Thread (18 messages) 18 messages, 3 authors, 2021-04-14

Re: [PATCH 4/4] can: m_can_platform: Add support for transceiver as phy

From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2021-04-12 10:22:58
Also in: linux-can, linux-devicetree, linux-phy, lkml

On 4/9/21 3:40 PM, Aswath Govindraju wrote:
quoted hunk ↗ jump to hunk
From: Faiz Abbas <redacted>

Add support for implementing transceiver node as phy. The max_bitrate is
obtained by getting a phy attribute.

Signed-off-by: Faiz Abbas <redacted>
Signed-off-by: Aswath Govindraju <redacted>
---
 drivers/net/can/m_can/m_can_platform.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
index 599de0e08cd7..4a762b5a21d8 100644
--- a/drivers/net/can/m_can/m_can_platform.c
+++ b/drivers/net/can/m_can/m_can_platform.c
@@ -6,6 +6,7 @@
 // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
 
 #include <linux/platform_device.h>
+#include <linux/phy/phy.h>
 
 #include "m_can.h"
 
@@ -67,7 +68,9 @@ static int m_can_plat_probe(struct platform_device *pdev)
 	struct resource *res;
 	void __iomem *addr;
 	void __iomem *mram_addr;
+	struct phy *transceiver;
 	int irq, ret = 0;
+	u32 bitrate_max;
 
 	mcan_class = m_can_class_allocate_dev(&pdev->dev,
 					      sizeof(struct m_can_plat_priv));
@@ -101,6 +104,28 @@ static int m_can_plat_probe(struct platform_device *pdev)
 		goto probe_fail;
 	}
 
+	transceiver = devm_phy_optional_get(&pdev->dev, "can_transceiver");
+	if (IS_ERR(transceiver)) {
+		ret = PTR_ERR(transceiver);
+		dev_err(&pdev->dev, "error while getting phy, err=%d\n", ret);
+		return ret;
+	}
+
+	if (!transceiver) {
+		dev_warn(&pdev->dev, "No transceiver phy found\n");
I think that's a bit to loud.
+	} else {
+		ret = phy_power_on(transceiver);
Please move the phy power on/off to the ndo_open and ndo_stop callbacks. There's
no need to power the transceivers if the CAN interface is down.
+		if (ret) {
+			dev_err(&pdev->dev, "error powering on phy, err=%d\n", ret);
+			return ret;
+		}
+		/* converting from Mbps to bps */
+		bitrate_max = (transceiver->attrs.max_link_rate) * 1000000;
+		if (!bitrate_max)
+			dev_warn(&pdev->dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n");
Please move this check to the generic transcevier code.
+		priv->cdev.can.bitrate_max = bitrate_max;
+	}
+
 	priv->base = addr;
 	priv->mram_base = mram_addr;
 
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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