From patchwork Wed May 27 12:25:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 207562 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B9C4C433E1 for ; Wed, 27 May 2020 12:25:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56799207D8 for ; Wed, 27 May 2020 12:25:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729937AbgE0MZc (ORCPT ); Wed, 27 May 2020 08:25:32 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:35186 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729929AbgE0MZc (ORCPT ); Wed, 27 May 2020 08:25:32 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id B9C75803080A; Wed, 27 May 2020 12:25:28 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rvINEbGss5Ot; Wed, 27 May 2020 15:25:28 +0300 (MSK) From: Serge Semin To: CC: Serge Semin , Serge Semin , Alexey Malahov , Thomas Bogendoerfer , Wolfram Sang , Jarkko Nikula , Andy Shevchenko , Frank Rowand , Rob Herring , , , Subject: [PATCH] check: Add 10bit/slave i2c reg flags support Date: Wed, 27 May 2020 15:25:25 +0300 Message-ID: <20200527122525.6929-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Recently the I2C-controllers slave interface support was added to the kernel I2C subsystem. In this case Linux can be used as, for example, a I2C EEPROM machine. See [1] for details. Other than instantiating the EEPROM-slave device from user-space there is a way to declare the device in dts. In this case firstly the I2C bus controller must support the slave interface. Secondly I2C-slave sub-node of that controller must have "reg"-property with flag I2C_OWN_SLAVE_ADDRESS set (flag is declared in [2]). That flag is declared as (1 << 30), which when set makes dtc unhappy about too big address set for a I2C-slave: Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64: I2C bus unit address format error, expected "40000064" Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64:reg: I2C address must be less than 10-bits, got "0x40000064" Similar problem would have happened if we had set the 10-bit address flag I2C_TEN_BIT_ADDRESS in the "reg"-property. In order to fix the problem we suggest to alter the I2C-bus reg-check algorithm, so one would be aware of the upper bits set. Normally if no flag specified, the 7-bit address is expected in the "reg"-property. If I2C_TEN_BIT_ADDRESS is set, then the 10-bit address check will be performed. The I2C_OWN_SLAVE_ADDRESS flag will be just ignored. [1] kernel/Documentation/i2c/slave-interface.rst [2] kernel/include/dt-bindings/i2c/i2c.h Signed-off-by: Serge Semin Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Wolfram Sang Cc: Jarkko Nikula Cc: Andy Shevchenko Cc: Frank Rowand Cc: Rob Herring Cc: devicetree-compiler@vger.kernel.org Cc: devicetree@vger.kernel.org Cc: linux-i2c@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- checks.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/checks.c b/checks.c index 4b3c486f1399..6321fc5b7404 100644 --- a/checks.c +++ b/checks.c @@ -1028,6 +1028,7 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node const char *unitname = get_unitname(node); char unit_addr[17]; uint32_t reg = 0; + uint32_t addr; int len; cell_t *cells = NULL; @@ -1044,17 +1045,21 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node } reg = fdt32_to_cpu(*cells); - snprintf(unit_addr, sizeof(unit_addr), "%x", reg); + addr = reg & 0x3FFFFFFFU; + snprintf(unit_addr, sizeof(unit_addr), "%x", addr); if (!streq(unitname, unit_addr)) FAIL(c, dti, node, "I2C bus unit address format error, expected \"%s\"", unit_addr); for (len = prop->val.len; len > 0; len -= 4) { reg = fdt32_to_cpu(*(cells++)); - if (reg > 0x3ff) + addr = reg & 0x3FFFFFFFU; + if ((reg & (1 << 31)) && addr > 0x3ff) FAIL_PROP(c, dti, node, prop, "I2C address must be less than 10-bits, got \"0x%x\"", - reg); - + addr); + else if (!(reg & (1 << 31)) && addr > 0x7f) + FAIL_PROP(c, dti, node, prop, "I2C address must be less than 7-bits, got \"0x%x\"", + addr); } } WARNING(i2c_bus_reg, check_i2c_bus_reg, NULL, ®_format, &i2c_bus_bridge);