Re: [RFC Patch net-next 03/10] net: dsa: microchip: add common 100/10Mbps selection function

[<Arun.Ramadoss@microchip.com>]

Hi Vladimir,
On Tue, 2022-07-19 at 13:48 +0300, Vladimir Oltean wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you
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> 
> On Tue, Jul 12, 2022 at 09:33:01PM +0530, Arun Ramadoss wrote:
> > This patch adds the function for configuring the 100/10Mbps speed
> > selection for the ksz switches. KSZ8795 switch uses Global control
> > 4
> > register 0x06 bit 4 for choosing 100/10Mpbs. Other switches uses
> > xMII
> > control 1 0xN300 for it.
> > For KSZ8795, if the bit is set then 10Mbps is chosen and if bit is
> > clear then 100Mbps chosen. For all other switches it is other way
> > around, if the bit is set then 100Mbps is chosen.
> > So, this patch add the generic function for ksz switch to select
> > the
> > 100/10Mbps speed selection. While configuring, first it disables
> > the
> > gigabit functionality and then configure the respective speed.
> > 
> > Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
> > ---
> >  drivers/net/dsa/microchip/ksz9477_reg.h  |  1 -
> >  drivers/net/dsa/microchip/ksz_common.c   | 29
> > ++++++++++++++++++++++++
> >  drivers/net/dsa/microchip/ksz_common.h   |  6 +++++
> >  drivers/net/dsa/microchip/lan937x_main.c | 14 ++++--------
> >  drivers/net/dsa/microchip/lan937x_reg.h  |  1 -
> >  5 files changed, 40 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/net/dsa/microchip/ksz9477_reg.h
> > b/drivers/net/dsa/microchip/ksz9477_reg.h
> > index f23ed4809e47..2649fdf0bae1 100644
> > --- a/drivers/net/dsa/microchip/ksz9477_reg.h
> > +++ b/drivers/net/dsa/microchip/ksz9477_reg.h
> > @@ -1179,7 +1179,6 @@
> > 
> >  #define PORT_SGMII_SEL                       BIT(7)
> >  #define PORT_MII_FULL_DUPLEX         BIT(6)
> > -#define PORT_MII_100MBIT             BIT(4)
> >  #define PORT_GRXC_ENABLE             BIT(0)
> > 
> >  #define REG_PORT_XMII_CTRL_1         0x0301
> > diff --git a/drivers/net/dsa/microchip/ksz_common.c
> > b/drivers/net/dsa/microchip/ksz_common.c
> > index 5ebcd87fc531..f41cd2801210 100644
> > --- a/drivers/net/dsa/microchip/ksz_common.c
> > +++ b/drivers/net/dsa/microchip/ksz_common.c
> > @@ -256,6 +256,7 @@ static const u16 ksz8795_regs[] = {
> >       [S_START_CTRL]                  = 0x01,
> >       [S_BROADCAST_CTRL]              = 0x06,
> >       [S_MULTICAST_CTRL]              = 0x04,
> > +     [P_XMII_CTRL_0]                 = 0x06,
> >       [P_XMII_CTRL_1]                 = 0x56,
> >  };
> > 
> > @@ -284,6 +285,8 @@ static const u32 ksz8795_masks[] = {
> >  static const u8 ksz8795_values[] = {
> >       [P_MII_1GBIT]                   = 1,
> >       [P_MII_NOT_1GBIT]               = 0,
> > +     [P_MII_100MBIT]                 = 0,
> > +     [P_MII_10MBIT]                  = 1,
> 
> Can you namespace P_GMII_1GBIT/P_GMII_NOT_1GBIT separately from
> P_MII_100MBIT/P_MII_10MBIT? Otherwise it's not obvious that the first
> set writes to regs[P_XMII_CTRL_1] and the other to
> regs[P_XMII_CTRL_0].

Yes, I can do it.

> 
> >  };
> > 
> >  static const u8 ksz8795_shifts[] = {
> > @@ -356,6 +359,7 @@ static const u16 ksz9477_regs[] = {
> >       [S_START_CTRL]                  = 0x0300,
> >       [S_BROADCAST_CTRL]              = 0x0332,
> >       [S_MULTICAST_CTRL]              = 0x0331,
> > +     [P_XMII_CTRL_0]                 = 0x0300,
> >       [P_XMII_CTRL_1]                 = 0x0301,
> >  };
> > 
> > 
> > diff --git a/drivers/net/dsa/microchip/ksz_common.h
> > b/drivers/net/dsa/microchip/ksz_common.h
> > index a76dfef6309c..f1fa6feca559 100644
> > --- a/drivers/net/dsa/microchip/ksz_common.h
> > +++ b/drivers/net/dsa/microchip/ksz_common.h
> > @@ -172,6 +172,7 @@ enum ksz_regs {
> >       S_START_CTRL,
> >       S_BROADCAST_CTRL,
> >       S_MULTICAST_CTRL,
> > +     P_XMII_CTRL_0,
> >       P_XMII_CTRL_1,
> >  };
> > 
> > 
> >  /* Regmap tables generation */
> > diff --git a/drivers/net/dsa/microchip/lan937x_main.c
> > b/drivers/net/dsa/microchip/lan937x_main.c
> > index efca96b02e15..37f63110e5bb 100644
> > --- a/drivers/net/dsa/microchip/lan937x_main.c
> > +++ b/drivers/net/dsa/microchip/lan937x_main.c
> > @@ -346,21 +346,18 @@ static void lan937x_config_interface(struct
> > ksz_device *dev, int port,
> >                                    int speed, int duplex,
> >                                    bool tx_pause, bool rx_pause)
> >  {
> > -     u8 xmii_ctrl0, xmii_ctrl1;
> > +     u8 xmii_ctrl0;
> > 
> >       ksz_pread8(dev, port, REG_PORT_XMII_CTRL_0, &xmii_ctrl0);
> > -     ksz_pread8(dev, port, REG_PORT_XMII_CTRL_1, &xmii_ctrl1);
> > 
> > -     xmii_ctrl0 &= ~(PORT_MII_100MBIT | PORT_MII_FULL_DUPLEX |
> > -                     PORT_MII_TX_FLOW_CTRL |
> > PORT_MII_RX_FLOW_CTRL);
> > +     xmii_ctrl0 &= ~(PORT_MII_FULL_DUPLEX | PORT_MII_TX_FLOW_CTRL
> > |
> > +                     PORT_MII_RX_FLOW_CTRL);
> > 
> >       if (speed == SPEED_1000)
> >               ksz_set_gbit(dev, port, true);
> > -     else
> > -             ksz_set_gbit(dev, port, false);
> > 
> > -     if (speed == SPEED_100)
> > -             xmii_ctrl0 |= PORT_MII_100MBIT;
> > +     if (speed == SPEED_100 || speed == SPEED_10)
> > +             ksz_set_100_10mbit(dev, port, speed);
> 
> Why don't you create a single ksz_port_set_xmii_speed() entry point,
> and
> this decides whether to call ksz_set_gbit() with true or false
> depending
> on whether the speed was 1000, and ksz_set_100_10mbit() as
> appropriate?

Ok, I will create new function.

> > 
> >       if (duplex)
> >               xmii_ctrl0 |= PORT_MII_FULL_DUPLEX;
> > @@ -372,7 +369,6 @@ static void lan937x_config_interface(struct
> > ksz_device *dev, int port,
> >               xmii_ctrl0 |= PORT_MII_RX_FLOW_CTRL;
> > 
> >       ksz_pwrite8(dev, port, REG_PORT_XMII_CTRL_0, xmii_ctrl0);
> > -     ksz_pwrite8(dev, port, REG_PORT_XMII_CTRL_1, xmii_ctrl1);
> 
> Will these remaining ksz_pwrite8 calls to REG_PORT_XMII_CTRL_0 not
> overwrite what ksz_set_gbit() is doing?

Yes, this ksz_pwrite8 overwrites the ksz_set_gbit. But the next patch
updates the duplex and flow control separately, I tested the phylink
register configuration only after applying entire series. So I missed
this. Thanks for pointing it.
I will move the reading the xmii_ctrl0 after configuring the
ksz_set_gbit().

> 
> >  }
> > 
> >  void lan937x_phylink_get_caps(struct ksz_device *dev, int port,
> > diff --git a/drivers/net/dsa/microchip/lan937x_reg.h
> > b/drivers/net/dsa/microchip/lan937x_reg.h
> > index 747295d34411..b9364f6a4f8f 100644
> > --- a/drivers/net/dsa/microchip/lan937x_reg.h
> > +++ b/drivers/net/dsa/microchip/lan937x_reg.h
> > @@ -135,7 +135,6 @@
> >  #define PORT_SGMII_SEL                       BIT(7)
> >  #define PORT_MII_FULL_DUPLEX         BIT(6)
> >  #define PORT_MII_TX_FLOW_CTRL                BIT(5)
> > -#define PORT_MII_100MBIT             BIT(4)
> >  #define PORT_MII_RX_FLOW_CTRL                BIT(3)
> >  #define PORT_GRXC_ENABLE             BIT(0)
> > 
> > --
> > 2.36.1
> >