On Thu, 2016-12-15 at 16:59 +0800, Zhangfei Gao wrote: > Some platforms like hi3660 need do reset first to allow accessing > registers Patch itself looks good, but would be nice to have it tested. Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > Signed-off-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx> > --- > drivers/i2c/busses/i2c-designware-core.h | 1 + > drivers/i2c/busses/i2c-designware-platdrv.c | 28 > ++++++++++++++++++++++++---- > 2 files changed, 25 insertions(+), 4 deletions(-) > > 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..e9016ae 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 +177,14 @@ static int dw_i2c_plat_probe(struct > platform_device *pdev) > dev->irq = irq; > platform_set_drvdata(pdev, dev); > > + dev->rst = devm_reset_control_get_optional(&pdev->dev, NULL); > + if (IS_ERR(dev->rst)) { > + if (PTR_ERR(dev->rst) == -EPROBE_DEFER) > + return -EPROBE_DEFER; > + } else { > + reset_control_deassert(dev->rst); > + } > + > /* fast mode by default because of legacy reasons */ > dev->clk_freq = 400000; > > @@ -207,12 +216,13 @@ static int dw_i2c_plat_probe(struct > platform_device *pdev) > && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) > { > dev_err(&pdev->dev, > "Only 100kHz, 400kHz, 1MHz and 3.4MHz > supported"); > - return -EINVAL; > + r = -EINVAL; > + goto exit_reset; > } > > r = i2c_dw_eval_lock_support(dev); > if (r) > - return r; > + goto exit_reset; > > dev->functionality = > I2C_FUNC_I2C | > @@ -270,10 +280,18 @@ static int dw_i2c_plat_probe(struct > platform_device *pdev) > } > > r = i2c_dw_probe(dev); > - if (r && !dev->pm_runtime_disabled) > - pm_runtime_disable(&pdev->dev); > + if (r) > + goto exit_probe; > > return r; > + > +exit_probe: > + if (!dev->pm_runtime_disabled) > + pm_runtime_disable(&pdev->dev); > +exit_reset: > + if (!IS_ERR_OR_NULL(dev->rst)) > + reset_control_assert(dev->rst); > + return r; > } > > static int dw_i2c_plat_remove(struct platform_device *pdev) > @@ -290,6 +308,8 @@ static int dw_i2c_plat_remove(struct > platform_device *pdev) > pm_runtime_put_sync(&pdev->dev); > if (!dev->pm_runtime_disabled) > pm_runtime_disable(&pdev->dev); > + if (!IS_ERR_OR_NULL(dev->rst)) > + reset_control_assert(dev->rst); > > return 0; > } -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html