drivers/media/tuners/qm1d1c0042.c

Source file repositories/reference/linux-study-clean/drivers/media/tuners/qm1d1c0042.c

File Facts

System
Linux kernel
Corpus path
drivers/media/tuners/qm1d1c0042.c
Extension
.c
Size
10696 bytes
Lines
456
Domain
Driver Families
Bucket
drivers/media
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 qm1d1c0042_state {
	struct qm1d1c0042_config cfg;
	struct i2c_client *i2c;
	u8 regs[QM1D1C0042_NUM_REGS];
};

static struct qm1d1c0042_state *cfg_to_state(struct qm1d1c0042_config *c)
{
	return container_of(c, struct qm1d1c0042_state, cfg);
}

static int reg_write(struct qm1d1c0042_state *state, u8 reg, u8 val)
{
	u8 wbuf[2] = { reg, val };
	int ret;

	ret = i2c_master_send(state->i2c, wbuf, sizeof(wbuf));
	if (ret >= 0 && ret < sizeof(wbuf))
		ret = -EIO;
	return (ret == sizeof(wbuf)) ? 0 : ret;
}

static int reg_read(struct qm1d1c0042_state *state, u8 reg, u8 *val)
{
	struct i2c_msg msgs[2] = {
		{
			.addr = state->i2c->addr,
			.flags = 0,
			.buf = &reg,
			.len = 1,
		},
		{
			.addr = state->i2c->addr,
			.flags = I2C_M_RD,
			.buf = val,
			.len = 1,
		},
	};
	int ret;

	ret = i2c_transfer(state->i2c->adapter, msgs, ARRAY_SIZE(msgs));
	if (ret >= 0 && ret < ARRAY_SIZE(msgs))
		ret = -EIO;
	return (ret == ARRAY_SIZE(msgs)) ? 0 : ret;
}


static int qm1d1c0042_set_srch_mode(struct qm1d1c0042_state *state, bool fast)
{
	if (fast)
		state->regs[0x03] |= 0x01; /* set fast search mode */
	else
		state->regs[0x03] &= ~0x01 & 0xff;

	return reg_write(state, 0x03, state->regs[0x03]);
}

static int qm1d1c0042_wakeup(struct qm1d1c0042_state *state)
{
	int ret;

	state->regs[0x01] |= 1 << 3;             /* BB_Reg_enable */
	state->regs[0x01] &= (~(1 << 0)) & 0xff; /* NORMAL (wake-up) */
	state->regs[0x05] &= (~(1 << 3)) & 0xff; /* pfd_rst NORMAL */
	ret = reg_write(state, 0x01, state->regs[0x01]);
	if (ret == 0)
		ret = reg_write(state, 0x05, state->regs[0x05]);

	if (ret < 0)
		dev_warn(&state->i2c->dev, "(%s) failed. [adap%d-fe%d]\n",
			__func__, state->cfg.fe->dvb->num, state->cfg.fe->id);
	return ret;
}

/* tuner_ops */

static int qm1d1c0042_set_config(struct dvb_frontend *fe, void *priv_cfg)
{
	struct qm1d1c0042_state *state;
	struct qm1d1c0042_config *cfg;

	state = fe->tuner_priv;
	cfg = priv_cfg;

	if (cfg->fe)
		state->cfg.fe = cfg->fe;

	if (cfg->xtal_freq != QM1D1C0042_CFG_XTAL_DFLT)
		dev_warn(&state->i2c->dev,
			"(%s) changing xtal_freq not supported. ", __func__);

Annotation

Implementation Notes