drivers/i2c/busses/i2c-nct6694.c

Source file repositories/reference/linux-study-clean/drivers/i2c/busses/i2c-nct6694.c

File Facts

System
Linux kernel
Corpus path
drivers/i2c/busses/i2c-nct6694.c
Extension
.c
Size
4858 bytes
Lines
197
Domain
Driver Families
Bucket
drivers/i2c
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 nct6694_i2c_data {
	struct device *dev;
	struct nct6694 *nct6694;
	struct i2c_adapter adapter;
	struct nct6694_i2c_deliver deliver;
	unsigned char port;
	unsigned char br;
};

static int nct6694_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
	struct nct6694_i2c_data *data = adap->algo_data;
	struct nct6694_i2c_deliver *deliver = &data->deliver;
	static const struct nct6694_cmd_header cmd_hd = {
		.mod = NCT6694_I2C_MOD,
		.cmd = NCT6694_I2C_DELIVER,
		.sel = NCT6694_I2C_DELIVER_SEL,
		.len = cpu_to_le16(sizeof(*deliver))
	};
	int ret, i;

	for (i = 0; i < num; i++) {
		struct i2c_msg *msg_temp = &msgs[i];

		memset(deliver, 0, sizeof(*deliver));

		deliver->port = data->port;
		deliver->br = data->br;
		deliver->addr = i2c_8bit_addr_from_msg(msg_temp);
		if (msg_temp->flags & I2C_M_RD) {
			deliver->r_cnt = msg_temp->len;
			ret = nct6694_write_msg(data->nct6694, &cmd_hd, deliver);
			if (ret < 0)
				return ret;

			memcpy(msg_temp->buf, deliver->read_data, msg_temp->len);
		} else {
			deliver->w_cnt = msg_temp->len;
			memcpy(deliver->write_data, msg_temp->buf, msg_temp->len);
			ret = nct6694_write_msg(data->nct6694, &cmd_hd, deliver);
			if (ret < 0)
				return ret;
		}
	}

	return num;
}

static u32 nct6694_i2c_func(struct i2c_adapter *adapter)
{
	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}

static const struct i2c_adapter_quirks nct6694_i2c_quirks = {
	.max_read_len = NCT6694_I2C_MAX_XFER_SIZE,
	.max_write_len = NCT6694_I2C_MAX_XFER_SIZE,
};

static const struct i2c_algorithm nct6694_i2c_algo = {
	.xfer = nct6694_i2c_xfer,
	.functionality = nct6694_i2c_func,
};

static int nct6694_i2c_set_baudrate(struct nct6694_i2c_data *data)
{
	if (data->port >= NCT6694_I2C_MAX_DEVS) {
		dev_err(data->dev, "Invalid I2C port index %d\n", data->port);
		return -EINVAL;
	}

	if (br_reg[data->port] > NCT6694_I2C_BR_1M) {
		dev_warn(data->dev, "Invalid baudrate %d for I2C%d, using 100K\n",
			 br_reg[data->port], data->port);
		br_reg[data->port] = NCT6694_I2C_BR_100K;
	}

	data->br = br_reg[data->port];

	return 0;
}

static void nct6694_i2c_ida_free(void *d)
{
	struct nct6694_i2c_data *data = d;
	struct nct6694 *nct6694 = data->nct6694;

	ida_free(&nct6694->i2c_ida, data->port);
}

static int nct6694_i2c_probe(struct platform_device *pdev)

Annotation

Implementation Notes