From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757217Ab3DPPEL (ORCPT ); Tue, 16 Apr 2013 11:04:11 -0400 Received: from mail.abilis.ch ([195.70.19.74]:29046 "EHLO mail.abilis.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756604Ab3DPPEJ (ORCPT ); Tue, 16 Apr 2013 11:04:09 -0400 From: Christian Ruppert To: linux-i2c@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Christian Ruppert , Pierrick Hascoet Subject: [PATCH v7] i2c-designware: make SDA hold time configurable Date: Tue, 16 Apr 2013 17:03:55 +0200 Message-Id: <1366124635-15196-1-git-send-email-christian.ruppert@abilis.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <20130218132843.GA2439@intel.com> References: <20130218132843.GA2439@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Looks like this was eaten by the spam filter last time so i'm resending it to the lists only: This patch makes the SDA hold time configurable through device tree. Signed-off-by: Christian Ruppert Signed-off-by: Pierrick Hascoet --- .../devicetree/bindings/i2c/i2c-designware.txt | 14 ++++++++++++++ drivers/i2c/busses/i2c-designware-core.c | 5 +++++ drivers/i2c/busses/i2c-designware-core.h | 1 + drivers/i2c/busses/i2c-designware-platdrv.c | 9 +++++++++ 4 files changed, 29 insertions(+), 0 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt index e42a2ee..21fabe7 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 : + - sda-hold-time : 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>; + sda-hold-time = <300>; + }; diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index 94fd818..ba40e14 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -67,6 +67,7 @@ #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_COMP_PARAM_1 0xf4 #define DW_IC_COMP_TYPE 0xfc @@ -310,6 +311,10 @@ 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 */ + if (dev->sda_hold_time) + dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD); + /* 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 9c1840e..33dfec3 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -88,6 +88,7 @@ struct dw_i2c_dev { u32 master_cfg; unsigned int tx_fifo_depth; unsigned int rx_fifo_depth; + 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 0ceb6e1..0a6e29b 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 @@ -136,6 +137,14 @@ static int dw_i2c_probe(struct platform_device *pdev) } clk_prepare_enable(dev->clk); + if (pdev->dev.of_node) { + u32 ht; + u32 ic_clk = dev->get_clk_rate_khz(dev); + + of_property_read_u32(pdev->dev.of_node, "sda-hold-time", &ht); + dev->sda_hold_time = ((u64)ic_clk * ht + 500000) / 1000000; + } + dev->functionality = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | -- 1.7.1