+ case PHY_INTERFACE_MODE_MII:
+ conv_mode = CONV_MODE_MII;
+ /* When in MII mode, speed should be set to 0 (which is actually
+ * CONV_MODE_10MBPS)
+ */
+ speed = CONV_MODE_10MBPS;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ val = FIELD_PREP(MIIC_CONVCTRL_CONV_MODE, conv_mode) |
+ FIELD_PREP(MIIC_CONVCTRL_CONV_SPEED, speed);
+
+ miic_reg_rmw(miic, MIIC_CONVCTRL(port),
+ MIIC_CONVCTRL_CONV_MODE | MIIC_CONVCTRL_CONV_SPEED, val);
+ miic_converter_enable(miic_port->miic, miic_port->port, 1);
+
+ return 0;
+}
+
+static void miic_link_up(struct phylink_pcs *pcs, unsigned int mode,
+ phy_interface_t interface, int speed, int duplex)
+{
+ struct miic_port *miic_port = phylink_pcs_to_miic_port(pcs);
+ struct miic *miic = miic_port->miic;
+ u32 conv_speed = 0, val = 0;
+ int port = miic_port->port;
+
+ if (duplex == DUPLEX_FULL)
+ val |= MIIC_CONVCTRL_FULLD;
+
+ /* No speed in MII through-mode */
+ if (interface != PHY_INTERFACE_MODE_MII) {
+ switch (speed) {
+ case SPEED_1000:
+ conv_speed = CONV_MODE_1000MBPS;
+ break;
+ case SPEED_100:
+ conv_speed = CONV_MODE_100MBPS;
+ break;
+ case SPEED_10:
+ conv_speed = CONV_MODE_10MBPS;
+ break;
+ default:
+ return;
+ }
+ }
+
+ val |= FIELD_PREP(MIIC_CONVCTRL_CONV_SPEED, conv_speed);
+
+ miic_reg_rmw(miic, MIIC_CONVCTRL(port),
+ (MIIC_CONVCTRL_CONV_SPEED | MIIC_CONVCTRL_FULLD), val);
+}
+
+static int miic_validate(struct phylink_pcs *pcs, unsigned long *supported,
+ const struct phylink_link_state *state)
+{
+ if (state->interface == PHY_INTERFACE_MODE_RGMII ||
+ state->interface == PHY_INTERFACE_MODE_RGMII_ID ||
+ state->interface == PHY_INTERFACE_MODE_RGMII_TXID ||
+ state->interface == PHY_INTERFACE_MODE_RGMII_RXID ||
+ state->interface == PHY_INTERFACE_MODE_RMII ||
+ state->interface == PHY_INTERFACE_MODE_MII)
+ return 1;
+
+ return -EINVAL;
+}
+
+static const struct phylink_pcs_ops miic_phylink_ops = {
+ .pcs_validate = miic_validate,
+ .pcs_config = miic_config,
+ .pcs_link_up = miic_link_up,
+};
+
+struct phylink_pcs *miic_create(struct device_node *np)
+{
+ struct platform_device *pdev;
+ struct miic_port *miic_port;
+ struct device_node *pcs_np;
+ u32 port;
+
+ if (!of_device_is_available(np))
+ return ERR_PTR(-ENODEV);
+
+ if (of_property_read_u32(np, "reg", &port))
+ return ERR_PTR(-EINVAL);
+
+ if (port > MIIC_MAX_NR_PORTS || port < 1)
+ return ERR_PTR(-EINVAL);
+
+ /* The PCS pdev is attached to the parent node */
+ pcs_np = of_get_parent(np);
+ if (!pcs_np)
+ return ERR_PTR(-ENODEV);
+
+ if (!of_device_is_available(pcs_np))
+ return ERR_PTR(-ENODEV);
+
+ pdev = of_find_device_by_node(pcs_np);
+ if (!pdev || !platform_get_drvdata(pdev))
+ return ERR_PTR(-EPROBE_DEFER);
+
+ miic_port = kzalloc(sizeof(*miic_port), GFP_KERNEL);
+ if (!miic_port)
+ return ERR_PTR(-ENOMEM);
+
+ miic_port->miic = platform_get_drvdata(pdev);
+ miic_port->port = port - 1;
+ miic_port->pcs.ops = &miic_phylink_ops;
+
+ return &miic_port->pcs;
+}
+EXPORT_SYMBOL(miic_create);
+
+void miic_destroy(struct phylink_pcs *pcs)
+{
+ struct miic_port *miic_port = phylink_pcs_to_miic_port(pcs);
+
+ miic_converter_enable(miic_port->miic, miic_port->port, 0);
+ kfree(miic_port);
+}
+EXPORT_SYMBOL(miic_destroy);
+
+static int miic_init_hw(struct miic *miic, u32 cfg_mode)
+{
+ int port;
+
+ /* Unlock write access to accessory registers (cf datasheet). If this
+ * is going to be used in conjunction with the Cortex-M3, this sequence
+ * will have to be moved in register write
+ */
+ miic_reg_writel(miic, MIIC_PRCMD, 0x00A5);
+ miic_reg_writel(miic, MIIC_PRCMD, 0x0001);
+ miic_reg_writel(miic, MIIC_PRCMD, 0xFFFE);
+ miic_reg_writel(miic, MIIC_PRCMD, 0x0001);
+
+ miic_reg_writel(miic, MIIC_MODCTRL,
+ FIELD_PREP(MIIC_MODCTRL_SW_MODE, cfg_mode));
+
+ for (port = 0; port < MIIC_MAX_NR_PORTS; port++) {
+ miic_converter_enable(miic, port, 0);
+ /* Disable speed/duplex control from these registers, datasheet
+ * says switch registers should be used to setup switch port
+ * speed and duplex.
+ */
+ miic_reg_writel(miic, MIIC_SWCTRL, 0x0);
+ miic_reg_writel(miic, MIIC_SWDUPC, 0x0);
+ }
+
+ return 0;
+}
+
+static bool miic_modctrl_match(s8 table_val[MIIC_MODCTRL_CONF_CONV_NUM],
+ s8 dt_val[MIIC_MODCTRL_CONF_CONV_NUM])
+{
+ int i;
+
+ for (i = 0; i < MIIC_MODCTRL_CONF_CONV_NUM; i++) {
+ if (dt_val[i] == MIIC_MODCTRL_CONF_NONE)
+ continue;
+
+ if (dt_val[i] != table_val[i])
+ return false;
+ }
+
+ return true;
+}
+
+static void miic_dump_conf(struct device *dev,
+ s8 conf[MIIC_MODCTRL_CONF_CONV_NUM])
+{
+ const char *conf_name;
+ int i;
+
+ for (i = 0; i < MIIC_MODCTRL_CONF_CONV_NUM; i++) {
+ if (conf[i] != MIIC_MODCTRL_CONF_NONE)
+ conf_name = conf_to_string[conf[i]];
+ else
+ conf_name = "NONE";
+
+ dev_err(dev, "%s: %s\n", index_to_string[i], conf_name);
+ }
+}
+
+static int miic_match_dt_conf(struct device *dev,
+ s8 dt_val[MIIC_MODCTRL_CONF_CONV_NUM],
+ u32 *mode_cfg)
+{
+ struct modctrl_match *table_entry;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(modctrl_match_table); i++) {
+ table_entry = &modctrl_match_table[i];
+
+ if (miic_modctrl_match(table_entry->conv, dt_val)) {
+ *mode_cfg = table_entry->mode_cfg;
+ return 0;
+ }
+ }
+
+ dev_err(dev, "Failed to apply requested configuration\n");
+ miic_dump_conf(dev, dt_val);
+
+ return -EINVAL;
+}
+
+static int miic_parse_dt(struct device *dev, u32 *mode_cfg)
+{
+ s8 dt_val[MIIC_MODCTRL_CONF_CONV_NUM];
+ struct device_node *np = dev->of_node;
+ struct device_node *conv;
+ u32 conf;
+ int port;
+
+ memset(dt_val, MIIC_MODCTRL_CONF_NONE, sizeof(dt_val));
+
+ of_property_read_u32(np, "renesas,miic-switch-portin", &conf);
+ dt_val[0] = conf;
+
+ for_each_child_of_node(np, conv) {
+ if (of_property_read_u32(conv, "reg", &port))
+ continue;
+
+ if (!of_device_is_available(conv))
+ continue;
+
+ if (of_property_read_u32(conv, "renesas,miic-input", &conf) == 0)
+ dt_val[port] = conf;
+
+ of_node_put(conv);
+ }
+
+ return miic_match_dt_conf(dev, dt_val, mode_cfg);
+}
+
+static int miic_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct miic *miic;
+ u32 mode_cfg;
+ int ret;
+
+ ret = miic_parse_dt(dev, &mode_cfg);
+ if (ret < 0)
+ return -EINVAL;
+
+ miic = devm_kzalloc(dev, sizeof(*miic), GFP_KERNEL);
+ if (!miic)
+ return -ENOMEM;
+
+ spin_lock_init(&miic->lock);
+ miic->dev = dev;
+ miic->base = devm_platform_ioremap_resource(pdev, 0);
+ if (!miic->base)
+ return -EINVAL;
+
+ ret = devm_pm_runtime_enable(dev);
+ if (ret < 0)
+ return ret;
+
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret < 0)
+ return ret;
+
+ ret = miic_init_hw(miic, mode_cfg);
+ if (ret)
+ goto disable_runtime_pm;
+
+ /* miic_create() relies on that fact that data are attached to the
+ * platform device to determine if the driver is ready so this needs to
+ * be the last thing to be done after everything is initialized
+ * properly.
+ */
+ platform_set_drvdata(pdev, miic);
+
+ return 0;
+
+disable_runtime_pm:
+ pm_runtime_put(dev);
+
+ return ret;
+}
+
+static int miic_remove(struct platform_device *pdev)
+{
+ pm_runtime_put(&pdev->dev);
+
+ return 0;
+}
+
+static const struct of_device_id miic_of_mtable[] = {
+ { .compatible = "renesas,rzn1-miic" },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, miic_of_mtable);
+
+static struct platform_driver miic_driver = {
+ .driver = {
+ .name = "rzn1_miic",
+ .of_match_table = of_match_ptr(miic_of_mtable),
+ },
+ .probe = miic_probe,
+ .remove = miic_remove,
+};
+module_platform_driver(miic_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Renesas MII converter PCS driver");
+MODULE_AUTHOR("Clément Léger <clement.leger@bootlin.com>");
diff --git a/include/linux/pcs-rzn1-miic.h b/include/linux/pcs-rzn1-miic.h
new file mode 100644
index 000000000000..7a303af57e40
--- /dev/null
+++ b/include/linux/pcs-rzn1-miic.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2022 Schneider Electric
+ *
+ * Clément Léger <clement.leger@bootlin.com>
+ */
+
+#ifndef __LINUX_PCS_MIIC_H
+#define __LINUX_PCS_MIIC_H
+
+struct phylink;
+struct device_node;
+
+struct phylink_pcs *miic_create(struct device_node *np);
+
+void miic_destroy(struct phylink_pcs *pcs);
+
+#endif /* __LINUX_PCS_MIIC_H */
--
2.36.0