On Tue, Nov 22, 2016 at 12:41:40PM +0800, Zhangfei Gao wrote:
> Some platforms like hi3660 need do reset first to allow accessing registers
>
> Signed-off-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx>
Adding designware maintainers to CC...
> ---
> drivers/i2c/busses/i2c-designware-core.h | 1 +
> drivers/i2c/busses/i2c-designware-platdrv.c | 5 +++++
> 2 files changed, 6 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
> index 0d44d2a..94b14fa 100644
> --- a/drivers/i2c/busses/i2c-designware-core.h
> +++ b/drivers/i2c/busses/i2c-designware-core.h
> @@ -80,6 +80,7 @@ struct dw_i2c_dev {
> void __iomem *base;
> struct completion cmd_complete;
> struct clk *clk;
> + struct reset_control *rst;
> u32 (*get_clk_rate_khz) (struct dw_i2c_dev *dev);
> struct dw_pci_controller *controller;
> int cmd_err;
> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
> index 0b42a12..fd80e58 100644
> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> @@ -38,6 +38,7 @@
> #include <linux/pm_runtime.h>
> #include <linux/property.h>
> #include <linux/io.h>
> +#include <linux/reset.h>
> #include <linux/slab.h>
> #include <linux/acpi.h>
> #include <linux/platform_data/i2c-designware.h>
> @@ -176,6 +177,10 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
> dev->irq = irq;
> platform_set_drvdata(pdev, dev);
>
> + dev->rst = devm_reset_control_get(&pdev->dev, NULL);
> + if (!IS_ERR(dev->rst))
> + reset_control_reset(dev->rst);
> +
> /* fast mode by default because of legacy reasons */
> dev->clk_freq = 400000;
>
> --
> 2.7.4
>
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