Re: [PATCH V3 1/2] i2c-designware: Add i2c bus locking support

From: Jarkko Nikula
Date: Thu Dec 04 2014 - 02:59:23 EST


Hi

On 12/02/2014 02:09 AM, David E. Box wrote:
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 <david.e.box@xxxxxxxxxxxxxxx>
---
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-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);
i2c_dw_eval_lock_support() is added in the next patch.
+
+ 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);
Should there be similar conditional call or locking around i2c_dw_init() and i2c_dw_disable_int() also in dw_i2c_probe()?

--
Jarkko
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