1 /* 2 * Copyright (C) 2000,2001,2004 Broadcom Corporation 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 17 */ 18 #include <linux/clocksource.h> 19 20 #include <asm/addrspace.h> 21 #include <asm/io.h> 22 #include <asm/time.h> 23 24 #include <asm/sibyte/bcm1480_regs.h> 25 #include <asm/sibyte/sb1250_regs.h> 26 #include <asm/sibyte/bcm1480_int.h> 27 #include <asm/sibyte/bcm1480_scd.h> 28 29 #include <asm/sibyte/sb1250.h> 30 31 static cycle_t bcm1480_hpt_read(struct clocksource *cs) 32 { 33 return (cycle_t) __raw_readq(IOADDR(A_SCD_ZBBUS_CYCLE_COUNT)); 34 } 35 36 struct clocksource bcm1480_clocksource = { 37 .name = "zbbus-cycles", 38 .rating = 200, 39 .read = bcm1480_hpt_read, 40 .mask = CLOCKSOURCE_MASK(64), 41 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 42 }; 43 44 void __init sb1480_clocksource_init(void) 45 { 46 struct clocksource *cs = &bcm1480_clocksource; 47 unsigned int plldiv; 48 unsigned long zbbus; 49 50 plldiv = G_BCM1480_SYS_PLL_DIV(__raw_readq(IOADDR(A_SCD_SYSTEM_CFG))); 51 zbbus = ((plldiv >> 1) * 50000000) + ((plldiv & 1) * 25000000); 52 clocksource_register_hz(cs, zbbus); 53 } 54