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Commit 8c2d7821 authored by Steven Toth's avatar Steven Toth Committed by Mauro Carvalho Chehab
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V4L/DVB (13092): cx25840: Improvements to the cx23885/7/8 chip detection mechanism. 



The prior mechanism wasn't reliable with the cx23887. This new mechanism
tests correctly against cx23885, 7 and 8 based products.

Signed-off-by: default avatarSteven Toth <stoth@kernellabs.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent c6b7053b

drivers/media/video/cx25840/cx25840-core.c

+18 −3
Original line number Diff line number Diff line
@@ -1598,14 +1598,29 @@ static u32 get_cx2388x_ident(struct i2c_client *client) 
	/* Come out of digital power down */

	cx25840_write(client, 0x000, 0);



	/* Detecting whether the part is cx23885/7/8 is more

	 * difficult than it needs to be. No ID register. Instead we

	 * probe certain registers indicated in the datasheets to look

	 * for specific defaults that differ between the silicon designs. */



	/* It's either 885/7 if the IR Tx Clk Divider register exists */

	if (cx25840_read4(client, 0x204) & 0xffff) {

		/* IR Tx Clk Divider register exists; chip must be a CX23885 */

		/* CX23885 returns bogus repetitive byte values for the DIF,

		 * which doesn't exist for it. (Ex. 8a8a8a8a or 31313131) */

		ret = cx25840_read4(client, 0x300);

		if (((ret & 0xffff0000) >> 16) == (ret & 0xffff)) {

			/* No DIF */

			ret = V4L2_IDENT_CX23885_AV;

		} else {

			/* CX23887 has a broken DIF, but the registers

			 * appear valid (but unsed), good enough to detect. */

			ret = V4L2_IDENT_CX23887_AV;

		}

	} else if (cx25840_read4(client, 0x300) & 0x0fffffff) {

		/* DIF PLL Freq Word reg exists; chip must be a CX23888 */

		ret = V4L2_IDENT_CX23888_AV;

	} else {

		/* A CX23887 A/V core has neither IR nor DIF */

		v4l_err(client, "Unable to detect h/w, assuming cx23887\n");

		ret = V4L2_IDENT_CX23887_AV;

	}