drivers/media/dvb-frontends/mb86a20s.c

File Facts

System

Linux kernel

Corpus path

drivers/media/dvb-frontends/mb86a20s.c

Extension

.c

Size

53389 bytes

Lines

2113

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.

• 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.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/kernel.h
• asm/div64.h
• media/dvb_frontend.h
• mb86a20s.h

Detected Declarations

• struct mb86a20s_state
• struct regdata
• struct linear_segments
• enum mb86a20s_bandwidth
• function mb86a20s_i2c_writereg
• function mb86a20s_i2c_writeregdata
• function mb86a20s_i2c_readreg
• function routines
• function mb86a20s_read_signal_strength
• function mb86a20s_get_modulation
• function mb86a20s_get_fec
• function mb86a20s_get_interleaving
• function mb86a20s_get_segment_count
• function mb86a20s_reset_frontend_cache
• function isdbt_layer_min_bitrate
• function mb86a20s_get_frontend
• function mb86a20s_reset_counters
• function mb86a20s_get_pre_ber
• function mb86a20s_get_post_ber
• function mb86a20s_get_blk_error
• function interpolate_value
• function mb86a20s_get_main_CNR
• function mb86a20s_get_blk_error_layer_CNR
• function mb86a20s_stats_not_ready
• function mb86a20s_get_stats
• function mb86a20s_initfe
• function mb86a20s_set_frontend
• function mb86a20s_read_status_and_stats
• function mb86a20s_read_signal_strength_from_cache
• function mb86a20s_tune
• function mb86a20s_release
• function mb86a20s_get_frontend_algo
• export mb86a20s_attach

Annotated Snippet

struct mb86a20s_state {
	struct i2c_adapter *i2c;
	const struct mb86a20s_config *config;
	u32 last_frequency;

	struct dvb_frontend frontend;

	u32 if_freq;
	enum mb86a20s_bandwidth bw;
	bool inversion;
	u32 subchannel;

	u32 estimated_rate[NUM_LAYERS];
	unsigned long get_strength_time;

	bool need_init;
};

struct regdata {
	u8 reg;
	u8 data;
};

#define BER_SAMPLING_RATE	1	/* Seconds */

/*
 * Initialization sequence: Use whatevere default values that PV SBTVD
 * does on its initialisation, obtained via USB snoop
 */
static struct regdata mb86a20s_init1[] = {
	{ 0x70, 0x0f },
	{ 0x70, 0xff },
	{ 0x08, 0x01 },
	{ 0x50, 0xd1 }, { 0x51, 0x20 },
};

static struct regdata mb86a20s_init2[] = {
	{ 0x50, 0xd1 }, { 0x51, 0x22 },
	{ 0x39, 0x01 },
	{ 0x71, 0x00 },
	{ 0x3b, 0x21 },
	{ 0x3c, 0x3a },
	{ 0x01, 0x0d },
	{ 0x04, 0x08 }, { 0x05, 0x05 },
	{ 0x04, 0x0e }, { 0x05, 0x00 },
	{ 0x04, 0x0f }, { 0x05, 0x14 },
	{ 0x04, 0x0b }, { 0x05, 0x8c },
	{ 0x04, 0x00 }, { 0x05, 0x00 },
	{ 0x04, 0x01 }, { 0x05, 0x07 },
	{ 0x04, 0x02 }, { 0x05, 0x0f },
	{ 0x04, 0x03 }, { 0x05, 0xa0 },
	{ 0x04, 0x09 }, { 0x05, 0x00 },
	{ 0x04, 0x0a }, { 0x05, 0xff },
	{ 0x04, 0x27 }, { 0x05, 0x64 },
	{ 0x04, 0x28 }, { 0x05, 0x00 },
	{ 0x04, 0x1e }, { 0x05, 0xff },
	{ 0x04, 0x29 }, { 0x05, 0x0a },
	{ 0x04, 0x32 }, { 0x05, 0x0a },
	{ 0x04, 0x14 }, { 0x05, 0x02 },
	{ 0x04, 0x04 }, { 0x05, 0x00 },
	{ 0x04, 0x05 }, { 0x05, 0x22 },
	{ 0x04, 0x06 }, { 0x05, 0x0e },
	{ 0x04, 0x07 }, { 0x05, 0xd8 },
	{ 0x04, 0x12 }, { 0x05, 0x00 },
	{ 0x04, 0x13 }, { 0x05, 0xff },

	/*
	 * On this demod, when the bit count reaches the count below,
	 * it collects the bit error count. The bit counters are initialized
	 * to 65535 here. This warrants that all of them will be quickly
	 * calculated when device gets locked. As TMCC is parsed, the values
	 * will be adjusted later in the driver's code.
	 */
	{ 0x52, 0x01 },				/* Turn on BER before Viterbi */
	{ 0x50, 0xa7 }, { 0x51, 0x00 },
	{ 0x50, 0xa8 }, { 0x51, 0xff },
	{ 0x50, 0xa9 }, { 0x51, 0xff },
	{ 0x50, 0xaa }, { 0x51, 0x00 },
	{ 0x50, 0xab }, { 0x51, 0xff },
	{ 0x50, 0xac }, { 0x51, 0xff },
	{ 0x50, 0xad }, { 0x51, 0x00 },
	{ 0x50, 0xae }, { 0x51, 0xff },
	{ 0x50, 0xaf }, { 0x51, 0xff },

	/*
	 * On this demod, post BER counts blocks. When the count reaches the
	 * value below, it collects the block error count. The block counters
	 * are initialized to 127 here. This warrants that all of them will be
	 * quickly calculated when device gets locked. As TMCC is parsed, the
	 * values will be adjusted later in the driver's code.

Annotation

• Immediate include surface: `linux/kernel.h`, `asm/div64.h`, `media/dvb_frontend.h`, `mb86a20s.h`.
• Detected declarations: `struct mb86a20s_state`, `struct regdata`, `struct linear_segments`, `enum mb86a20s_bandwidth`, `function mb86a20s_i2c_writereg`, `function mb86a20s_i2c_writeregdata`, `function mb86a20s_i2c_readreg`, `function routines`, `function mb86a20s_read_signal_strength`, `function mb86a20s_get_modulation`.
• Atlas domain: Driver Families / drivers/media.
• Implementation status: integration implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.