diff mbox series

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

Message ID 20220519153107.696864-6-clement.leger@bootlin.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series add support for Renesas RZ/N1 ethernet subsystem devices | expand

Commit Message

Clément Léger May 19, 2022, 3:30 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>
---
 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

Comments

Russell King (Oracle) May 19, 2022, 4:25 p.m. UTC | #1
Hi,

On Thu, May 19, 2022 at 05:30:59PM +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>

Looks much better now, thanks. Only one thing I've spotted is:

> +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 ||

The above could use:

	if (phy_interface_mode_is_rgmii(state->interface) ||

Also, as a request to unbind this driver would be disasterous to users,
I think you should set ".suppress_bind_attrs = true" to prevent the
sysfs bind/unbind facility being available. This doesn't completely
solve the problem.

Thanks.
Clément Léger May 20, 2022, 7:52 a.m. UTC | #2
Le Thu, 19 May 2022 17:25:10 +0100,
"Russell King (Oracle)" <linux@armlinux.org.uk> a écrit :

> Hi,
> 
> On Thu, May 19, 2022 at 05:30:59PM +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>  
> 
> Looks much better now, thanks. Only one thing I've spotted is:
> 
> > +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 ||  
> 
> The above could use:
> 
> 	if (phy_interface_mode_is_rgmii(state->interface) ||

Thanks, I did found the one to set the bit for phylink part but not
this one.

> 
> Also, as a request to unbind this driver would be disasterous to users,
> I think you should set ".suppress_bind_attrs = true" to prevent the
> sysfs bind/unbind facility being available. This doesn't completely
> solve the problem.

Acked. What should I do to make it more robust ? Should I use a
refcount per pdev and check that in the remove() callback to avoid
removing the pdev if used ?

Thanks,
Vladimir Oltean May 20, 2022, 8:49 a.m. UTC | #3
On Fri, May 20, 2022 at 09:52:41AM +0200, Clément Léger wrote:
> > Also, as a request to unbind this driver would be disasterous to users,
> > I think you should set ".suppress_bind_attrs = true" to prevent the
> > sysfs bind/unbind facility being available. This doesn't completely
> > solve the problem.
> 
> Acked. What should I do to make it more robust ? Should I use a
> refcount per pdev and check that in the remove() callback to avoid
> removing the pdev if used ?

I wonder, if you call device_link_add(ds->dev, miic->dev, DL_FLAG_AUTOREMOVE_CONSUMER),
wouldn't that be enough to auto-unbind the DSA driver when the MII
converter driver unbinds?
Clément Léger May 20, 2022, 3:22 p.m. UTC | #4
Le Fri, 20 May 2022 11:49:14 +0300,
Vladimir Oltean <olteanv@gmail.com> a écrit :

> On Fri, May 20, 2022 at 09:52:41AM +0200, Clément Léger wrote:
> > > Also, as a request to unbind this driver would be disasterous to users,
> > > I think you should set ".suppress_bind_attrs = true" to prevent the
> > > sysfs bind/unbind facility being available. This doesn't completely
> > > solve the problem.  
> > 
> > Acked. What should I do to make it more robust ? Should I use a
> > refcount per pdev and check that in the remove() callback to avoid
> > removing the pdev if used ?  
> 
> I wonder, if you call device_link_add(ds->dev, miic->dev, DL_FLAG_AUTOREMOVE_CONSUMER),
> wouldn't that be enough to auto-unbind the DSA driver when the MII
> converter driver unbinds?

I looiked at that a bit and I'm not sure how to achieve that cleanly. If
I need to create this link, then I need to do it once for the dsa switch
device. However, currently, the way I get the references to the MII
converter are via the pcs-handle properties which are for each port.

So, I'm not sure creating the link multiple times in miic_create() would
be ok and also, I'm not sure how to create the link once without adding
a specific property which points on the MII converter node and use that
to create the link by adding miic_device_add_link() for instance.

Do you have any preference ?

Thanks,
Vladimir Oltean May 20, 2022, 3:44 p.m. UTC | #5
On Fri, May 20, 2022 at 05:22:44PM +0200, Clément Léger wrote:
> Le Fri, 20 May 2022 11:49:14 +0300,
> Vladimir Oltean <olteanv@gmail.com> a écrit :
>
> > On Fri, May 20, 2022 at 09:52:41AM +0200, Clément Léger wrote:
> > > > Also, as a request to unbind this driver would be disasterous to users,
> > > > I think you should set ".suppress_bind_attrs = true" to prevent the
> > > > sysfs bind/unbind facility being available. This doesn't completely
> > > > solve the problem.
> > >
> > > Acked. What should I do to make it more robust ? Should I use a
> > > refcount per pdev and check that in the remove() callback to avoid
> > > removing the pdev if used ?
> >
> > I wonder, if you call device_link_add(ds->dev, miic->dev, DL_FLAG_AUTOREMOVE_CONSUMER),
> > wouldn't that be enough to auto-unbind the DSA driver when the MII
> > converter driver unbinds?
>
> I looiked at that a bit and I'm not sure how to achieve that cleanly. If
> I need to create this link, then I need to do it once for the dsa switch
> device. However, currently, the way I get the references to the MII
> converter are via the pcs-handle properties which are for each port.
>
> So, I'm not sure creating the link multiple times in miic_create() would
> be ok and also, I'm not sure how to create the link once without adding
> a specific property which points on the MII converter node and use that
> to create the link by adding miic_device_add_link() for instance.
>
> Do you have any preference ?

The simplest (although not the most elegant) way would probably be to
pass the ds->dev as a second argument to miic_create(), and call
device_link_add() multiple times, letting all but the first call fail,
and ignoring the resulting NULL return code. Maybe others have a better idea.
Clément Léger May 20, 2022, 3:49 p.m. UTC | #6
Le Fri, 20 May 2022 18:44:40 +0300,
Vladimir Oltean <olteanv@gmail.com> a écrit :

> On Fri, May 20, 2022 at 05:22:44PM +0200, Clément Léger wrote:
> > Le Fri, 20 May 2022 11:49:14 +0300,
> > Vladimir Oltean <olteanv@gmail.com> a écrit :
> >  
> > > On Fri, May 20, 2022 at 09:52:41AM +0200, Clément Léger wrote:  
> > > > > Also, as a request to unbind this driver would be disasterous to users,
> > > > > I think you should set ".suppress_bind_attrs = true" to prevent the
> > > > > sysfs bind/unbind facility being available. This doesn't completely
> > > > > solve the problem.  
> > > >
> > > > Acked. What should I do to make it more robust ? Should I use a
> > > > refcount per pdev and check that in the remove() callback to avoid
> > > > removing the pdev if used ?  
> > >
> > > I wonder, if you call device_link_add(ds->dev, miic->dev, DL_FLAG_AUTOREMOVE_CONSUMER),
> > > wouldn't that be enough to auto-unbind the DSA driver when the MII
> > > converter driver unbinds?  
> >
> > I looiked at that a bit and I'm not sure how to achieve that cleanly. If
> > I need to create this link, then I need to do it once for the dsa switch
> > device. However, currently, the way I get the references to the MII
> > converter are via the pcs-handle properties which are for each port.
> >
> > So, I'm not sure creating the link multiple times in miic_create() would
> > be ok and also, I'm not sure how to create the link once without adding
> > a specific property which points on the MII converter node and use that
> > to create the link by adding miic_device_add_link() for instance.
> >
> > Do you have any preference ?  
> 
> The simplest (although not the most elegant) way would probably be to
> pass the ds->dev as a second argument to miic_create(), and call
> device_link_add() multiple times, letting all but the first call fail,
> and ignoring the resulting NULL return code. Maybe others have a better idea.

That's indeed what I started to do although it's nasty to say the
least... Moreover, the device_link_del() calls in miic_destroy() would
have to be carefully made after all miic ports have been
destroyed. Not sure this is going to be cleaner ! I'll try to think
about it a bit more.

Thanks,
Vladimir Oltean May 20, 2022, 3:58 p.m. UTC | #7
On Fri, May 20, 2022 at 05:49:34PM +0200, Clément Léger wrote:
> Le Fri, 20 May 2022 18:44:40 +0300,
> Vladimir Oltean <olteanv@gmail.com> a écrit :
> 
> > On Fri, May 20, 2022 at 05:22:44PM +0200, Clément Léger wrote:
> > > Le Fri, 20 May 2022 11:49:14 +0300,
> > > Vladimir Oltean <olteanv@gmail.com> a écrit :
> > >  
> > > > On Fri, May 20, 2022 at 09:52:41AM +0200, Clément Léger wrote:  
> > > > > > Also, as a request to unbind this driver would be disasterous to users,
> > > > > > I think you should set ".suppress_bind_attrs = true" to prevent the
> > > > > > sysfs bind/unbind facility being available. This doesn't completely
> > > > > > solve the problem.  
> > > > >
> > > > > Acked. What should I do to make it more robust ? Should I use a
> > > > > refcount per pdev and check that in the remove() callback to avoid
> > > > > removing the pdev if used ?  
> > > >
> > > > I wonder, if you call device_link_add(ds->dev, miic->dev, DL_FLAG_AUTOREMOVE_CONSUMER),
> > > > wouldn't that be enough to auto-unbind the DSA driver when the MII
> > > > converter driver unbinds?  
> > >
> > > I looiked at that a bit and I'm not sure how to achieve that cleanly. If
> > > I need to create this link, then I need to do it once for the dsa switch
> > > device. However, currently, the way I get the references to the MII
> > > converter are via the pcs-handle properties which are for each port.
> > >
> > > So, I'm not sure creating the link multiple times in miic_create() would
> > > be ok and also, I'm not sure how to create the link once without adding
> > > a specific property which points on the MII converter node and use that
> > > to create the link by adding miic_device_add_link() for instance.
> > >
> > > Do you have any preference ?  
> > 
> > The simplest (although not the most elegant) way would probably be to
> > pass the ds->dev as a second argument to miic_create(), and call
> > device_link_add() multiple times, letting all but the first call fail,
> > and ignoring the resulting NULL return code. Maybe others have a better idea.
> 
> That's indeed what I started to do although it's nasty to say the
> least... Moreover, the device_link_del() calls in miic_destroy() would
> have to be carefully made after all miic ports have been
> destroyed. Not sure this is going to be cleaner ! I'll try to think
> about it a bit more.

Wait... the whole idea with AUTOREMOVE_CONSUMER is that you _don't_
remove the device link.. you let it sit there such that the device core
knows there are other consumers it needs to remove when this driver
unbinds from the device.
Clément Léger May 20, 2022, 4:22 p.m. UTC | #8
Le Fri, 20 May 2022 18:58:15 +0300,
Vladimir Oltean <olteanv@gmail.com> a écrit :

> On Fri, May 20, 2022 at 05:49:34PM +0200, Clément Léger wrote:
> > Le Fri, 20 May 2022 18:44:40 +0300,
> > Vladimir Oltean <olteanv@gmail.com> a écrit :
> >   
> > > On Fri, May 20, 2022 at 05:22:44PM +0200, Clément Léger wrote:  
> > > > Le Fri, 20 May 2022 11:49:14 +0300,
> > > > Vladimir Oltean <olteanv@gmail.com> a écrit :
> > > >    
> > > > > On Fri, May 20, 2022 at 09:52:41AM +0200, Clément Léger wrote:    
> > > > > > > Also, as a request to unbind this driver would be disasterous to users,
> > > > > > > I think you should set ".suppress_bind_attrs = true" to prevent the
> > > > > > > sysfs bind/unbind facility being available. This doesn't completely
> > > > > > > solve the problem.    
> > > > > >
> > > > > > Acked. What should I do to make it more robust ? Should I use a
> > > > > > refcount per pdev and check that in the remove() callback to avoid
> > > > > > removing the pdev if used ?    
> > > > >
> > > > > I wonder, if you call device_link_add(ds->dev, miic->dev, DL_FLAG_AUTOREMOVE_CONSUMER),
> > > > > wouldn't that be enough to auto-unbind the DSA driver when the MII
> > > > > converter driver unbinds?    
> > > >
> > > > I looiked at that a bit and I'm not sure how to achieve that cleanly. If
> > > > I need to create this link, then I need to do it once for the dsa switch
> > > > device. However, currently, the way I get the references to the MII
> > > > converter are via the pcs-handle properties which are for each port.
> > > >
> > > > So, I'm not sure creating the link multiple times in miic_create() would
> > > > be ok and also, I'm not sure how to create the link once without adding
> > > > a specific property which points on the MII converter node and use that
> > > > to create the link by adding miic_device_add_link() for instance.
> > > >
> > > > Do you have any preference ?    
> > > 
> > > The simplest (although not the most elegant) way would probably be to
> > > pass the ds->dev as a second argument to miic_create(), and call
> > > device_link_add() multiple times, letting all but the first call fail,
> > > and ignoring the resulting NULL return code. Maybe others have a better idea.  
> > 
> > That's indeed what I started to do although it's nasty to say the
> > least... Moreover, the device_link_del() calls in miic_destroy() would
> > have to be carefully made after all miic ports have been
> > destroyed. Not sure this is going to be cleaner ! I'll try to think
> > about it a bit more.  
> 
> Wait... the whole idea with AUTOREMOVE_CONSUMER is that you _don't_
> remove the device link.. you let it sit there such that the device core
> knows there are other consumers it needs to remove when this driver
> unbinds from the device.

Hum ok, got it, so let's try this solution.
diff mbox series

Patch

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 */