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Mon, 22 Sep 2014 13:44:59 +0900 (KST) From: Pankaj Dubey To: linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5] mfd: syscon: Decouple syscon interface from platform devices Date: Mon, 22 Sep 2014 10:10:07 +0530 Message-id: <1411360807-7750-1-git-send-email-pankaj.dubey@samsung.com> X-Mailer: git-send-email 1.7.9.5 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrFLMWRmVeSWpSXmKPExsWyRsSkRtd7pXyIQfdxC4u/k46xWzzc2c9i sWzSXTaL77u+sFv0LrjKZnH/61FGi84LHawWmx5fY7W4vGsOm8WM8/uYLG5f5rX4dPQ/q8Wi rUC1HcsYLVbt+sNocfPZdiYHAY+W5h42j9+/JjF6/Dvcz+Sxc9Zddo871/aweWxeUu/Rt2UV o8fnTXIBHFFcNimpOZllqUX6dglcGbMW1xfcNKto2NvO3MB4S6eLkZNDQsBEYsrTjWwQtpjE hXvrgWwuDiGBpYwSZyadZepi5AArOjUhGSK+iFHi77+VzBDOBCaJeZ9uMYN0swnoSjx5PxfM FhHIlui/vZoFxGYW2M0kcWh7IogtLBAg8eLmXVYQm0VAVWJ95yOwzbwC7hKbV95khFimIDFn kg3IfAmBS+wSl4+fYIGoF5D4NvkQC0SNrMSmA8wQR0tKHFxxg2UCo+ACRoZVjKKpBckFxUnp RSZ6xYm5xaV56XrJ+bmbGIFRcvrfswk7GO8dsD7EKMDBqMTD+6NFPkSINbGsuDL3EKMp0IaJ zFKiyfnAWMwriTc0NjOyMDUxNTYytzRTEud9LfUzWEggPbEkNTs1tSC1KL6oNCe1+BAjEwen VANjejC/t2uqreq+uJlPdu3b7X74/Yei1a221bsdrR6uFHfx79Xl6gxOiZ+uwiPeP31y1Ysn c2LmlaR/TRZd7lmelqHSoWI6/faLW2/1Ls8tddvwKt4us9A+/QPDb94y+SnKp6f4F95qP3PU aeaziDObnrw9uE9dcaps4FR5t6m+BfM+Ba71zLZSYinOSDTUYi4qTgQAzNSyPo0CAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrCIsWRmVeSWpSXmKPExsVy+t9jAV3vlfIhBqvPGVj8nXSM3eLhzn4W i2WT7rJZfN/1hd2id8FVNov7X48yWnRe6GC12PT4GqvF5V1z2CxmnN/HZHH7Mq/Fp6P/WS0W bQWq7VjGaLFq1x9Gi5vPtjM5CHi0NPewefz+NYnR49/hfiaPnbPusnvcubaHzWPzknqPvi2r GD0+b5IL4IhqYLTJSE1MSS1SSM1Lzk/JzEu3VfIOjneONzUzMNQ1tLQwV1LIS8xNtVVy8QnQ dcvMAXpASaEsMacUKBSQWFyspG+HaUJoiJuuBUxjhK5vSBBcj5EBGkhYw5gxa3F9wU2zioa9 7cwNjLd0uhg5OCQETCROTUjuYuQEMsUkLtxbz9bFyMUhJLCIUeLvv5XMEM4EJol5n24xg1Sx CehKPHk/F8wWEciW6L+9mgXEZhbYzSRxaHsiiC0sECDx4uZdVhCbRUBVYn3nIzYQm1fAXWLz ypuMEIsVJOZMspnAyL2AkWEVo2hqQXJBcVJ6rqFecWJucWleul5yfu4mRnAMPpPawbiyweIQ owAHoxIP74Im+RAh1sSy4srcQ4wSHMxKIrxHc4BCvCmJlVWpRfnxRaU5qcWHGE2Blk9klhJN zgemh7ySeENjE3NTY1NLEwsTM0slcd4DrdaBQgLpiSWp2ampBalFMH1MHJxSDYwZZZOLnqyQ Z+It8Z2aevW8Wcf+COV5j69ONdt+ymGNykYm3m+V7OsCjpR35Mw6kpe887lb7OkOv3mlzO/Y 11+cnvJJfdWkvl9cM4v0E8VvvDU/NWNq+GK5VfY+dxNmRj+vvVSfv3PZ9WbJhzPmm6nvctvw 1y3Oe+vPI5x7JjHFX9jb+ItB+2mbEktxRqKhFnNRcSIAdLHi3dcCAAA= DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140921_214523_402161_293DB5E6 X-CRM114-Status: GOOD ( 21.74 ) X-Spam-Score: -5.8 (-----) Cc: kgene.kim@samsung.com, linux@arm.linux.org.uk, arnd@arndb.de, naushad@samsung.com, b29396@freescale.com, tomasz.figa@gmail.com, joshi@samsung.com, thomas.ab@samsung.com, Li.Xiubo@freescale.com, Pankaj Dubey , vikas.sajjan@samsung.com, chow.kim@samsung.com, lee.jones@linaro.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently a syscon entity can be only registered directly through a platform device that binds to a dedicated syscon driver. However in certain use cases it is desirable to make a device used with another driver a syscon interface provider. For example, certain SoCs (e.g. Exynos) contain system controller blocks which perform various functions such as power domain control, CPU power management, low power mode control, but in addition contain certain IP integration glue, such as various signal masks, coprocessor power control, etc. In such case, there is a need to have a dedicated driver for such system controller but also share registers with other drivers. The latter is where the syscon interface is helpful. In case of DT based platforms, this patch decouples syscon object from syscon platform driver, and allows to create syscon objects first time when it is required by calling of syscon_regmap_lookup_by APIs and keep a list of such syscon objects along with syscon provider device_nodes and regmap handles. For non-DT based platforms, this patch keeps syscon platform driver structure where is can be probed and such non-DT based drivers can use syscon_regmap_lookup_by_pdev API and get access to regmap handles. Once all users of "syscon_regmap_lookup_by_pdev" migrated to DT based, we can completly remove platform driver of syscon, and keep only helper functions to get regmap handles. Suggested-by: Arnd Bergmann Suggested-by: Tomasz Figa Tested-by: Vivek Gautam Tested-by: Javier Martinez Canillas Signed-off-by: Pankaj Dubey Tested-by: Joachim Eastwood --- Patch v4 and related discussions can be found here [1]. Changes since v4: - Addressed Tomasz Figa's comments for v4. - Added error handing in of_syscon_register function. - Using devm_regmap_init_mmio instead of regmap_init_mmio. Changes since v3: - Addressed Arnd's comment for v2. - Updated of_syscon_register for adding dev pointer in regmap_init_mmio. - For early users created dummy platform device. Changes since v2: - Added back platform device support from syscon, with one change that syscon will not be probed for DT based platform. - Added back syscon_regmap_lookup_by_pdevname API so that non-DT base users of syscon will not be broken. - Removed unwanted change in syscon.h. - Modified Signed-off-by list, added Suggested-by of Tomasz Figa and Arnd Bergmann. - Added Tested-by of Vivek Gautam for testing on Exynos platform. Changes since v1: - Removed of_syscon_unregister function. - Modified of_syscon_register function and it will be used by syscon.c to create syscon objects whenever required. - Removed platform device support from syscon. - Removed syscon_regmap_lookup_by_pdevname API support. - As there are significant changes w.r.t patchset v1, I am taking over author for this patchset from Tomasz Figa. [1]: https://lkml.org/lkml/2014/9/19/267 drivers/mfd/syscon.c | 107 +++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 85 insertions(+), 22 deletions(-) diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index ca15878..0b17f50 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -22,31 +23,105 @@ #include #include #include +#include static struct platform_driver syscon_driver; +static DEFINE_SPINLOCK(syscon_list_slock); +static LIST_HEAD(syscon_list); + struct syscon { + struct device_node *np; struct regmap *regmap; + struct list_head list; +}; + +static struct regmap_config syscon_regmap_config = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, }; -static int syscon_match_node(struct device *dev, void *data) +static struct syscon *of_syscon_register(struct device_node *np) { - struct device_node *dn = data; + struct platform_device *pdev = NULL; + struct syscon *syscon; + struct regmap *regmap; + void __iomem *base; + int ret; + + if (!of_device_is_compatible(np, "syscon")) + return ERR_PTR(-EINVAL); + + syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); + if (!syscon) + return ERR_PTR(-ENOMEM); + + base = of_iomap(np, 0); + if (!base) { + ret = -ENOMEM; + goto err_map; + } + + /* if device is already populated and available then use it */ + pdev = of_find_device_by_node(np); + if (!pdev) { + /* for early users create dummy syscon device and use it */ + pdev = platform_device_alloc("dummy-syscon", -1); + if (!pdev) { + ret = -ENOMEM; + goto err_pdev; + } + pdev->dev.of_node = of_node_get(np); + } + + regmap = devm_regmap_init_mmio(&pdev->dev, base, &syscon_regmap_config); + if (IS_ERR(regmap)) { + dev_err(&pdev->dev, "regmap init failed\n"); + ret = PTR_ERR(regmap); + goto err_regmap; + } + + syscon->regmap = regmap; + syscon->np = np; - return (dev->of_node == dn) ? 1 : 0; + spin_lock(&syscon_list_slock); + list_add_tail(&syscon->list, &syscon_list); + spin_unlock(&syscon_list_slock); + + return syscon; + +err_regmap: + if (!strcmp(pdev->name, "dummy-syscon")) { + of_node_put(np); + platform_device_put(pdev); + } +err_pdev: + iounmap(base); +err_map: + kfree(syscon); + return ERR_PTR(ret); } struct regmap *syscon_node_to_regmap(struct device_node *np) { - struct syscon *syscon; - struct device *dev; + struct syscon *entry, *syscon = NULL; - dev = driver_find_device(&syscon_driver.driver, NULL, np, - syscon_match_node); - if (!dev) - return ERR_PTR(-EPROBE_DEFER); + spin_lock(&syscon_list_slock); - syscon = dev_get_drvdata(dev); + list_for_each_entry(entry, &syscon_list, list) + if (entry->np == np) { + syscon = entry; + break; + } + + spin_unlock(&syscon_list_slock); + + if (!syscon) + syscon = of_syscon_register(np); + + if (IS_ERR(syscon)) + return ERR_CAST(syscon); return syscon->regmap; } @@ -110,17 +185,6 @@ struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np, } EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle); -static const struct of_device_id of_syscon_match[] = { - { .compatible = "syscon", }, - { }, -}; - -static struct regmap_config syscon_regmap_config = { - .reg_bits = 32, - .val_bits = 32, - .reg_stride = 4, -}; - static int syscon_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -167,7 +231,6 @@ static struct platform_driver syscon_driver = { .driver = { .name = "syscon", .owner = THIS_MODULE, - .of_match_table = of_syscon_match, }, .probe = syscon_probe, .id_table = syscon_ids,