Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:3 as permitted sender) client-ip=2620:137:e000::3:3;
From:   Claudiu <claudiu.beznea@tuxon.dev>
To:     s.shtylyov@omp.ru, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, p.zabel@pengutronix.de,
        yoshihiro.shimoda.uh@renesas.com, geert+renesas@glider.be,
        wsa+renesas@sang-engineering.com, biju.das.jz@bp.renesas.com,
        prabhakar.mahadev-lad.rj@bp.renesas.com,
        sergei.shtylyov@cogentembedded.com,
        mitsuhiro.kimura.kc@renesas.com, masaru.nagai.vx@renesas.com
Cc:     netdev@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Subject: [PATCH 08/13] net: ravb: Rely on PM domain to enable refclk
Date:   Mon, 20 Nov 2023 10:46:01 +0200
Message-Id: <20231120084606.4083194-9-claudiu.beznea.uj@bp.renesas.com>
In-Reply-To: <20231120084606.4083194-1-claudiu.beznea.uj@bp.renesas.com>
References: <20231120084606.4083194-1-claudiu.beznea.uj@bp.renesas.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

For RZ/G3S and RZ/G2L SoCs the Ethernet's reference clock is part of the
Ethernet's power domain. It is controlled though CPG driver that is
providing the support for power domain that Ethernet belongs. Thus,
to be able to implement runtime PM (at least for RZ/G3S at the moment)
w/o the need to add clock enable/disable specific calls in runtime PM
ops of ravb driver and interfere with other IP specific implementations,
add a new variable to struct_hw_info and enable the reference clock
based on the value of this variable (the variable states if reference
clock is part of the Ethernet's power domain).

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---
 drivers/net/ethernet/renesas/ravb.h      |  1 +
 drivers/net/ethernet/renesas/ravb_main.c | 19 ++++++++++++-------
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index e0f8276cffed..c2d8d890031f 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -1043,6 +1043,7 @@ struct ravb_hw_info {
 	unsigned nc_queues:1;		/* AVB-DMAC has RX and TX NC queues */
 	unsigned magic_pkt:1;		/* E-MAC supports magic packet detection */
 	unsigned half_duplex:1;		/* E-MAC supports half duplex mode */
+	unsigned refclk_in_pd:1;	/* Reference clock is part of a power domain. */
 };
 
 struct ravb_private {
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 836fdb4b3bfd..ddd8cd2c0f89 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2502,6 +2502,7 @@ static const struct ravb_hw_info gbeth_hw_info = {
 	.tx_counters = 1,
 	.carrier_counters = 1,
 	.half_duplex = 1,
+	.refclk_in_pd = 1,
 };
 
 static const struct of_device_id ravb_match_table[] = {
@@ -2749,12 +2750,14 @@ static int ravb_probe(struct platform_device *pdev)
 		goto out_release;
 	}
 
-	priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
-	if (IS_ERR(priv->refclk)) {
-		error = PTR_ERR(priv->refclk);
-		goto out_release;
+	if (!info->refclk_in_pd) {
+		priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
+		if (IS_ERR(priv->refclk)) {
+			error = PTR_ERR(priv->refclk);
+			goto out_release;
+		}
+		clk_prepare_enable(priv->refclk);
 	}
-	clk_prepare_enable(priv->refclk);
 
 	if (info->gptp_ref_clk) {
 		priv->gptp_clk = devm_clk_get(&pdev->dev, "gptp");
@@ -2869,7 +2872,8 @@ static int ravb_probe(struct platform_device *pdev)
 	if (info->ccc_gac)
 		ravb_ptp_stop(ndev);
 out_disable_refclk:
-	clk_disable_unprepare(priv->refclk);
+	if (!info->refclk_in_pd)
+		clk_disable_unprepare(priv->refclk);
 out_release:
 	free_netdev(ndev);
 pm_runtime_put:
@@ -2890,7 +2894,8 @@ static void ravb_remove(struct platform_device *pdev)
 	if (info->ccc_gac)
 		ravb_ptp_stop(ndev);
 
-	clk_disable_unprepare(priv->refclk);
+	if (!info->refclk_in_pd)
+		clk_disable_unprepare(priv->refclk);
 
 	/* Set reset mode */
 	ravb_write(ndev, CCC_OPC_RESET, CCC);
-- 
2.39.2