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/export.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);