projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| c793c1b0 MD |
1 | /* |
| 2 | * SH-Mobile Timer | |
| 3 | * | |
| 4 | * Copyright (C) 2010 Magnus Damm | |
| 5 | * Copyright (C) 2002 - 2009 Paul Mundt | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or modify | |
| 8 | * it under the terms of the GNU General Public License as published by | |
| 9 | * the Free Software Foundation; version 2 of the License. | |
| 10 | * | |
| 11 | * This program is distributed in the hope that it will be useful, | |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 14 | * GNU General Public License for more details. | |
| c793c1b0 MD |
15 | */ |
| 16 | #include <linux/platform_device.h> | |
| 0583fe47 | 17 | #include <linux/clocksource.h> |
| 0f2c9f20 | 18 | #include <linux/delay.h> |
| c39dae38 | 19 | #include <linux/of_address.h> |
| c793c1b0 | 20 | |
| 7dd4cfd7 MD |
21 | static void __init shmobile_setup_delay_hz(unsigned int max_cpu_core_hz, |
| 22 | unsigned int mult, unsigned int div) | |
| f492b817 SH |
23 | { |
| 24 | /* calculate a worst-case loops-per-jiffy value | |
| 25 | * based on maximum cpu core hz setting and the | |
| 26 | * __delay() implementation in arch/arm/lib/delay.S | |
| 27 | * | |
| 28 | * this will result in a longer delay than expected | |
| 29 | * when the cpu core runs on lower frequencies. | |
| 30 | */ | |
| 31 | ||
| 32 | unsigned int value = HZ * div / mult; | |
| 33 | ||
| 34 | if (!preset_lpj) | |
| 35 | preset_lpj = max_cpu_core_hz / value; | |
| 36 | } | |
| 37 | ||
| c39dae38 MD |
38 | void __init shmobile_init_delay(void) |
| 39 | { | |
| edc8fb1d | 40 | struct device_node *np, *cpus; |
| 0dc50fd3 | 41 | bool is_a7_a8_a9 = false; |
| edc8fb1d | 42 | bool is_a15 = false; |
| 27f3c708 | 43 | bool has_arch_timer = false; |
| edc8fb1d LP |
44 | u32 max_freq = 0; |
| 45 | ||
| 46 | cpus = of_find_node_by_path("/cpus"); | |
| 47 | if (!cpus) | |
| 48 | return; | |
| 49 | ||
| 50 | for_each_child_of_node(cpus, np) { | |
| 51 | u32 freq; | |
| 52 | ||
| 53 | if (!of_property_read_u32(np, "clock-frequency", &freq)) | |
| 54 | max_freq = max(max_freq, freq); | |
| c39dae38 | 55 | |
| 27f3c708 MD |
56 | if (of_device_is_compatible(np, "arm,cortex-a8") || |
| 57 | of_device_is_compatible(np, "arm,cortex-a9")) { | |
| 0dc50fd3 | 58 | is_a7_a8_a9 = true; |
| 27f3c708 MD |
59 | } else if (of_device_is_compatible(np, "arm,cortex-a7")) { |
| 60 | is_a7_a8_a9 = true; | |
| 61 | has_arch_timer = true; | |
| 62 | } else if (of_device_is_compatible(np, "arm,cortex-a15")) { | |
| edc8fb1d | 63 | is_a15 = true; |
| 27f3c708 MD |
64 | has_arch_timer = true; |
| 65 | } | |
| c39dae38 | 66 | } |
| edc8fb1d LP |
67 | |
| 68 | of_node_put(cpus); | |
| 69 | ||
| 70 | if (!max_freq) | |
| 71 | return; | |
| 72 | ||
| 27f3c708 MD |
73 | if (!has_arch_timer || !IS_ENABLED(CONFIG_ARM_ARCH_TIMER)) { |
| 74 | if (is_a7_a8_a9) | |
| 75 | shmobile_setup_delay_hz(max_freq, 1, 3); | |
| 76 | else if (is_a15) | |
| 77 | shmobile_setup_delay_hz(max_freq, 2, 4); | |
| 78 | } | |
| c39dae38 | 79 | } |