net: ravb: Split GTI computation and set operations

ravb_set_gti() was computing the value of GTI based on the reference clock
rate and then applied it to register. This was done on the driver's probe
function. In order to implement runtime PM for all IP variants (as some IP
variants switches to reset mode (and thus the registers content is lost)
when module standby is configured through clock APIs) the GTI setup was
split in 2 parts: one computing the value of the GTI register (done in the
driver's probe function) and one applying the computed value to register
(done in the driver's ndo_open API).
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/renesas/ravb.h

@@ -1102,6 +1102,8 @@ struct ravb_private {
 
 	const struct ravb_hw_info *info;
 	struct reset_control *rstc;
+
+	u32 gti_tiv;
 };
 
 static inline u32 ravb_read(struct net_device *ndev, enum ravb_reg reg)

drivers/net/ethernet/renesas/ravb_main.c

@@ -1756,6 +1756,50 @@ static const struct ethtool_ops ravb_ethtool_ops = {
 	.set_wol		= ravb_set_wol,
 };
 
+static void ravb_set_gti(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	const struct ravb_hw_info *info = priv->info;
+
+	if (!(info->gptp || info->ccc_gac))
+		return;
+
+	ravb_write(ndev, priv->gti_tiv, GTI);
+
+	/* Request GTI loading */
+	ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI);
+}
+
+static int ravb_compute_gti(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	const struct ravb_hw_info *info = priv->info;
+	struct device *dev = ndev->dev.parent;
+	unsigned long rate;
+	u64 inc;
+
+	if (!(info->gptp || info->ccc_gac))
+		return 0;
+
+	if (info->gptp_ref_clk)
+		rate = clk_get_rate(priv->gptp_clk);
+	else
+		rate = clk_get_rate(priv->clk);
+	if (!rate)
+		return -EINVAL;
+
+	inc = div64_ul(1000000000ULL << 20, rate);
+
+	if (inc < GTI_TIV_MIN || inc > GTI_TIV_MAX) {
+		dev_err(dev, "gti.tiv increment 0x%llx is outside the range 0x%x - 0x%x\n",
+			inc, GTI_TIV_MIN, GTI_TIV_MAX);
+		return -EINVAL;
+	}
+	priv->gti_tiv = inc;
+
+	return 0;
+}
+
 /* Network device open function for Ethernet AVB */
 static int ravb_open(struct net_device *ndev)
 {
@@ -1773,6 +1817,8 @@ static int ravb_open(struct net_device *ndev)
 		goto out_napi_off;
 	ravb_emac_init(ndev);
 
+	ravb_set_gti(ndev);
+
 	/* Initialise PTP Clock driver */
 	if (info->gptp)
 		ravb_ptp_init(ndev, priv->pdev);
@@ -2464,34 +2510,6 @@ static const struct of_device_id ravb_match_table[] = {
 };
 MODULE_DEVICE_TABLE(of, ravb_match_table);
 
-static int ravb_set_gti(struct net_device *ndev)
-{
-	struct ravb_private *priv = netdev_priv(ndev);
-	const struct ravb_hw_info *info = priv->info;
-	struct device *dev = ndev->dev.parent;
-	unsigned long rate;
-	uint64_t inc;
-
-	if (info->gptp_ref_clk)
-		rate = clk_get_rate(priv->gptp_clk);
-	else
-		rate = clk_get_rate(priv->clk);
-	if (!rate)
-		return -EINVAL;
-
-	inc = div64_ul(1000000000ULL << 20, rate);
-
-	if (inc < GTI_TIV_MIN || inc > GTI_TIV_MAX) {
-		dev_err(dev, "gti.tiv increment 0x%llx is outside the range 0x%x - 0x%x\n",
-			inc, GTI_TIV_MIN, GTI_TIV_MAX);
-		return -EINVAL;
-	}
-
-	ravb_write(ndev, inc, GTI);
-
-	return 0;
-}
-
 static int ravb_set_config_mode(struct net_device *ndev)
 {
 	struct ravb_private *priv = netdev_priv(ndev);
@@ -2763,15 +2781,9 @@ static int ravb_probe(struct platform_device *pdev)
 	if (error)
 		goto out_rpm_put;
 
-	if (info->gptp || info->ccc_gac) {
-		/* Set GTI value */
-		error = ravb_set_gti(ndev);
-		if (error)
-			goto out_rpm_put;
-
-		/* Request GTI loading */
-		ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI);
-	}
+	error = ravb_compute_gti(ndev);
+	if (error)
+		goto out_rpm_put;
 
 	if (info->internal_delay) {
 		ravb_parse_delay_mode(np, ndev);
@@ -2984,15 +2996,7 @@ static int ravb_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	if (info->gptp || info->ccc_gac) {
-		/* Set GTI value */
-		ret = ravb_set_gti(ndev);
-		if (ret)
-			return ret;
-
-		/* Request GTI loading */
-		ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI);
-	}
+	ravb_set_gti(ndev);
 
 	if (info->internal_delay)
 		ravb_set_delay_mode(ndev);