diff mbox series

[v3,3/3] net: dsa: mv88e6xxx: Support serdes ports on MV88E6123/6131

Message ID 20201020034558.19438-4-chris.packham@alliedtelesis.co.nz
State Changes Requested
Delegated to: David Miller
Headers show
Series net: dsa: mv88e6xxx: serdes link without phy | expand

Commit Message

Chris Packham Oct. 20, 2020, 3:45 a.m. UTC
Implement serdes_power, serdes_get_lane and serdes_pcs_get_state ops for
the MV88E6123 so that the ports without a built-in PHY supported as
serdes ports and directly connected to other network interfaces or to
SFPs. Also implement serdes_get_regs_len and serdes_get_regs to aid
future debugging.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---

This is untested (apart from compilation) it assumes the SERDES "phy"
address corresponds to the port number but I'm not confident that is a
valid assumption.

Changes in v3:
- None
Changes in v2:
- new

 drivers/net/dsa/mv88e6xxx/chip.c   | 10 +++++++
 drivers/net/dsa/mv88e6xxx/serdes.c | 44 ++++++++++++++++++++++++++++++
 drivers/net/dsa/mv88e6xxx/serdes.h |  4 +++
 3 files changed, 58 insertions(+)

Comments

Russell King (Oracle) Oct. 20, 2020, 10:18 a.m. UTC | #1
On Tue, Oct 20, 2020 at 04:45:58PM +1300, Chris Packham wrote:
> +void mv88e6123_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
> +{
> +	u16 *p = _p;
> +	u16 reg;
> +	int i;
> +
> +	if (mv88e6xxx_serdes_get_lane(chip, port) == 0)
> +		return;
> +
> +	for (i = 0; i < 26; i++) {
> +		mv88e6xxx_phy_read(chip, port, i, &reg);

Shouldn't this deal with a failed read in some way, rather than just
assigning the last or possibly uninitialised value to p[i] ?
Chris Packham Oct. 20, 2020, 9:24 p.m. UTC | #2
On 20/10/20 11:18 pm, Russell King - ARM Linux admin wrote:
> On Tue, Oct 20, 2020 at 04:45:58PM +1300, Chris Packham wrote:
>> +void mv88e6123_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
>> +{
>> +	u16 *p = _p;
>> +	u16 reg;
>> +	int i;
>> +
>> +	if (mv88e6xxx_serdes_get_lane(chip, port) == 0)
>> +		return;
>> +
>> +	for (i = 0; i < 26; i++) {
>> +		mv88e6xxx_phy_read(chip, port, i, &reg);
> Shouldn't this deal with a failed read in some way, rather than just
> assigning the last or possibly uninitialised value to p[i] ?

mv88e6390_serdes_get_regs() and mv88e6352_serdes_get_regs() also ignore 
the error. The generic mv88e6xxx_get_regs() memsets p[] to 0xff so if 
the serdes_get_regs functions just left it alone we'd return 0xffff 
which is probably better than repeating the last value although it's 
still ambiguous because 0xffff is a valid value for plenty of these 
registers.

Since it looks like I need to come up with an alternative to patch #1 
I'll concentrate on that but making the serdes_get_regs() a little more 
error tolerant is a cleanup I can easily tack on onto this series.
Russell King (Oracle) Oct. 20, 2020, 9:34 p.m. UTC | #3
On Tue, Oct 20, 2020 at 09:24:04PM +0000, Chris Packham wrote:
> 
> On 20/10/20 11:18 pm, Russell King - ARM Linux admin wrote:
> > On Tue, Oct 20, 2020 at 04:45:58PM +1300, Chris Packham wrote:
> >> +void mv88e6123_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
> >> +{
> >> +	u16 *p = _p;
> >> +	u16 reg;
> >> +	int i;
> >> +
> >> +	if (mv88e6xxx_serdes_get_lane(chip, port) == 0)
> >> +		return;
> >> +
> >> +	for (i = 0; i < 26; i++) {
> >> +		mv88e6xxx_phy_read(chip, port, i, &reg);
> > Shouldn't this deal with a failed read in some way, rather than just
> > assigning the last or possibly uninitialised value to p[i] ?
> 
> mv88e6390_serdes_get_regs() and mv88e6352_serdes_get_regs() also ignore 
> the error. The generic mv88e6xxx_get_regs() memsets p[] to 0xff so if 
> the serdes_get_regs functions just left it alone we'd return 0xffff 
> which is probably better than repeating the last value although it's 
> still ambiguous because 0xffff is a valid value for plenty of these 
> registers.
> 
> Since it looks like I need to come up with an alternative to patch #1 
> I'll concentrate on that but making the serdes_get_regs() a little more 
> error tolerant is a cleanup I can easily tack on onto this series.

Yep, it looks like they all suffer the same problem. Interestingly,
mv88e6xxx_get_regs() does handle the error by avoiding writing the
register entry (so it gets left as 0xffff.)

Incidentally, that's also the value you'll get when reading from a
PHY that doesn't respond, since the MDIO data line is pulled high
when undriven.
diff mbox series

Patch

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 62d4d7b5d9ac..5344fc84b03e 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -3574,6 +3574,11 @@  static const struct mv88e6xxx_ops mv88e6123_ops = {
 	.set_egress_port = mv88e6095_g1_set_egress_port,
 	.watchdog_ops = &mv88e6097_watchdog_ops,
 	.mgmt_rsvd2cpu = mv88e6352_g2_mgmt_rsvd2cpu,
+	.serdes_power = mv88e6123_serdes_power,
+	.serdes_get_lane = mv88e6185_serdes_get_lane,
+	.serdes_pcs_get_state = mv88e6185_serdes_pcs_get_state,
+	.serdes_get_regs_len = mv88e6123_serdes_get_regs_len,
+	.serdes_get_regs = mv88e6123_serdes_get_regs,
 	.pot_clear = mv88e6xxx_g2_pot_clear,
 	.reset = mv88e6352_g1_reset,
 	.atu_get_hash = mv88e6165_g1_atu_get_hash,
@@ -3613,6 +3618,11 @@  static const struct mv88e6xxx_ops mv88e6131_ops = {
 	.set_egress_port = mv88e6095_g1_set_egress_port,
 	.watchdog_ops = &mv88e6097_watchdog_ops,
 	.mgmt_rsvd2cpu = mv88e6185_g2_mgmt_rsvd2cpu,
+	.serdes_power = mv88e6123_serdes_power,
+	.serdes_get_lane = mv88e6185_serdes_get_lane,
+	.serdes_pcs_get_state = mv88e6185_serdes_pcs_get_state,
+	.serdes_get_regs_len = mv88e6123_serdes_get_regs_len,
+	.serdes_get_regs = mv88e6123_serdes_get_regs,
 	.ppu_enable = mv88e6185_g1_ppu_enable,
 	.set_cascade_port = mv88e6185_g1_set_cascade_port,
 	.ppu_disable = mv88e6185_g1_ppu_disable,
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index d4f40a739b17..eb89debbf576 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -428,6 +428,50 @@  u8 mv88e6341_serdes_get_lane(struct mv88e6xxx_chip *chip, int port)
 	return lane;
 }
 
+int mv88e6123_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
+			   bool up)
+{
+	u16 val, new_val;
+	int err;
+
+	err = mv88e6xxx_phy_read(chip, port, MII_BMCR, &val);
+	if (err)
+		return err;
+
+	if (up)
+		new_val = val & ~BMCR_PDOWN;
+	else
+		new_val = val | BMCR_PDOWN;
+
+	if (val != new_val)
+		err = mv88e6xxx_phy_write(chip, port, MII_BMCR, val);
+
+	return err;
+}
+
+int mv88e6123_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port)
+{
+	if (mv88e6xxx_serdes_get_lane(chip, port) == 0)
+		return 0;
+
+	return 26 * sizeof(u16);
+}
+
+void mv88e6123_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
+{
+	u16 *p = _p;
+	u16 reg;
+	int i;
+
+	if (mv88e6xxx_serdes_get_lane(chip, port) == 0)
+		return;
+
+	for (i = 0; i < 26; i++) {
+		mv88e6xxx_phy_read(chip, port, i, &reg);
+		p[i] = reg;
+	}
+}
+
 int mv88e6185_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
 			   bool up)
 {
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.h b/drivers/net/dsa/mv88e6xxx/serdes.h
index c24ec4122c9e..b573139928c4 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.h
+++ b/drivers/net/dsa/mv88e6xxx/serdes.h
@@ -104,6 +104,8 @@  unsigned int mv88e6352_serdes_irq_mapping(struct mv88e6xxx_chip *chip,
 					  int port);
 unsigned int mv88e6390_serdes_irq_mapping(struct mv88e6xxx_chip *chip,
 					  int port);
+int mv88e6123_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
+			   bool up);
 int mv88e6185_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
 			   bool up);
 int mv88e6352_serdes_power(struct mv88e6xxx_chip *chip, int port, u8 lane,
@@ -129,6 +131,8 @@  int mv88e6390_serdes_get_strings(struct mv88e6xxx_chip *chip,
 int mv88e6390_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
 			       uint64_t *data);
 
+int mv88e6123_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port);
+void mv88e6123_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p);
 int mv88e6352_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port);
 void mv88e6352_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p);
 int mv88e6390_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port);