Re: [PATCH v4 3/4] pinctrl: Implementation of the generic scmi-pinctrl driver

From: Cristian Marussi
Date: Wed Aug 16 2023 - 08:26:55 EST


On Tue, Aug 08, 2023 at 06:25:35PM +0000, Oleksii Moisieiev wrote:
> scmi-pinctrl driver implements pinctrl driver interface and using
> SCMI protocol to redirect messages from pinctrl subsystem SDK to
> SCMI platform firmware, which does the changes in HW.
>
> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> ---
> Changes v3 -> v4
> - ordered config option alphabetically
> - ordered object file alphabetically
> - rephrased PINCTRL_SCMI config description
> - formatting fixes, removed blank lines after get_drvdata call
> - code style adjustments
> - add set_drvdata call
> - removed goto label
> - refactoring of the devm resource management
> - removed pctldev != NULL check
> - fix parameter name in pinconf-group-get
> - probe function refactoring
> - removed unneeded pmx checks
> ---
> MAINTAINERS | 1 +
> drivers/pinctrl/Kconfig | 11 +
> drivers/pinctrl/Makefile | 1 +
> drivers/pinctrl/pinctrl-scmi.c | 442 +++++++++++++++++++++++++++++++++
> 4 files changed, 455 insertions(+)
> create mode 100644 drivers/pinctrl/pinctrl-scmi.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 2d81d00e5f4f..c4e36f955e53 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -20527,6 +20527,7 @@ M: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> L: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> S: Maintained
> F: drivers/firmware/arm_scmi/pinctrl.c
> +F: drivers/pinctrl/pinctrl-scmi.c
>
> SYSTEM RESET/SHUTDOWN DRIVERS
> M: Sebastian Reichel <sre@xxxxxxxxxx>
> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> index 5787c579dcf6..956cfe76fbc6 100644
> --- a/drivers/pinctrl/Kconfig
> +++ b/drivers/pinctrl/Kconfig
> @@ -428,6 +428,17 @@ config PINCTRL_ROCKCHIP
> help
> This support pinctrl and GPIO driver for Rockchip SoCs.
>
> +config PINCTRL_SCMI
> + tristate "Pinctrl driver using SCMI protocol interface"
> + depends on ARM_SCMI_PROTOCOL || COMPILE_TEST
> + select PINMUX
> + select GENERIC_PINCONF
> + help
> + This driver provides support for pinctrl which is controlled
> + by firmware that implements the SCMI interface.
> + It uses SCMI Message Protocol to interact with the
> + firmware providing all the pinctrl controls.
> +
> config PINCTRL_SINGLE
> tristate "One-register-per-pin type device tree based pinctrl driver"
> depends on OF
> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
> index e196c6e324ad..25d67bac9ee0 100644
> --- a/drivers/pinctrl/Makefile
> +++ b/drivers/pinctrl/Makefile
> @@ -44,6 +44,7 @@ obj-$(CONFIG_PINCTRL_PIC32) += pinctrl-pic32.o
> obj-$(CONFIG_PINCTRL_PISTACHIO) += pinctrl-pistachio.o
> obj-$(CONFIG_PINCTRL_RK805) += pinctrl-rk805.o
> obj-$(CONFIG_PINCTRL_ROCKCHIP) += pinctrl-rockchip.o
> +obj-$(CONFIG_PINCTRL_SCMI) += pinctrl-scmi.o
> obj-$(CONFIG_PINCTRL_SINGLE) += pinctrl-single.o
> obj-$(CONFIG_PINCTRL_ST) += pinctrl-st.o
> obj-$(CONFIG_PINCTRL_STMFX) += pinctrl-stmfx.o
> diff --git a/drivers/pinctrl/pinctrl-scmi.c b/drivers/pinctrl/pinctrl-scmi.c
> new file mode 100644
> index 000000000000..a9304402ddf1
> --- /dev/null
> +++ b/drivers/pinctrl/pinctrl-scmi.c
> @@ -0,0 +1,442 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * System Control and Power Interface (SCMI) Protocol based pinctrl driver
> + *
> + * Copyright (C) 2023 EPAM
> + */
> +
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/seq_file.h>
> +#include <linux/scmi_protocol.h>
> +#include <linux/slab.h>
> +
> +#include <linux/pinctrl/machine.h>
> +#include <linux/pinctrl/pinconf.h>
> +#include <linux/pinctrl/pinconf-generic.h>
> +#include <linux/pinctrl/pinctrl.h>
> +#include <linux/pinctrl/pinmux.h>
> +
> +#include "pinctrl-utils.h"
> +#include "core.h"
> +#include "pinconf.h"
> +
> +#define DRV_NAME "scmi-pinctrl"
> +
> +static const struct scmi_pinctrl_proto_ops *pinctrl_ops;
> +
> +struct scmi_pinctrl_funcs {
> + unsigned int num_groups;
> + const char **groups;
> +};
> +
> +struct scmi_pinctrl {
> + struct device *dev;
> + struct scmi_protocol_handle *ph;
> + struct pinctrl_dev *pctldev;
> + struct pinctrl_desc pctl_desc;
> + struct scmi_pinctrl_funcs *functions;
> + unsigned int nr_functions;
> + char **groups;
> + unsigned int nr_groups;
> + struct pinctrl_pin_desc *pins;
> + unsigned int nr_pins;
> +};
> +
> +static int pinctrl_scmi_get_groups_count(struct pinctrl_dev *pctldev)
> +{
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> +
> + return pinctrl_ops->count_get(pmx->ph, GROUP_TYPE);
> +}
> +
> +static const char *pinctrl_scmi_get_group_name(struct pinctrl_dev *pctldev, unsigned int selector)
> +{
> + int ret;
> + const char *name;
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> +
> + ret = pinctrl_ops->name_get(pmx->ph, selector, GROUP_TYPE, &name);
> + if (ret) {
> + dev_err(pmx->dev, "get name failed with err %d", ret);
> + return NULL;
> + }
> +
> + return name;
> +}
> +
> +static int pinctrl_scmi_get_group_pins(struct pinctrl_dev *pctldev,
> + unsigned int selector,
> + const unsigned int **pins,
> + unsigned int *num_pins)
> +{
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> +
> + return pinctrl_ops->group_pins_get(pmx->ph, selector, pins, num_pins);
> +}
> +
> +#ifdef CONFIG_OF
> +static int pinctrl_scmi_dt_node_to_map(struct pinctrl_dev *pctldev,
> + struct device_node *np_config,
> + struct pinctrl_map **map,
> + u32 *num_maps)
> +{
> + return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
> + PIN_MAP_TYPE_INVALID);
> +}
> +
> +static void pinctrl_scmi_dt_free_map(struct pinctrl_dev *pctldev, struct pinctrl_map *map,
> + u32 num_maps)
> +{
> + kfree(map);
> +}
> +
> +#endif /* CONFIG_OF */
> +
> +static const struct pinctrl_ops pinctrl_scmi_pinctrl_ops = {
> + .get_groups_count = pinctrl_scmi_get_groups_count,
> + .get_group_name = pinctrl_scmi_get_group_name,
> + .get_group_pins = pinctrl_scmi_get_group_pins,
> +#ifdef CONFIG_OF
> + .dt_node_to_map = pinctrl_scmi_dt_node_to_map,
> + .dt_free_map = pinctrl_scmi_dt_free_map,
> +#endif
> +};
> +
> +static int pinctrl_scmi_get_functions_count(struct pinctrl_dev *pctldev)
> +{
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> +
> + return pinctrl_ops->count_get(pmx->ph, FUNCTION_TYPE);
> +}
> +
> +static const char *pinctrl_scmi_get_function_name(struct pinctrl_dev *pctldev,
> + unsigned int selector)
> +{
> + int ret;
> + const char *name;
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> +
> + ret = pinctrl_ops->name_get(pmx->ph, selector, FUNCTION_TYPE, &name);
> + if (ret) {
> + dev_err(pmx->dev, "get name failed with err %d", ret);
> + return NULL;
> + }
> +
> + return name;
> +}
> +
> +static int pinctrl_scmi_get_function_groups(struct pinctrl_dev *pctldev,
> + unsigned int selector,
> + const char * const **groups,
> + unsigned int * const num_groups)
> +{
> + const unsigned int *group_ids;
> + int ret, i;
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> +
> + if (!groups || !num_groups)
> + return -EINVAL;
> +
> + if (selector < pmx->nr_functions &&
> + pmx->functions[selector].num_groups) {
> + *groups = (const char * const *)pmx->functions[selector].groups;
> + *num_groups = pmx->functions[selector].num_groups;
> + return 0;
> + }
> +
> + ret = pinctrl_ops->function_groups_get(pmx->ph, selector,
> + &pmx->functions[selector].num_groups,
> + &group_ids);
> + if (ret) {
> + dev_err(pmx->dev, "Unable to get function groups, err %d", ret);
> + return ret;
> + }
> +
> + *num_groups = pmx->functions[selector].num_groups;
> + if (!*num_groups)
> + return -EINVAL;
> +
> + pmx->functions[selector].groups =
> + devm_kcalloc(pmx->dev, *num_groups, sizeof(*pmx->functions[selector].groups),
> + GFP_KERNEL);
> + if (!pmx->functions[selector].groups)
> + return -ENOMEM;
> +
> + for (i = 0; i < *num_groups; i++) {
> + pmx->functions[selector].groups[i] =
> + pinctrl_scmi_get_group_name(pmx->pctldev,
> + group_ids[i]);
> + if (!pmx->functions[selector].groups[i]) {
> + ret = -ENOMEM;
> + goto err_free;
> + }
> + }
> +
> + *groups = (const char * const *)pmx->functions[selector].groups;
> +
> + return 0;
> +
> +err_free:
> + devm_kfree(pmx->dev, pmx->functions[selector].groups);
> +
> + return ret;
> +}
> +
> +static int pinctrl_scmi_func_set_mux(struct pinctrl_dev *pctldev, unsigned int selector,
> + unsigned int group)
> +{
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> +
> + return pinctrl_ops->mux_set(pmx->ph, selector, group);
> +}
> +
> +static int pinctrl_scmi_request(struct pinctrl_dev *pctldev, unsigned int offset)
> +{
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> +
> + return pinctrl_ops->pin_request(pmx->ph, offset);
> +}
> +
> +static int pinctrl_scmi_free(struct pinctrl_dev *pctldev, unsigned int offset)
> +{
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> +
> + return pinctrl_ops->pin_free(pmx->ph, offset);
> +}
> +
> +static const struct pinmux_ops pinctrl_scmi_pinmux_ops = {
> + .request = pinctrl_scmi_request,
> + .free = pinctrl_scmi_free,
> + .get_functions_count = pinctrl_scmi_get_functions_count,
> + .get_function_name = pinctrl_scmi_get_function_name,
> + .get_function_groups = pinctrl_scmi_get_function_groups,
> + .set_mux = pinctrl_scmi_func_set_mux,
> +};
> +
> +static int pinctrl_scmi_pinconf_get(struct pinctrl_dev *pctldev, unsigned int _pin,
> + unsigned long *config)
> +{
> + int ret;
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> + enum pin_config_param config_type;
> + unsigned long config_value;
> +
> + if (!config)
> + return -EINVAL;
> +
> + config_type = pinconf_to_config_param(*config);
> +
> + ret = pinctrl_ops->config_get(pmx->ph, _pin, PIN_TYPE, config_type, &config_value);
> + if (ret)
> + return ret;
> +
> + *config = pinconf_to_config_packed(config_type, config_value);
> +
> + return 0;
> +}
> +
> +static int pinctrl_scmi_pinconf_set(struct pinctrl_dev *pctldev,
> + unsigned int _pin,
> + unsigned long *configs,
> + unsigned int num_configs)
> +{
> + int i, ret;
> + struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
> + enum pin_config_param config_type;
> + unsigned long config_value;
> +
> + if (!configs || num_configs == 0)
> + return -EINVAL;
> +
Here if you re-implement the Pinctrl SCMI protocol with the latest spec
you could pack this into one config_set() with multiple config/values
pair (and let the SCMI Pinctrl protocol to chunk the request in messages
appropriate for the underlying transport size.

Thanks,
Cristian