[PATCH] i2c: designware: add reset interface
Andy Shevchenko
andriy.shevchenko at linux.intel.com
Wed Dec 14 11:00:50 PST 2016
On Tue, 2016-12-13 at 21:34 +0100, Wolfram Sang wrote:
> 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 at linaro.org>
>
> 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);
Do we care about EPROBE_DEFER?
Perhaps on error path we need to assert it.
And I guess it should be devm_reset_control_get_optional().
> > +
> > /* fast mode by default because of legacy reasons */
> > dev->clk_freq = 400000;
> >
> > --
> > 2.7.4
> >
--
Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Intel Finland Oy
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