drivers/staging/fbtft/fb_ra8875.c

Source file repositories/reference/linux-study-clean/drivers/staging/fbtft/fb_ra8875.c

File Facts

System
Linux kernel
Corpus path
drivers/staging/fbtft/fb_ra8875.c
Extension
.c
Size
7372 bytes
Lines
299
Domain
Driver Families
Bucket
drivers/staging
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 (ret < 0) {
			va_end(args);
			dev_err(par->info->device,
				"write() failed and returned %dn", ret);
			return;
		}
	}
	va_end(args);

	/* restore user spi-speed */
	par->fbtftops.write = fbtft_write_spi;
	udelay(100);
}

static int write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
{
	u16 *vmem16;
	__be16 *txbuf16;
	size_t remain;
	size_t to_copy;
	size_t tx_array_size;
	int i;
	int ret = 0;
	size_t startbyte_size = 0;

	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
		      __func__, offset, len);

	remain = len / 2;
	vmem16 = (u16 *)(par->info->screen_buffer + offset);
	tx_array_size = par->txbuf.len / 2;
	txbuf16 = par->txbuf.buf + 1;
	tx_array_size -= 2;
	*(u8 *)(par->txbuf.buf) = 0x00;
	startbyte_size = 1;

	while (remain) {
		to_copy = min(tx_array_size, remain);
		dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
			to_copy, remain - to_copy);

		for (i = 0; i < to_copy; i++)
			txbuf16[i] = cpu_to_be16(vmem16[i]);

		vmem16 = vmem16 + to_copy;
		ret = par->fbtftops.write(par, par->txbuf.buf,
			startbyte_size + to_copy * 2);
		if (ret < 0)
			return ret;
		remain -= to_copy;
	}

	return ret;
}

static struct fbtft_display display = {
	.regwidth = 8,
	.fbtftops = {
		.init_display = init_display,
		.set_addr_win = set_addr_win,
		.write_register = write_reg8_bus8,
		.write_vmem = write_vmem16_bus8,
		.write = write_spi,
	},
};

FBTFT_REGISTER_DRIVER(DRVNAME, "raio,ra8875", &display);

MODULE_ALIAS("spi:" DRVNAME);
MODULE_ALIAS("platform:" DRVNAME);
MODULE_ALIAS("spi:ra8875");
MODULE_ALIAS("platform:ra8875");

MODULE_DESCRIPTION("FB driver for the RA8875 LCD Controller");
MODULE_AUTHOR("Pf@nne");
MODULE_LICENSE("GPL");

Annotation

Implementation Notes