From: Frank Li Date: Mon, 4 May 2026 23:54:39 +0000 (-0400) Subject: pinctrl: add generic board-level pinctrl driver using mux framework X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=34acc5a8adfb76f2de63c8b8317397fb72b0aec8;p=thirdparty%2Fkernel%2Flinux.git pinctrl: add generic board-level pinctrl driver using mux framework Many boards use on-board mux chips (often controlled by GPIOs from an I2C expander) to switch shared signals between peripherals. Add a generic pinctrl driver built on top of the mux framework to centralize mux handling and avoid probe ordering issues. Keep board-level routing out of individual drivers and supports boot-time only mux selection. Ensure correct probe ordering, especially when the GPIO expander is probed later. Signed-off-by: Frank Li Signed-off-by: Linus Walleij --- diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig index 03f2e3ee065f4..31d698fbaa01d 100644 --- a/drivers/pinctrl/Kconfig +++ b/drivers/pinctrl/Kconfig @@ -272,6 +272,15 @@ config PINCTRL_GEMINI select GENERIC_PINCONF select MFD_SYSCON +config PINCTRL_GENERIC_MUX + tristate "Generic Pinctrl driver by using multiplexer" + depends on MULTIPLEXER + select PINMUX + select GENERIC_PINCTRL + help + Generic pinctrl driver by MULTIPLEXER framework to control on + board pin selection. + config PINCTRL_INGENIC bool "Pinctrl driver for the Ingenic JZ47xx SoCs" default MACH_INGENIC diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile index f7d5d5f76d0c8..fcd1703440d24 100644 --- a/drivers/pinctrl/Makefile +++ b/drivers/pinctrl/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_PINCTRL_EQUILIBRIUM) += pinctrl-equilibrium.o obj-$(CONFIG_PINCTRL_EP93XX) += pinctrl-ep93xx.o obj-$(CONFIG_PINCTRL_EYEQ5) += pinctrl-eyeq5.o obj-$(CONFIG_PINCTRL_GEMINI) += pinctrl-gemini.o +obj-$(CONFIG_PINCTRL_GENERIC_MUX) += pinctrl-generic-mux.o obj-$(CONFIG_PINCTRL_INGENIC) += pinctrl-ingenic.o obj-$(CONFIG_PINCTRL_K210) += pinctrl-k210.o obj-$(CONFIG_PINCTRL_K230) += pinctrl-k230.o diff --git a/drivers/pinctrl/pinctrl-generic-mux.c b/drivers/pinctrl/pinctrl-generic-mux.c new file mode 100644 index 0000000000000..da5a5ec015833 --- /dev/null +++ b/drivers/pinctrl/pinctrl-generic-mux.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Generic Pin Control Driver for Board-Level Mux Chips + * Copyright 2026 NXP + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "core.h" +#include "pinconf.h" +#include "pinmux.h" +#include "pinctrl-utils.h" + +struct mux_pin_function { + struct mux_state *mux_state; +}; + +struct mux_pinctrl { + struct device *dev; + struct pinctrl_dev *pctl; + + /* mutex protect [pinctrl|pinmux]_generic functions */ + struct mutex lock; +}; + +static int +mux_pinmux_dt_node_to_map(struct pinctrl_dev *pctldev, + struct device_node *np_config, + struct pinctrl_map **maps, unsigned int *num_maps) +{ + unsigned int num_reserved_maps = 0; + struct mux_pin_function *function; + const char **group_names; + int ret; + + function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL); + if (!function) + return -ENOMEM; + + group_names = devm_kcalloc(pctldev->dev, 1, sizeof(*group_names), GFP_KERNEL); + if (!group_names) + return -ENOMEM; + + function->mux_state = devm_mux_state_get_from_np(pctldev->dev, NULL, np_config); + if (IS_ERR(function->mux_state)) + return PTR_ERR(function->mux_state); + + ret = pinctrl_generic_to_map(pctldev, np_config, np_config, maps, + num_maps, &num_reserved_maps, group_names, + 0, &np_config->name, NULL, 0); + + if (ret) + return ret; + + ret = pinmux_generic_add_function(pctldev, np_config->name, group_names, + 1, function); + if (ret < 0) { + pinctrl_utils_free_map(pctldev, *maps, *num_maps); + return ret; + } + + return 0; +} + +static const struct pinctrl_ops mux_pinctrl_ops = { + .get_groups_count = pinctrl_generic_get_group_count, + .get_group_name = pinctrl_generic_get_group_name, + .get_group_pins = pinctrl_generic_get_group_pins, + .dt_node_to_map = mux_pinmux_dt_node_to_map, + .dt_free_map = pinctrl_utils_free_map, +}; + +static int mux_pinmux_set_mux(struct pinctrl_dev *pctldev, + unsigned int func_selector, + unsigned int group_selector) +{ + struct mux_pinctrl *mpctl = pinctrl_dev_get_drvdata(pctldev); + const struct function_desc *function; + struct mux_pin_function *func; + int ret; + + guard(mutex)(&mpctl->lock); + + function = pinmux_generic_get_function(pctldev, func_selector); + func = function->data; + + ret = mux_state_select(func->mux_state); + if (ret) + return ret; + + return 0; +} + +static void mux_pinmux_release_mux(struct pinctrl_dev *pctldev, + unsigned int func_selector, + unsigned int group_selector) +{ + struct mux_pinctrl *mpctl = pinctrl_dev_get_drvdata(pctldev); + const struct function_desc *function; + struct mux_pin_function *func; + + guard(mutex)(&mpctl->lock); + + function = pinmux_generic_get_function(pctldev, func_selector); + func = function->data; + + mux_state_deselect(func->mux_state); +} + +static const struct pinmux_ops mux_pinmux_ops = { + .get_functions_count = pinmux_generic_get_function_count, + .get_function_name = pinmux_generic_get_function_name, + .get_function_groups = pinmux_generic_get_function_groups, + .set_mux = mux_pinmux_set_mux, + .release_mux = mux_pinmux_release_mux, +}; + +static int mux_pinctrl_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mux_pinctrl *mpctl; + struct pinctrl_desc *pctl_desc; + int ret; + + mpctl = devm_kzalloc(dev, sizeof(*mpctl), GFP_KERNEL); + if (!mpctl) + return -ENOMEM; + + mpctl->dev = dev; + + platform_set_drvdata(pdev, mpctl); + + pctl_desc = devm_kzalloc(dev, sizeof(*pctl_desc), GFP_KERNEL); + if (!pctl_desc) + return -ENOMEM; + + ret = devm_mutex_init(dev, &mpctl->lock); + if (ret) + return ret; + + pctl_desc->name = dev_name(dev); + pctl_desc->owner = THIS_MODULE; + pctl_desc->pctlops = &mux_pinctrl_ops; + pctl_desc->pmxops = &mux_pinmux_ops; + + ret = devm_pinctrl_register_and_init(dev, pctl_desc, mpctl, + &mpctl->pctl); + if (ret) + return dev_err_probe(dev, ret, "Failed to register pinctrl.\n"); + + ret = pinctrl_enable(mpctl->pctl); + if (ret) + return dev_err_probe(dev, ret, "Failed to enable pinctrl.\n"); + + return 0; +} + +static const struct of_device_id mux_pinctrl_of_match[] = { + { .compatible = "pinctrl-multiplexer" }, + { } +}; +MODULE_DEVICE_TABLE(of, mux_pinctrl_of_match); + +static struct platform_driver mux_pinctrl_driver = { + .driver = { + .name = "generic-pinctrl-mux", + .of_match_table = mux_pinctrl_of_match, + }, + .probe = mux_pinctrl_probe, +}; +module_platform_driver(mux_pinctrl_driver); + +MODULE_AUTHOR("Frank Li "); +MODULE_DESCRIPTION("Generic Pin Control Driver for Board-Level Mux Chips"); +MODULE_LICENSE("GPL");