[RFC 4/6] gpio: add scmi driver based on pinctrl
AKASHI Takahiro
takahiro.akashi at linaro.org
Wed Sep 6 04:40:09 CEST 2023
This DM-compliant driver deals with SCMI pinctrl protocol and presents
gpio devices exposed by SCMI firmware (server).
Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
drivers/pinctrl/pinctrl-scmi.c | 544 ++++++++++++++++++++++++++++++++-
1 file changed, 539 insertions(+), 5 deletions(-)
diff --git a/drivers/pinctrl/pinctrl-scmi.c b/drivers/pinctrl/pinctrl-scmi.c
index 3ebdad57b86c..73d385bdbfcc 100644
--- a/drivers/pinctrl/pinctrl-scmi.c
+++ b/drivers/pinctrl/pinctrl-scmi.c
@@ -11,21 +11,20 @@
#include <malloc.h>
#include <scmi_agent.h>
#include <scmi_protocols.h>
+#include <asm-generic/gpio.h>
#include <dm/device_compat.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
#include <dm/pinctrl.h>
/**
* struct scmi_pin - attributes for a pin
* @name: Name of pin
- * @value: Value of pin
- * @flags: A set of flags
* @function: Function selected
* @status: An array of status of configuration types
*/
struct scmi_pin {
char *name;
- u32 value;
- u32 flags;
unsigned int function;
u32 status[SCMI_PINCTRL_CONFIG_RESERVED];
};
@@ -308,7 +307,6 @@ static int scmi_pinmux_group_set(struct udevice *dev,
return 0;
}
-/* TODO: may be driver-specific */
/**
* pinmux_property_set - Enable a pinmux group
* @dev: SCMI pinctrl device to use
@@ -424,6 +422,539 @@ const struct pinctrl_ops scmi_pinctrl_ops = {
.set_state = pinctrl_generic_set_state,
};
+#if CONFIG_IS_ENABLED(DM_GPIO)
+/*
+ * GPIO part
+ */
+
+/**
+ * struct scmi_pinctrl_gpio_plat - platform data
+ * @pinctrl_dev: Associated SCMI pinctrl device
+ * @gpio_map: A list of gpio mapping information
+ * @name: Name of ?
+ * @ngpios: A number of gpio pins
+ */
+struct scmi_pinctrl_gpio_plat {
+ struct list_head gpio_map;
+ char *name;
+ u32 ngpios;
+};
+
+/**
+ * struct scmi_pinctrl_gpio_map - gpio mapping information
+ * @gpio_pin: Start gpio pin selector
+ * @pinctrl_pin: Mapped start pinctrl pin selector, used for linear mapping
+ * @pinctrl_group: Name of an associated group, used for group namee mapping
+ * @num_pins: A number of pins
+ * @node: Node for a mapping list
+ */
+struct scmi_pinctrl_gpio_map {
+ struct udevice *pinctrl_dev;
+ u32 gpio_pin;
+ u32 pinctrl_pin;
+ u16 *pinctrl_group;
+ u32 num_pins;
+ struct list_head node;
+};
+
+/**
+ * map_to_id - Map a gpio pin offset to a pinctrl pin selector
+ * @dev: SCMI pinctrl device
+ * @offset: Pin offset
+ * @id: Pinctrl pin selector
+ *
+ * Map a gpio pin offset, @offset, to an associated pinctrl pin selector
+ *
+ * Return: 0 on success, -1 on failure
+ */
+static int map_to_id(struct udevice *dev, unsigned int offset,
+ struct udevice **pinctrl_dev, u32 *id)
+{
+ struct scmi_pinctrl_gpio_plat *plat = dev_get_plat(dev);
+ struct scmi_pinctrl_gpio_map *map;
+
+ /* if no mapping is defined, return 1:1 pin */
+ if (list_empty(&plat->gpio_map)) {
+ uclass_first_device(UCLASS_PINCTRL, pinctrl_dev);
+ if (!*pinctrl_dev)
+ return -1;
+
+ *id = offset;
+ return 0;
+ }
+
+ list_for_each_entry(map, &plat->gpio_map, node) {
+ if (offset >= map->gpio_pin &&
+ offset < (map->gpio_pin + map->num_pins)) {
+ *pinctrl_dev = map->pinctrl_dev;
+ if (!pinctrl_dev)
+ return -1;
+
+ if (map->pinctrl_group)
+ *id = map->pinctrl_group[offset
+ - map->gpio_pin];
+ else
+ *id = map->pinctrl_pin
+ + (offset - map->gpio_pin);
+
+ return 0;
+ }
+ }
+
+ return -1;
+}
+
+/**
+ * scmi_gpio_get_value - Get a value of a gpio pin
+ * @dev: SCMI gpio device
+ * @offset: Pin offset
+ *
+ * Get a value of a gpio pin in @offset
+ *
+ * Return: Value of a pin on success, error code on failure
+ */
+static int scmi_gpio_get_value(struct udevice *dev, unsigned int offset)
+{
+ struct scmi_pinctrl_priv *priv;
+ u32 id;
+ struct udevice *pinctrl_dev;
+ struct scmi_pin_entry *config;
+ int config_type, ret;
+
+ if (map_to_id(dev, offset, &pinctrl_dev, &id)) {
+ dev_err(dev, "Invalid pin: %u\n", offset);
+ return -EINVAL;
+ }
+
+ priv = dev_get_priv(pinctrl_dev);
+ if (priv->pins[id].status[SCMI_PINCTRL_CONFIG_INPUT_MODE]) {
+ config_type = SCMI_PINCTRL_CONFIG_INPUT_VALUE;
+ } else if (priv->pins[id].status[SCMI_PINCTRL_CONFIG_OUTPUT_MODE]) {
+ config_type = SCMI_PINCTRL_CONFIG_OUTPUT_VALUE;
+ } else {
+ dev_err(dev, "Invalid pin mode: %u\n", offset);
+ return -EINVAL;
+ }
+
+ ret = scmi_pinctrl_config_get(pinctrl_dev, id, false,
+ SCMI_PINCTRL_TYPE_PIN, config_type,
+ &config);
+ if (ret) {
+ dev_err(dev, "config_get failed (%d)\n", ret);
+ return ret;
+ }
+
+ return config->value;
+}
+
+/**
+ * config_pin_set - Configure a pinctrl pin
+ * @dev: SCMI pinctrl device
+ * @id: Pin selector
+ * @config_type: Configuration type
+ * @value: Value
+ *
+ * Set a configuration of @config_type of a pinctrl pin, @id, to @value.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int config_pin_set(struct udevice *dev, u32 id, u32 config_type,
+ u32 value)
+{
+ struct scmi_pinctrl_priv *priv = dev_get_priv(dev);
+ struct scmi_pin_entry config;
+ int ret;
+
+ config.type = config_type;
+ config.value = value;
+ ret = scmi_pinctrl_config_set(dev, id, SCMI_PINCTRL_TYPE_PIN,
+ 1, &config);
+ if (ret) {
+ dev_err(dev, "config_set failed (%d)\n", ret);
+ return ret;
+ }
+
+ priv->pins[id].status[config_type] = value;
+
+ return 0;
+}
+
+/**
+ * scmi_gpio_set_value - Set a value of a gpio pin
+ * @dev: SCMI gpio device
+ * @offset: Pin offset
+ * @value: Value
+ *
+ * Set a value of a gpio pin in @offset to @value.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_gpio_set_value(struct udevice *dev, unsigned int offset,
+ int value)
+{
+ struct udevice *pinctrl_dev;
+ u32 id;
+
+ if (map_to_id(dev, offset, &pinctrl_dev, &id)) {
+ dev_err(dev, "Invalid pin: %u\n", offset);
+ return -EINVAL;
+ }
+
+ return config_pin_set(pinctrl_dev, id,
+ SCMI_PINCTRL_CONFIG_OUTPUT_VALUE,
+ (u32)value);
+}
+
+/**
+ * scmi_gpio_get_function - Get a gpio function of a gpio pin
+ * @dev: SCMI gpio device
+ * @offset: Pin offset
+ *
+ * Get a gpio function of a gpio pin in @offset.
+ *
+ * Return: GPIOF_OUTPUT or GPIO_INPUT on success, otherwise GPIOF_UNKNOWN
+ */
+static int scmi_gpio_get_function(struct udevice *dev, unsigned int offset)
+{
+ struct udevice *pinctrl_dev;
+ u32 id;
+ struct scmi_pin_entry *config;
+ int ret;
+
+ if (map_to_id(dev, offset, &pinctrl_dev, &id)) {
+ dev_err(dev, "Invalid pin: %u\n", offset);
+ return -EINVAL;
+ }
+
+ ret = scmi_pinctrl_config_get(pinctrl_dev, id, false,
+ SCMI_PINCTRL_TYPE_PIN,
+ SCMI_PINCTRL_CONFIG_INPUT_MODE, &config);
+ if (!ret && config->value == 1)
+ return GPIOF_INPUT;
+
+ ret = scmi_pinctrl_config_get(pinctrl_dev, id, false,
+ SCMI_PINCTRL_TYPE_PIN,
+ SCMI_PINCTRL_CONFIG_OUTPUT_MODE,
+ &config);
+ if (!ret && config->value == 1)
+ return GPIOF_OUTPUT;
+
+ return GPIOF_UNKNOWN;
+}
+
+/**
+ * set_flags - Adjust GPIO flags
+ * @dev: SCMI gpio device
+ * @offset: Pin offset
+ * @flags: New flags value
+ *
+ * This function should set up the GPIO configuration according to information
+ * provided by @flags (GPIOD_xxx).
+ *
+ * @return 0 if OK, otherwise -ve on error
+ */
+static int scmi_gpio_set_flags(struct udevice *dev, unsigned int offset,
+ ulong flags)
+{
+ struct udevice *pinctrl_dev;
+ struct scmi_pin_entry config[5]; /* 5 is enough for now */
+ u32 id;
+ struct scmi_pinctrl_priv *priv;
+ int i = 0, ret;
+
+ if (map_to_id(dev, offset, &pinctrl_dev, &id)) {
+ dev_err(dev, "Invalid pin: %u\n", offset);
+ return -EINVAL;
+ }
+
+ if (flags & GPIOD_IS_OUT) {
+ config[i].type = SCMI_PINCTRL_CONFIG_INPUT_MODE;
+ config[i++].value = 0;
+
+ config[i].type = SCMI_PINCTRL_CONFIG_OUTPUT_MODE;
+ config[i++].value = 1;
+ config[i].type = SCMI_PINCTRL_CONFIG_OUTPUT_VALUE;
+ config[i++].value = (u32)!!(flags & GPIOD_IS_OUT_ACTIVE);
+ } else if (flags & GPIOD_IS_IN) {
+ config[i].type = SCMI_PINCTRL_CONFIG_OUTPUT_MODE;
+ config[i++].value = 0;
+
+ config[i].type = SCMI_PINCTRL_CONFIG_INPUT_MODE;
+ config[i++].value = 1;
+ }
+
+ if (flags & GPIOD_OPEN_DRAIN) {
+ config[i].type = SCMI_PINCTRL_CONFIG_DRIVE_OPEN_DRAIN;
+ config[i++].value = 1;
+ } else if (flags & GPIOD_OPEN_SOURCE) {
+ config[i].type = SCMI_PINCTRL_CONFIG_DRIVE_OPEN_SOURCE;
+ config[i++].value = 1;
+ }
+
+ if (flags & GPIOD_PULL_UP) {
+ config[i].type = SCMI_PINCTRL_CONFIG_BIAS_PULL_UP;
+ config[i++].value = 1;
+ } else if (flags & GPIOD_PULL_DOWN) {
+ config[i].type = SCMI_PINCTRL_CONFIG_BIAS_PULL_DOWN;
+ config[i++].value = 1;
+ }
+
+ ret = scmi_pinctrl_config_set(pinctrl_dev, id, SCMI_PINCTRL_TYPE_PIN,
+ i, config);
+ if (ret) {
+ dev_err(dev, "config_set failed (%d)\n", ret);
+ return ret;
+ }
+
+ /* update local status */
+ priv = dev_get_priv(pinctrl_dev);
+
+ if (flags & GPIOD_IS_OUT) {
+ priv->pins[id].status[SCMI_PINCTRL_CONFIG_OUTPUT_MODE] = 1;
+ priv->pins[id].status[SCMI_PINCTRL_CONFIG_OUTPUT_VALUE] = 1;
+
+ priv->pins[id].status[SCMI_PINCTRL_CONFIG_INPUT_MODE] = 0;
+ } else if (flags & GPIOD_IS_IN) {
+ priv->pins[id].status[SCMI_PINCTRL_CONFIG_INPUT_MODE] = 1;
+ priv->pins[id].status[SCMI_PINCTRL_CONFIG_OUTPUT_MODE] = 0;
+ }
+
+ if (flags & GPIOD_OPEN_DRAIN)
+ priv->pins[id].status[SCMI_PINCTRL_CONFIG_DRIVE_OPEN_DRAIN] = 1;
+ else if (flags & GPIOD_OPEN_SOURCE)
+ priv->pins[id].status[SCMI_PINCTRL_CONFIG_DRIVE_OPEN_SOURCE] =
+ 1;
+
+ if (flags & GPIOD_PULL_UP)
+ priv->pins[id].status[SCMI_PINCTRL_CONFIG_BIAS_PULL_UP] = 1;
+ else if (flags & GPIOD_PULL_DOWN)
+ priv->pins[id].status[SCMI_PINCTRL_CONFIG_BIAS_PULL_DOWN] = 1;
+
+ return 0;
+}
+
+/**
+ * lookup_pin_group - find out a list of pins for group name
+ * @dev: SCMI pinctrl device
+ * @name: Name of a group
+ * @num_pins: Pointer to a number of pins
+ * @pins: Pointer to array of pin selectors
+ *
+ * Look up a group named @name and return a list of pin selectors associated with
+ * the group in @pins.
+ *
+ * Return: 0 on success, -1 on failure
+ */
+static int lookup_pin_group(struct udevice *dev, const char *name,
+ u32 *num_pins, u16 **pins)
+{
+ struct scmi_pinctrl_priv *priv = dev_get_priv(dev);
+ int i;
+
+ for (i = 0; i < priv->num_groups; i++)
+ if (!strcmp(name, priv->groups[i].name)) {
+ *num_pins = priv->groups[i].num_pins;
+ *pins = priv->groups[i].pins;
+ return 0;
+ }
+
+ return -1;
+}
+
+/**
+ * get_pinctrl_dev - Get a pin control device at node
+ * @node: Reference to the node
+ *
+ * Get a pin control device at @node.
+ *
+ * Return: 0 on success, otherwise NULL
+ */
+static struct udevice *get_pinctrl_dev(ofnode *node)
+{
+ struct udevice *dev;
+ struct uclass *uc;
+
+ if (uclass_get(UCLASS_PINCTRL, &uc))
+ return NULL;
+
+ uclass_foreach_dev(dev, uc)
+ if (dev->node_.np == node->np)
+ return dev;
+
+ return NULL;
+}
+
+/**
+ * scmi_gpio_probe - Probe a SCMI gpio device
+ * @dev: SCMI gpio device
+ *
+ * Probe and initialize a SCMI gpio device.
+ *
+ * 0 on success, error code on failure
+ */
+static int scmi_gpio_probe(struct udevice *dev)
+{
+ struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+ struct scmi_pinctrl_gpio_plat *plat = dev_get_plat(dev);
+
+ struct scmi_pinctrl_gpio_map *range;
+ struct ofnode_phandle_args args;
+ const char *name;
+ int num_pins = 0, index, ret;
+
+ uc_priv->bank_name = dev_read_string(dev, "gpio-bank-name");
+ if (!uc_priv->bank_name)
+ uc_priv->bank_name = dev->name;
+
+ INIT_LIST_HEAD(&plat->gpio_map);
+ for (index = 0; ; index++) {
+ ret = dev_read_phandle_with_args(dev, "gpio-ranges",
+ NULL, 3, index, &args);
+ if (ret)
+ break;
+
+ range = malloc(sizeof(*range));
+ if (!range) {
+ dev_err(dev, "Memory not available\n");
+ return -ENOMEM;
+ }
+
+ range->pinctrl_dev = get_pinctrl_dev(&args.node);
+ if (!range->pinctrl_dev) {
+ dev_err(dev, "Pin control device not found\n");
+ return -ENODEV;
+ }
+
+ /* make sure pinctrl is activated */
+ ret = device_probe(range->pinctrl_dev);
+ if (ret)
+ return ret;
+
+ if (args.args[2]) {
+ range->gpio_pin = args.args[0];
+ range->pinctrl_pin = args.args[1];
+ range->num_pins = args.args[2];
+ range->pinctrl_group = NULL;
+ } else {
+ ret = of_property_read_string_index(dev_np(dev),
+ "gpio-ranges-group-names",
+ index, &name);
+ if (ret) {
+ dev_err(dev,
+ "gpio-ranges-group-names required\n");
+ return ret;
+ }
+
+ ret = lookup_pin_group(range->pinctrl_dev, name,
+ &range->num_pins,
+ &range->pinctrl_group);
+ if (ret) {
+ dev_err(dev, "Group not found: %s\n", name);
+ return -EINVAL;
+ }
+
+ range->gpio_pin = args.args[0];
+ }
+ num_pins += range->num_pins;
+ list_add_tail(&range->node, &plat->gpio_map);
+ }
+
+ uc_priv->gpio_count = num_pins;
+
+ return 0;
+}
+
+static const struct dm_gpio_ops scmi_gpio_ops = {
+ .get_function = scmi_gpio_get_function,
+ .get_value = scmi_gpio_get_value,
+ .set_value = scmi_gpio_set_value,
+ .set_flags = scmi_gpio_set_flags,
+};
+
+static const struct udevice_id scmi_gpio_ids[] = {
+ { .compatible = "arm,scmi-gpio-generic" },
+ { }
+};
+
+U_BOOT_DRIVER(scmi_gpio) = {
+ .name = "scmi_gpio",
+ .id = UCLASS_GPIO,
+ .of_match = scmi_gpio_ids,
+ .of_to_plat = scmi_gpio_probe,
+ .ops = &scmi_gpio_ops,
+ .plat_auto = sizeof(struct scmi_pinctrl_gpio_plat),
+};
+
+/**
+ * scmi_gpiochip_register - Create a pinctrl-controlled gpio device
+ * @parent: SCMI pinctrl device
+ *
+ * Create a pinctrl-controlled gpio device
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_gpiochip_register(struct udevice *parent)
+{
+ ofnode node;
+ struct driver *drv;
+ struct udevice *gpio_dev;
+ int ret;
+
+ /* TODO: recovery if failed */
+ dev_for_each_subnode(node, parent) {
+ if (!ofnode_is_enabled(node))
+ continue;
+
+ if (!ofnode_read_prop(node, "gpio-controller", NULL))
+ /* not a GPIO node */
+ continue;
+
+ drv = DM_DRIVER_GET(scmi_gpio);
+ if (!drv) {
+ dev_err(parent, "No gpio driver?\n");
+ return -ENODEV;
+ }
+
+ ret = device_bind(parent, drv, ofnode_get_name(node), NULL,
+ node, &gpio_dev);
+ if (ret) {
+ dev_err(parent, "failed to bind %s to gpio (%d)\n",
+ ofnode_get_name(node), ret);
+ return -ENODEV;
+ }
+
+ return 0;
+ }
+
+ return -ENODEV;
+}
+
+/**
+ * scmi_pinctrl_bind - Bind a pinctrl-controlled gpio device
+ * @dev: SCMI pinctrl device
+ *
+ * Bind a pinctrl-controlled gpio device
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_pinctrl_bind(struct udevice *dev)
+{
+ int ret;
+
+ /* gpiochip register */
+ if (CONFIG_IS_ENABLED(DM_GPIO)) {
+ ret = scmi_gpiochip_register(dev);
+ if (ret && ret != -ENODEV) {
+ dev_err(dev, "failed to register gpio driver (%d)\n",
+ ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+#endif /* CONFIG_DM_GPIO */
+
/**
* scmi_pinctrl_probe - probe a device
* @dev: SCMI pinctrl device
@@ -532,6 +1063,9 @@ U_BOOT_DRIVER(scmi_pinctrl) = {
.name = "scmi_pinctrl",
.id = UCLASS_PINCTRL,
.ops = &scmi_pinctrl_ops,
+#if CONFIG_IS_ENABLED(DM_GPIO)
+ .bind = scmi_pinctrl_bind,
+#endif
.probe = scmi_pinctrl_probe,
.priv_auto = sizeof(struct scmi_pinctrl_priv),
};
--
2.34.1
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