drivers/media/dvb-frontends/ec100.c

Source file repositories/reference/linux-study-clean/drivers/media/dvb-frontends/ec100.c

File Facts

System
Linux kernel
Corpus path
drivers/media/dvb-frontends/ec100.c
Extension
.c
Size
6836 bytes
Lines
332
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 ec100_state {
	struct i2c_adapter *i2c;
	struct dvb_frontend frontend;
	struct ec100_config config;

	u16 ber;
};

/* write single register */
static int ec100_write_reg(struct ec100_state *state, u8 reg, u8 val)
{
	int ret;
	u8 buf[2] = {reg, val};
	struct i2c_msg msg[1] = {
		{
			.addr = state->config.demod_address,
			.flags = 0,
			.len = sizeof(buf),
			.buf = buf,
		}
	};

	ret = i2c_transfer(state->i2c, msg, 1);
	if (ret == 1) {
		ret = 0;
	} else {
		dev_warn(&state->i2c->dev, "%s: i2c wr failed=%d reg=%02x\n",
				KBUILD_MODNAME, ret, reg);
		ret = -EREMOTEIO;
	}

	return ret;
}

/* read single register */
static int ec100_read_reg(struct ec100_state *state, u8 reg, u8 *val)
{
	int ret;
	struct i2c_msg msg[2] = {
		{
			.addr = state->config.demod_address,
			.flags = 0,
			.len = 1,
			.buf = &reg
		}, {
			.addr = state->config.demod_address,
			.flags = I2C_M_RD,
			.len = 1,
			.buf = val
		}
	};

	ret = i2c_transfer(state->i2c, msg, 2);
	if (ret == 2) {
		ret = 0;
	} else {
		dev_warn(&state->i2c->dev, "%s: i2c rd failed=%d reg=%02x\n",
				KBUILD_MODNAME, ret, reg);
		ret = -EREMOTEIO;
	}

	return ret;
}

static int ec100_set_frontend(struct dvb_frontend *fe)
{
	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
	struct ec100_state *state = fe->demodulator_priv;
	int ret;
	u8 tmp, tmp2;

	dev_dbg(&state->i2c->dev, "%s: frequency=%d bandwidth_hz=%d\n",
			__func__, c->frequency, c->bandwidth_hz);

	/* program tuner */
	if (fe->ops.tuner_ops.set_params)
		fe->ops.tuner_ops.set_params(fe);

	ret = ec100_write_reg(state, 0x04, 0x06);
	if (ret)
		goto error;
	ret = ec100_write_reg(state, 0x67, 0x58);
	if (ret)
		goto error;
	ret = ec100_write_reg(state, 0x05, 0x18);
	if (ret)
		goto error;

	/* reg/bw |   6  |   7  |   8
	   -------+------+------+------

Annotation

Implementation Notes