diff mbox series

[net-next,v9,05/16] net: pcs: add Renesas MII converter driver

Message ID 20220624144001.95518-6-clement.leger@bootlin.com (mailing list archive)
State Accepted
Commit 7dc54d3b8d9100c65b0860f76342fc9f3b4694d9
Delegated to: Netdev Maintainers
Headers show
Series add support for Renesas RZ/N1 ethernet subsystem devices | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 10 of 10 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning CHECK: spinlock_t definition without comment WARNING: 'ment' may be misspelled - perhaps 'meant'? WARNING: added, moved or deleted file(s), does MAINTAINERS need updating? WARNING: line length of 81 exceeds 80 columns WARNING: please write a help paragraph that fully describes the config symbol
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Clément Léger June 24, 2022, 2:39 p.m. UTC
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>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
---
 drivers/net/pcs/Kconfig         |   8 +
 drivers/net/pcs/Makefile        |   1 +
 drivers/net/pcs/pcs-rzn1-miic.c | 520 ++++++++++++++++++++++++++++++++
 include/linux/pcs-rzn1-miic.h   |  18 ++
 4 files changed, 547 insertions(+)
 create mode 100644 drivers/net/pcs/pcs-rzn1-miic.c
 create mode 100644 include/linux/pcs-rzn1-miic.h

Comments

Florian Fainelli June 25, 2022, 2:35 a.m. UTC | #1
On 6/24/2022 7:39 AM, Clément Léger wrote:
> 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>
> Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Russell King (Oracle) June 28, 2022, 4:42 p.m. UTC | #2
On Fri, Jun 24, 2022 at 04:39:50PM +0200, Clément Léger wrote:
> 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>
> Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

Looks good to me, thanks.

The only issue I haven't brought up is:

> +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;
> +}

the stting of the speed here. As this function can be called as a result
of ethtool setting the configuration while the link is up, this could
have disasterous effects on the link. This will only happen if there is
no PHY present and we aren't using fixed-link mode.

Therefore, I'm willing to get this pass, but I think it would be better
if the speed was only updated if the interface setting is actually
being changed. So:

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Clément Léger June 28, 2022, 4:49 p.m. UTC | #3
Le Tue, 28 Jun 2022 17:42:58 +0100,
"Russell King (Oracle)" <linux@armlinux.org.uk> a écrit :

> > +		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;
> > +}  
> 
> the stting of the speed here. As this function can be called as a result
> of ethtool setting the configuration while the link is up, this could
> have disasterous effects on the link. This will only happen if there is
> no PHY present and we aren't using fixed-link mode.
> 
> Therefore, I'm willing to get this pass, but I think it would be better
> if the speed was only updated if the interface setting is actually
> being changed. So:

Hi Russell,

Ok, I'll make a follow-up patch to handle that properly.
diff mbox series

Patch

diff --git a/drivers/net/pcs/Kconfig b/drivers/net/pcs/Kconfig
index 22ba7b0b476d..44fba34ae80c 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 OF && (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..8f5e910f443d
--- /dev/null
+++ b/drivers/net/pcs/pcs-rzn1-miic.c
@@ -0,0 +1,520 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 Schneider Electric
+ *
+ * Clément Léger <clement.leger@bootlin.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/device.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 (phy_interface_mode_is_rgmii(state->interface) ||
+	    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 *dev, struct device_node *np)
+{
+	struct platform_device *pdev;
+	struct miic_port *miic_port;
+	struct device_node *pcs_np;
+	struct miic *miic;
+	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)) {
+		of_node_put(pcs_np);
+		return ERR_PTR(-ENODEV);
+	}
+
+	pdev = of_find_device_by_node(pcs_np);
+	of_node_put(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 = platform_get_drvdata(pdev);
+	device_link_add(dev, miic->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
+
+	miic_port->miic = miic;
+	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));
+
+	if (of_property_read_u32(np, "renesas,miic-switch-portin", &conf) == 0)
+		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;
+	}
+
+	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 ret;
+
+	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",
+		.suppress_bind_attrs = true,
+		.of_match_table = 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..56d12b21365d
--- /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 *dev, struct device_node *np);
+
+void miic_destroy(struct phylink_pcs *pcs);
+
+#endif /* __LINUX_PCS_MIIC_H */