drivers/media/dvb-frontends/cxd2820r_c.c

Source file repositories/reference/linux-study-clean/drivers/media/dvb-frontends/cxd2820r_c.c

File Facts

System
Linux kernel
Corpus path
drivers/media/dvb-frontends/cxd2820r_c.c
Extension
.c
Size
7410 bytes
Lines
332
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

if (((utmp >> 0) & 0x03) % 2) {
			const_a = 8750;
			const_b = 650;
		} else {
			const_a = 9500;
			const_b = 760;
		}

		ret = regmap_read(priv->regmap[1], 0x004d, &utmp);
		if (ret)
			goto error;

		#define CXD2820R_LOG2_E_24 24204406 /* log2(e) << 24 */
		if (utmp)
			cnr = div_u64((u64)(intlog2(const_b) - intlog2(utmp))
				      * const_a, CXD2820R_LOG2_E_24);
		else
			cnr = 0;

		c->cnr.len = 1;
		c->cnr.stat[0].scale = FE_SCALE_DECIBEL;
		c->cnr.stat[0].svalue = cnr;
	} else {
		c->cnr.len = 1;
		c->cnr.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
	}

	/* BER */
	if (*status & FE_HAS_SYNC) {
		unsigned int post_bit_error;
		bool start_ber;

		if (priv->ber_running) {
			ret = regmap_bulk_read(priv->regmap[1], 0x0076, buf, 3);
			if (ret)
				goto error;

			if ((buf[2] >> 7) & 0x01) {
				post_bit_error = buf[2] << 16 | buf[1] << 8 |
						 buf[0] << 0;
				post_bit_error &= 0x0fffff;
				start_ber = true;
			} else {
				post_bit_error = 0;
				start_ber = false;
			}
		} else {
			post_bit_error = 0;
			start_ber = true;
		}

		if (start_ber) {
			ret = regmap_write(priv->regmap[1], 0x0079, 0x01);
			if (ret)
				goto error;
			priv->ber_running = true;
		}

		priv->post_bit_error += post_bit_error;

		c->post_bit_error.len = 1;
		c->post_bit_error.stat[0].scale = FE_SCALE_COUNTER;
		c->post_bit_error.stat[0].uvalue = priv->post_bit_error;
	} else {
		c->post_bit_error.len = 1;
		c->post_bit_error.stat[0].scale = FE_SCALE_NOT_AVAILABLE;
	}

	return ret;
error:
	dev_dbg(&client->dev, "failed=%d\n", ret);
	return ret;
}

int cxd2820r_init_c(struct dvb_frontend *fe)
{
	struct cxd2820r_priv *priv = fe->demodulator_priv;
	struct i2c_client *client = priv->client[0];
	int ret;

	dev_dbg(&client->dev, "\n");

	ret = regmap_write(priv->regmap[0], 0x0085, 0x07);
	if (ret)
		goto error;

	return ret;
error:
	dev_dbg(&client->dev, "failed=%d\n", ret);
	return ret;

Annotation

Implementation Notes