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Wed, 17 Sep 2014 15:36:28 +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 v3] mfd: syscon: Decouple syscon interface from platform devices Date: Wed, 17 Sep 2014 12:01:50 +0530 Message-id: <1410935510-1567-1-git-send-email-pankaj.dubey@samsung.com> X-Mailer: git-send-email 1.7.9.5 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrFLMWRmVeSWpSXmKPExsWyRsSkWvettmSIwZJnPBZ/Jx1jt1g26S6b xfddX9gtehdcZbO4//Uoo8Wmx9dYLS7vmsNmMeP8PiaL25d5LT4d/c9qsWgrUFnHMkaLVbv+ MFrcfLadyYHPo6W5h83j969JjB47Z91l97hzbQ+bx+Yl9R59W1YxenzeJBfAHsVlk5Kak1mW WqRvl8CVcWbWQ5aCc3oVpw6fYm1gXKbWxcjBISFgIvFuUVYXIyeQKSZx4d56ti5GLg4hgaWM En/f/GKFSJhIPDs8kxUisYhRov31amaQhJDABCaJufOcQWw2AV2JJ+/ngsVFBLIl+m+vZgFp YBboZpLY/HwaO0hCWCBAYs+me0wgNouAqsTetvNsIFfwCrhLfGiOhjhIQWLOJBuIvYfYJf4f 8oGoFpD4NvkQC0SJrMSmA8wQJZISB1fcYJnAKLiAkWEVo2hqQXJBcVJ6kbFecWJucWleul5y fu4mRmAUnP73rH8H490D1ocYBTgYlXh4N1yWCBFiTSwrrsw9xGgKtGEis5Rocj4w1vJK4g2N zYwsTE1MjY3MLc2UxHkXSv0MFhJITyxJzU5NLUgtii8qzUktPsTIxMEp1cCYtfeT0z4R78V7 ZzIWLzE8s+Xjmx8q5vHSwp6CjJsXv5RoC38wu3ED66zLN6dbJunFNTS7qHjdkdsYV+PXXnMn 6XTFRLmr9yen/r846a/F+fIPpRlT77CYJr1gizynFnd+inTXRtP1vhHMdcIH3rKvC+25OW/B s6t9xUtEYy21ZhWYLLggnhuuxFKckWioxVxUnAgAEVUnu30CAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrGIsWRmVeSWpSXmKPExsVy+t9jAd232pIhBlvfMFn8nXSM3WLZpLts Ft93fWG36F1wlc3i/tejjBabHl9jtbi8aw6bxYzz+5gsbl/mtfh09D+rxaKtQGUdyxgtVu36 w2hx89l2Jgc+j5bmHjaP378mMXrsnHWX3ePOtT1sHpuX1Hv0bVnF6PF5k1wAe1QDo01GamJK apFCal5yfkpmXrqtkndwvHO8qZmBoa6hpYW5kkJeYm6qrZKLT4CuW2YO0MVKCmWJOaVAoYDE 4mIlfTtME0JD3HQtYBojdH1DguB6jAzQQMIaxowzsx6yFJzTqzh1+BRrA+MytS5GTg4JAROJ Z4dnskLYYhIX7q1n62Lk4hASWMQo0f56NTNIQkhgApPE3HnOIDabgK7Ek/dzweIiAtkS/bdX s4A0MAt0M0lsfj6NHSQhLBAgsWfTPSYQm0VAVWJv23mgqRwcvALuEh+ao0FMCQEFiTmTbCYw ci9gZFjFKJpakFxQnJSea6RXnJhbXJqXrpecn7uJERxnz6R3MK5qsDjEKMDBqMTDu+GyRIgQ a2JZcWXuIUYJDmYlEV6Re0Ah3pTEyqrUovz4otKc1OJDjKZAuycyS4km5wNTQF5JvKGxibmp samliYWJmaWSOO/BVutAIYH0xJLU7NTUgtQimD4mDk6pBkanabvjKuwWtcYt2Wi2UPX5i6/t QX+s1p64Nad7z7vTOv+WXcwwf75N3unWrs6ThsVLY6erWT388lhR5FzXBfGJOXmiEo88a1Nu p4Wk+/zjscw+2NURrJGiKa49daV7rp6085l9S2siN2rcUYuT+2vGoC1VNlXx0S139jkFl3o/ v2rQ/Gu7cL8SS3FGoqEWc1FxIgAtHU3ryQIAAA== 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-20140916_233653_438926_2A058544 X-CRM114-Status: GOOD ( 19.02 ) X-Spam-Score: -5.7 (-----) Cc: kgene.kim@samsung.com, linux@arm.linux.org.uk, arnd@arndb.de, naushad@samsung.com, Pankaj Dubey , tomasz.figa@gmail.com, joshi@samsung.com, thomas.ab@samsung.com, 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=-2.6 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 Signed-off-by: Pankaj Dubey Acked-by: Arnd Bergmann --- V2 of this patchset and related discussion can be found here [1]. 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/2014/9/2/299 drivers/mfd/syscon.c | 78 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 57 insertions(+), 21 deletions(-) diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index ca15878..4a4bad9 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -15,40 +15,49 @@ #include #include #include +#include #include #include -#include #include #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 int syscon_match_node(struct device *dev, void *data) -{ - struct device_node *dn = data; - - return (dev->of_node == dn) ? 1 : 0; -} +static struct syscon *of_syscon_register(struct device_node *np); 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; + } - return syscon->regmap; + spin_unlock(&syscon_list_slock); + + if (!syscon) + syscon = of_syscon_register(np); + + if (!IS_ERR(syscon)) + return syscon->regmap; + + return ERR_CAST(syscon); } EXPORT_SYMBOL_GPL(syscon_node_to_regmap); @@ -110,17 +119,45 @@ 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 struct syscon *of_syscon_register(struct device_node *np) +{ + struct syscon *syscon; + struct regmap *regmap; + void __iomem *base; + + 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) + return ERR_PTR(-ENOMEM); + + regmap = regmap_init_mmio(NULL, base, &syscon_regmap_config); + if (IS_ERR(regmap)) { + pr_err("regmap init failed\n"); + return ERR_CAST(regmap); + } + + syscon->regmap = regmap; + syscon->np = np; + + spin_lock(&syscon_list_slock); + list_add_tail(&syscon->list, &syscon_list); + spin_unlock(&syscon_list_slock); + + return syscon; +} + static int syscon_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -167,7 +204,6 @@ 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,