9b9f2b8bc2
Prior to this commit the smbalert_irq was handling in the hard irq context. This change switch to using a thread irq which avoids the need for the work thread. Using threaded irq also removes the need for the edge_triggered flag as the enabling / disabling of the hard irq for level triggered interrupts will be handled by the irq core. Without this change have an irq connected to something like an i2c gpio resulted in a null ptr deferences. Specifically handle_nested_irq calls the threaded irq handler. There are currently 3 in tree drivers affected by this change. i2c-parport driver calls i2c_handle_smbus_alert in a hard irq context. This driver use edge trigger interrupts which skip the enable / disable calls. But it still need to handle the smbus transaction on a thread. So the work thread is kept for this driver. i2c-parport-light & i2c-thunderx-pcidrv provide the irq number in the setup which will result in the thread irq being used. i2c-parport-light is edge trigger so the enable / disable call was skipped as well. i2c-thunderx-pcidrv is getting the edge / level trigger setting from of data and was setting the flag as required. However the irq core should handle this automatically. Signed-off-by: Phil Reid <preid@electromag.com.au> Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
53 lines
1.7 KiB
C
53 lines
1.7 KiB
C
/*
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* i2c-smbus.h - SMBus extensions to the I2C protocol
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*
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* Copyright (C) 2010 Jean Delvare <jdelvare@suse.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301 USA.
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*/
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#ifndef _LINUX_I2C_SMBUS_H
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#define _LINUX_I2C_SMBUS_H
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#include <linux/i2c.h>
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#include <linux/spinlock.h>
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#include <linux/workqueue.h>
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/**
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* i2c_smbus_alert_setup - platform data for the smbus_alert i2c client
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* @alert_edge_triggered: whether the alert interrupt is edge (1) or level (0)
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* triggered
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* @irq: IRQ number, if the smbus_alert driver should take care of interrupt
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* handling
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*
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* If irq is not specified, the smbus_alert driver doesn't take care of
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* interrupt handling. In that case it is up to the I2C bus driver to either
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* handle the interrupts or to poll for alerts.
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*
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* If irq is specified then it it crucial that alert_edge_triggered is
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* properly set.
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*/
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struct i2c_smbus_alert_setup {
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int irq;
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};
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struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
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struct i2c_smbus_alert_setup *setup);
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int i2c_handle_smbus_alert(struct i2c_client *ara);
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#endif /* _LINUX_I2C_SMBUS_H */
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