From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932892AbaLBANS (ORCPT ); Mon, 1 Dec 2014 19:13:18 -0500 Received: from mga02.intel.com ([134.134.136.20]:6237 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753636AbaLBANM (ORCPT ); Mon, 1 Dec 2014 19:13:12 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,497,1413270000"; d="scan'208";a="616952915" From: "David E. Box" To: wsa@the-dreams.de Cc: jdelvare@suse.de, arnd@arndb.de, maxime.ripard@free-electrons.com, dianders@chromium.org, u.kleine-koenig@pengutronix.de, laurent.pinchart+renesas@ideasonboard.com, boris.brezillon@free-electrons.com, andrew@lunn.ch, sjg@chromium.org, markus.mayer@linaro.org, jacob.jun.pan@linux.intel.com, max.schwarz@online.de, mika.westerberg@linux.intel.com, skuribay@pobox.com, Romain.Baeriswyl@abilis.com, wenkai.du@intel.com, chiau.ee.chew@intel.com, alan@linux.intel.com, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org Subject: [PATCH V3 1/2] i2c-designware: Add i2c bus locking support Date: Mon, 1 Dec 2014 16:09:32 -0800 Message-Id: <1417478973-25522-2-git-send-email-david.e.box@linux.intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1417478973-25522-1-git-send-email-david.e.box@linux.intel.com> References: <1411497626-7984-1-git-send-email-david.e.box@linux.intel.com> <1417478973-25522-1-git-send-email-david.e.box@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Adds support for acquiring and releasing a hardware bus lock in the i2c designware core transfer function. This is needed for i2c bus controllers that are shared with but not controlled by the kernel. Signed-off-by: David E. Box --- drivers/i2c/busses/i2c-designware-core.c | 11 +++++++++++ drivers/i2c/busses/i2c-designware-core.h | 6 ++++++ drivers/i2c/busses/i2c-designware-platdrv.c | 18 +++++++++++++----- 3 files changed, 30 insertions(+), 5 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index 3c20e4b..377deeb 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -631,6 +631,14 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) dev->abort_source = 0; dev->rx_outstanding = 0; + if (dev->acquire_lock) { + ret = dev->acquire_lock(dev); + if (ret) { + dev_err(dev->dev, "couldn't acquire bus ownership\n"); + goto done; + } + } + ret = i2c_dw_wait_bus_not_busy(dev); if (ret < 0) goto done; @@ -676,6 +684,9 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) ret = -EIO; done: + if (dev->release_lock) + dev->release_lock(dev); + pm_runtime_mark_last_busy(dev->dev); pm_runtime_put_autosuspend(dev->dev); mutex_unlock(&dev->lock); diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index d66b6cb..a472c91 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -65,6 +65,9 @@ * @ss_lcnt: standard speed LCNT value * @fs_hcnt: fast speed HCNT value * @fs_lcnt: fast speed LCNT value + * @acquire_lock: function to acquire a hardware lock on the bus + * @release_lock: function to release a hardware lock on the bus + * @pm_runtime_disabled: true if pm runtime is disabled * * HCNT and LCNT parameters can be used if the platform knows more accurate * values than the one computed based only on the input clock frequency. @@ -105,6 +108,9 @@ struct dw_i2c_dev { u16 ss_lcnt; u16 fs_hcnt; u16 fs_lcnt; + int (*acquire_lock)(struct dw_i2c_dev *dev); + void (*release_lock)(struct dw_i2c_dev *dev); + bool pm_runtime_disabled; }; #define ACCESS_SWAP 0x00000001 diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index a743115..afdff3b 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -261,10 +261,16 @@ static int dw_i2c_probe(struct platform_device *pdev) return r; } - pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); - pm_runtime_use_autosuspend(&pdev->dev); - pm_runtime_set_active(&pdev->dev); - pm_runtime_enable(&pdev->dev); + i2c_dw_eval_lock_support(dev); + + if (dev->pm_runtime_disabled) { + pm_runtime_forbid(&pdev->dev); + } else { + pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + } return 0; } @@ -314,7 +320,9 @@ static int dw_i2c_resume(struct device *dev) struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); clk_prepare_enable(i_dev->clk); - i2c_dw_init(i_dev); + + if (!i_dev->pm_runtime_disabled) + i2c_dw_init(i_dev); return 0; } -- 1.9.1