Re: [PATCH v2 2/3] can: m_can: m_can_platform: Add support for enabling transceiver

Hi Dan,

On 17/02/20 8:40 pm, Dan Murphy wrote:

Faiz

On 2/17/20 8:28 AM, Faiz Abbas wrote:

quoted

CAN transceivers on some boards have a standby line which can be
toggled to enable/disable the transceiver. Model this as an optional
fixed xceiver regulator.

Signed-off-by: Faiz Abbas <redacted>
Acked-by: Sriram Dash <redacted>
---
  drivers/net/can/m_can/m_can_platform.c | 6 ++++++
  1 file changed, 6 insertions(+)

diff --git a/drivers/net/can/m_can/m_can_platform.c

b/drivers/net/can/m_can/m_can_platform.c
index 38ea5e600fb8..719468fab507 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/regulator/consumer.h>
    #include "m_can.h"
  @@ -57,6 +58,7 @@ static int m_can_plat_probe(struct platform_device
*pdev)
  {
      struct m_can_classdev *mcan_class;
      struct m_can_plat_priv *priv;
+    struct regulator *reg_xceiver;
      struct resource *res;
      void __iomem *addr;
      void __iomem *mram_addr;

@@ -111,6 +113,10 @@ static int m_can_plat_probe(struct

platform_device *pdev)
        m_can_init_ram(mcan_class);
  +    reg_xceiver = devm_regulator_get_optional(&pdev->dev, "xceiver");
+    if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
+        return -EPROBE_DEFER;
+

Where is this regulator enabled?

I have set regulator-boot-on flag in the dt so this didn't require an
enable.

Shouldn't the regulator be managed by runtime PM as well?

Let me try this out.

Thanks,
Faiz