From patchwork Wed Jul 3 09:52:40 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Westerberg X-Patchwork-Id: 256568 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 121632C00A1 for ; Wed, 3 Jul 2013 19:49:53 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755129Ab3GCJtv (ORCPT ); Wed, 3 Jul 2013 05:49:51 -0400 Received: from mga02.intel.com ([134.134.136.20]:7854 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754628Ab3GCJtv (ORCPT ); Wed, 3 Jul 2013 05:49:51 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 03 Jul 2013 02:49:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,987,1363158000"; d="scan'208";a="364087329" Received: from blue.fi.intel.com ([10.237.72.156]) by orsmga002.jf.intel.com with ESMTP; 03 Jul 2013 02:49:44 -0700 Received: by blue.fi.intel.com (Postfix, from userid 1004) id E3CD0E0090; Wed, 3 Jul 2013 12:52:40 +0300 (EEST) From: Mika Westerberg To: linux-i2c@vger.kernel.org Cc: Wolfram Sang , Christian Ruppert , Mika Westerberg , linux-kernel@vger.kernel.org Subject: [PATCH] i2c-designware: configure SDA hold time from ACPI Date: Wed, 3 Jul 2013 12:52:40 +0300 Message-Id: <1372845160-32625-1-git-send-email-mika.westerberg@linux.intel.com> X-Mailer: git-send-email 1.8.3.2 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Some Intel LPSS I2C devices make the SDA hold time parameter available via SSCN (standard mode) and FMCN (fast mode) ACPI methods. If we find that such method exist, we evaluate it and pass the returned SDA hold value to the i2c-designware core analogous to Device Tree. Signed-off-by: Mika Westerberg --- drivers/i2c/busses/i2c-designware-platdrv.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 8b9d3f1..c7cfdac 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -57,13 +57,30 @@ static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) static int dw_i2c_acpi_configure(struct platform_device *pdev) { struct dw_i2c_dev *dev = platform_get_drvdata(pdev); + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; + acpi_handle handle = ACPI_HANDLE(&pdev->dev); + acpi_string name; - if (!ACPI_HANDLE(&pdev->dev)) + if (!handle) return -ENODEV; dev->adapter.nr = -1; dev->tx_fifo_depth = 32; dev->rx_fifo_depth = 32; + + name = dev->master_cfg & DW_IC_CON_SPEED_FAST ? "FMCN" : "SSCN"; + if (ACPI_SUCCESS(acpi_evaluate_object(handle, name, NULL, &buf))) { + union acpi_object *obj = (union acpi_object *)buf.pointer; + + if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { + const union acpi_object *objs = obj->package.elements; + + dev->sda_hold_time = (u32)objs[2].integer.value; + } + + kfree(buf.pointer); + } + return 0; }