projects / linux-2.6-block.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. | |
| 15 | * | |
| 16 | * You should have received a copy of the GNU General Public License | |
| 17 | * along with this program; if not, write to the Free Software | |
| 18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
| 19 | * | |
| 20 | */ | |
| 21 | #include <linux/platform_device.h> | |
| 0583fe47 | 22 | #include <linux/clocksource.h> |
| 0f2c9f20 | 23 | #include <linux/delay.h> |
| c39dae38 | 24 | #include <linux/of_address.h> |
| c793c1b0 | 25 | |
| 7dd4cfd7 MD |
26 | static void __init shmobile_setup_delay_hz(unsigned int max_cpu_core_hz, |
| 27 | unsigned int mult, unsigned int div) | |
| f492b817 SH |
28 | { |
| 29 | /* calculate a worst-case loops-per-jiffy value | |
| 30 | * based on maximum cpu core hz setting and the | |
| 31 | * __delay() implementation in arch/arm/lib/delay.S | |
| 32 | * | |
| 33 | * this will result in a longer delay than expected | |
| 34 | * when the cpu core runs on lower frequencies. | |
| 35 | */ | |
| 36 | ||
| 37 | unsigned int value = HZ * div / mult; | |
| 38 | ||
| 39 | if (!preset_lpj) | |
| 40 | preset_lpj = max_cpu_core_hz / value; | |
| 41 | } | |
| 42 | ||
| c39dae38 MD |
43 | void __init shmobile_init_delay(void) |
| 44 | { | |
| edc8fb1d | 45 | struct device_node *np, *cpus; |
| 0dc50fd3 | 46 | bool is_a7_a8_a9 = false; |
| edc8fb1d LP |
47 | bool is_a15 = false; |
| 48 | u32 max_freq = 0; | |
| 49 | ||
| 50 | cpus = of_find_node_by_path("/cpus"); | |
| 51 | if (!cpus) | |
| 52 | return; | |
| 53 | ||
| 54 | for_each_child_of_node(cpus, np) { | |
| 55 | u32 freq; | |
| 56 | ||
| 57 | if (!of_property_read_u32(np, "clock-frequency", &freq)) | |
| 58 | max_freq = max(max_freq, freq); | |
| c39dae38 | 59 | |
| 0dc50fd3 UH |
60 | if (of_device_is_compatible(np, "arm,cortex-a7") || |
| 61 | of_device_is_compatible(np, "arm,cortex-a8") || | |
| edc8fb1d | 62 | of_device_is_compatible(np, "arm,cortex-a9")) |
| 0dc50fd3 | 63 | is_a7_a8_a9 = true; |
| edc8fb1d LP |
64 | else if (of_device_is_compatible(np, "arm,cortex-a15")) |
| 65 | is_a15 = true; | |
| c39dae38 | 66 | } |
| edc8fb1d LP |
67 | |
| 68 | of_node_put(cpus); | |
| 69 | ||
| 70 | if (!max_freq) | |
| 71 | return; | |
| 72 | ||
| 0dc50fd3 | 73 | if (is_a7_a8_a9) |
| edc8fb1d LP |
74 | shmobile_setup_delay_hz(max_freq, 1, 3); |
| 75 | else if (is_a15 && !IS_ENABLED(CONFIG_ARM_ARCH_TIMER)) | |
| 76 | shmobile_setup_delay_hz(max_freq, 2, 4); | |
| c39dae38 MD |
77 | } |
| 78 | ||
| c793c1b0 MD |
79 | static void __init shmobile_late_time_init(void) |
| 80 | { | |
| 81 | /* | |
| 82 | * Make sure all compiled-in early timers register themselves. | |
| 83 | * | |
| 84 | * Run probe() for two "earlytimer" devices, these will be the | |
| 85 | * clockevents and clocksource devices respectively. In the event | |
| 86 | * that only a clockevents device is available, we -ENODEV on the | |
| 87 | * clocksource and the jiffies clocksource is used transparently | |
| 88 | * instead. No error handling is necessary here. | |
| 89 | */ | |
| 90 | early_platform_driver_register_all("earlytimer"); | |
| 91 | early_platform_driver_probe("earlytimer", 2, 0); | |
| 92 | } | |
| 93 | ||
| 08ad42fb | 94 | void __init shmobile_earlytimer_init(void) |
| c793c1b0 MD |
95 | { |
| 96 | late_time_init = shmobile_late_time_init; | |
| 97 | } | |
| 98 |