Hi Andy and Zhangfei
On 12/15/2016 12:33 PM, Andy Shevchenko wrote:
> 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>
>
I tested the patch and it's working for the ARC architecture.
>>
>> 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);
devm_reset_control_get_optional() is deprecated as explained in linux/reset.h,
you should use devm_reset_control_get_optional_exclusive() or
devm_reset_control_get_optional_shared() instead, as applicable.
I submitted a similar patch earlier today and I made the same mistake.
>> + 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;
>> }
>
Tested-by: Ramiro Oliveira <ramiro.oliveira@xxxxxxxxxxxx>
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