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

On 2/21/20 8:54 AM, Faiz Abbas wrote:

Hi Dan,

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

quoted

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.

Please don't do this, please handle it properly.

quoted

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

If so, then make the runtime pm kconfig option mandatory.

Marc

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