drivers/media/dvb-frontends/tua6100.c

Source file repositories/reference/linux-study-clean/drivers/media/dvb-frontends/tua6100.c

File Facts

System
Linux kernel
Corpus path
drivers/media/dvb-frontends/tua6100.c
Extension
.c
Size
4769 bytes
Lines
194
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 tua6100_priv {
	/* i2c details */
	int i2c_address;
	struct i2c_adapter *i2c;
	u32 frequency;
};

static void tua6100_release(struct dvb_frontend *fe)
{
	kfree(fe->tuner_priv);
	fe->tuner_priv = NULL;
}

static int tua6100_sleep(struct dvb_frontend *fe)
{
	struct tua6100_priv *priv = fe->tuner_priv;
	int ret;
	u8 reg0[] = { 0x00, 0x00 };
	struct i2c_msg msg = { .addr = priv->i2c_address, .flags = 0, .buf = reg0, .len = 2 };

	if (fe->ops.i2c_gate_ctrl)
		fe->ops.i2c_gate_ctrl(fe, 1);
	if ((ret = i2c_transfer (priv->i2c, &msg, 1)) != 1) {
		printk("%s: i2c error\n", __func__);
	}
	if (fe->ops.i2c_gate_ctrl)
		fe->ops.i2c_gate_ctrl(fe, 0);

	return (ret == 1) ? 0 : ret;
}

static int tua6100_set_params(struct dvb_frontend *fe)
{
	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
	struct tua6100_priv *priv = fe->tuner_priv;
	u32 div;
	u32 prediv;
	u8 reg0[] = { 0x00, 0x00 };
	u8 reg1[] = { 0x01, 0x00, 0x00, 0x00 };
	u8 reg2[] = { 0x02, 0x00, 0x00 };
	struct i2c_msg msg0 = { .addr = priv->i2c_address, .flags = 0, .buf = reg0, .len = 2 };
	struct i2c_msg msg1 = { .addr = priv->i2c_address, .flags = 0, .buf = reg1, .len = 4 };
	struct i2c_msg msg2 = { .addr = priv->i2c_address, .flags = 0, .buf = reg2, .len = 3 };

#define _R_VAL 4
#define _P_VAL 32
#define _ri 4000000

	// setup register 0
	if (c->frequency < 2000000)
		reg0[1] = 0x03;
	else
		reg0[1] = 0x07;

	// setup register 1
	if (c->frequency < 1630000)
		reg1[1] = 0x2c;
	else
		reg1[1] = 0x0c;

	if (_P_VAL == 64)
		reg1[1] |= 0x40;
	if (c->frequency >= 1525000)
		reg1[1] |= 0x80;

	// register 2
	reg2[1] = (_R_VAL >> 8) & 0x03;
	reg2[2] = _R_VAL;
	if (c->frequency < 1455000)
		reg2[1] |= 0x1c;
	else if (c->frequency < 1630000)
		reg2[1] |= 0x0c;
	else
		reg2[1] |= 0x1c;

	/*
	 * The N divisor ratio (note: c->frequency is in kHz, but we
	 * need it in Hz)
	 */
	prediv = (c->frequency * _R_VAL) / (_ri / 1000);
	div = prediv / _P_VAL;
	reg1[1] |= (div >> 9) & 0x03;
	reg1[2] = div >> 1;
	reg1[3] = (div << 7);
	priv->frequency = ((div * _P_VAL) * (_ri / 1000)) / _R_VAL;

	// Finally, calculate and store the value for A
	reg1[3] |= (prediv - (div*_P_VAL)) & 0x7f;

#undef _R_VAL

Annotation

Implementation Notes