| Message ID | 1470910620-9898-7-git-send-email-jonathanh@nvidia.com |
|---|---|
| State | Changes Requested |
| Headers | show |
On Thursday 11 August 2016 03:47 PM, Jon Hunter wrote: > On Tegra124/132 the pins for I2C6 are shared with the Display Port AUX > (DPAUX) channel and on Tegra210 the pins for I2C4 and I2C6 are shared > with DPAUX1 and DPAUX0, respectively. The multiplexing of the pins is > handled by a register in the DPAUX and so the Tegra DPAUX driver has > been updated to register a pinctrl device for managing these pins. > > The pins for these particular I2C devices are bound to the I2C device > prior to probing. However, these I2C devices are in a different power > partition to the DPAUX devices that own the pins. Hence, it is desirable > to place the pins in the 'idle' state and allow the DPAUX power > partition to switch off, when these I2C devices is not in use. > Therefore, add calls to place the I2C pins in the 'default' and 'idle' > states when the I2C device is runtime resumed and suspended, > respectively. > > Please note that the pinctrl functions that set the state of the pins > check to see if the devices has pins associated and will return zero > if they do not. Therefore, it is safe to call these pinctrl functions > even for I2C devices that do not have any pins associated. > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > Acked-by: Laxman Dewangan <ldewangan@nvidia.com> -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 4391a74d7616..189795842aee 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -28,6 +28,7 @@ #include <linux/of_device.h> #include <linux/module.h> #include <linux/reset.h> +#include <linux/pinctrl/consumer.h> #include <linux/pm_runtime.h> #include <asm/unaligned.h> @@ -402,6 +403,10 @@ static int tegra_i2c_runtime_resume(struct device *dev) struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev); int ret; + ret = pinctrl_pm_select_default_state(i2c_dev->dev); + if (ret) + return ret; + if (!i2c_dev->hw->has_single_clk_source) { ret = clk_enable(i2c_dev->fast_clk); if (ret < 0) { @@ -430,7 +435,7 @@ static int tegra_i2c_runtime_suspend(struct device *dev) if (!i2c_dev->hw->has_single_clk_source) clk_disable(i2c_dev->fast_clk); - return 0; + return pinctrl_pm_select_idle_state(i2c_dev->dev); } static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
On Tegra124/132 the pins for I2C6 are shared with the Display Port AUX (DPAUX) channel and on Tegra210 the pins for I2C4 and I2C6 are shared with DPAUX1 and DPAUX0, respectively. The multiplexing of the pins is handled by a register in the DPAUX and so the Tegra DPAUX driver has been updated to register a pinctrl device for managing these pins. The pins for these particular I2C devices are bound to the I2C device prior to probing. However, these I2C devices are in a different power partition to the DPAUX devices that own the pins. Hence, it is desirable to place the pins in the 'idle' state and allow the DPAUX power partition to switch off, when these I2C devices is not in use. Therefore, add calls to place the I2C pins in the 'default' and 'idle' states when the I2C device is runtime resumed and suspended, respectively. Please note that the pinctrl functions that set the state of the pins check to see if the devices has pins associated and will return zero if they do not. Therefore, it is safe to call these pinctrl functions even for I2C devices that do not have any pins associated. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> --- drivers/i2c/busses/i2c-tegra.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)