diff mbox series

[net-next,5/5] net: sfp: add support for multigig RollBall transceivers

Message ID 20201028221427.22968-6-kabel@kernel.org
State Changes Requested
Delegated to: David Miller
Headers show
Series Support for RollBall 10G copper SFP modules | expand

Checks

Context Check Description
jkicinski/cover_letter success Link
jkicinski/fixes_present success Link
jkicinski/patch_count success Link
jkicinski/tree_selection success Clearly marked for net-next
jkicinski/subject_prefix success Link
jkicinski/source_inline success Was 0 now: 0
jkicinski/verify_signedoff success Link
jkicinski/module_param success Was 0 now: 0
jkicinski/build_32bit fail Errors and warnings before: 4 this patch: 4
jkicinski/kdoc success Errors and warnings before: 0 this patch: 0
jkicinski/verify_fixes success Link
jkicinski/checkpatch fail Link
jkicinski/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
jkicinski/header_inline success Link
jkicinski/stable success Stable not CCed

Commit Message

Marek Behún Oct. 28, 2020, 10:14 p.m. UTC 
This adds support for multigig copper SFP modules from RollBall/Hilink.
These modules have a specific way to access clause 45 registers of the
internal PHY.

We also need to wait at least 25 seconds after deasserting TX disable
before accessing the PHY. The code waits for 30 seconds just to be sure.

Signed-off-by: Marek Behún <kabel@kernel.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/sfp.c | 72 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 65 insertions(+), 7 deletions(-)

Comments

Russell King (Oracle) Oct. 29, 2020, 1:38 p.m. UTC | #1 
On Wed, Oct 28, 2020 at 11:14:27PM +0100, Marek Behún wrote:
> This adds support for multigig copper SFP modules from RollBall/Hilink.
> These modules have a specific way to access clause 45 registers of the
> internal PHY.
> 
> We also need to wait at least 25 seconds after deasserting TX disable
> before accessing the PHY. The code waits for 30 seconds just to be sure.

Any ideas why it takes 25 seconds for the module to initialise - the
88x3310 startup is pretty fast in itself. However, it never amazes me
how broken SFP modules can be.

Extending T_WAIT is one way around this, and luckily I already catered
for the case where T_WAIT is extended beyond module_t_start_up.

Usual comment about line lengths...

> 
> Signed-off-by: Marek Behún <kabel@kernel.org>
> Cc: Andrew Lunn <andrew@lunn.ch>
> Cc: Russell King <rmk+kernel@armlinux.org.uk>
> ---
>  drivers/net/phy/sfp.c | 72 ++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 65 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
> index a392d5fc6ab4..379358f194ee 100644
> --- a/drivers/net/phy/sfp.c
> +++ b/drivers/net/phy/sfp.c
> @@ -165,6 +165,7 @@ static const enum gpiod_flags gpio_flags[] = {
>   * on board (for a copper SFP) time to initialise.
>   */
>  #define T_WAIT			msecs_to_jiffies(50)
> +#define T_WAIT_LONG_PHY		msecs_to_jiffies(30000)

I think call this T_WAIT_ROLLBALL.

> @@ -1675,12 +1681,40 @@ static int sfp_cotsworks_fixup_check(struct sfp *sfp, struct sfp_eeprom_id *id)
>  	return 0;
>  }
>  
> +static int sfp_rollball_init_mdio(struct sfp *sfp)
> +{
> +	u8 page, password[4];
> +	int err;
> +
> +	page = 3;
> +
> +	err = sfp_write(sfp, true, SFP_PAGE, &page, 1);
> +	if (err != 1) {
> +		dev_err(sfp->dev, "Failed to set SFP page for RollBall MDIO access: %d\n", err);
> +		return err;
> +	}
> +
> +	password[0] = 0xff;
> +	password[1] = 0xff;
> +	password[2] = 0xff;
> +	password[3] = 0xff;
> +
> +	err = sfp_write(sfp, true, 0x7b, password, 4);
> +	if (err != 4) {
> +		dev_err(sfp->dev, "Failed to write password for RollBall MDIO access: %d\n", err);
> +		return err;
> +	}
> +
> +	return 0;
> +}

I think this needs to be done in the MDIO driver - if we have userspace
or otherwise expand what we're doing, relying on page 3 remaining
selected will be very fragile.
Marek Behún Oct. 29, 2020, 4:49 p.m. UTC | #2 
On Thu, 29 Oct 2020 13:38:00 +0000
Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote:

> Any ideas why it takes 25 seconds for the module to initialise - the
> 88x3310 startup is pretty fast in itself. However, it never amazes me
> how broken SFP modules can be.

I don't know, but for the first 25 seconds the SFP returns 0xffff on
all reads. I think it is due to the internal MCU doing it's own stuff
with the PHY during that time.

Marek
diff mbox series

Patch

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index a392d5fc6ab4..379358f194ee 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -165,6 +165,7 @@  static const enum gpiod_flags gpio_flags[] = {
  * on board (for a copper SFP) time to initialise.
  */
 #define T_WAIT			msecs_to_jiffies(50)
+#define T_WAIT_LONG_PHY		msecs_to_jiffies(30000)
 #define T_START_UP		msecs_to_jiffies(300)
 #define T_START_UP_BAD_GPON	msecs_to_jiffies(60000)
 
@@ -204,8 +205,11 @@  static const enum gpiod_flags gpio_flags[] = {
 
 /* SFP modules appear to always have their PHY configured for bus address
  * 0x56 (which with mdio-i2c, translates to a PHY address of 22).
+ * RollBall SFPs access phy via SFP Enhanced Digital Diagnostic Interface
+ * via address 0x51 (mdio-i2c will use RollBall protocol on this address).
  */
-#define SFP_PHY_ADDR	22
+#define SFP_PHY_ADDR		22
+#define SFP_PHY_ADDR_ROLLBALL	17
 
 struct sff_data {
 	unsigned int gpios;
@@ -220,6 +224,7 @@  struct sfp {
 	struct phy_device *mod_phy;
 	const struct sff_data *type;
 	u32 max_power_mW;
+	int phy_addr;
 
 	unsigned int (*get_state)(struct sfp *);
 	void (*set_state)(struct sfp *, unsigned int);
@@ -248,6 +253,7 @@  struct sfp {
 	struct sfp_eeprom_id id;
 	unsigned int module_power_mW;
 	unsigned int module_t_start_up;
+	unsigned int module_t_wait;
 
 #if IS_ENABLED(CONFIG_HWMON)
 	struct sfp_diag diag;
@@ -1442,7 +1448,7 @@  static int sfp_sm_probe_phy(struct sfp *sfp, bool is_c45)
 	struct phy_device *phy;
 	int err;
 
-	phy = get_phy_device(sfp->i2c_mii, SFP_PHY_ADDR, is_c45);
+	phy = get_phy_device(sfp->i2c_mii, sfp->phy_addr, is_c45);
 	if (phy == ERR_PTR(-ENODEV))
 		return PTR_ERR(phy);
 	if (IS_ERR(phy)) {
@@ -1675,12 +1681,40 @@  static int sfp_cotsworks_fixup_check(struct sfp *sfp, struct sfp_eeprom_id *id)
 	return 0;
 }
 
+static int sfp_rollball_init_mdio(struct sfp *sfp)
+{
+	u8 page, password[4];
+	int err;
+
+	page = 3;
+
+	err = sfp_write(sfp, true, SFP_PAGE, &page, 1);
+	if (err != 1) {
+		dev_err(sfp->dev, "Failed to set SFP page for RollBall MDIO access: %d\n", err);
+		return err;
+	}
+
+	password[0] = 0xff;
+	password[1] = 0xff;
+	password[2] = 0xff;
+	password[3] = 0xff;
+
+	err = sfp_write(sfp, true, 0x7b, password, 4);
+	if (err != 4) {
+		dev_err(sfp->dev, "Failed to write password for RollBall MDIO access: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
 static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
 {
 	/* SFP module inserted - read I2C data */
 	struct sfp_eeprom_id id;
 	bool cotsworks_sfbg;
 	bool cotsworks;
+	bool rollball;
 	u8 check;
 	int ret;
 
@@ -1755,6 +1789,24 @@  static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
 		 (int)sizeof(id.ext.vendor_sn), id.ext.vendor_sn,
 		 (int)sizeof(id.ext.datecode), id.ext.datecode);
 
+	sfp->phy_addr = SFP_PHY_ADDR;
+
+	rollball = ((!memcmp(id.base.vendor_name, "OEM             ", 16) ||
+		     !memcmp(id.base.vendor_name, "Turris          ", 16)) &&
+		    (!memcmp(id.base.vendor_pn, "SFP-10G-T       ", 16) ||
+		     !memcmp(id.base.vendor_pn, "RTSFP-10", 8)));
+	if (rollball) {
+		sfp->phy_addr = SFP_PHY_ADDR_ROLLBALL;
+		ret = sfp_rollball_init_mdio(sfp);
+		if (ret < 0)
+			return ret;
+
+		/* RollBall SFPs may have wrong (zero) extended compliacne code burned in EEPROM.
+		 * For PHY probing we need the correct one.
+		 */
+		id.base.extended_cc = SFF8024_ECC_10GBASE_T_SFI;
+	}
+
 	/* Check whether we support this module */
 	if (!sfp->type->module_supported(&id)) {
 		dev_err(sfp->dev,
@@ -1779,8 +1831,13 @@  static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
 	else
 		sfp->module_t_start_up = T_START_UP;
 
+	if (rollball)
+		sfp->module_t_wait = T_WAIT_LONG_PHY;
+	else
+		sfp->module_t_wait = T_WAIT;
+
 	/* Configure mdiobus */
-	ret = sfp_i2c_mdiobus_configure(sfp, MDIO_I2C_DEFAULT);
+	ret = sfp_i2c_mdiobus_configure(sfp, rollball ? MDIO_I2C_ROLLBALL : MDIO_I2C_DEFAULT);
 	if (ret < 0)
 		return ret;
 
@@ -1979,9 +2036,10 @@  static void sfp_sm_main(struct sfp *sfp, unsigned int event)
 
 		/* We need to check the TX_FAULT state, which is not defined
 		 * while TX_DISABLE is asserted. The earliest we want to do
-		 * anything (such as probe for a PHY) is 50ms.
+		 * anything (such as probe for a PHY) is 50ms (or more on
+		 * specific modules).
 		 */
-		sfp_sm_next(sfp, SFP_S_WAIT, T_WAIT);
+		sfp_sm_next(sfp, SFP_S_WAIT, sfp->module_t_wait);
 		break;
 
 	case SFP_S_WAIT:
@@ -1995,8 +2053,8 @@  static void sfp_sm_main(struct sfp *sfp, unsigned int event)
 			 * deasserting.
 			 */
 			timeout = sfp->module_t_start_up;
-			if (timeout > T_WAIT)
-				timeout -= T_WAIT;
+			if (timeout > sfp->module_t_wait)
+				timeout -= sfp->module_t_wait;
 			else
 				timeout = 1;