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2021-07-10Merge tag 'i3c/for-5.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull i3c updates from Alexandre Belloni: - two small fixes to the svc driver * tag 'i3c/for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: i3c: master: svc: fix doc warning in svc-i3c-master.c i3c: master: svc: drop free_irq of devm_request_irq allocated irq
2021-06-29i3c: master: cdns: Fix fall-through warning for ClangGustavo A. R. Silva
In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2021-06-09i3c: master: svc: fix doc warning in svc-i3c-master.cYang Yingliang
Fix the following make W=1 warning: drivers/i3c/master/svc-i3c-master.c:207: warning: expecting prototype for struct svc_i3c_i3c_dev_data. Prototype was for struct svc_i3c_i2c_dev_data instead Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210602085544.4101980-1-yangyingliang@huawei.com
2021-06-09i3c: master: svc: drop free_irq of devm_request_irq allocated irqYang Yingliang
irq allocated with devm_request_irq() will be freed in devm_irq_release(), using free_irq() in ->remove() will causes a dangling pointer, and a subsequent double free. So remove the free_irq() in svc_i3c_master_remove(). Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210602084935.3977636-1-yangyingliang@huawei.com
2021-03-09i3c: master: svc: remove redundant assignment to cmd->read_lenColin Ian King
The assignment of xfer_len to cmd->read_len appears to be redundant as the next statement re-assigns the value 0 to it. Clean up the code by removing the redundant first assignment. Addresses-Coverity: ("Unused value") Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver") Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210224151349.202332-1-colin.king@canonical.com
2021-02-22Merge tag 'i3c/for-5.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull i3c update from Alexandre Belloni: "Subsystem: - Handle drivers without probe or remove callback - Remove callback now returns void - DT documentation is now in yaml New driver: - Silvaco I3C master" * tag 'i3c/for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: i3c: master: dw: Drop redundant disec call MAINTAINERS: Add Silvaco I3C master i3c: master: svc: Add Silvaco I3C master driver dt-bindings: i3c: Describe Silvaco master binding dt-bindings: Add vendor prefix for Silvaco dt-bindings: i3c: mipi-hci: Include the bus binding dt-bindings: i3c: Convert the bus description to yaml i3c: Make remove callback return void i3c: Handle drivers without probe or remove callback i3c/master/mipi-i3c-hci: Specify HAS_IOMEM dependency
2021-02-06i3c: master: dw: Drop redundant disec callMiquel Raynal
Disabling all event calls is already handled by the core right before starting the DAA process. Do not do it again when the DAA process completes, it is redundant. Fixes: 1dd728f5d4d4 ("i3c: master: Add driver for Synopsys DesignWare IP") Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201228105501.6104-1-miquel.raynal@bootlin.com
2021-02-06i3c: master: svc: Add Silvaco I3C master driverMiquel Raynal
Add support for Silvaco I3C dual-role IP. The master role is supported in SDR mode only. I2C transfers have not been tested but are shared because they are very close to the I3C transfers in terms of register configuration. The IBI processing follows this logic: - When a slave advertizes an interrupt (SDA pulled low) an interrupt gets generated by the master. This time is unbounded and may be deferred. - The IRQ handler itself does not process anything: it only queues a work that will be run in non-atomic context. This is needed because short wait periods must be experienced. - The IBI job is divided in two parts: the first one is "critical" in the sense that it may not support getting interrupted. If this happens, after this first section the driver checks the master error register and depending on its content either flushes everything and errors out, or ends the processing (this second section may be interrupted). - If the critical section got interrupted, the slave will automatically respin it's IBI request when it will be allowed to. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210121101808.14654-6-miquel.raynal@bootlin.com
2021-02-01i3c/master/mipi-i3c-hci: Specify HAS_IOMEM dependencyDavid Gow
The MIPI i3c HCI driver makes use of IOMEM functions like devm_platform_ioremap_resource(), which are only available if CONFIG_HAS_IOMEM is defined. This causes the driver to be enabled under make ARCH=um allyesconfig, even though it won't build. By adding a dependency on HAS_IOMEM, the driver will not be enabled on architectures which don't support it. Fixes: 9ad9a52cce28 ("i3c/master: introduce the mipi-i3c-hci driver") Signed-off-by: David Gow <davidgow@google.com> Acked-by: Nicolas Pitre <npitre@baylibre.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210127040636.1535722-1-davidgow@google.com
2020-12-31i3c/master/mipi-i3c-hci: Fix position of __maybe_unused in i3c_hci_of_matchNathan Chancellor
Clang warns: ../drivers/i3c/master/mipi-i3c-hci/core.c:780:21: warning: attribute declaration must precede definition [-Wignored-attributes] static const struct __maybe_unused of_device_id i3c_hci_of_match[] = { ^ ../include/linux/compiler_attributes.h:267:56: note: expanded from macro '__maybe_unused' #define __maybe_unused __attribute__((__unused__)) ^ ../include/linux/mod_devicetable.h:262:8: note: previous definition is here struct of_device_id { ^ 1 warning generated. 'struct of_device_id' should not be split, as it is a type. Move the __maybe_unused attribute after the static and const qualifiers so that there are no warnings about this variable, period. Fixes: 95393f3e07ab ("i3c/master/mipi-i3c-hci: quiet maybe-unused variable warning") Link: https://github.com/ClangBuiltLinux/linux/issues/1221 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Nicolas Pitre <npitre@baylibre.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20201222025931.3043480-1-natechancellor@gmail.com
2020-12-17i3c/master/mipi-i3c-hci: quiet maybe-unused variable warningNicolas Pitre
If CONFIG_OF is disabled then the matching table is notreferenced. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Nicolas Pitre <npitre@baylibre.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2020-11-25i3c/master: Fix uninitialized variable next_addrColin Ian King
The variable next_addr is not initialized and is being used in a call to i3c_master_get_free_addr as a starting point to find the next address. Fix this by initializing next_addr to 0 to avoid an uninitialized garbage starting address from being used. Addresses-Coverity: ("Uninitialized scalar variable") Fixes: 9ad9a52cce28 ("i3c/master: introduce the mipi-i3c-hci driver") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Nicolas Pitre <npitre@baylibre.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> Link: https://lore.kernel.org/linux-i3c/20201124123504.396249-1-colin.king@canonical.com
2020-11-23i3c/master: introduce the mipi-i3c-hci driverNicolas Pitre
This adds basic support for hardware implementing the MIPI I3C HCI specification. This driver is currently limited by the capabilities of the I3C subsystem, meaning things like scheduled commands, auto-commands and NCM mode are not yet supported. This supports version 1.0 of the MIPI I3C HCI spec, as well as the imminent release of version 1.1. Support for draft version 2.0 of the spec is also largely included with the caveat that future adjustments to this code are likely as the spec is still a work in progress. This is also lightly tested as actual hardware is still very scarce, even for HCI v1.0. Hence the EXPERIMENTAL tag. Further contributions to this driver are expected once vendor implementations and new I3C devices become available. Signed-off-by: Nicolas Pitre <npitre@baylibre.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> Link: https://lore.kernel.org/linux-i3c/20201111220510.3622216-3-nico@fluxnic.net
2020-10-17Merge tag 'i3c/for-5.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull i3c updates from Boris Brezillon: - Fix DAA for the pre-reserved address case - Fix an error path in the cadence driver * tag 'i3c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: i3c: master: Fix error return in cdns_i3c_master_probe() i3c: master: fix for SETDASA and DAA process i3c: master add i3c_master_attach_boardinfo to preserve boardinfo
2020-10-07i3c: master: Fix error return in cdns_i3c_master_probe()Jing Xiangfeng
Fix to return negative error code -ENOMEM from the error handling case instead of 0. Fixes: 603f2bee2c54 ("i3c: master: Add driver for Cadence IP") Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> Link: https://lore.kernel.org/linux-i3c/20200911033350.23904-1-jingxiangfeng@huawei.com
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-02-28i3c: master: Replace zero-length array with flexible-array memberGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com> Link: https://lore.kernel.org/linux-i3c/20200227131307.GA24935@embeddedor
2020-01-13i3c: master: dw: reattach device on first available location of address tableVitor Soares
For today the reattach function only update the device address on the controller. Update the location to the first available too, will optimize the enumeration process avoiding additional checks to keep the available positions on address table consecutive. Signed-off-by: Vitor Soares <vitor.soares@synopsys.com> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2020-01-13i3c: master: cdns: convert to devm_platform_ioremap_resourceYangtao Li
Use devm_platform_ioremap_resource() to simplify code. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2020-01-13i3c: master: dw: convert to devm_platform_ioremap_resourceYangtao Li
Use devm_platform_ioremap_resource() to simplify code. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Acked-by: Vitor Soares <vitor.soares@synopsys.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-12-09i3c: master: cdns: add data hold delay supportPrzemyslaw Gaj
This patch adds support for THD_DEL (Data Hold Delay) to Cadence I3C master constoller driver. As per MIPI I3C Specification 1.0, Table 75 (page 142) defines non-zero minimal tHD_PP timing on master output (Fig 65). This setting allows to meet this timing on master's soc outputs, regardless of PCB balancing. Signed-off-by: Przemyslaw Gaj <pgaj@cadence.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-08-11i3c: add addr and lvr to i2c_dev_desc structurePrzemyslaw Gaj
I need to store address and lvr value for I2C devices without static definition in DT. This allows secondary master to transmit DEFSLVS command properly. Main changes between v4 and v5: - Change in defslvs to use addr and lvr from i2c_dev_desc structure - Change in CDNS and DW drivers to use addr and lvr from i2c_dev_desc structure Signed-off-by: Przemyslaw Gaj <pgaj@cadence.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-08-11i3c: master: cdns: Use for_each_set_bit()Andy Shevchenko
This simplifies and standardizes slot manipulation code by using for_each_set_bit() library function. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-07-09Merge tag 'i3c/for-5.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull ic3 updates from Boris Brezillon: - Drop support for 10-bit I2C addresses - Add support for limited bus mode - Fix the Cadence DT binding doc - Use struct_size() to allocate a DEFSLVS packet * tag 'i3c/for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: i3c: master: Use struct_size() helper dt-bindings: i3c: cdns: Use correct cells for I2C device i3c: dw: add limited bus mode support i3c: add mixed limited bus mode i3c: fix i2c and i3c scl rate by bus mode dt-bindings: i3c: Document dropped support for I2C 10 bit devices i3c: Drop support for I2C 10 bit addresing
2019-06-20i3c: dw: add limited bus mode supportVitor Soares
This patch add limited bus mode support for DesignWare i3c master Signed-off-by: Vitor Soares <vitor.soares@synopsys.com> Cc: Boris Brezillon <bbrezillon@kernel.org> Cc: <linux-kernel@vger.kernel.org> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-05-28i3c: Drop support for I2C 10 bit addresingPrzemyslaw Gaj
This patch drops support for I2C devices with 10 bit addressing. When I2C device with 10 bit address is defined in DT, I3C master registration fails. Address space for I2C devices has been reduced and ->i2c_funcs() hook has been removed. Because this patch series dropped support for 10 bit I2C devices, support is also dropped in Cadence I3C master driver and Synopsys DesignWare I3C master driver. Signed-off-by: Przemyslaw Gaj <pgaj@cadence.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-07Merge tag 'i3c/for-5.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull i3c update from Boris Brezillon: - Fix a shift wrap bug in the core - Remove dead code in the DW driver * tag 'i3c/for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: i3c: Fix a shift wrap bug in i3c_bus_set_addr_slot_status() i3c: master: dw: remove dead code from dw_i3c_master_*_xfers()
2019-04-10i3c: dw: Fix dw_i3c_master_disable controller by using correct maskVitor Soares
The controller was being disabled incorrectly. The correct way is to clear the DEV_CTRL_ENABLE bit. Fix this by clearing this bit. Cc: Boris Brezillon <bbrezillon@kernel.org> Cc: <stable@vger.kernel.org> Fixes: 1dd728f5d4d4 ("i3c: master: Add driver for Synopsys DesignWare IP") Signed-off-by: Vitor Soares <vitor.soares@synopsys.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-03-30i3c: master: dw: remove dead code from dw_i3c_master_*_xfers()Vitor Soares
Detected by CoverityScan (Event result_independent_of_operands): "(i3c_xfers + i).len > 65536" is always false regardless of the values of its operands. This occurs as the logical operand of "if" "(i2c_xfers + i).len > 65536" is always false regardless of the values of its operands. This occurs as the logical operand of "if" Signed-off-by: Vitor Soares <vitor.soares@synopsys.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-03-04Merge tag 'i3c/for-5.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull i3c updates from Boris Brezillon: - Add a /* fall-through */ comment in the dw-i3c-master driver - Update the I3C entries in MAINTAINERS to add an IRC chan * tag 'i3c/for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: i3c: master: dw-i3c-master: mark expected switch fall-through MAINTAINERS: Add an IRC channel for the I3C subsystem
2019-02-28i3c: master: dw-i3c-master: mark expected switch fall-throughGustavo A. R. Silva
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. This patch fixes the following warning: drivers/i3c/master/dw-i3c-master.c: In function ‘dw_i3c_master_bus_init’: drivers/i3c/master/dw-i3c-master.c:603:6: warning: this statement may fall through [-Wimplicit-fallthrough=] if (ret) ^ drivers/i3c/master/dw-i3c-master.c:605:2: note: here case I3C_BUS_MODE_PURE: ^~~~ Warning level 3 was used: -Wimplicit-fallthrough=3 This patch is part of the ongoing efforts to enable -Wimplicit-fallthrough. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Acked-by: Vitor Soares <vitor.soares@synopsys.com> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
2019-01-26i3c: master: dw: fix deadlockJisheng Zhang
In dw_i3c_master_irq_handler(), we already have gotten &master->xferqueue.lock, if we try to get the same lock again in dw_i3c_master_dequeue_xfer(), deadlock happens. We fix this issue by introduing dw_i3c_master_dequeue_xfer_locked() which does all what dw_i3c_master_dequeue_xfer() does without trying to lock &master->xferqueue.lock. Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Acked-by: Vitor Soares <vitor.soares@synopsys.com> Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
2019-01-15i3c: master: dw-i3c-master: fix i3c_attach/reattachVitor Soares
This patch fix i3c_attach/reattach functions. During the i3c_attach the driver ignores the static address used for SETDASA CCC command. During the i3c_reattach the driver doesn't update master->addrs[data->index] with new address if old_dyn_addr = 0. Fixes: 1dd728f5d4d4 ("i3c: master: Add driver for Synopsys DesignWare IP") Signed-off-by: Vitor Soares <vitor.soares@synopsys.com> Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
2019-01-07i3c: master: Fix an error checking typo in 'cdns_i3c_master_probe()'Christophe JAILLET
Fix a cut'n'paste typo. Checking 'master->sysclk' is expected here. Fixes: 603f2bee2c54 ("i3c: master: Add driver for Cadence IP") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
2018-12-12i3c: master: cdns: fix I2C transfers in Cadence I3C master driverPrzemyslaw Gaj
This patch fixes I2C transfers in Cadence I3C master driver. There was no way to queue more than one I2C transfer before. Fixes: 603f2bee2c54 ("i3c: master: Add driver for Cadence IP") Signed-off-by: Przemyslaw Gaj <pgaj@cadence.com> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
2018-12-05i3c: master: dw: fix mask operation by using the correct operatorColin Ian King
The masking operation on status is using a bitwise 'or' rather than a bitwise 'and' operator, and hence the result is always non-zero which is probably not what is intended. Fix this by using the correct operator. Detected by CoverityScan, CID#1475523 ("Wrong operator used") Fixes: 88acc98a712a ("i3c: master: Add driver for Synopsys DesignWare IP") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Vitor Soares <vitor.soares@synopsys.com> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
2018-12-05i3c: master: Add driver for Synopsys DesignWare IPVitor Soares
Add driver for Synopsys DesignWare I3C master IP Signed-off-by: Vitor Soares <vitor.soares@synopsys.com> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
2018-12-05i3c: master: Remove set but not used variable 'old_i3c_scl_lim'YueHaibing
Fixes gcc '-Wunused-but-set-variable' warning: drivers/i3c/master/i3c-master-cdns.c: In function 'cdns_i3c_master_do_daa': drivers/i3c/master/i3c-master-cdns.c:1137:16: warning: variable 'old_i3c_scl_lim' set but not used [-Wunused-but-set-variable] It never used since introdution in commit acfab7d324b2 ("i3c: master: Add driver for Cadence IP") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
2018-12-05i3c: master: Add driver for Cadence IPBoris Brezillon
Add a driver for Cadence I3C master IP. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-12i3c: Add core I3C infrastructureBoris Brezillon
Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>