From f6ac28d61675e05cb1227cbba44ff538f8671e54 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Sat, 2 Mar 2019 14:47:29 +0100 Subject: i2c: apply coding style for struct i2c_adapter Signed-off-by: Wolfram Sang Reviewed-by: Simon Horman Reviewed-by: Andy Shevchenko Signed-off-by: Wolfram Sang --- include/linux/i2c.h | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'include/linux') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 383510b4f083..758a6db864c9 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -517,20 +517,23 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info, * Documentation file Documentation/i2c/fault-codes. */ struct i2c_algorithm { - /* If an adapter algorithm can't do I2C-level access, set master_xfer - to NULL. If an adapter algorithm can do SMBus access, set - smbus_xfer. If set to NULL, the SMBus protocol is simulated - using common I2C messages */ - /* master_xfer should return the number of messages successfully - processed, or a negative value on error */ + /* + * If an adapter algorithm can't do I2C-level access, set master_xfer + * to NULL. If an adapter algorithm can do SMBus access, set + * smbus_xfer. If set to NULL, the SMBus protocol is simulated + * using common I2C messages. + * + * master_xfer should return the number of messages successfully + * processed, or a negative value on error + */ int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); - int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, - unsigned short flags, char read_write, - u8 command, int size, union i2c_smbus_data *data); + int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, union i2c_smbus_data *data); /* To determine what the adapter supports */ - u32 (*functionality) (struct i2c_adapter *); + u32 (*functionality)(struct i2c_adapter *adap); #if IS_ENABLED(CONFIG_I2C_SLAVE) int (*reg_slave)(struct i2c_client *client); -- cgit v1.2.3 From 63b96983a5ddfedd7daea72dbbc08ea873c54f27 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 3 Apr 2019 14:40:10 +0200 Subject: i2c: core: introduce callbacks for atomic transfers We had the request to access devices very late when interrupts are not available anymore multiple times now. Mostly to prepare shutdown or reboot. Allow adapters to specify a specific callback for this case. Note that we fall back to the generic {master|smbus}_xfer callback if this new atomic one is not present. This is intentional to preserve the previous behaviour and avoid regressions. Because there are drivers not using interrupts or because it might have worked "accidently" before. Signed-off-by: Wolfram Sang Reviewed-by Andy Shevchenko Tested-by: Stefan Lengfeld Signed-off-by: Wolfram Sang --- include/linux/i2c.h | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 758a6db864c9..03755d4c9229 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -499,9 +499,13 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info, * @master_xfer: Issue a set of i2c transactions to the given I2C adapter * defined by the msgs array, with num messages available to transfer via * the adapter specified by adap. + * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context + * so e.g. PMICs can be accessed very late before shutdown. Optional. * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this * is not present, then the bus layer will try and convert the SMBus calls * into I2C transfers instead. + * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context + * so e.g. PMICs can be accessed very late before shutdown. Optional. * @functionality: Return the flags that this algorithm/adapter pair supports * from the I2C_FUNC_* flags. * @reg_slave: Register given client to I2C slave mode of this adapter @@ -512,9 +516,9 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info, * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 * to name two of the most common. * - * The return codes from the @master_xfer field should indicate the type of - * error code that occurred during the transfer, as documented in the kernel - * Documentation file Documentation/i2c/fault-codes. + * The return codes from the @master_xfer{_atomic} fields should indicate the + * type of error code that occurred during the transfer, as documented in the + * Kernel Documentation file Documentation/i2c/fault-codes. */ struct i2c_algorithm { /* @@ -528,9 +532,14 @@ struct i2c_algorithm { */ int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, int num); + int (*master_xfer_atomic)(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num); int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data *data); + int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, union i2c_smbus_data *data); /* To determine what the adapter supports */ u32 (*functionality)(struct i2c_adapter *adap); -- cgit v1.2.3 From 8927fbf481248954ca1fc5e652171936b94905ac Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 3 Apr 2019 14:40:18 +0200 Subject: i2c: algo: bit: add flag to whitelist atomic transfers Use the new xfer_atomic callback to check a newly introduced flag to whitelist atomic transfers. This will report configurations which worked accidently. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang --- include/linux/i2c-algo-bit.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/i2c-algo-bit.h b/include/linux/i2c-algo-bit.h index 69045df78e2d..7fd5575a368f 100644 --- a/include/linux/i2c-algo-bit.h +++ b/include/linux/i2c-algo-bit.h @@ -33,6 +33,7 @@ struct i2c_algo_bit_data { minimum 5 us for standard-mode I2C and SMBus, maximum 50 us for SMBus */ int timeout; /* in jiffies */ + bool can_do_atomic; /* callbacks don't sleep, we can be atomic */ }; int i2c_bit_add_bus(struct i2c_adapter *); -- cgit v1.2.3 From 590085f0f25a169772180f57f56deb92b18ea302 Mon Sep 17 00:00:00 2001 From: Robert Shearman Date: Thu, 28 Feb 2019 11:43:42 +0000 Subject: i2c: mux: pca9541: remove support for unused platform data There are no in-tree users of the platform data, so remove it to simplify the code slightly. Remove the now unused pca954x.h platform data header. Signed-off-by: Robert Shearman Signed-off-by: Peter Rosin --- include/linux/platform_data/pca954x.h | 48 ----------------------------------- 1 file changed, 48 deletions(-) delete mode 100644 include/linux/platform_data/pca954x.h (limited to 'include/linux') diff --git a/include/linux/platform_data/pca954x.h b/include/linux/platform_data/pca954x.h deleted file mode 100644 index 1712677d5904..000000000000 --- a/include/linux/platform_data/pca954x.h +++ /dev/null @@ -1,48 +0,0 @@ -/* - * - * pca954x.h - I2C multiplexer/switch support - * - * Copyright (c) 2008-2009 Rodolfo Giometti - * Copyright (c) 2008-2009 Eurotech S.p.A. - * Michael Lawnick - * - * 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. - */ - - -#ifndef _LINUX_I2C_PCA954X_H -#define _LINUX_I2C_PCA954X_H - -/* Platform data for the PCA954x I2C multiplexers */ - -/* Per channel initialisation data: - * @adap_id: bus number for the adapter. 0 = don't care - * @deselect_on_exit: set this entry to 1, if your H/W needs deselection - * of this channel after transaction. - * - */ -struct pca954x_platform_mode { - int adap_id; - unsigned int deselect_on_exit:1; - unsigned int class; -}; - -/* Per mux/switch data, used with i2c_register_board_info */ -struct pca954x_platform_data { - struct pca954x_platform_mode *modes; - int num_modes; -}; - -#endif /* _LINUX_I2C_PCA954X_H */ -- cgit v1.2.3 From 4db61c2a16fce2ef85d82751de4ba43a39347cfb Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Thu, 25 Apr 2019 16:19:47 +0200 Subject: i2c: core: ratelimit 'transfer when suspended' errors There are two problems with WARN_ON() here. One: It is not ratelimited. Two: We don't see which adapter was used when trying to transfer something when already suspended. Implement a custom ratelimit once per adapter and use dev_WARN there. This fixes both issues. Drawback is that we don't see if multiple drivers are trying to transfer with the same adapter while suspended. They need to be discovered one after the other now. This is better than a high CPU load because a really broken driver might try to resend endlessly. Fixes: 9ac6cb5fbb17 ("i2c: add suspended flag and accessors for i2c adapters") Signed-off-by: Wolfram Sang Reviewed-by: Simon Horman Signed-off-by: Wolfram Sang Cc: stable@vger.kernel.org # v5.1+ --- include/linux/i2c.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 03755d4c9229..be27062f8ed1 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -694,7 +694,8 @@ struct i2c_adapter { int retries; struct device dev; /* the adapter device */ unsigned long locked_flags; /* owned by the I2C core */ -#define I2C_ALF_IS_SUSPENDED 0 +#define I2C_ALF_IS_SUSPENDED 0 +#define I2C_ALF_SUSPEND_REPORTED 1 int nr; char name[48]; -- cgit v1.2.3