| Ralf Baechle | 217dd11 | 2007-11-01 01:57:55 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2000, 2001 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/sb1250.h> |
| 25 | #include <asm/sibyte/sb1250_regs.h> |
| 26 | #include <asm/sibyte/sb1250_int.h> |
| 27 | #include <asm/sibyte/sb1250_scd.h> |
| 28 | |
| 29 | #define SB1250_HPT_NUM 3 |
| 30 | #define SB1250_HPT_VALUE M_SCD_TIMER_CNT /* max value */ |
| 31 | |
| 32 | /* |
| 33 | * The HPT is free running from SB1250_HPT_VALUE down to 0 then starts over |
| 34 | * again. |
| 35 | */ |
| 36 | static cycle_t sb1250_hpt_read(void) |
| 37 | { |
| 38 | unsigned int count; |
| 39 | |
| 40 | count = G_SCD_TIMER_CNT(__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CNT)))); |
| 41 | |
| 42 | return SB1250_HPT_VALUE - count; |
| 43 | } |
| 44 | |
| 45 | struct clocksource bcm1250_clocksource = { |
| Ralf Baechle | f99f2cc | 2007-11-13 00:35:13 +0000 | [diff] [blame] | 46 | .name = "bcm1250-counter-3", |
| Ralf Baechle | 217dd11 | 2007-11-01 01:57:55 +0000 | [diff] [blame] | 47 | .rating = 200, |
| 48 | .read = sb1250_hpt_read, |
| 49 | .mask = CLOCKSOURCE_MASK(23), |
| 50 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| 51 | }; |
| 52 | |
| 53 | void __init sb1250_clocksource_init(void) |
| 54 | { |
| 55 | struct clocksource *cs = &bcm1250_clocksource; |
| 56 | |
| 57 | /* Setup hpt using timer #3 but do not enable irq for it */ |
| 58 | __raw_writeq(0, |
| 59 | IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, |
| 60 | R_SCD_TIMER_CFG))); |
| 61 | __raw_writeq(SB1250_HPT_VALUE, |
| 62 | IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, |
| 63 | R_SCD_TIMER_INIT))); |
| 64 | __raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, |
| 65 | IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, |
| 66 | R_SCD_TIMER_CFG))); |
| 67 | |
| 68 | clocksource_set_clock(cs, V_SCD_TIMER_FREQ); |
| 69 | clocksource_register(cs); |
| 70 | } |