1 /***********************license start***************
2  * Author: Cavium Networks
3  *
4  * Contact: support@caviumnetworks.com
5  * This file is part of the OCTEON SDK
6  *
7  * Copyright (c) 2003-2008 Cavium Networks
8  *
9  * This file is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License, Version 2, as
11  * published by the Free Software Foundation.
12  *
13  * This file is distributed in the hope that it will be useful, but
14  * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
16  * NONINFRINGEMENT.  See the GNU General Public License for more
17  * details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this file; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22  * or visit http://www.gnu.org/licenses/.
23  *
24  * This file may also be available under a different license from Cavium.
25  * Contact Cavium Networks for more information
26  ***********************license end**************************************/
27 
28 /**
29  *
30  * Fixes and workaround for Octeon chip errata. This file
31  * contains functions called by cvmx-helper to workaround known
32  * chip errata. For the most part, code doesn't need to call
33  * these functions directly.
34  *
35  */
36 #include <linux/module.h>
37 
38 #include <asm/octeon/octeon.h>
39 
40 #include <asm/octeon/cvmx-helper-jtag.h>
41 
42 /**
43  * Due to errata G-720, the 2nd order CDR circuit on CN52XX pass
44  * 1 doesn't work properly. The following code disables 2nd order
45  * CDR for the specified QLM.
46  *
47  * @qlm:    QLM to disable 2nd order CDR for.
48  */
49 void __cvmx_helper_errata_qlm_disable_2nd_order_cdr(int qlm)
50 {
51 	int lane;
52 	cvmx_helper_qlm_jtag_init();
53 	/* We need to load all four lanes of the QLM, a total of 1072 bits */
54 	for (lane = 0; lane < 4; lane++) {
55 		/*
56 		 * Each lane has 268 bits. We need to set
57 		 * cfg_cdr_incx<67:64> = 3 and cfg_cdr_secord<77> =
58 		 * 1. All other bits are zero. Bits go in LSB first,
59 		 * so start off with the zeros for bits <63:0>.
60 		 */
61 		cvmx_helper_qlm_jtag_shift_zeros(qlm, 63 - 0 + 1);
62 		/* cfg_cdr_incx<67:64>=3 */
63 		cvmx_helper_qlm_jtag_shift(qlm, 67 - 64 + 1, 3);
64 		/* Zeros for bits <76:68> */
65 		cvmx_helper_qlm_jtag_shift_zeros(qlm, 76 - 68 + 1);
66 		/* cfg_cdr_secord<77>=1 */
67 		cvmx_helper_qlm_jtag_shift(qlm, 77 - 77 + 1, 1);
68 		/* Zeros for bits <267:78> */
69 		cvmx_helper_qlm_jtag_shift_zeros(qlm, 267 - 78 + 1);
70 	}
71 	cvmx_helper_qlm_jtag_update(qlm);
72 }
73 EXPORT_SYMBOL(__cvmx_helper_errata_qlm_disable_2nd_order_cdr);
74