regulator: core: Parse coupled regulators properties
On Odroid XU3/4 and other Exynos5422 based boards there is a case, that
different devices on the board are supplied by different regulators
with non-fixed voltages. If one of these devices temporarily requires
higher voltage, there might occur a situation that the spread between
devices' voltages is so high, that there is a risk of changing
'high' and 'low' states on the interconnection between devices powered
by those regulators.
Add new structure "coupling_desc" to regulator_dev, which contains
pointers to all coupled regulators including the owner of the structure,
number of coupled regulators and counter of currently resolved
regulators.
Add of_functions to parse all data needed in regulator coupling.
Provide method to check DTS data consistency. Check if each coupled
regulator's max_spread is equal and if their lists of regulators match.
Signed-off-by: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index d61fed2..638f17d 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -166,6 +166,10 @@
if (!of_property_read_u32(np, "regulator-system-load", &pval))
constraints->system_load = pval;
+ if (!of_property_read_u32(np, "regulator-coupled-max-spread",
+ &pval))
+ constraints->max_spread = pval;
+
constraints->over_current_protection = of_property_read_bool(np,
"regulator-over-current-protection");
@@ -435,3 +439,150 @@
return dev ? dev_to_rdev(dev) : NULL;
}
+
+/*
+ * Returns number of regulators coupled with rdev.
+ */
+int of_get_n_coupled(struct regulator_dev *rdev)
+{
+ struct device_node *node = rdev->dev.of_node;
+ int n_phandles;
+
+ n_phandles = of_count_phandle_with_args(node,
+ "regulator-coupled-with",
+ NULL);
+
+ return (n_phandles > 0) ? n_phandles : 0;
+}
+
+/* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
+static bool of_coupling_find_node(struct device_node *src,
+ struct device_node *to_find)
+{
+ int n_phandles, i;
+ bool found = false;
+
+ n_phandles = of_count_phandle_with_args(src,
+ "regulator-coupled-with",
+ NULL);
+
+ for (i = 0; i < n_phandles; i++) {
+ struct device_node *tmp = of_parse_phandle(src,
+ "regulator-coupled-with", i);
+
+ if (!tmp)
+ break;
+
+ /* found */
+ if (tmp == to_find)
+ found = true;
+
+ of_node_put(tmp);
+
+ if (found)
+ break;
+ }
+
+ return found;
+}
+
+/**
+ * of_check_coupling_data - Parse rdev's coupling properties and check data
+ * consistency
+ * @rdev - pointer to regulator_dev whose data is checked
+ *
+ * Function checks if all the following conditions are met:
+ * - rdev's max_spread is greater than 0
+ * - all coupled regulators have the same max_spread
+ * - all coupled regulators have the same number of regulator_dev phandles
+ * - all regulators are linked to each other
+ *
+ * Returns true if all conditions are met.
+ */
+bool of_check_coupling_data(struct regulator_dev *rdev)
+{
+ int max_spread = rdev->constraints->max_spread;
+ struct device_node *node = rdev->dev.of_node;
+ int n_phandles = of_get_n_coupled(rdev);
+ struct device_node *c_node;
+ int i;
+ bool ret = true;
+
+ if (max_spread <= 0) {
+ dev_err(&rdev->dev, "max_spread value invalid\n");
+ return false;
+ }
+
+ /* iterate over rdev's phandles */
+ for (i = 0; i < n_phandles; i++) {
+ int c_max_spread, c_n_phandles;
+
+ c_node = of_parse_phandle(node,
+ "regulator-coupled-with", i);
+
+ if (!c_node)
+ ret = false;
+
+ c_n_phandles = of_count_phandle_with_args(c_node,
+ "regulator-coupled-with",
+ NULL);
+
+ if (c_n_phandles != n_phandles) {
+ dev_err(&rdev->dev, "number of couped reg phandles mismatch\n");
+ ret = false;
+ goto clean;
+ }
+
+ if (of_property_read_u32(c_node, "regulator-coupled-max-spread",
+ &c_max_spread)) {
+ ret = false;
+ goto clean;
+ }
+
+ if (c_max_spread != max_spread) {
+ dev_err(&rdev->dev,
+ "coupled regulators max_spread mismatch\n");
+ ret = false;
+ goto clean;
+ }
+
+ if (!of_coupling_find_node(c_node, node)) {
+ dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
+ ret = false;
+ }
+
+clean:
+ of_node_put(c_node);
+ if (!ret)
+ break;
+ }
+
+ return ret;
+}
+
+/**
+ * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
+ * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
+ * "regulator-coupled-with" property
+ * @index: Index in phandles array
+ *
+ * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
+ * registered, returns NULL
+ */
+struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
+ int index)
+{
+ struct device_node *node = rdev->dev.of_node;
+ struct device_node *c_node;
+ struct regulator_dev *c_rdev;
+
+ c_node = of_parse_phandle(node, "regulator-coupled-with", index);
+ if (!c_node)
+ return NULL;
+
+ c_rdev = of_find_regulator_by_node(c_node);
+
+ of_node_put(c_node);
+
+ return c_rdev;
+}