drivers/media/dvb-frontends/lnbh25.c

Source file repositories/reference/linux-study-clean/drivers/media/dvb-frontends/lnbh25.c

File Facts

System
Linux kernel
Corpus path
drivers/media/dvb-frontends/lnbh25.c
Extension
.c
Size
4105 bytes
Lines
181
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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 lnbh25_priv {
	struct i2c_adapter	*i2c;
	u8			i2c_address;
	u8			config[3];
};

#define LNBH25_STATUS_OFL	0x1
#define LNBH25_STATUS_VMON	0x4
#define LNBH25_VSEL_13		0x03
#define LNBH25_VSEL_18		0x0a

static int lnbh25_read_vmon(struct lnbh25_priv *priv)
{
	int i, ret;
	u8 addr = 0x00;
	u8 status[6];
	struct i2c_msg msg[2] = {
		{
			.addr = priv->i2c_address,
			.flags = 0,
			.len = 1,
			.buf = &addr
		}, {
			.addr = priv->i2c_address,
			.flags = I2C_M_RD,
			.len = sizeof(status),
			.buf = status
		}
	};

	for (i = 0; i < 2; i++) {
		ret = i2c_transfer(priv->i2c, &msg[i], 1);
		if (ret >= 0 && ret != 1)
			ret = -EIO;
		if (ret < 0) {
			dev_dbg(&priv->i2c->dev,
				"%s(): I2C transfer %d failed (%d)\n",
				__func__, i, ret);
			return ret;
		}
	}
	dev_dbg(&priv->i2c->dev, "%s(): %*ph\n",
		__func__, (int) sizeof(status), status);
	if ((status[0] & (LNBH25_STATUS_OFL | LNBH25_STATUS_VMON)) != 0) {
		dev_err(&priv->i2c->dev,
			"%s(): voltage in failure state, status reg 0x%x\n",
			__func__, status[0]);
		return -EIO;
	}
	return 0;
}

static int lnbh25_set_voltage(struct dvb_frontend *fe,
			      enum fe_sec_voltage voltage)
{
	int ret;
	u8 data1_reg;
	const char *vsel;
	struct lnbh25_priv *priv = fe->sec_priv;
	struct i2c_msg msg = {
		.addr = priv->i2c_address,
		.flags = 0,
		.len = sizeof(priv->config),
		.buf = priv->config
	};

	switch (voltage) {
	case SEC_VOLTAGE_OFF:
		data1_reg = 0x00;
		vsel = "Off";
		break;
	case SEC_VOLTAGE_13:
		data1_reg = LNBH25_VSEL_13;
		vsel = "13V";
		break;
	case SEC_VOLTAGE_18:
		data1_reg = LNBH25_VSEL_18;
		vsel = "18V";
		break;
	default:
		return -EINVAL;
	}
	priv->config[1] = data1_reg;
	dev_dbg(&priv->i2c->dev,
		"%s(): %s, I2C 0x%x write [ %02x %02x %02x ]\n",
		__func__, vsel, priv->i2c_address,
		priv->config[0], priv->config[1], priv->config[2]);
	ret = i2c_transfer(priv->i2c, &msg, 1);
	if (ret >= 0 && ret != 1)
		ret = -EIO;

Annotation

Implementation Notes