| wdenk | e0c812a | 2005-04-03 15:51:42 +0000 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2000 |
| 3 | * Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
| 4 | * |
| Wolfgang Denk | d79de1d | 2013-07-08 09:37:19 +0200 | [diff] [blame] | 5 | * SPDX-License-Identifier: GPL-2.0+ |
| wdenk | e0c812a | 2005-04-03 15:51:42 +0000 | [diff] [blame] | 6 | */ |
| 7 | |
| 8 | /*----------------------------------------------------------------------- |
| 9 | * Timer value for timer 2, ICLK = 10 |
| 10 | * |
| 11 | * SPEED_FCOUNT2 = GCLK / (16 * (TIMER_TMR_PS + 1)) |
| 12 | * SPEED_TMR3_PS = (GCLK / (16 * SPEED_FCOUNT3)) - 1 |
| 13 | * |
| 14 | * SPEED_FCOUNT2 timer 2 counting frequency |
| Wolfgang Denk | a1be476 | 2008-05-20 16:00:29 +0200 | [diff] [blame] | 15 | * GCLK CPU clock |
| wdenk | e0c812a | 2005-04-03 15:51:42 +0000 | [diff] [blame] | 16 | * SPEED_TMR2_PS prescaler |
| 17 | */ |
| Wolfgang Denk | a1be476 | 2008-05-20 16:00:29 +0200 | [diff] [blame] | 18 | #define SPEED_TMR2_PS (250 - 1) /* divide by 250 */ |
| wdenk | e0c812a | 2005-04-03 15:51:42 +0000 | [diff] [blame] | 19 | |
| 20 | /*----------------------------------------------------------------------- |
| 21 | * Timer value for PIT |
| 22 | * |
| 23 | * PIT_TIME = SPEED_PITC / PITRTCLK |
| 24 | * PITRTCLK = 8192 |
| 25 | */ |
| 26 | #define SPEED_PITC (82 << 16) /* start counting from 82 */ |
| 27 | |
| 28 | /* |
| 29 | * The new value for PTA is calculated from |
| 30 | * |
| 31 | * PTA = (gclk * Trefresh) / (2 ^ (2 * DFBRG) * PTP * NCS) |
| 32 | * |
| 33 | * gclk CPU clock (not bus clock !) |
| 34 | * Trefresh Refresh cycle * 4 (four word bursts used) |
| 35 | * DFBRG For normal mode (no clock reduction) always 0 |
| 36 | * PTP Prescaler (already adjusted for no. of banks and 4K / 8K refresh) |
| 37 | * NCS Number of SDRAM banks (chip selects) on this UPM. |
| 38 | */ |