[RFC PATCH v3 06/18] i2c: tegra: Fix runtime resume to re-init VI I2C
From: Sowjanya Komatineni <skomatineni@nvidia.com>
Date: 2020-07-15 04:20:41
Also in:
linux-i2c, linux-media, linux-tegra, lkml
Subsystem:
i2c subsystem, i2c subsystem host drivers, tegra i2c driver, the rest · Maintainers:
Wolfram Sang, Andi Shyti, Laxman Dewangan, Linus Torvalds
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 <skomatineni@nvidia.com> --- 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