net: sfp: re-implement soft state polling setup

Re-implement the decision making for soft state polling. Instead of
generating the soft state mask in sfp_soft_start_poll() by looking at
which GPIOs are available, record their availability in
sfp_sm_mod_probe() in sfp->state_hw_mask.

This will then allow us to clear bits in sfp->state_hw_mask in module
specific quirks when the hardware signals should not be used, thereby
allowing us to switch to using the software state polling.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/sfp.c

@@ -234,6 +234,7 @@ struct sfp {
 	bool need_poll;
 
 	struct mutex st_mutex;			/* Protects state */
+	unsigned int state_hw_mask;
 	unsigned int state_soft_mask;
 	unsigned int state;
 	struct delayed_work poll;
@@ -499,17 +500,18 @@ static void sfp_soft_set_state(struct sfp *sfp, unsigned int state)
 static void sfp_soft_start_poll(struct sfp *sfp)
 {
 	const struct sfp_eeprom_id *id = &sfp->id;
+	unsigned int mask = 0;
 
 	sfp->state_soft_mask = 0;
-	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_DISABLE &&
-	    !sfp->gpio[GPIO_TX_DISABLE])
-		sfp->state_soft_mask |= SFP_F_TX_DISABLE;
-	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_FAULT &&
-	    !sfp->gpio[GPIO_TX_FAULT])
-		sfp->state_soft_mask |= SFP_F_TX_FAULT;
-	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_RX_LOS &&
-	    !sfp->gpio[GPIO_LOS])
-		sfp->state_soft_mask |= SFP_F_LOS;
+	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_DISABLE)
+		mask |= SFP_F_TX_DISABLE;
+	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_FAULT)
+		mask |= SFP_F_TX_FAULT;
+	if (id->ext.enhopts & SFP_ENHOPTS_SOFT_RX_LOS)
+		mask |= SFP_F_LOS;
+
+	// Poll the soft state for hardware pins we want to ignore
+	sfp->state_soft_mask = ~sfp->state_hw_mask & mask;
 
 	if (sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT) &&
 	    !sfp->need_poll)
@@ -523,10 +525,11 @@ static void sfp_soft_stop_poll(struct sfp *sfp)
 
 static unsigned int sfp_get_state(struct sfp *sfp)
 {
-	unsigned int state = sfp->get_state(sfp);
+	unsigned int soft = sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT);
+	unsigned int state;
 
-	if (state & SFP_F_PRESENT &&
-	    sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT))
+	state = sfp->get_state(sfp) & sfp->state_hw_mask;
+	if (state & SFP_F_PRESENT && soft)
 		state |= sfp_soft_get_state(sfp);
 
 	return state;
@@ -1902,6 +1905,15 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
 	if (ret < 0)
 		return ret;
 
+	/* Initialise state bits to use from hardware */
+	sfp->state_hw_mask = SFP_F_PRESENT;
+	if (sfp->gpio[GPIO_TX_DISABLE])
+		sfp->state_hw_mask |= SFP_F_TX_DISABLE;
+	if (sfp->gpio[GPIO_TX_FAULT])
+		sfp->state_hw_mask |= SFP_F_TX_FAULT;
+	if (sfp->gpio[GPIO_LOS])
+		sfp->state_hw_mask |= SFP_F_LOS;
+
 	if (!memcmp(id.base.vendor_name, "ALCATELLUCENT   ", 16) &&
 	    !memcmp(id.base.vendor_pn, "3FE46541AA      ", 16))
 		sfp->module_t_start_up = T_START_UP_BAD_GPON;
@@ -2528,6 +2540,8 @@ static int sfp_probe(struct platform_device *pdev)
 				return PTR_ERR(sfp->gpio[i]);
 		}
 
+	sfp->state_hw_mask = SFP_F_PRESENT;
+
 	sfp->get_state = sfp_gpio_get_state;
 	sfp->set_state = sfp_gpio_set_state;