drivers/media/dvb-frontends/lnbh29.c

Source file repositories/reference/linux-study-clean/drivers/media/dvb-frontends/lnbh29.c

File Facts

System
Linux kernel
Corpus path
drivers/media/dvb-frontends/lnbh29.c
Extension
.c
Size
3782 bytes
Lines
169
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 lnbh29_priv {
	struct i2c_adapter *i2c;
	u8 i2c_address;
	u8 config[2];
};

#define LNBH29_STATUS_OLF     BIT(0)
#define LNBH29_STATUS_OTF     BIT(1)
#define LNBH29_STATUS_VMON    BIT(2)
#define LNBH29_STATUS_PNG     BIT(3)
#define LNBH29_STATUS_PDO     BIT(4)
#define LNBH29_VSEL_MASK      GENMASK(2, 0)
#define LNBH29_VSEL_0         0x00
/* Min: 13.188V, Typ: 13.667V, Max:14V */
#define LNBH29_VSEL_13        0x03
/* Min: 18.158V, Typ: 18.817V, Max:19.475V */
#define LNBH29_VSEL_18        0x07

static int lnbh29_read_vmon(struct lnbh29_priv *priv)
{
	u8 addr = 0x00;
	u8 status[2];
	int ret;
	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
		}
	};

	ret = i2c_transfer(priv->i2c, msg, 2);
	if (ret >= 0 && ret != 2)
		ret = -EIO;
	if (ret < 0) {
		dev_dbg(&priv->i2c->dev, "LNBH29 I2C transfer failed (%d)\n",
			ret);
		return ret;
	}

	if (status[0] & (LNBH29_STATUS_OLF | LNBH29_STATUS_VMON)) {
		dev_err(&priv->i2c->dev,
			"LNBH29 voltage in failure state, status reg 0x%x\n",
			status[0]);
		return -EIO;
	}

	return 0;
}

static int lnbh29_set_voltage(struct dvb_frontend *fe,
			      enum fe_sec_voltage voltage)
{
	struct lnbh29_priv *priv = fe->sec_priv;
	u8 data_reg;
	int ret;
	struct i2c_msg msg = {
		.addr = priv->i2c_address,
		.flags = 0,
		.len = sizeof(priv->config),
		.buf = priv->config
	};

	switch (voltage) {
	case SEC_VOLTAGE_OFF:
		data_reg = LNBH29_VSEL_0;
		break;
	case SEC_VOLTAGE_13:
		data_reg = LNBH29_VSEL_13;
		break;
	case SEC_VOLTAGE_18:
		data_reg = LNBH29_VSEL_18;
		break;
	default:
		return -EINVAL;
	}
	priv->config[1] &= ~LNBH29_VSEL_MASK;
	priv->config[1] |= data_reg;

	ret = i2c_transfer(priv->i2c, &msg, 1);
	if (ret >= 0 && ret != 1)
		ret = -EIO;
	if (ret < 0) {
		dev_err(&priv->i2c->dev, "LNBH29 I2C transfer error (%d)\n",

Annotation

Implementation Notes