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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 | /* * PPS kernel consumer API * * Copyright (C) 2009-2010 Alexander Gordeev <lasaine@lvk.cs.msu.su> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/module.h> #include <linux/device.h> #include <linux/init.h> #include <linux/spinlock.h> #include <linux/pps_kernel.h> #include "kc.h" /* * Global variables */ /* state variables to bind kernel consumer */ DEFINE_SPINLOCK(pps_kc_hardpps_lock); /* PPS API (RFC 2783): current source and mode for kernel consumer */ struct pps_device *pps_kc_hardpps_dev; /* unique pointer to device */ int pps_kc_hardpps_mode; /* mode bits for kernel consumer */ /* pps_kc_bind - control PPS kernel consumer binding * @pps: the PPS source * @bind_args: kernel consumer bind parameters * * This function is used to bind or unbind PPS kernel consumer according to * supplied parameters. Should not be called in interrupt context. */ int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args) { /* Check if another consumer is already bound */ spin_lock_irq(&pps_kc_hardpps_lock); if (bind_args->edge == 0) if (pps_kc_hardpps_dev == pps) { pps_kc_hardpps_mode = 0; pps_kc_hardpps_dev = NULL; spin_unlock_irq(&pps_kc_hardpps_lock); dev_info(pps->dev, "unbound kernel" " consumer\n"); } else { spin_unlock_irq(&pps_kc_hardpps_lock); dev_err(pps->dev, "selected kernel consumer" " is not bound\n"); return -EINVAL; } else if (pps_kc_hardpps_dev == NULL || pps_kc_hardpps_dev == pps) { pps_kc_hardpps_mode = bind_args->edge; pps_kc_hardpps_dev = pps; spin_unlock_irq(&pps_kc_hardpps_lock); dev_info(pps->dev, "bound kernel consumer: " "edge=0x%x\n", bind_args->edge); } else { spin_unlock_irq(&pps_kc_hardpps_lock); dev_err(pps->dev, "another kernel consumer" " is already bound\n"); return -EINVAL; } return 0; } /* pps_kc_remove - unbind kernel consumer on PPS source removal * @pps: the PPS source * * This function is used to disable kernel consumer on PPS source removal * if this source was bound to PPS kernel consumer. Can be called on any * source safely. Should not be called in interrupt context. */ void pps_kc_remove(struct pps_device *pps) { spin_lock_irq(&pps_kc_hardpps_lock); if (pps == pps_kc_hardpps_dev) { pps_kc_hardpps_mode = 0; pps_kc_hardpps_dev = NULL; spin_unlock_irq(&pps_kc_hardpps_lock); dev_info(pps->dev, "unbound kernel consumer" " on device removal\n"); } else spin_unlock_irq(&pps_kc_hardpps_lock); } /* pps_kc_event - call hardpps() on PPS event * @pps: the PPS source * @ts: PPS event timestamp * @event: PPS event edge * * This function calls hardpps() when an event from bound PPS source occurs. */ void pps_kc_event(struct pps_device *pps, struct pps_event_time *ts, int event) { unsigned long flags; /* Pass some events to kernel consumer if activated */ spin_lock_irqsave(&pps_kc_hardpps_lock, flags); if (pps == pps_kc_hardpps_dev && event & pps_kc_hardpps_mode) hardpps(&ts->ts_real, &ts->ts_raw); spin_unlock_irqrestore(&pps_kc_hardpps_lock, flags); } |