[PATCH v1 05/15] pwrseq: implement onecell helper

[Dmitry Baryshkov]

Provide of_pwrseq_xlate_onecell() - a helper easing implementation of
power sequencers using one cell to determine pwrseq instance to return.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
 drivers/power/pwrseq/core.c   | 26 ++++++++++++++++++++++++++
 include/linux/pwrseq/driver.h | 12 ++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/drivers/power/pwrseq/core.c b/drivers/power/pwrseq/core.c
index 0aaba4e79a44..3dffa52f65ee 100644
--- a/drivers/power/pwrseq/core.c
+++ b/drivers/power/pwrseq/core.c
@@ -449,6 +449,32 @@ struct pwrseq_provider *__devm_of_pwrseq_provider_register(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(__devm_of_pwrseq_provider_register);
 
+/**
+ * of_pwrseq_xlate_single() - returns the pwrseq instance from pwrseq provider using single index
+ * @data: the pwrseq provider data, struct pwrseq_onecell_data
+ * @args: of_phandle_args containing single integer index
+ *
+ * Intended to be used by pwrseq provider for the common case where
+ * #pwrseq-cells is 1. It will return corresponding pwrseq instance.
+ */
+struct pwrseq *of_pwrseq_xlate_onecell(void *data, struct of_phandle_args *args)
+{
+	struct pwrseq_onecell_data *pwrseq_data = data;
+	unsigned int idx;
+
+	if (args->args_count != 1)
+		return ERR_PTR(-EINVAL);
+
+	idx = args->args[0];
+	if (idx >= pwrseq_data->num) {
+		pr_err("%s: invalid index %u\n", __func__, idx);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return pwrseq_data->pwrseqs[idx];
+}
+EXPORT_SYMBOL_GPL(of_pwrseq_xlate_onecell);
+
 static int __init pwrseq_core_init(void)
 {
 	return class_register(&pwrseq_class);
diff --git a/include/linux/pwrseq/driver.h b/include/linux/pwrseq/driver.h
index 0ca1d0311ab6..8d46940981bf 100644
--- a/include/linux/pwrseq/driver.h
+++ b/include/linux/pwrseq/driver.h
@@ -157,4 +157,16 @@ static inline struct pwrseq *of_pwrseq_xlate_single(void *data,
 	return data;
 }
 
+/**
+ * struct pwrseq_onecell_data - pwrseq data for of_pwrseq_xlate_onecell
+ * @num: amount of instances in @owrseqs
+ * @pwrseqs: array of pwrseq instances
+ */
+struct pwrseq_onecell_data {
+	unsigned int num;
+	struct pwrseq *pwrseqs[];
+};
+
+struct pwrseq *of_pwrseq_xlate_onecell(void *data, struct of_phandle_args *args);
+
 #endif /* __LINUX_PWRSEQ_DRIVER_H__ */
-- 
2.33.0