| Stefano Babic | 1c2b3ac | 2011-01-20 07:49:52 +0000 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2007 |
| 3 | * Sascha Hauer, Pengutronix |
| 4 | * |
| 5 | * (C) Copyright 2008-2009 Freescale Semiconductor, Inc. |
| 6 | * |
| 7 | * See file CREDITS for list of people who contributed to this |
| 8 | * project. |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License as |
| 12 | * published by the Free Software Foundation; either version 2 of |
| 13 | * the License, or (at your option) any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License |
| 21 | * along with this program; if not, write to the Free Software |
| 22 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 23 | * MA 02111-1307 USA |
| 24 | */ |
| 25 | |
| 26 | #include <common.h> |
| 27 | #include <asm/io.h> |
| 28 | #include <asm/arch/imx-regs.h> |
| 29 | |
| 30 | /* General purpose timers bitfields */ |
| 31 | #define GPTCR_SWR (1<<15) /* Software reset */ |
| 32 | #define GPTCR_FRR (1<<9) /* Freerun / restart */ |
| 33 | #define GPTCR_CLKSOURCE_32 (0x100<<6) /* Clock source */ |
| 34 | #define GPTCR_CLKSOURCE_IPG (0x001<<6) /* Clock source */ |
| 35 | #define GPTCR_TEN (1) /* Timer enable */ |
| 36 | #define GPTPR_VAL (66) |
| 37 | |
| 38 | int timer_init(void) |
| 39 | { |
| 40 | int i; |
| 41 | struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR; |
| 42 | |
| 43 | /* setup GP Timer 1 */ |
| 44 | writel(GPTCR_SWR, &gpt->ctrl); |
| 45 | for (i = 0; i < 100; i++) |
| 46 | writel(0, &gpt->ctrl); /* We have no udelay by now */ |
| 47 | |
| 48 | writel(GPTPR_VAL, &gpt->pre); |
| 49 | /* Freerun Mode, PERCLK1 input */ |
| 50 | writel(readl(&gpt->ctrl) | |
| 51 | GPTCR_CLKSOURCE_IPG | GPTCR_TEN, |
| 52 | &gpt->ctrl); |
| 53 | |
| 54 | return 0; |
| 55 | } |
| 56 | |
| 57 | void reset_timer_masked(void) |
| 58 | { |
| 59 | struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR; |
| 60 | |
| 61 | writel(0, &gpt->ctrl); |
| 62 | /* Freerun Mode, PERCLK1 input */ |
| 63 | writel(GPTCR_CLKSOURCE_IPG | GPTCR_TEN, |
| 64 | &gpt->ctrl); |
| 65 | } |
| 66 | |
| 67 | inline ulong get_timer_masked(void) |
| 68 | { |
| 69 | |
| 70 | struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR; |
| 71 | ulong val = readl(&gpt->counter); |
| 72 | |
| 73 | return val; |
| 74 | } |
| 75 | |
| Stefano Babic | 1c2b3ac | 2011-01-20 07:49:52 +0000 | [diff] [blame] | 76 | ulong get_timer(ulong base) |
| 77 | { |
| 78 | ulong tmp; |
| 79 | |
| 80 | tmp = get_timer_masked(); |
| 81 | |
| 82 | if (tmp <= (base * 1000)) { |
| 83 | /* Overflow */ |
| 84 | tmp += (0xffffffff - base); |
| 85 | } |
| 86 | |
| 87 | return (tmp / 1000) - base; |
| 88 | } |
| 89 | |
| Stefano Babic | 1c2b3ac | 2011-01-20 07:49:52 +0000 | [diff] [blame] | 90 | /* |
| 91 | * delay x useconds AND preserve advance timstamp value |
| 92 | * GPTCNT is now supposed to tick 1 by 1 us. |
| 93 | */ |
| 94 | void __udelay(unsigned long usec) |
| 95 | { |
| 96 | ulong tmp; |
| 97 | |
| 98 | tmp = get_timer_masked(); /* get current timestamp */ |
| 99 | |
| 100 | /* if setting this forward will roll time stamp */ |
| 101 | if ((usec + tmp + 1) < tmp) { |
| 102 | /* reset "advancing" timestamp to 0, set lastinc value */ |
| 103 | reset_timer_masked(); |
| 104 | } else { |
| 105 | /* else, set advancing stamp wake up time */ |
| 106 | tmp += usec; |
| 107 | } |
| 108 | |
| 109 | while (get_timer_masked() < tmp) /* loop till event */ |
| 110 | /*NOP*/; |
| 111 | } |