Messages in this thread | | | Date | Sat, 23 Sep 2023 11:35:41 -0700 | From | Zev Weiss <> | Subject | Re: [RESEND PATCH] regulator: userspace-consumer: Retrieve supplies from DT |
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On Sat, Sep 23, 2023 at 05:16:12AM PDT, Zev Weiss wrote: >On Sat, Sep 23, 2023 at 05:02:59AM PDT, Zev Weiss wrote: >>Hi Naresh, >> >>This looks basically alright to me, though a few suggested tweaks >>below... >> >>On Fri, Sep 22, 2023 at 02:03:29AM PDT, Naresh Solanki wrote: >>>From: Naresh Solanki <Naresh.Solanki@9elements.com> >>> >>>Instead of hardcoding a single supply, retrieve supplies from DT. >>> >>>Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com> >>>--- >>>drivers/regulator/userspace-consumer.c | 43 ++++++++++++++++++++++++-- >>>1 file changed, 40 insertions(+), 3 deletions(-) >>> >>>diff --git a/drivers/regulator/userspace-consumer.c b/drivers/regulator/userspace-consumer.c >>>index 97f075ed68c9..a3d3e1e6ca74 100644 >>>--- a/drivers/regulator/userspace-consumer.c >>>+++ b/drivers/regulator/userspace-consumer.c >>>@@ -115,11 +115,32 @@ static const struct attribute_group attr_group = { >>> .is_visible = attr_visible, >>>}; >>> >>>+#define SUPPLY_SUFFIX "-supply" >>>+#define SUPPLY_SUFFIX_LEN 7 >> >>I think 'strlen(SUPPLY_SUFFIX)' would be preferable to a numeric >>literal here; it's less fragile and the compiler can evaluate it at >>compile-time anyway (not that it's likely to be performance-critical >>in this context I'd expect). >> >>>+ >>>+static int get_num_supplies(struct platform_device *pdev) >>>+{ >>>+ struct property *prop; >>>+ int num_supplies = 0; >>>+ >>>+ for_each_property_of_node(pdev->dev.of_node, prop) { >>>+ const char *prop_name = prop->name; >>>+ int len = strlen(prop_name); >>>+ >>>+ if (len > SUPPLY_SUFFIX_LEN && >>>+ strcmp(prop_name + len - SUPPLY_SUFFIX_LEN, SUPPLY_SUFFIX) == 0) { >>>+ num_supplies++; >>>+ } >> >>Preferred coding style is to omit braces around single-line 'if' blocks. >> >>>+ } >>>+ return num_supplies; >>>+} >>>+ >>>static int regulator_userspace_consumer_probe(struct platform_device *pdev) >>>{ >>> struct regulator_userspace_consumer_data tmpdata; >>> struct regulator_userspace_consumer_data *pdata; >>> struct userspace_consumer_data *drvdata; >>>+ struct property *prop; >> >>Looks like there's an extra space after 'struct' here. >> >>> int ret; >>> >>> pdata = dev_get_platdata(&pdev->dev); >>>@@ -131,11 +152,27 @@ static int regulator_userspace_consumer_probe(struct platform_device *pdev) >>> memset(pdata, 0, sizeof(*pdata)); >>> >>> pdata->no_autoswitch = true; >>>- pdata->num_supplies = 1; >>>- pdata->supplies = devm_kzalloc(&pdev->dev, sizeof(*pdata->supplies), GFP_KERNEL); >>>+ pdata->num_supplies = get_num_supplies(pdev); >>>+ >>>+ pdata->supplies = devm_kzalloc(&pdev->dev, pdata->num_supplies * >>>+ sizeof(*pdata->supplies), GFP_KERNEL); >> >>Splitting the multiplication across two lines like that isn't great >>readability-wise IMO; it might be better to just assign it to a >>variable and use that instead to make things fit nicely. >> >>> if (!pdata->supplies) >>> return -ENOMEM; >>>- pdata->supplies[0].supply = "vout"; >>>+ >>>+ for_each_property_of_node(pdev->dev.of_node, prop) { >>>+ const char *prop_name = prop->name; >>>+ int len = strlen(prop_name); >>>+ >>>+ if (len > SUPPLY_SUFFIX_LEN && >>>+ strcmp(prop_name + len - SUPPLY_SUFFIX_LEN, SUPPLY_SUFFIX) == 0) { >> >>Rather than duplicating this suffix-checking code, how about >>factoring out a helper function like prop_is_supply() or something >>to use both here and in get_num_supplies()? >> >>Or actually to make it integrate here a little more nicely, you >>could have something like 'size_t prop_supply_name(char*)', >>returning zero > >Or rather prop_supply_name_len(), to make the name a bit more accurate. > >>if it doesn't end with "-supply", and the length of the name before >>the suffix if it does, so that get_num_supplies() could use it as a >>boolean and the code below could use the length to determine the >>allocation size. >> >>>+ char *supply_name = devm_kzalloc(&pdev->dev, >>>+ len - SUPPLY_SUFFIX_LEN + 1, >>>+ GFP_KERNEL); >>>+ strscpy(supply_name, prop_name, len - SUPPLY_SUFFIX_LEN); >>>+ supply_name[len - SUPPLY_SUFFIX_LEN] = '\0'; > >Also, kstrndup() would be a cleaner replacement for these lines, >though then the cleanup would get messy, and sadly a devm_kstrndup() >doesn't currently exist -- maybe it'd be worth adding separately? Or >alternately you could just use devm_kstrdup() and then truncate it by >inserting a '\0'. > >>>+ pdata->supplies[0].supply = supply_name; >>>+ } >>>+ } >>> } >>> >>> if (pdata->num_supplies < 1) { >>> >>>base-commit: 451e85e29c9d6f20639d4cfcff4b9dea280178cc >>>-- >>>2.41.0 >>>
Oh, and sorry for the barrage of self-replies here, but one more thing: I think we should also update the regulator-output DT binding to reflect the added flexibility that this provides.
Zev
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