drivers/gpu/drm/bridge/ite-it66121.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/bridge/ite-it66121.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/bridge/ite-it66121.c
Extension
.c
Size
46356 bytes
Lines
1742
Domain
Driver Families
Bucket
drivers/gpu
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 it66121_chip_info {
	enum chip_id id;
	u16 vid, pid;
};

struct it66121_ctx {
	struct regmap *regmap;
	struct drm_bridge bridge;
	struct device *dev;
	struct gpio_desc *gpio_reset;
	struct i2c_client *client;
	u32 bus_width;
	struct mutex lock; /* Protects fields below and device registers */
	struct {
		u8 ch_enable;
		u8 fs;
		u8 swl;
		bool auto_cts;
	} audio;
	enum chip_id id;
};

static const struct regmap_range_cfg it66121_regmap_banks[] = {
	{
		.name = "it66121",
		.range_min = 0x00,
		.range_max = 0x1FF,
		.selector_reg = IT66121_CLK_BANK_REG,
		.selector_mask = 0x1,
		.selector_shift = 0,
		.window_start = 0x00,
		.window_len = 0x100,
	},
};

static const struct regmap_config it66121_regmap_config = {
	.val_bits = 8,
	.reg_bits = 8,
	.max_register = 0x1FF,
	.ranges = it66121_regmap_banks,
	.num_ranges = ARRAY_SIZE(it66121_regmap_banks),
};

static void it66121_hw_reset(struct it66121_ctx *ctx)
{
	gpiod_set_value(ctx->gpio_reset, 1);
	msleep(20);
	gpiod_set_value(ctx->gpio_reset, 0);
}

static inline int it66121_preamble_ddc(struct it66121_ctx *ctx)
{
	return regmap_write(ctx->regmap, IT66121_MASTER_SEL_REG, IT66121_MASTER_SEL_HOST);
}

static inline int it66121_fire_afe(struct it66121_ctx *ctx)
{
	return regmap_write(ctx->regmap, IT66121_AFE_DRV_REG, 0);
}

/* TOFIX: Handle YCbCr Input & Output */
static int it66121_configure_input(struct it66121_ctx *ctx)
{
	int ret;
	u8 mode = IT66121_INPUT_MODE_RGB;

	if (ctx->bus_width == 12)
		mode |= IT66121_INPUT_MODE_DDR;

	ret = regmap_write(ctx->regmap, IT66121_INPUT_MODE_REG, mode);
	if (ret)
		return ret;

	return regmap_write(ctx->regmap, IT66121_INPUT_CSC_REG, IT66121_INPUT_CSC_NO_CONV);
}

/**
 * it66121_configure_afe() - Configure the analog front end
 * @ctx: it66121_ctx object
 * @mode: mode to configure
 *
 * RETURNS:
 * zero if success, a negative error code otherwise.
 */
static int it66121_configure_afe(struct it66121_ctx *ctx,
				 const struct drm_display_mode *mode)
{
	int ret;

	ret = regmap_write(ctx->regmap, IT66121_AFE_DRV_REG,

Annotation

Implementation Notes