drivers/staging/media/av7110/sp8870.c

Source file repositories/reference/linux-study-clean/drivers/staging/media/av7110/sp8870.c

File Facts

System
Linux kernel
Corpus path
drivers/staging/media/av7110/sp8870.c
Extension
.c
Size
14100 bytes
Lines
626
Domain
Driver Families
Bucket
drivers/staging
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 sp8870_state {
	struct i2c_adapter *i2c;

	const struct sp8870_config *config;

	struct dvb_frontend frontend;

	/* demodulator private data */
	u8 initialised:1;
};

static int debug;
#define dprintk(fmt, arg...) \
	do { \
		if (debug) \
			pr_info("%s(): " fmt, __func__, ##arg); \
	} while (0)

/* firmware size for sp8870 */
#define SP8870_FIRMWARE_SIZE 16382

/* starting point for firmware in file 'Sc_main.mc' */
#define SP8870_FIRMWARE_OFFSET 0x0A

static int sp8870_writereg(struct sp8870_state *state, u16 reg, u16 data)
{
	u8 buf[] = { reg >> 8, reg & 0xff, data >> 8, data & 0xff };
	struct i2c_msg msg = {
		.addr = state->config->demod_address,
		.flags = 0,
		.buf = buf,
		.len = 4
	};

	int err;

	err = i2c_transfer(state->i2c, &msg, 1);
	if (err != 1) {
		dprintk("writereg error (err == %i, reg == 0x%02x, data == 0x%02x)\n", err, reg, data);
		return -EREMOTEIO;
	}

	return 0;
}

static int sp8870_readreg(struct sp8870_state *state, u16 reg)
{
	int ret;
	u8 b0[] = { reg >> 8, reg & 0xff };
	u8 b1[] = { 0, 0 };
	struct i2c_msg msg[] = {
		{ .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 2 },
		{ .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b1, .len = 2 }
	};

	ret = i2c_transfer(state->i2c, msg, 2);

	if (ret != 2) {
		dprintk("readreg error (ret == %i)\n", ret);
		return -1;
	}

	return (b1[0] << 8 | b1[1]);
}

static int sp8870_firmware_upload(struct sp8870_state *state, const struct firmware *fw)
{
	struct i2c_msg msg;
	const char *fw_buf = fw->data;
	int fw_pos;
	u8 tx_buf[255];
	int tx_len;
	int err = 0;

	dprintk("start firmware upload...\n");

	if (fw->size < SP8870_FIRMWARE_SIZE + SP8870_FIRMWARE_OFFSET)
		return -EINVAL;

	// system controller stop
	sp8870_writereg(state, 0x0F00, 0x0000);

	// instruction RAM register hiword
	sp8870_writereg(state, 0x8F08, ((SP8870_FIRMWARE_SIZE / 2) & 0xFFFF));

	// instruction RAM MWR
	sp8870_writereg(state, 0x8F0A, ((SP8870_FIRMWARE_SIZE / 2) >> 16));

	// do firmware upload
	fw_pos = SP8870_FIRMWARE_OFFSET;

Annotation

Implementation Notes