Re: [PATCH v4 01/21] drivers: reset: Add devm_to_reset() to return dummy "struct reset_ctl"

Hi Kishon,

On Mon, 12 Jul 2021 at 00:20, Kishon Vijay Abraham I kishon@ti.com wrote:

Add devm_to_reset() to return dummy "struct reset_ctl", useful for invoking reset APIs which doesn't have a valid "struct reset_ctl".

Suggested-by: Simon Glass sjg@chromium.org Signed-off-by: Kishon Vijay Abraham I kishon@ti.com

---

drivers/reset/reset-uclass.c | 16 ++++++++++++++++ drivers/reset/sandbox-reset-test.c | 4 +++- include/reset.h | 17 +++++++++++++++++ 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/reset/reset-uclass.c b/drivers/reset/reset-uclass.c index 8caa616ed9..9f2eeb4fe4 100644 --- a/drivers/reset/reset-uclass.c +++ b/drivers/reset/reset-uclass.c @@ -15,6 +15,8 @@ #include <dm/devres.h> #include <dm/lists.h>

+static struct reset_ctl devm_no_reset;

static inline struct reset_ops *reset_dev_ops(struct udevice *dev) { return (struct reset_ops *)dev->driver->ops; @@ -256,6 +258,20 @@ int reset_release_all(struct reset_ctl *reset_ctl, int count) return 0; }

+int devm_to_reset(struct reset_ctl *in, struct reset_ctl **outp) +{

•   if (IS_ERR_OR_NULL(in)) {
  

•           *outp = &devm_no_reset;
  

This var ends up in BSS so won't work in early SPL / pre-relocation in U-Boot. Please add a priv_auto struct in the UCLASS_DRIVER() and put this value in there.

•           if (!in)
  

•                   return -ENOENT;
  

•           else
  

•                   return PTR_ERR(in);
  

•   }
  

•   *outp = in;
  

•   return 0;
  

+}

static void devm_reset_release(struct udevice *dev, void *res) { reset_free(res); diff --git a/drivers/reset/sandbox-reset-test.c b/drivers/reset/sandbox-reset-test.c index 51b79810c8..4389bde5e7 100644 --- a/drivers/reset/sandbox-reset-test.c +++ b/drivers/reset/sandbox-reset-test.c @@ -32,13 +32,15 @@ int sandbox_reset_test_get_devm(struct udevice *dev)

Can this function move into the test itself? It seems strange for it to be here.

{ struct sandbox_reset_test *sbrt = dev_get_priv(dev); struct reset_ctl *r;

•   int ret;
  
    r = devm_reset_control_get(dev, "not-a-valid-reset-ctl");
    if (!IS_ERR(r))
            return -EINVAL;
  
    r = devm_reset_control_get_optional(dev, "not-a-valid-reset-ctl");
  

•   if (r)
  

•   ret = devm_to_reset(r, &r);
  

•   if (reset_valid(r))
            return -EINVAL;
  

Can you not do:

if (ret) return ret;

?

    sbrt->ctlp = devm_reset_control_get(dev, "test");

diff --git a/include/reset.h b/include/reset.h index cde2c4b4a8..21affc1455 100644 --- a/include/reset.h +++ b/include/reset.h @@ -341,6 +341,18 @@ int reset_status(struct reset_ctl *reset_ctl); */ int reset_release_all(struct reset_ctl *reset_ctl, int count);

+/**

• • devm_to_reset - Provide a dummy reset_ctl for invalid reset_ctl

Returns the reset_ctl to use for a devm reset?

• • Provide a dummy reset_ctl for invalid reset_ctl or give the same
• • input reset_ctl
• • @in: Input reset_ctl returned by devm_reset_control_get()
• • @outp: Dummy reset_ctl for invalid reset_ctl or Input reset_ctl

Put the positive case first.

Returns @in if valid. If not valid, returns a dummy reset_ctl for which reset_valid() will always return false.

• • @return 0 if OK, or a negative error code.

Please document what specific errors this returns as this is important.

• */

+int devm_to_reset(struct reset_ctl *in, struct reset_ctl **outp);

/**

• reset_release_bulk - Assert/Free an array of previously requested reset
• signals in a reset control bulk struct.

@@ -456,6 +468,11 @@ static inline int reset_release_bulk(struct reset_ctl_bulk *bulk) { return 0; }

+static inline int devm_to_reset(struct reset_ctl *in, struct reset_ctl **outp) +{

•   return 0;
  

That indicates success but *outp is not set. Is that OK? Should you return -ENOSYS, or maybe set *outp to something?

+} #endif

/**

2.17.1

Regards, Simon