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e890591413
When a siox master device is registered a kthread is created that is only started when triggered by userspace. So this thread might be in TASK_UNINTERRUPTIBLE state for long and trigger a warning [ 241.130465] INFO: task siox-0:626 blocked for more than 120 seconds. with the respective debug settings enabled. It might be right to put an unstarted thread to TASK_IDLE (in kernel/kthread.c:kthread()) instead, but independant of this discussion it is cleaner for siox_master_register() to start the thread immediately. The effect is that it enters its own waiting state and then stays in state TASK_IDLE which doesn't trigger the above warning. As siox_poll_thread() uses some variables of the device the initialisation of these is moved before thread creation. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Gavin Schenk <g.schenk@eckelmann.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
935 lines
21 KiB
C
935 lines
21 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2015-2017 Pengutronix, Uwe Kleine-König <kernel@pengutronix.de>
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*/
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include "siox.h"
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/*
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* The lowest bit in the SIOX status word signals if the in-device watchdog is
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* ok. If the bit is set, the device is functional.
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*
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* On writing the watchdog timer is reset when this bit toggles.
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*/
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#define SIOX_STATUS_WDG 0x01
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/*
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* Bits 1 to 3 of the status word read as the bitwise negation of what was
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* clocked in before. The value clocked in is changed in each cycle and so
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* allows to detect transmit/receive problems.
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*/
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#define SIOX_STATUS_COUNTER 0x0e
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/*
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* Each Siox-Device has a 4 bit type number that is neither 0 nor 15. This is
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* available in the upper nibble of the read status.
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*
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* On write these bits are DC.
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*/
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#define SIOX_STATUS_TYPE 0xf0
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#define CREATE_TRACE_POINTS
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#include <trace/events/siox.h>
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static bool siox_is_registered;
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static void siox_master_lock(struct siox_master *smaster)
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{
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mutex_lock(&smaster->lock);
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}
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static void siox_master_unlock(struct siox_master *smaster)
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{
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mutex_unlock(&smaster->lock);
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}
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static inline u8 siox_status_clean(u8 status_read, u8 status_written)
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{
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/*
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* bits 3:1 of status sample the respective bit in the status
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* byte written in the previous cycle but inverted. So if you wrote the
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* status word as 0xa before (counter = 0b101), it is expected to get
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* back the counter bits as 0b010.
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*
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* So given the last status written this function toggles the there
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* unset counter bits in the read value such that the counter bits in
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* the return value are all zero iff the bits were read as expected to
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* simplify error detection.
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*/
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return status_read ^ (~status_written & 0xe);
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}
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static bool siox_device_counter_error(struct siox_device *sdevice,
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u8 status_clean)
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{
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return (status_clean & SIOX_STATUS_COUNTER) != 0;
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}
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static bool siox_device_type_error(struct siox_device *sdevice, u8 status_clean)
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{
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u8 statustype = (status_clean & SIOX_STATUS_TYPE) >> 4;
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/*
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* If the device knows which value the type bits should have, check
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* against this value otherwise just rule out the invalid values 0b0000
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* and 0b1111.
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*/
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if (sdevice->statustype) {
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if (statustype != sdevice->statustype)
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return true;
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} else {
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switch (statustype) {
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case 0:
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case 0xf:
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return true;
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}
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}
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return false;
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}
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static bool siox_device_wdg_error(struct siox_device *sdevice, u8 status_clean)
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{
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return (status_clean & SIOX_STATUS_WDG) == 0;
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}
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/*
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* If there is a type or counter error the device is called "unsynced".
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*/
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bool siox_device_synced(struct siox_device *sdevice)
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{
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if (siox_device_type_error(sdevice, sdevice->status_read_clean))
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return false;
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return !siox_device_counter_error(sdevice, sdevice->status_read_clean);
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}
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EXPORT_SYMBOL_GPL(siox_device_synced);
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/*
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* A device is called "connected" if it is synced and the watchdog is not
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* asserted.
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*/
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bool siox_device_connected(struct siox_device *sdevice)
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{
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if (!siox_device_synced(sdevice))
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return false;
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return !siox_device_wdg_error(sdevice, sdevice->status_read_clean);
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}
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EXPORT_SYMBOL_GPL(siox_device_connected);
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static void siox_poll(struct siox_master *smaster)
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{
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struct siox_device *sdevice;
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size_t i = smaster->setbuf_len;
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unsigned int devno = 0;
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int unsync_error = 0;
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smaster->last_poll = jiffies;
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/*
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* The counter bits change in each second cycle, the watchdog bit
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* toggles each time.
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* The counter bits hold values from [0, 6]. 7 would be possible
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* theoretically but the protocol designer considered that a bad idea
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* for reasons unknown today. (Maybe that's because then the status read
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* back has only zeros in the counter bits then which might be confused
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* with a stuck-at-0 error. But for the same reason (with s/0/1/) 0
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* could be skipped.)
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*/
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if (++smaster->status > 0x0d)
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smaster->status = 0;
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memset(smaster->buf, 0, smaster->setbuf_len);
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/* prepare data pushed out to devices in buf[0..setbuf_len) */
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list_for_each_entry(sdevice, &smaster->devices, node) {
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struct siox_driver *sdriver =
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to_siox_driver(sdevice->dev.driver);
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sdevice->status_written = smaster->status;
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i -= sdevice->inbytes;
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/*
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* If the device or a previous one is unsynced, don't pet the
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* watchdog. This is done to ensure that the device is kept in
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* reset when something is wrong.
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*/
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if (!siox_device_synced(sdevice))
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unsync_error = 1;
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if (sdriver && !unsync_error)
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sdriver->set_data(sdevice, sdevice->status_written,
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&smaster->buf[i + 1]);
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else
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/*
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* Don't trigger watchdog if there is no driver or a
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* sync problem
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*/
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sdevice->status_written &= ~SIOX_STATUS_WDG;
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smaster->buf[i] = sdevice->status_written;
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trace_siox_set_data(smaster, sdevice, devno, i);
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devno++;
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}
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smaster->pushpull(smaster, smaster->setbuf_len, smaster->buf,
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smaster->getbuf_len,
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smaster->buf + smaster->setbuf_len);
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unsync_error = 0;
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/* interpret data pulled in from devices in buf[setbuf_len..] */
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devno = 0;
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i = smaster->setbuf_len;
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list_for_each_entry(sdevice, &smaster->devices, node) {
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struct siox_driver *sdriver =
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to_siox_driver(sdevice->dev.driver);
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u8 status = smaster->buf[i + sdevice->outbytes - 1];
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u8 status_clean;
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u8 prev_status_clean = sdevice->status_read_clean;
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bool synced = true;
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bool connected = true;
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if (!siox_device_synced(sdevice))
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unsync_error = 1;
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/*
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* If the watchdog bit wasn't toggled in this cycle, report the
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* watchdog as active to give a consistent view for drivers and
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* sysfs consumers.
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*/
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if (!sdriver || unsync_error)
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status &= ~SIOX_STATUS_WDG;
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status_clean =
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siox_status_clean(status,
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sdevice->status_written_lastcycle);
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/* Check counter and type bits */
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if (siox_device_counter_error(sdevice, status_clean) ||
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siox_device_type_error(sdevice, status_clean)) {
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bool prev_error;
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synced = false;
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/* only report a new error if the last cycle was ok */
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prev_error =
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siox_device_counter_error(sdevice,
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prev_status_clean) ||
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siox_device_type_error(sdevice,
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prev_status_clean);
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if (!prev_error) {
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sdevice->status_errors++;
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sysfs_notify_dirent(sdevice->status_errors_kn);
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}
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}
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/* If the device is unsynced report the watchdog as active */
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if (!synced) {
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status &= ~SIOX_STATUS_WDG;
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status_clean &= ~SIOX_STATUS_WDG;
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}
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if (siox_device_wdg_error(sdevice, status_clean))
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connected = false;
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/* The watchdog state changed just now */
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if ((status_clean ^ prev_status_clean) & SIOX_STATUS_WDG) {
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sysfs_notify_dirent(sdevice->watchdog_kn);
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if (siox_device_wdg_error(sdevice, status_clean)) {
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struct kernfs_node *wd_errs =
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sdevice->watchdog_errors_kn;
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sdevice->watchdog_errors++;
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sysfs_notify_dirent(wd_errs);
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}
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}
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if (connected != sdevice->connected)
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sysfs_notify_dirent(sdevice->connected_kn);
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sdevice->status_read_clean = status_clean;
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sdevice->status_written_lastcycle = sdevice->status_written;
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sdevice->connected = connected;
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trace_siox_get_data(smaster, sdevice, devno, status_clean, i);
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/* only give data read to driver if the device is connected */
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if (sdriver && connected)
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sdriver->get_data(sdevice, &smaster->buf[i]);
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devno++;
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i += sdevice->outbytes;
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}
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}
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static int siox_poll_thread(void *data)
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{
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struct siox_master *smaster = data;
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signed long timeout = 0;
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get_device(&smaster->dev);
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for (;;) {
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if (kthread_should_stop()) {
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put_device(&smaster->dev);
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return 0;
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}
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siox_master_lock(smaster);
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if (smaster->active) {
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unsigned long next_poll =
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smaster->last_poll + smaster->poll_interval;
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if (time_is_before_eq_jiffies(next_poll))
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siox_poll(smaster);
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timeout = smaster->poll_interval -
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(jiffies - smaster->last_poll);
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} else {
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timeout = MAX_SCHEDULE_TIMEOUT;
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}
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/*
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* Set the task to idle while holding the lock. This makes sure
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* that we don't sleep too long when the bus is reenabled before
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* schedule_timeout is reached.
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*/
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if (timeout > 0)
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set_current_state(TASK_IDLE);
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siox_master_unlock(smaster);
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if (timeout > 0)
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schedule_timeout(timeout);
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/*
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* I'm not clear if/why it is important to set the state to
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* RUNNING again, but it fixes a "do not call blocking ops when
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* !TASK_RUNNING;"-warning.
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*/
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set_current_state(TASK_RUNNING);
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}
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}
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static int __siox_start(struct siox_master *smaster)
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{
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if (!(smaster->setbuf_len + smaster->getbuf_len))
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return -ENODEV;
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if (!smaster->buf)
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return -ENOMEM;
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if (smaster->active)
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return 0;
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smaster->active = 1;
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wake_up_process(smaster->poll_thread);
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return 1;
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}
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static int siox_start(struct siox_master *smaster)
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{
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int ret;
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siox_master_lock(smaster);
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ret = __siox_start(smaster);
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siox_master_unlock(smaster);
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return ret;
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}
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static int __siox_stop(struct siox_master *smaster)
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{
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if (smaster->active) {
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struct siox_device *sdevice;
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smaster->active = 0;
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list_for_each_entry(sdevice, &smaster->devices, node) {
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if (sdevice->connected)
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sysfs_notify_dirent(sdevice->connected_kn);
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sdevice->connected = false;
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}
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return 1;
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}
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return 0;
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}
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static int siox_stop(struct siox_master *smaster)
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{
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int ret;
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siox_master_lock(smaster);
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ret = __siox_stop(smaster);
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siox_master_unlock(smaster);
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return ret;
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}
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static ssize_t type_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct siox_device *sdev = to_siox_device(dev);
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return sprintf(buf, "%s\n", sdev->type);
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}
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static DEVICE_ATTR_RO(type);
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static ssize_t inbytes_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct siox_device *sdev = to_siox_device(dev);
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return sprintf(buf, "%zu\n", sdev->inbytes);
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}
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static DEVICE_ATTR_RO(inbytes);
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static ssize_t outbytes_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct siox_device *sdev = to_siox_device(dev);
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return sprintf(buf, "%zu\n", sdev->outbytes);
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}
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static DEVICE_ATTR_RO(outbytes);
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static ssize_t status_errors_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct siox_device *sdev = to_siox_device(dev);
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unsigned int status_errors;
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siox_master_lock(sdev->smaster);
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status_errors = sdev->status_errors;
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siox_master_unlock(sdev->smaster);
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return sprintf(buf, "%u\n", status_errors);
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}
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static DEVICE_ATTR_RO(status_errors);
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static ssize_t connected_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct siox_device *sdev = to_siox_device(dev);
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bool connected;
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siox_master_lock(sdev->smaster);
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connected = sdev->connected;
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siox_master_unlock(sdev->smaster);
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return sprintf(buf, "%u\n", connected);
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}
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static DEVICE_ATTR_RO(connected);
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static ssize_t watchdog_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct siox_device *sdev = to_siox_device(dev);
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u8 status;
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siox_master_lock(sdev->smaster);
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status = sdev->status_read_clean;
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siox_master_unlock(sdev->smaster);
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return sprintf(buf, "%d\n", status & SIOX_STATUS_WDG);
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}
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static DEVICE_ATTR_RO(watchdog);
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static ssize_t watchdog_errors_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct siox_device *sdev = to_siox_device(dev);
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unsigned int watchdog_errors;
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siox_master_lock(sdev->smaster);
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watchdog_errors = sdev->watchdog_errors;
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siox_master_unlock(sdev->smaster);
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return sprintf(buf, "%u\n", watchdog_errors);
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}
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static DEVICE_ATTR_RO(watchdog_errors);
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static struct attribute *siox_device_attrs[] = {
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&dev_attr_type.attr,
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&dev_attr_inbytes.attr,
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&dev_attr_outbytes.attr,
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&dev_attr_status_errors.attr,
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&dev_attr_connected.attr,
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&dev_attr_watchdog.attr,
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&dev_attr_watchdog_errors.attr,
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NULL
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};
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ATTRIBUTE_GROUPS(siox_device);
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static void siox_device_release(struct device *dev)
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{
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struct siox_device *sdevice = to_siox_device(dev);
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kfree(sdevice);
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}
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static struct device_type siox_device_type = {
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.groups = siox_device_groups,
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.release = siox_device_release,
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};
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static int siox_match(struct device *dev, struct device_driver *drv)
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{
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if (dev->type != &siox_device_type)
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return 0;
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/* up to now there is only a single driver so keeping this simple */
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return 1;
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}
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static struct bus_type siox_bus_type = {
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.name = "siox",
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.match = siox_match,
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};
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static int siox_driver_probe(struct device *dev)
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{
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struct siox_driver *sdriver = to_siox_driver(dev->driver);
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struct siox_device *sdevice = to_siox_device(dev);
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int ret;
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ret = sdriver->probe(sdevice);
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return ret;
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}
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static int siox_driver_remove(struct device *dev)
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{
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struct siox_driver *sdriver =
|
|
container_of(dev->driver, struct siox_driver, driver);
|
|
struct siox_device *sdevice = to_siox_device(dev);
|
|
int ret;
|
|
|
|
ret = sdriver->remove(sdevice);
|
|
return ret;
|
|
}
|
|
|
|
static void siox_driver_shutdown(struct device *dev)
|
|
{
|
|
struct siox_driver *sdriver =
|
|
container_of(dev->driver, struct siox_driver, driver);
|
|
struct siox_device *sdevice = to_siox_device(dev);
|
|
|
|
sdriver->shutdown(sdevice);
|
|
}
|
|
|
|
static ssize_t active_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct siox_master *smaster = to_siox_master(dev);
|
|
|
|
return sprintf(buf, "%d\n", smaster->active);
|
|
}
|
|
|
|
static ssize_t active_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct siox_master *smaster = to_siox_master(dev);
|
|
int ret;
|
|
int active;
|
|
|
|
ret = kstrtoint(buf, 0, &active);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (active)
|
|
ret = siox_start(smaster);
|
|
else
|
|
ret = siox_stop(smaster);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return count;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(active);
|
|
|
|
static struct siox_device *siox_device_add(struct siox_master *smaster,
|
|
const char *type, size_t inbytes,
|
|
size_t outbytes, u8 statustype);
|
|
|
|
static ssize_t device_add_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct siox_master *smaster = to_siox_master(dev);
|
|
int ret;
|
|
char type[20] = "";
|
|
size_t inbytes = 0, outbytes = 0;
|
|
u8 statustype = 0;
|
|
|
|
ret = sscanf(buf, "%19s %zu %zu %hhu", type, &inbytes,
|
|
&outbytes, &statustype);
|
|
if (ret != 3 && ret != 4)
|
|
return -EINVAL;
|
|
|
|
if (strcmp(type, "siox-12x8") || inbytes != 2 || outbytes != 4)
|
|
return -EINVAL;
|
|
|
|
siox_device_add(smaster, "siox-12x8", inbytes, outbytes, statustype);
|
|
|
|
return count;
|
|
}
|
|
|
|
static DEVICE_ATTR_WO(device_add);
|
|
|
|
static void siox_device_remove(struct siox_master *smaster);
|
|
|
|
static ssize_t device_remove_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct siox_master *smaster = to_siox_master(dev);
|
|
|
|
/* XXX? require to write <type> <inbytes> <outbytes> */
|
|
siox_device_remove(smaster);
|
|
|
|
return count;
|
|
}
|
|
|
|
static DEVICE_ATTR_WO(device_remove);
|
|
|
|
static ssize_t poll_interval_ns_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct siox_master *smaster = to_siox_master(dev);
|
|
|
|
return sprintf(buf, "%lld\n", jiffies_to_nsecs(smaster->poll_interval));
|
|
}
|
|
|
|
static ssize_t poll_interval_ns_store(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct siox_master *smaster = to_siox_master(dev);
|
|
int ret;
|
|
u64 val;
|
|
|
|
ret = kstrtou64(buf, 0, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
siox_master_lock(smaster);
|
|
|
|
smaster->poll_interval = nsecs_to_jiffies(val);
|
|
|
|
siox_master_unlock(smaster);
|
|
|
|
return count;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(poll_interval_ns);
|
|
|
|
static struct attribute *siox_master_attrs[] = {
|
|
&dev_attr_active.attr,
|
|
&dev_attr_device_add.attr,
|
|
&dev_attr_device_remove.attr,
|
|
&dev_attr_poll_interval_ns.attr,
|
|
NULL
|
|
};
|
|
ATTRIBUTE_GROUPS(siox_master);
|
|
|
|
static void siox_master_release(struct device *dev)
|
|
{
|
|
struct siox_master *smaster = to_siox_master(dev);
|
|
|
|
kfree(smaster);
|
|
}
|
|
|
|
static struct device_type siox_master_type = {
|
|
.groups = siox_master_groups,
|
|
.release = siox_master_release,
|
|
};
|
|
|
|
struct siox_master *siox_master_alloc(struct device *dev,
|
|
size_t size)
|
|
{
|
|
struct siox_master *smaster;
|
|
|
|
if (!dev)
|
|
return NULL;
|
|
|
|
smaster = kzalloc(sizeof(*smaster) + size, GFP_KERNEL);
|
|
if (!smaster)
|
|
return NULL;
|
|
|
|
device_initialize(&smaster->dev);
|
|
|
|
smaster->busno = -1;
|
|
smaster->dev.bus = &siox_bus_type;
|
|
smaster->dev.type = &siox_master_type;
|
|
smaster->dev.parent = dev;
|
|
smaster->poll_interval = DIV_ROUND_UP(HZ, 40);
|
|
|
|
dev_set_drvdata(&smaster->dev, &smaster[1]);
|
|
|
|
return smaster;
|
|
}
|
|
EXPORT_SYMBOL_GPL(siox_master_alloc);
|
|
|
|
int siox_master_register(struct siox_master *smaster)
|
|
{
|
|
int ret;
|
|
|
|
if (!siox_is_registered)
|
|
return -EPROBE_DEFER;
|
|
|
|
if (!smaster->pushpull)
|
|
return -EINVAL;
|
|
|
|
dev_set_name(&smaster->dev, "siox-%d", smaster->busno);
|
|
|
|
mutex_init(&smaster->lock);
|
|
INIT_LIST_HEAD(&smaster->devices);
|
|
|
|
smaster->last_poll = jiffies;
|
|
smaster->poll_thread = kthread_run(siox_poll_thread, smaster,
|
|
"siox-%d", smaster->busno);
|
|
if (IS_ERR(smaster->poll_thread)) {
|
|
smaster->active = 0;
|
|
return PTR_ERR(smaster->poll_thread);
|
|
}
|
|
|
|
ret = device_add(&smaster->dev);
|
|
if (ret)
|
|
kthread_stop(smaster->poll_thread);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(siox_master_register);
|
|
|
|
void siox_master_unregister(struct siox_master *smaster)
|
|
{
|
|
/* remove device */
|
|
device_del(&smaster->dev);
|
|
|
|
siox_master_lock(smaster);
|
|
|
|
__siox_stop(smaster);
|
|
|
|
while (smaster->num_devices) {
|
|
struct siox_device *sdevice;
|
|
|
|
sdevice = container_of(smaster->devices.prev,
|
|
struct siox_device, node);
|
|
list_del(&sdevice->node);
|
|
smaster->num_devices--;
|
|
|
|
siox_master_unlock(smaster);
|
|
|
|
device_unregister(&sdevice->dev);
|
|
|
|
siox_master_lock(smaster);
|
|
}
|
|
|
|
siox_master_unlock(smaster);
|
|
|
|
put_device(&smaster->dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(siox_master_unregister);
|
|
|
|
static struct siox_device *siox_device_add(struct siox_master *smaster,
|
|
const char *type, size_t inbytes,
|
|
size_t outbytes, u8 statustype)
|
|
{
|
|
struct siox_device *sdevice;
|
|
int ret;
|
|
size_t buf_len;
|
|
|
|
sdevice = kzalloc(sizeof(*sdevice), GFP_KERNEL);
|
|
if (!sdevice)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
sdevice->type = type;
|
|
sdevice->inbytes = inbytes;
|
|
sdevice->outbytes = outbytes;
|
|
sdevice->statustype = statustype;
|
|
|
|
sdevice->smaster = smaster;
|
|
sdevice->dev.parent = &smaster->dev;
|
|
sdevice->dev.bus = &siox_bus_type;
|
|
sdevice->dev.type = &siox_device_type;
|
|
|
|
siox_master_lock(smaster);
|
|
|
|
dev_set_name(&sdevice->dev, "siox-%d-%d",
|
|
smaster->busno, smaster->num_devices);
|
|
|
|
buf_len = smaster->setbuf_len + inbytes +
|
|
smaster->getbuf_len + outbytes;
|
|
if (smaster->buf_len < buf_len) {
|
|
u8 *buf = krealloc(smaster->buf, buf_len, GFP_KERNEL);
|
|
|
|
if (!buf) {
|
|
dev_err(&smaster->dev,
|
|
"failed to realloc buffer to %zu\n", buf_len);
|
|
ret = -ENOMEM;
|
|
goto err_buf_alloc;
|
|
}
|
|
|
|
smaster->buf_len = buf_len;
|
|
smaster->buf = buf;
|
|
}
|
|
|
|
ret = device_register(&sdevice->dev);
|
|
if (ret) {
|
|
dev_err(&smaster->dev, "failed to register device: %d\n", ret);
|
|
|
|
goto err_device_register;
|
|
}
|
|
|
|
smaster->num_devices++;
|
|
list_add_tail(&sdevice->node, &smaster->devices);
|
|
|
|
smaster->setbuf_len += sdevice->inbytes;
|
|
smaster->getbuf_len += sdevice->outbytes;
|
|
|
|
sdevice->status_errors_kn = sysfs_get_dirent(sdevice->dev.kobj.sd,
|
|
"status_errors");
|
|
sdevice->watchdog_kn = sysfs_get_dirent(sdevice->dev.kobj.sd,
|
|
"watchdog");
|
|
sdevice->watchdog_errors_kn = sysfs_get_dirent(sdevice->dev.kobj.sd,
|
|
"watchdog_errors");
|
|
sdevice->connected_kn = sysfs_get_dirent(sdevice->dev.kobj.sd,
|
|
"connected");
|
|
|
|
siox_master_unlock(smaster);
|
|
|
|
return sdevice;
|
|
|
|
err_device_register:
|
|
/* don't care to make the buffer smaller again */
|
|
|
|
err_buf_alloc:
|
|
siox_master_unlock(smaster);
|
|
|
|
kfree(sdevice);
|
|
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
static void siox_device_remove(struct siox_master *smaster)
|
|
{
|
|
struct siox_device *sdevice;
|
|
|
|
siox_master_lock(smaster);
|
|
|
|
if (!smaster->num_devices) {
|
|
siox_master_unlock(smaster);
|
|
return;
|
|
}
|
|
|
|
sdevice = container_of(smaster->devices.prev, struct siox_device, node);
|
|
list_del(&sdevice->node);
|
|
smaster->num_devices--;
|
|
|
|
smaster->setbuf_len -= sdevice->inbytes;
|
|
smaster->getbuf_len -= sdevice->outbytes;
|
|
|
|
if (!smaster->num_devices)
|
|
__siox_stop(smaster);
|
|
|
|
siox_master_unlock(smaster);
|
|
|
|
/*
|
|
* This must be done without holding the master lock because we're
|
|
* called from device_remove_store which also holds a sysfs mutex.
|
|
* device_unregister tries to aquire the same lock.
|
|
*/
|
|
device_unregister(&sdevice->dev);
|
|
}
|
|
|
|
int __siox_driver_register(struct siox_driver *sdriver, struct module *owner)
|
|
{
|
|
int ret;
|
|
|
|
if (unlikely(!siox_is_registered))
|
|
return -EPROBE_DEFER;
|
|
|
|
if (!sdriver->set_data && !sdriver->get_data) {
|
|
pr_err("Driver %s doesn't provide needed callbacks\n",
|
|
sdriver->driver.name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
sdriver->driver.owner = owner;
|
|
sdriver->driver.bus = &siox_bus_type;
|
|
|
|
if (sdriver->probe)
|
|
sdriver->driver.probe = siox_driver_probe;
|
|
if (sdriver->remove)
|
|
sdriver->driver.remove = siox_driver_remove;
|
|
if (sdriver->shutdown)
|
|
sdriver->driver.shutdown = siox_driver_shutdown;
|
|
|
|
ret = driver_register(&sdriver->driver);
|
|
if (ret)
|
|
pr_err("Failed to register siox driver %s (%d)\n",
|
|
sdriver->driver.name, ret);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__siox_driver_register);
|
|
|
|
static int __init siox_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = bus_register(&siox_bus_type);
|
|
if (ret) {
|
|
pr_err("Registration of SIOX bus type failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
siox_is_registered = true;
|
|
|
|
return 0;
|
|
}
|
|
subsys_initcall(siox_init);
|
|
|
|
static void __exit siox_exit(void)
|
|
{
|
|
bus_unregister(&siox_bus_type);
|
|
}
|
|
module_exit(siox_exit);
|
|
|
|
MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
|
|
MODULE_DESCRIPTION("Eckelmann SIOX driver core");
|
|
MODULE_LICENSE("GPL v2");
|