From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowjanya Komatineni Subject: [RFC PATCH v4 04/14] i2c: tegra: Fix runtime resume to re-init VI I2C Date: Thu, 23 Jul 2020 16:51:02 -0700 Message-ID: <1595548272-9809-5-git-send-email-skomatineni@nvidia.com> References: <1595548272-9809-1-git-send-email-skomatineni@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1595548272-9809-1-git-send-email-skomatineni@nvidia.com> Sender: linux-media-owner@vger.kernel.org To: skomatineni@nvidia.com, thierry.reding@gmail.com, jonathanh@nvidia.com, frankc@nvidia.com, hverkuil@xs4all.nl, sakari.ailus@iki.fi, robh+dt@kernel.org, helen.koike@collabora.com Cc: digetx@gmail.com, sboyd@kernel.org, gregkh@linuxfoundation.org, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org List-Id: linux-tegra@vger.kernel.org VI I2C is on host1x bus and is part of VE power domain. During suspend/resume VE power domain goes through power off/on. So, controller reset followed by i2c re-initialization is required after the domain power up. This patch fixes it. Signed-off-by: Sowjanya Komatineni --- drivers/i2c/busses/i2c-tegra.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 7b93c45..1bf3666 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -293,6 +293,8 @@ struct tegra_i2c_dev { bool is_curr_atomic_xfer; }; +static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit); + static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg) { @@ -675,8 +677,22 @@ static int __maybe_unused tegra_i2c_runtime_resume(struct device *dev) goto disable_slow_clk; } + /* + * VI I2C device is attached to VE power domain which goes through + * power ON/OFF during PM runtime resume/suspend. So, controller + * should go through reset and need to re-initialize after power + * domain ON. + */ + if (i2c_dev->is_vi) { + ret = tegra_i2c_init(i2c_dev, true); + if (ret) + goto disable_div_clk; + } + return 0; +disable_div_clk: + clk_disable(i2c_dev->div_clk); disable_slow_clk: clk_disable(i2c_dev->slow_clk); disable_fast_clk: -- 2.7.4