drivers/firmware/arm_scmi/voltage.c

Source file repositories/reference/linux-study-clean/drivers/firmware/arm_scmi/voltage.c

File Facts

System
Linux kernel
Corpus path
drivers/firmware/arm_scmi/voltage.c
Extension
.c
Size
11085 bytes
Lines
445
Domain
Driver Families
Bucket
drivers/firmware
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct scmi_msg_resp_domain_attributes {
	__le32 attr;
#define SUPPORTS_ASYNC_LEVEL_SET(x)	((x) & BIT(31))
#define SUPPORTS_EXTENDED_NAMES(x)	((x) & BIT(30))
	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
};

struct scmi_msg_cmd_describe_levels {
	__le32 domain_id;
	__le32 level_index;
};

struct scmi_msg_resp_describe_levels {
	__le32 flags;
#define NUM_REMAINING_LEVELS(f)	((u16)(FIELD_GET(REMAINING_LEVELS_MASK, (f))))
#define NUM_RETURNED_LEVELS(f)	((u16)(FIELD_GET(RETURNED_LEVELS_MASK, (f))))
#define SUPPORTS_SEGMENTED_LEVELS(f)	((f) & BIT(12))
	__le32 voltage[];
};

struct scmi_msg_cmd_config_set {
	__le32 domain_id;
	__le32 config;
};

struct scmi_msg_cmd_level_set {
	__le32 domain_id;
	__le32 flags;
	__le32 voltage_level;
};

struct scmi_resp_voltage_level_set_complete {
	__le32 domain_id;
	__le32 voltage_level;
};

struct voltage_info {
	unsigned int num_domains;
	struct scmi_voltage_info *domains;
};

static int scmi_protocol_attributes_get(const struct scmi_protocol_handle *ph,
					struct voltage_info *vinfo)
{
	int ret;
	struct scmi_xfer *t;

	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
				      sizeof(__le32), &t);
	if (ret)
		return ret;

	ret = ph->xops->do_xfer(ph, t);
	if (!ret)
		vinfo->num_domains =
			NUM_VOLTAGE_DOMAINS(get_unaligned_le32(t->rx.buf));

	ph->xops->xfer_put(ph, t);
	return ret;
}

static int scmi_init_voltage_levels(struct device *dev,
				    struct scmi_voltage_info *v,
				    u32 num_returned, u32 num_remaining,
				    bool segmented)
{
	u32 num_levels;

	num_levels = num_returned + num_remaining;
	/*
	 * segmented levels entries are represented by a single triplet
	 * returned all in one go.
	 */
	if (!num_levels ||
	    (segmented && (num_remaining || num_returned != 3))) {
		dev_err(dev,
			"Invalid level descriptor(%d/%d/%d) for voltage dom %d\n",
			num_levels, num_returned, num_remaining, v->id);
		return -EINVAL;
	}

	v->levels_uv = devm_kcalloc(dev, num_levels, sizeof(u32), GFP_KERNEL);
	if (!v->levels_uv)
		return -ENOMEM;

	v->num_levels = num_levels;
	v->segmented = segmented;

	return 0;
}

Annotation

Implementation Notes