From patchwork Fri Jun 21 09:53:42 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Ruppert X-Patchwork-Id: 253169 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 32CE42C02F3 for ; Fri, 21 Jun 2013 19:55:00 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757979Ab3FUJyl (ORCPT ); Fri, 21 Jun 2013 05:54:41 -0400 Received: from mail.abilis.ch ([195.70.19.74]:13587 "EHLO mail.abilis.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756049Ab3FUJyi (ORCPT ); Fri, 21 Jun 2013 05:54:38 -0400 Received: from vzimbra0.lan (vzimbra0.lan [10.41.22.42]) by mail.abilis.ch (8.13.8/8.13.8) with ESMTP id r5L9rkWK010183; Fri, 21 Jun 2013 11:53:46 +0200 Received: from ab42.lan (ab42.lan [10.41.22.170]) by vzimbra0.lan (Postfix) with ESMTP id AA003900E7A; Fri, 21 Jun 2013 11:53:46 +0200 (CEST) Received: by ab42.lan (Postfix, from userid 2100) id 8C5421635; Fri, 21 Jun 2013 11:53:46 +0200 (CEST) From: Christian Ruppert To: Wolfram Sang Cc: Rob Herring , Mika Westerberg , linux-i2c@vger.kernel.org, "Ben Dooks (embedded platforms)" , Grant Likely , Rob Landley , devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Vineet Gupta , Pierrick Hascoet , Christian Ruppert Subject: [PATCH v9] i2c-designware: make SDA hold time configurable Date: Fri, 21 Jun 2013 11:53:42 +0200 Message-Id: <1371808422-27742-1-git-send-email-christian.ruppert@abilis.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <20130620203716.GF2961@katana> References: <20130620203716.GF2961@katana> X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on dmmail0.lan Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org This patch makes the SDA hold time configurable through device tree. Signed-off-by: Christian Ruppert Signed-off-by: Pierrick Hascoet Acked-by: Vineet Gupta # for arch/arc/boot/dts/* --- .../devicetree/bindings/i2c/i2c-designware.txt | 14 ++++++++++++++ arch/arc/boot/dts/abilis_tb100_dvk.dts | 10 +++++----- arch/arc/boot/dts/abilis_tb101_dvk.dts | 10 +++++----- drivers/i2c/busses/i2c-designware-core.c | 13 +++++++++++++ drivers/i2c/busses/i2c-designware-core.h | 1 + drivers/i2c/busses/i2c-designware-platdrv.c | 10 ++++++++++ 6 files changed, 48 insertions(+), 10 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt index e42a2ee..3266cc7 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt @@ -10,6 +10,9 @@ Recommended properties : - clock-frequency : desired I2C bus clock frequency in Hz. +Optional properties : + - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds. + Example : i2c@f0000 { @@ -20,3 +23,14 @@ Example : interrupts = <11>; clock-frequency = <400000>; }; + + i2c@1120000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "snps,designware-i2c"; + reg = <0x1120000 0x1000>; + interrupt-parent = <&ictl>; + interrupts = <12 1>; + clock-frequency = <400000>; + i2c-sda-hold-time-ns = <300>; + }; diff --git a/arch/arc/boot/dts/abilis_tb100_dvk.dts b/arch/arc/boot/dts/abilis_tb100_dvk.dts index 0fa0d4a..ebc313a 100644 --- a/arch/arc/boot/dts/abilis_tb100_dvk.dts +++ b/arch/arc/boot/dts/abilis_tb100_dvk.dts @@ -45,19 +45,19 @@ }; i2c0: i2c@FF120000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c1: i2c@FF121000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c2: i2c@FF122000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c3: i2c@FF123000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c4: i2c@FF124000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; leds { diff --git a/arch/arc/boot/dts/abilis_tb101_dvk.dts b/arch/arc/boot/dts/abilis_tb101_dvk.dts index a4d80ce..b204657 100644 --- a/arch/arc/boot/dts/abilis_tb101_dvk.dts +++ b/arch/arc/boot/dts/abilis_tb101_dvk.dts @@ -45,19 +45,19 @@ }; i2c0: i2c@FF120000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c1: i2c@FF121000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c2: i2c@FF122000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c3: i2c@FF123000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; i2c4: i2c@FF124000 { - sda-hold-time = <432>; + i2c-sda-hold-time-ns = <432>; }; leds { diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index c41ca63..66119e2 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -67,9 +67,12 @@ #define DW_IC_STATUS 0x70 #define DW_IC_TXFLR 0x74 #define DW_IC_RXFLR 0x78 +#define DW_IC_SDA_HOLD 0x7c #define DW_IC_TX_ABRT_SOURCE 0x80 #define DW_IC_ENABLE_STATUS 0x9c #define DW_IC_COMP_PARAM_1 0xf4 +#define DW_IC_COMP_VERSION 0xf8 +#define DW_IC_SDA_HOLD_MIN_VERS 0x3131312A #define DW_IC_COMP_TYPE 0xfc #define DW_IC_COMP_TYPE_VALUE 0x44570140 @@ -332,6 +335,16 @@ int i2c_dw_init(struct dw_i2c_dev *dev) dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT); dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); + /* Configure SDA Hold Time if required */ + reg = dw_readl(dev, DW_IC_COMP_VERSION); + if (dev->sda_hold_time) { + if (reg >= DW_IC_SDA_HOLD_MIN_VERS) + dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD); + else + dev_warn(dev->dev, + "Hardware too old to adjust SDA hold time."); + } + /* Configure Tx/Rx FIFO threshold levels */ dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL); dw_writel(dev, 0, DW_IC_RX_TL); diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index e761ad1..912aa22 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -90,6 +90,7 @@ struct dw_i2c_dev { unsigned int tx_fifo_depth; unsigned int rx_fifo_depth; int rx_outstanding; + u32 sda_hold_time; }; #define ACCESS_SWAP 0x00000001 diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 35b70a1..8b9d3f1 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include #include @@ -121,6 +122,15 @@ static int dw_i2c_probe(struct platform_device *pdev) return PTR_ERR(dev->clk); clk_prepare_enable(dev->clk); + if (pdev->dev.of_node) { + u32 ht = 0; + u32 ic_clk = dev->get_clk_rate_khz(dev); + + of_property_read_u32(pdev->dev.of_node, + "i2c-sda-hold-time-ns", &ht); + dev->sda_hold_time = ((u64)ic_clk * ht + 500000) / 1000000; + } + dev->functionality = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |