[RFC v2 2/5] pinctrl: add generic functions + pins mapper

Conor Dooley
2025-11-27T10:58:12Z

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
drivers/pinctrl/Kconfig | 6 +
drivers/pinctrl/Makefile | 1 +
drivers/pinctrl/pinconf.h | 7 ++
drivers/pinctrl/pinctrl-generic.c | 186 ++++++++++++++++++++++++++++++
4 files changed, 200 insertions(+)
create mode 100644 drivers/pinctrl/pinctrl-generic.c

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 4ec2bb7f67cf..b43d4d7d25a8 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -25,6 +25,12 @@ config GENERIC_PINCONF
bool
select PINCONF

+config GENERIC_PINCTRL_BELLS_AND_WHISTLES
+ bool
+ depends on GENERIC_PINCONF
+ depends on GENERIC_PINCTRL_GROUPS
+ depends on GENERIC_PINMUX_FUNCTIONS
+
config DEBUG_PINCTRL
bool "Debug PINCTRL calls"
depends on DEBUG_KERNEL
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index ea4e890766e1..ea679ca84d85 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -7,6 +7,7 @@ obj-y += core.o pinctrl-utils.o
obj-$(CONFIG_PINMUX) += pinmux.o
obj-$(CONFIG_PINCONF) += pinconf.o
obj-$(CONFIG_GENERIC_PINCONF) += pinconf-generic.o
+obj-$(CONFIG_GENERIC_PINCTRL_BELLS_AND_WHISTLES) += pinctrl-generic.o
obj-$(CONFIG_OF) += devicetree.o

obj-$(CONFIG_PINCTRL_AMD) += pinctrl-amd.o
diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h
index e1ae71610526..127da9a1e30e 100644
--- a/drivers/pinctrl/pinconf.h
+++ b/drivers/pinctrl/pinconf.h
@@ -160,3 +160,10 @@ pinconf_generic_parse_dt_pinmux(struct device_node *np, struct device *dev,
return -ENOTSUPP;
}
#endif
+
+#if defined(CONFIG_GENERIC_PINCTRL_BELLS_AND_WHISTLES) && defined (CONFIG_OF)
+int pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
+ struct device_node *np,
+ struct pinctrl_map **maps,
+ unsigned int *num_maps);
+#endif
diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
new file mode 100644
index 000000000000..08f21e25e1eb
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-generic.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#define pr_fmt(fmt) "generic pinconfig core: " fmt
+
+#include <linux/array_size.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+
+#include "core.h"
+#include "pinconf.h"
+#include "pinctrl-utils.h"
+#include "pinmux.h"
+
+static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
+ struct device_node *parent,
+ struct device_node *np,
+ struct pinctrl_map **maps,
+ unsigned int *num_maps,
+ unsigned int *num_reserved_maps,
+ const char **group_names,
+ unsigned int ngroups)
+{
+ struct device *dev = pctldev->dev;
+ const char **functions;
+ const char *group_name;
+ unsigned long *configs;
+ unsigned int num_configs, pin, *pins;
+ int npins, ret, reserve = 1;
+
+ npins = of_property_count_u32_elems(np, "pins");
+
+ if (npins < 1) {
+ dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
+ parent, np, npins);
+ return npins;
+ }
+
+ group_name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn.%pOFn", parent, np);
+ if (!group_name)
+ return -ENOMEM;
+
+ group_names[ngroups] = group_name;
+
+ pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
+ if (!pins)
+ return -ENOMEM;
+
+ functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
+ if (!functions)
+ return -ENOMEM;
+
+ for (int i = 0; i < npins; i++) {
+ ret = of_property_read_u32_index(np, "pins", i, &pin);
+ if (ret)
+ return ret;
+
+ pins[i] = pin;
+
+ ret = of_property_read_string(np, "function", &functions[i]);
+ if (ret)
+ return ret;
+ }
+
+ ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
+ if (ret)
+ return ret;
+
+ ret = pinctrl_utils_add_map_mux(pctldev, maps, num_reserved_maps, num_maps, group_name, parent->name);
+ if (ret < 0)
+ return ret;
+
+ ret = pinctrl_generic_add_group(pctldev, group_name, pins, npins, functions);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "failed to add group %s: %d\n",
+ group_name, ret);
+
+ ret = pinconf_generic_parse_dt_config(np, pctldev, &configs, &num_configs);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to parse pin config of group %s\n",
+ group_name);
+
+ if (num_configs == 0)
+ return 0;
+
+ ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
+ if (ret)
+ return ret;
+
+ ret = pinctrl_utils_add_map_configs(pctldev, maps, num_reserved_maps, num_maps, group_name, configs,
+ num_configs, PIN_MAP_TYPE_CONFIGS_GROUP);
+ kfree(configs);
+ if (ret)
+ return ret;
+
+ return 0;
+};
+
+/*
+ * For platforms that do not define groups or functions in the driver, but
+ * instead use the devicetree to describe them. This function will, unlike
+ * pinconf_generic_dt_node_to_map() etc which rely on driver defined groups
+ * and functions, create them in addition to parsing pinconf properties and
+ * adding mappings.
+ */
+int pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
+ struct device_node *np,
+ struct pinctrl_map **maps,
+ unsigned int *num_maps)
+{
+ struct device *dev = pctldev->dev;
+ struct device_node *child_np;
+ const char **group_names;
+ unsigned int num_reserved_maps = 0;
+ int ngroups = 0;
+ int ret;
+
+ *maps = NULL;
+ *num_maps = 0;
+
+ /*
+ * Check if this is actually the pins node, or a parent containing
+ * multiple pins nodes.
+ */
+ if (!of_property_present(np, "pins"))
+ goto parent;
+
+ group_names = devm_kcalloc(dev, 1, sizeof(*group_names), GFP_KERNEL);
+ if (!group_names)
+ return -ENOMEM;
+
+ ret = pinctrl_generic_pins_function_dt_subnode_to_map(pctldev, np, np,
+ maps, num_maps,
+ &num_reserved_maps,
+ group_names,
+ ngroups);
+ if (ret) {
+ pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+ return dev_err_probe(dev, ret, "error figuring out mappings for %s\n", np->name);
+ }
+
+ ret = pinmux_generic_add_function(pctldev, np->name, group_names, 1, NULL);
+ if (ret < 0) {
+ pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+ return dev_err_probe(dev, ret, "error adding function %s\n", np->name);
+ }
+
+ return 0;
+
+parent:
+ for_each_available_child_of_node(np, child_np)
+ ngroups += 1;
+
+ group_names = devm_kcalloc(dev, ngroups, sizeof(*group_names), GFP_KERNEL);
+ if (!group_names)
+ return -ENOMEM;
+
+ ngroups = 0;
+ for_each_available_child_of_node_scoped(np, child_np) {
+ ret = pinctrl_generic_pins_function_dt_subnode_to_map(pctldev, np, child_np,
+ maps,num_maps,
+ &num_reserved_maps,
+ group_names,
+ ngroups);
+ if (ret) {
+ pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+ return dev_err_probe(dev, ret, "error figuring out mappings for %s\n", np->name);
+ }
+
+ ngroups++;
+ }
+
+ ret = pinmux_generic_add_function(pctldev, np->name, group_names, ngroups, NULL);
+ if (ret < 0) {
+ pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+ return dev_err_probe(dev, ret, "error adding function %s\n", np->name);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pinctrl_generic_pins_function_dt_node_to_map);
--
2.51.0