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Fri, 17 Jun 2016 16:57:29 +0900 (KST) Received: from samsunx.samsung ([10.113.63.54]) by mmp2.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTPA id <0O8W00H9UORQH320@mmp2.samsung.com>; Fri, 17 Jun 2016 16:57:28 +0900 (KST) From: Andi Shyti To: Mark Brown Subject: [PATCH 1/5] spi: do not fail if the CS line is not connected Date: Fri, 17 Jun 2016 16:57:21 +0900 Message-id: <1466150245-2648-2-git-send-email-andi.shyti@samsung.com> X-Mailer: git-send-email 2.8.1 In-reply-to: <1466150245-2648-1-git-send-email-andi.shyti@samsung.com> References: <1466150245-2648-1-git-send-email-andi.shyti@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrPLMWRmVeSWpSXmKPExsWyRsSkWDdzbXK4wbmlYhbbjzxjtVj84zmT xdSHT9gsXr8wtOh//JrZYtPja6wWl3fNYbNo/HiT3YHD4/qST8wem1Z1snlsXlLv0bdlFaPH 501yAaxRXDYpqTmZZalF+nYJXBkHOh6xFRzjqWh9sIG9gXECVxcjJ4eEgIlE+7KL7BC2mMSF e+vZuhi5OIQEVjBKnGqcwQJT9P/NbhaIxCxGidMdd6Ccj4wSV5atAatiE9CUaLr9gw3EFhFQ lrj6fS9YEbPAT0aJq3dawYqEBVwl7rZMZwWxWQRUJVbfmMwEYvMCxR8ufsQIsU5O4vL0B2CD OAXcJBZe+QwU5wDa5ipx8aUmyEwJgUXsEsd2QNzNIiAg8W3yIRaQGgkBWYlNB5ghxkhKHFxx g2UCo/ACRoZVjKKpBckFxUnpRSZ6xYm5xaV56XrJ+bmbGIHhfvrfswk7GO8dsD7EKMDBqMTD GyGVHC7EmlhWXJl7iNEUaMNEZinR5HxgVOWVxBsamxlZmJqYGhuZW5opifO+lvoZLCSQnliS mp2aWpBaFF9UmpNafIiRiYNTqoGxbu7EmE+L9jtcmaq8aR5DisDa062Jig+FDap3h5+oXhH4 qOaV10yBZw73Jy5zmn2x8Ojc3S52X4JvCvw12/Zq7iOvfZ/FJbsFlt/y9zt+SMqswn3lr2kT 9ii/PPjhxbmulx2vF/r2e36YeH6O2KX5sjLP9pdzclYsET51sUBg+uV7HL9F9Tf8fanEUpyR aKjFXFScCAAz/J7BcgIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrDIsWRmVeSWpSXmKPExsVy+t9jQd3MtcnhBm+XCFpsP/KM1WLxj+dM FlMfPmGzeP3C0KL/8Wtmi02Pr7FaXN41h82i8eNNdgcOj+tLPjF7bFrVyeaxeUm9R9+WVYwe nzfJBbBGNTDaZKQmpqQWKaTmJeenZOal2yp5B8c7x5uaGRjqGlpamCsp5CXmptoqufgE6Lpl 5gCdoqRQlphTChQKSCwuVtK3wzQhNMRN1wKmMULXNyQIrsfIAA0krGHMONDxiK3gGE9F64MN 7A2ME7i6GDk5JARMJP6/2c0CYYtJXLi3nq2LkYtDSGAWo8TpjjssEM5HRokry9aAVbEJaEo0 3f7BBmKLCChLXP2+F6yIWeAno8TVO61gRcICrhJ3W6azgtgsAqoSq29MZgKxeYHiDxc/YoRY JydxefoDsEGcAm4SC698BopzAG1zlbj4UnMCI+8CRoZVjBKpBckFxUnpuYZ5qeV6xYm5xaV5 6XrJ+bmbGMEx9UxqB+PBXe6HGAU4GJV4eHcoJ4cLsSaWFVfmHmKU4GBWEuFlXAUU4k1JrKxK LcqPLyrNSS0+xGgKdNdEZinR5HxgvOeVxBsam5gZWRqZG1oYGZsrifM+/r8uTEggPbEkNTs1 tSC1CKaPiYNTqoGx6r2HxHapx6dbu6Imvdfadngz+/L5e/N5f/Dm1t3/FS6i+okvUqPqhslk GbUWnvv8Ef+WbEs8p8x7bd5Nph2OdlplC0MFFjLc9bUuFH/RZ2FnYSMu0WKUM9tuycJCB4u9 N41rOTluGb2UMoozvfP3Hn/ogdl5bLou1rzxK32+l/fcfqk0oV2JpTgj0VCLuag4EQAFprMv vwIAAA== 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-20160617_005755_320720_AE91A1C2 X-CRM114-Status: GOOD ( 14.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Krzysztof Kozlowski , linux-kernel@vger.kernel.org, Andi Shyti , linux-spi@vger.kernel.org, Kukjin Kim , Andi Shyti , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Some SPI connected devices do not have any CS line connected as some devices are alway enabled. Indeed, until now, a common workaround was to assign to num_chipselect a -1 value or 255 (num_chipselect is unsigned). In this case do not fail and defer to the SPI device drivers the responsibility to check whether the num-cs is '0'. Signed-off-by: Andi Shyti --- drivers/spi/spi.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 77e6e45..f22dc27 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -504,8 +504,13 @@ int spi_add_device(struct spi_device *spi) struct device *dev = master->dev.parent; int status; - /* Chipselects are numbered 0..max; validate. */ - if (spi->chip_select >= master->num_chipselect) { + /* + * Chipselects are numbered 0..max; validate. + * If there is no chip select (i.e. num_chipselect == 0), + * the comparison doesn't make sense. + */ + if (master->num_chipselect && + spi->chip_select >= master->num_chipselect) { dev_err(dev, "cs%d >= max %d\n", spi->chip_select, master->num_chipselect); @@ -1851,12 +1856,6 @@ int spi_register_master(struct spi_master *master) if (status) return status; - /* even if it's just one always-selected device, there must - * be at least one chipselect - */ - if (master->num_chipselect == 0) - return -EINVAL; - if ((master->bus_num < 0) && master->dev.of_node) master->bus_num = of_alias_get_id(master->dev.of_node, "spi");