linux-kernel - [PATCH v2 6/7] amba: Allow pclk to be controlled by power domain

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Date:   Sun,  6 Jan 2019 00:09:14 -0800
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Russell King <linux@...linux.org.uk>,
        Ulf Hansson <ulf.hansson@...aro.org>
Cc:     Andy Gross <andy.gross@...aro.org>,
        David Brown <david.brown@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Arun Kumar Neelakantam <aneela@...eaurora.org>,
        linux-arm-msm@...r.kernel.org, linux-soc@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 6/7] amba: Allow pclk to be controlled by power domain

On the Qualcomm SDM845 platform the apb_pclk is controlled as part of
the QDSS power/clock domain. Handle this by allowing amba to operate
without direct apb_pclk control, when a powerdomain is attached and no
clock is described.

Signed-off-by: Bjorn Andersson <bjorn.andersson@...aro.org>
---

Changes since v1:
- New patch

 drivers/amba/bus.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 41b706403ef7..3e13050c6d59 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -219,8 +219,13 @@ static int amba_get_enable_pclk(struct amba_device *pcdev)
 	int ret;
 
 	pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
-	if (IS_ERR(pcdev->pclk))
-		return PTR_ERR(pcdev->pclk);
+	if (IS_ERR(pcdev->pclk)) {
+		/* Continue with no clock specified, but pm_domain attached */
+		if (PTR_ERR(pcdev->pclk) == -ENOENT && pcdev->dev.pm_domain)
+			pcdev->pclk = NULL;
+		else
+			return PTR_ERR(pcdev->pclk);
+	}
 
 	ret = clk_prepare_enable(pcdev->pclk);
 	if (ret)
-- 
2.18.0