linux/drivers/rtc/rtc-ds1374.c
Kirill Smelkov c5bf68fe0c *: convert stream-like files from nonseekable_open -> stream_open
Using scripts/coccinelle/api/stream_open.cocci added in 10dce8af34
("fs: stream_open - opener for stream-like files so that read and write
can run simultaneously without deadlock"), search and convert to
stream_open all in-kernel nonseekable_open users for which read and
write actually do not depend on ppos and where there is no other methods
in file_operations which assume @offset access.

I've verified each generated change manually - that it is correct to convert -
and each other nonseekable_open instance left - that it is either not correct
to convert there, or that it is not converted due to current stream_open.cocci
limitations. The script also does not convert files that should be valid to
convert, but that currently have .llseek = noop_llseek or generic_file_llseek
for unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)

Among cases converted 14 were potentially vulnerable to read vs write deadlock
(see details in 10dce8af34):

	drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/infiniband/core/user_mad.c:988:1-17: ERROR: umad_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/input/misc/uinput.c:401:1-17: ERROR: uinput_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
	net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.

and the rest were just safe to convert to stream_open because their read and
write do not use ppos at all and corresponding file_operations do not
have methods that assume @offset file access(*):

	arch/powerpc/platforms/52xx/mpc52xx_gpt.c:631:8-24: WARNING: mpc52xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/um/drivers/harddog_kern.c:88:8-24: WARNING: harddog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	arch/x86/kernel/cpu/microcode/core.c:430:33-49: WARNING: microcode_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/ds1620.c:215:8-24: WARNING: ds1620_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/dtlk.c:301:1-17: WARNING: dtlk_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/ipmi/ipmi_watchdog.c:840:9-25: WARNING: ipmi_wdog_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/pcmcia/scr24x_cs.c:95:8-24: WARNING: scr24x_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/char/tb0219.c:246:9-25: WARNING: tb0219_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/firewire/nosy.c:306:8-24: WARNING: nosy_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/hwmon/fschmd.c:840:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/hwmon/w83793.c:1344:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/infiniband/core/ucma.c:1747:8-24: WARNING: ucma_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/infiniband/core/ucm.c:1178:8-24: WARNING: ucm_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/infiniband/core/uverbs_main.c:1086:8-24: WARNING: uverbs_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/input/joydev.c:282:1-17: WARNING: joydev_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/pci/switch/switchtec.c:393:1-17: WARNING: switchtec_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/platform/chrome/cros_ec_debugfs.c:135:8-24: WARNING: cros_ec_console_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/rtc/rtc-ds1374.c:470:9-25: WARNING: ds1374_wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/rtc/rtc-m41t80.c:805:9-25: WARNING: wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/s390/char/tape_char.c:293:2-18: WARNING: tape_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/s390/char/zcore.c:194:8-24: WARNING: zcore_reipl_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/s390/crypto/zcrypt_api.c:528:8-24: WARNING: zcrypt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/spi/spidev.c:594:1-17: WARNING: spidev_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/staging/pi433/pi433_if.c:974:1-17: WARNING: pi433_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/acquirewdt.c:203:8-24: WARNING: acq_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/advantechwdt.c:202:8-24: WARNING: advwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/alim1535_wdt.c:252:8-24: WARNING: ali_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/alim7101_wdt.c:217:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ar7_wdt.c:166:8-24: WARNING: ar7_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/at91rm9200_wdt.c:113:8-24: WARNING: at91wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ath79_wdt.c:135:8-24: WARNING: ath79_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/bcm63xx_wdt.c:119:8-24: WARNING: bcm63xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/cpu5wdt.c:143:8-24: WARNING: cpu5wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/cpwd.c:397:8-24: WARNING: cpwd_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/eurotechwdt.c:319:8-24: WARNING: eurwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/f71808e_wdt.c:528:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/gef_wdt.c:232:8-24: WARNING: gef_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/geodewdt.c:95:8-24: WARNING: geodewdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ib700wdt.c:241:8-24: WARNING: ibwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ibmasr.c:326:8-24: WARNING: asr_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/indydog.c:80:8-24: WARNING: indydog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/intel_scu_watchdog.c:307:8-24: WARNING: intel_scu_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/iop_wdt.c:104:8-24: WARNING: iop_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/it8712f_wdt.c:330:8-24: WARNING: it8712f_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ixp4xx_wdt.c:68:8-24: WARNING: ixp4xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/ks8695_wdt.c:145:8-24: WARNING: ks8695wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/m54xx_wdt.c:88:8-24: WARNING: m54xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/machzwd.c:336:8-24: WARNING: zf_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/mixcomwd.c:153:8-24: WARNING: mixcomwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/mtx-1_wdt.c:121:8-24: WARNING: mtx1_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/mv64x60_wdt.c:136:8-24: WARNING: mv64x60_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/nuc900_wdt.c:134:8-24: WARNING: nuc900wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/nv_tco.c:164:8-24: WARNING: nv_tco_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pc87413_wdt.c:289:8-24: WARNING: pc87413_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd.c:698:8-24: WARNING: pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd.c:737:8-24: WARNING: pcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_pci.c:581:8-24: WARNING: pcipcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_pci.c:623:8-24: WARNING: pcipcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_usb.c:488:8-24: WARNING: usb_pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pcwd_usb.c:527:8-24: WARNING: usb_pcwd_temperature_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pika_wdt.c:121:8-24: WARNING: pikawdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/pnx833x_wdt.c:119:8-24: WARNING: pnx833x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/rc32434_wdt.c:153:8-24: WARNING: rc32434_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/rdc321x_wdt.c:145:8-24: WARNING: rdc321x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/riowd.c:79:1-17: WARNING: riowd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sa1100_wdt.c:62:8-24: WARNING: sa1100dog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc60xxwdt.c:211:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc7240_wdt.c:139:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc8360.c:274:8-24: WARNING: sbc8360_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc_epx_c3.c:81:8-24: WARNING: epx_c3_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sbc_fitpc2_wdt.c:78:8-24: WARNING: fitpc2_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sb_wdog.c:108:1-17: WARNING: sbwdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sc1200wdt.c:181:8-24: WARNING: sc1200wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sc520_wdt.c:261:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/sch311x_wdt.c:319:8-24: WARNING: sch311x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/scx200_wdt.c:105:8-24: WARNING: scx200_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/smsc37b787_wdt.c:369:8-24: WARNING: wb_smsc_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/w83877f_wdt.c:227:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/w83977f_wdt.c:301:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wafer5823wdt.c:200:8-24: WARNING: wafwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/watchdog_dev.c:828:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdrtas.c:379:8-24: WARNING: wdrtas_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdrtas.c:445:8-24: WARNING: wdrtas_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt285.c:104:1-17: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt977.c:276:8-24: WARNING: wdt977_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt.c:424:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt.c:484:8-24: WARNING: wdt_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt_pci.c:464:8-24: WARNING: wdtpci_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open.
	drivers/watchdog/wdt_pci.c:527:8-24: WARNING: wdtpci_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	net/batman-adv/log.c:105:1-17: WARNING: batadv_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/control.c:57:7-23: WARNING: snd_ctl_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/rawmidi.c:385:7-23: WARNING: snd_rawmidi_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/seq/seq_clientmgr.c:310:7-23: WARNING: snd_seq_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open.
	sound/core/timer.c:1428:7-23: WARNING: snd_timer_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open.

One can also recheck/review the patch via generating it with explanation comments included via

	$ make coccicheck MODE=patch COCCI=scripts/coccinelle/api/stream_open.cocci SPFLAGS="-D explain"

(*) This second group also contains cases with read/write deadlocks that
stream_open.cocci don't yet detect, but which are still valid to convert to
stream_open since ppos is not used. For example drivers/pci/switch/switchtec.c
calls wait_for_completion_interruptible() in its .read, but stream_open.cocci
currently detects only "wait_event*" as blocking.

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James R. Van Zandt" <jrv@vanzandt.mv.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Harald Welte <laforge@gnumonks.org>
Acked-by: Lubomir Rintel <lkundrak@v3.sk> [scr24x_cs]
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Johan Hovold <johan@kernel.org>
Cc: David Herrmann <dh.herrmann@googlemail.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Jean Delvare <jdelvare@suse.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>	[watchdog/* hwmon/*]
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: Logan Gunthorpe <logang@deltatee.com> [drivers/pci/switch/switchtec]
Acked-by: Bjorn Helgaas <bhelgaas@google.com> [drivers/pci/switch/switchtec]
Cc: Benson Leung <bleung@chromium.org>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> [platform/chrome]
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> [rtc/*]
Cc: Mark Brown <broonie@kernel.org>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Zwane Mwaikambo <zwanem@gmail.com>
Cc: Marek Lindner <mareklindner@neomailbox.ch>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Cc: Antonio Quartulli <a@unstable.cc>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
2019-05-06 17:46:41 +03:00

726 lines
17 KiB
C

/*
* RTC client/driver for the Maxim/Dallas DS1374 Real-Time Clock over I2C
*
* Based on code by Randy Vinson <rvinson@mvista.com>,
* which was based on the m41t00.c by Mark Greer <mgreer@mvista.com>.
*
* Copyright (C) 2014 Rose Technology
* Copyright (C) 2006-2007 Freescale Semiconductor
*
* 2005 (c) MontaVista Software, Inc. This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*/
/*
* It would be more efficient to use i2c msgs/i2c_transfer directly but, as
* recommened in .../Documentation/i2c/writing-clients section
* "Sending and receiving", using SMBus level communication is preferred.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <linux/pm.h>
#ifdef CONFIG_RTC_DRV_DS1374_WDT
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/miscdevice.h>
#include <linux/reboot.h>
#include <linux/watchdog.h>
#endif
#define DS1374_REG_TOD0 0x00 /* Time of Day */
#define DS1374_REG_TOD1 0x01
#define DS1374_REG_TOD2 0x02
#define DS1374_REG_TOD3 0x03
#define DS1374_REG_WDALM0 0x04 /* Watchdog/Alarm */
#define DS1374_REG_WDALM1 0x05
#define DS1374_REG_WDALM2 0x06
#define DS1374_REG_CR 0x07 /* Control */
#define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */
#define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */
#define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */
#define DS1374_REG_SR 0x08 /* Status */
#define DS1374_REG_SR_OSF 0x80 /* Oscillator Stop Flag */
#define DS1374_REG_SR_AF 0x01 /* Alarm Flag */
#define DS1374_REG_TCR 0x09 /* Trickle Charge */
static const struct i2c_device_id ds1374_id[] = {
{ "ds1374", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ds1374_id);
#ifdef CONFIG_OF
static const struct of_device_id ds1374_of_match[] = {
{ .compatible = "dallas,ds1374" },
{ }
};
MODULE_DEVICE_TABLE(of, ds1374_of_match);
#endif
struct ds1374 {
struct i2c_client *client;
struct rtc_device *rtc;
struct work_struct work;
/* The mutex protects alarm operations, and prevents a race
* between the enable_irq() in the workqueue and the free_irq()
* in the remove function.
*/
struct mutex mutex;
int exiting;
};
static struct i2c_driver ds1374_driver;
static int ds1374_read_rtc(struct i2c_client *client, u32 *time,
int reg, int nbytes)
{
u8 buf[4];
int ret;
int i;
if (WARN_ON(nbytes > 4))
return -EINVAL;
ret = i2c_smbus_read_i2c_block_data(client, reg, nbytes, buf);
if (ret < 0)
return ret;
if (ret < nbytes)
return -EIO;
for (i = nbytes - 1, *time = 0; i >= 0; i--)
*time = (*time << 8) | buf[i];
return 0;
}
static int ds1374_write_rtc(struct i2c_client *client, u32 time,
int reg, int nbytes)
{
u8 buf[4];
int i;
if (nbytes > 4) {
WARN_ON(1);
return -EINVAL;
}
for (i = 0; i < nbytes; i++) {
buf[i] = time & 0xff;
time >>= 8;
}
return i2c_smbus_write_i2c_block_data(client, reg, nbytes, buf);
}
static int ds1374_check_rtc_status(struct i2c_client *client)
{
int ret = 0;
int control, stat;
stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
if (stat < 0)
return stat;
if (stat & DS1374_REG_SR_OSF)
dev_warn(&client->dev,
"oscillator discontinuity flagged, time unreliable\n");
stat &= ~(DS1374_REG_SR_OSF | DS1374_REG_SR_AF);
ret = i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
if (ret < 0)
return ret;
/* If the alarm is pending, clear it before requesting
* the interrupt, so an interrupt event isn't reported
* before everything is initialized.
*/
control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
if (control < 0)
return control;
control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
return i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
}
static int ds1374_read_time(struct device *dev, struct rtc_time *time)
{
struct i2c_client *client = to_i2c_client(dev);
u32 itime;
int ret;
ret = ds1374_read_rtc(client, &itime, DS1374_REG_TOD0, 4);
if (!ret)
rtc_time_to_tm(itime, time);
return ret;
}
static int ds1374_set_time(struct device *dev, struct rtc_time *time)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned long itime;
rtc_tm_to_time(time, &itime);
return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4);
}
#ifndef CONFIG_RTC_DRV_DS1374_WDT
/* The ds1374 has a decrementer for an alarm, rather than a comparator.
* If the time of day is changed, then the alarm will need to be
* reset.
*/
static int ds1374_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct i2c_client *client = to_i2c_client(dev);
struct ds1374 *ds1374 = i2c_get_clientdata(client);
u32 now, cur_alarm;
int cr, sr;
int ret = 0;
if (client->irq <= 0)
return -EINVAL;
mutex_lock(&ds1374->mutex);
cr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
if (ret < 0)
goto out;
sr = ret = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
if (ret < 0)
goto out;
ret = ds1374_read_rtc(client, &now, DS1374_REG_TOD0, 4);
if (ret)
goto out;
ret = ds1374_read_rtc(client, &cur_alarm, DS1374_REG_WDALM0, 3);
if (ret)
goto out;
rtc_time_to_tm(now + cur_alarm, &alarm->time);
alarm->enabled = !!(cr & DS1374_REG_CR_WACE);
alarm->pending = !!(sr & DS1374_REG_SR_AF);
out:
mutex_unlock(&ds1374->mutex);
return ret;
}
static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct i2c_client *client = to_i2c_client(dev);
struct ds1374 *ds1374 = i2c_get_clientdata(client);
struct rtc_time now;
unsigned long new_alarm, itime;
int cr;
int ret = 0;
if (client->irq <= 0)
return -EINVAL;
ret = ds1374_read_time(dev, &now);
if (ret < 0)
return ret;
rtc_tm_to_time(&alarm->time, &new_alarm);
rtc_tm_to_time(&now, &itime);
/* This can happen due to races, in addition to dates that are
* truly in the past. To avoid requiring the caller to check for
* races, dates in the past are assumed to be in the recent past
* (i.e. not something that we'd rather the caller know about via
* an error), and the alarm is set to go off as soon as possible.
*/
if (time_before_eq(new_alarm, itime))
new_alarm = 1;
else
new_alarm -= itime;
mutex_lock(&ds1374->mutex);
ret = cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
if (ret < 0)
goto out;
/* Disable any existing alarm before setting the new one
* (or lack thereof). */
cr &= ~DS1374_REG_CR_WACE;
ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
if (ret < 0)
goto out;
ret = ds1374_write_rtc(client, new_alarm, DS1374_REG_WDALM0, 3);
if (ret)
goto out;
if (alarm->enabled) {
cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
cr &= ~DS1374_REG_CR_WDALM;
ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
}
out:
mutex_unlock(&ds1374->mutex);
return ret;
}
#endif
static irqreturn_t ds1374_irq(int irq, void *dev_id)
{
struct i2c_client *client = dev_id;
struct ds1374 *ds1374 = i2c_get_clientdata(client);
disable_irq_nosync(irq);
schedule_work(&ds1374->work);
return IRQ_HANDLED;
}
static void ds1374_work(struct work_struct *work)
{
struct ds1374 *ds1374 = container_of(work, struct ds1374, work);
struct i2c_client *client = ds1374->client;
int stat, control;
mutex_lock(&ds1374->mutex);
stat = i2c_smbus_read_byte_data(client, DS1374_REG_SR);
if (stat < 0)
goto unlock;
if (stat & DS1374_REG_SR_AF) {
stat &= ~DS1374_REG_SR_AF;
i2c_smbus_write_byte_data(client, DS1374_REG_SR, stat);
control = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
if (control < 0)
goto out;
control &= ~(DS1374_REG_CR_WACE | DS1374_REG_CR_AIE);
i2c_smbus_write_byte_data(client, DS1374_REG_CR, control);
rtc_update_irq(ds1374->rtc, 1, RTC_AF | RTC_IRQF);
}
out:
if (!ds1374->exiting)
enable_irq(client->irq);
unlock:
mutex_unlock(&ds1374->mutex);
}
#ifndef CONFIG_RTC_DRV_DS1374_WDT
static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct i2c_client *client = to_i2c_client(dev);
struct ds1374 *ds1374 = i2c_get_clientdata(client);
int ret;
mutex_lock(&ds1374->mutex);
ret = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
if (ret < 0)
goto out;
if (enabled) {
ret |= DS1374_REG_CR_WACE | DS1374_REG_CR_AIE;
ret &= ~DS1374_REG_CR_WDALM;
} else {
ret &= ~DS1374_REG_CR_WACE;
}
ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, ret);
out:
mutex_unlock(&ds1374->mutex);
return ret;
}
#endif
static const struct rtc_class_ops ds1374_rtc_ops = {
.read_time = ds1374_read_time,
.set_time = ds1374_set_time,
#ifndef CONFIG_RTC_DRV_DS1374_WDT
.read_alarm = ds1374_read_alarm,
.set_alarm = ds1374_set_alarm,
.alarm_irq_enable = ds1374_alarm_irq_enable,
#endif
};
#ifdef CONFIG_RTC_DRV_DS1374_WDT
/*
*****************************************************************************
*
* Watchdog Driver
*
*****************************************************************************
*/
static struct i2c_client *save_client;
/* Default margin */
#define WD_TIMO 131762
#define DRV_NAME "DS1374 Watchdog"
static int wdt_margin = WD_TIMO;
static unsigned long wdt_is_open;
module_param(wdt_margin, int, 0);
MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)");
static const struct watchdog_info ds1374_wdt_info = {
.identity = "DS1374 WTD",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static int ds1374_wdt_settimeout(unsigned int timeout)
{
int ret = -ENOIOCTLCMD;
int cr;
ret = cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
if (ret < 0)
goto out;
/* Disable any existing watchdog/alarm before setting the new one */
cr &= ~DS1374_REG_CR_WACE;
ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
if (ret < 0)
goto out;
/* Set new watchdog time */
ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3);
if (ret) {
pr_info("couldn't set new watchdog time\n");
goto out;
}
/* Enable watchdog timer */
cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_WDALM;
cr &= ~DS1374_REG_CR_AIE;
ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
if (ret < 0)
goto out;
return 0;
out:
return ret;
}
/*
* Reload the watchdog timer. (ie, pat the watchdog)
*/
static void ds1374_wdt_ping(void)
{
u32 val;
int ret = 0;
ret = ds1374_read_rtc(save_client, &val, DS1374_REG_WDALM0, 3);
if (ret)
pr_info("WD TICK FAIL!!!!!!!!!! %i\n", ret);
}
static void ds1374_wdt_disable(void)
{
int ret = -ENOIOCTLCMD;
int cr;
cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
/* Disable watchdog timer */
cr &= ~DS1374_REG_CR_WACE;
ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
}
/*
* Watchdog device is opened, and watchdog starts running.
*/
static int ds1374_wdt_open(struct inode *inode, struct file *file)
{
struct ds1374 *ds1374 = i2c_get_clientdata(save_client);
if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
mutex_lock(&ds1374->mutex);
if (test_and_set_bit(0, &wdt_is_open)) {
mutex_unlock(&ds1374->mutex);
return -EBUSY;
}
/*
* Activate
*/
wdt_is_open = 1;
mutex_unlock(&ds1374->mutex);
return stream_open(inode, file);
}
return -ENODEV;
}
/*
* Close the watchdog device.
*/
static int ds1374_wdt_release(struct inode *inode, struct file *file)
{
if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
clear_bit(0, &wdt_is_open);
return 0;
}
/*
* Pat the watchdog whenever device is written to.
*/
static ssize_t ds1374_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
if (len) {
ds1374_wdt_ping();
return 1;
}
return 0;
}
static ssize_t ds1374_wdt_read(struct file *file, char __user *data,
size_t len, loff_t *ppos)
{
return 0;
}
/*
* Handle commands from user-space.
*/
static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int new_margin, options;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user((struct watchdog_info __user *)arg,
&ds1374_wdt_info, sizeof(ds1374_wdt_info)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int __user *)arg);
case WDIOC_KEEPALIVE:
ds1374_wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_margin, (int __user *)arg))
return -EFAULT;
/* the hardware's tick rate is 4096 Hz, so
* the counter value needs to be scaled accordingly
*/
new_margin <<= 12;
if (new_margin < 1 || new_margin > 16777216)
return -EINVAL;
wdt_margin = new_margin;
ds1374_wdt_settimeout(new_margin);
ds1374_wdt_ping();
/* fallthrough */
case WDIOC_GETTIMEOUT:
/* when returning ... inverse is true */
return put_user((wdt_margin >> 12), (int __user *)arg);
case WDIOC_SETOPTIONS:
if (copy_from_user(&options, (int __user *)arg, sizeof(int)))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
pr_info("disable watchdog\n");
ds1374_wdt_disable();
return 0;
}
if (options & WDIOS_ENABLECARD) {
pr_info("enable watchdog\n");
ds1374_wdt_settimeout(wdt_margin);
ds1374_wdt_ping();
return 0;
}
return -EINVAL;
}
return -ENOTTY;
}
static long ds1374_wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret;
struct ds1374 *ds1374 = i2c_get_clientdata(save_client);
mutex_lock(&ds1374->mutex);
ret = ds1374_wdt_ioctl(file, cmd, arg);
mutex_unlock(&ds1374->mutex);
return ret;
}
static int ds1374_wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
/* Disable Watchdog */
ds1374_wdt_disable();
return NOTIFY_DONE;
}
static const struct file_operations ds1374_wdt_fops = {
.owner = THIS_MODULE,
.read = ds1374_wdt_read,
.unlocked_ioctl = ds1374_wdt_unlocked_ioctl,
.write = ds1374_wdt_write,
.open = ds1374_wdt_open,
.release = ds1374_wdt_release,
.llseek = no_llseek,
};
static struct miscdevice ds1374_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &ds1374_wdt_fops,
};
static struct notifier_block ds1374_wdt_notifier = {
.notifier_call = ds1374_wdt_notify_sys,
};
#endif /*CONFIG_RTC_DRV_DS1374_WDT*/
/*
*****************************************************************************
*
* Driver Interface
*
*****************************************************************************
*/
static int ds1374_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ds1374 *ds1374;
int ret;
ds1374 = devm_kzalloc(&client->dev, sizeof(struct ds1374), GFP_KERNEL);
if (!ds1374)
return -ENOMEM;
ds1374->client = client;
i2c_set_clientdata(client, ds1374);
INIT_WORK(&ds1374->work, ds1374_work);
mutex_init(&ds1374->mutex);
ret = ds1374_check_rtc_status(client);
if (ret)
return ret;
if (client->irq > 0) {
ret = devm_request_irq(&client->dev, client->irq, ds1374_irq, 0,
"ds1374", client);
if (ret) {
dev_err(&client->dev, "unable to request IRQ\n");
return ret;
}
device_set_wakeup_capable(&client->dev, 1);
}
ds1374->rtc = devm_rtc_device_register(&client->dev, client->name,
&ds1374_rtc_ops, THIS_MODULE);
if (IS_ERR(ds1374->rtc)) {
dev_err(&client->dev, "unable to register the class device\n");
return PTR_ERR(ds1374->rtc);
}
#ifdef CONFIG_RTC_DRV_DS1374_WDT
save_client = client;
ret = misc_register(&ds1374_miscdev);
if (ret)
return ret;
ret = register_reboot_notifier(&ds1374_wdt_notifier);
if (ret) {
misc_deregister(&ds1374_miscdev);
return ret;
}
ds1374_wdt_settimeout(131072);
#endif
return 0;
}
static int ds1374_remove(struct i2c_client *client)
{
struct ds1374 *ds1374 = i2c_get_clientdata(client);
#ifdef CONFIG_RTC_DRV_DS1374_WDT
misc_deregister(&ds1374_miscdev);
ds1374_miscdev.parent = NULL;
unregister_reboot_notifier(&ds1374_wdt_notifier);
#endif
if (client->irq > 0) {
mutex_lock(&ds1374->mutex);
ds1374->exiting = 1;
mutex_unlock(&ds1374->mutex);
devm_free_irq(&client->dev, client->irq, client);
cancel_work_sync(&ds1374->work);
}
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int ds1374_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
if (client->irq > 0 && device_may_wakeup(&client->dev))
enable_irq_wake(client->irq);
return 0;
}
static int ds1374_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
if (client->irq > 0 && device_may_wakeup(&client->dev))
disable_irq_wake(client->irq);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(ds1374_pm, ds1374_suspend, ds1374_resume);
static struct i2c_driver ds1374_driver = {
.driver = {
.name = "rtc-ds1374",
.of_match_table = of_match_ptr(ds1374_of_match),
.pm = &ds1374_pm,
},
.probe = ds1374_probe,
.remove = ds1374_remove,
.id_table = ds1374_id,
};
module_i2c_driver(ds1374_driver);
MODULE_AUTHOR("Scott Wood <scottwood@freescale.com>");
MODULE_DESCRIPTION("Maxim/Dallas DS1374 RTC Driver");
MODULE_LICENSE("GPL");