Re: [PATCH 2/2] i2c: cadence: Add reset controller support

[Lars-Peter Clausen <lars@metafoo.de>]

On 3/30/23 23:49, Michal Simek wrote:
>
>
> On 3/30/23 20:04, Lars-Peter Clausen wrote:
>> The Cadence I2C controller has an external reset signal that needs to be
>> de-asserted before the I2C controller can be used.
>>
>> Add support to the driver to be able to take the peripheral out of reset
>> using the reset controller API. The reset is optional in the driver for
>> compatibility to systems where the reset managed by the bootloader.
>>
>> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
>> ---
>>   drivers/i2c/busses/i2c-cadence.c | 26 ++++++++++++++++++++++----
>>   1 file changed, 22 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-cadence.c 
>> b/drivers/i2c/busses/i2c-cadence.c
>> index 8f61a633c42c..102774ab2497 100644
>> --- a/drivers/i2c/busses/i2c-cadence.c
>> +++ b/drivers/i2c/busses/i2c-cadence.c
>> @@ -16,6 +16,7 @@
>>   #include <linux/of.h>
>>   #include <linux/pm_runtime.h>
>>   #include <linux/pinctrl/consumer.h>
>> +#include <linux/reset.h>
>>     /* Register offsets for the I2C device. */
>>   #define CDNS_I2C_CR_OFFSET        0x00 /* Control Register, RW */
>> @@ -178,6 +179,7 @@ enum cdns_i2c_slave_state {
>>    * @bus_hold_flag:    Flag used in repeated start for clearing HOLD 
>> bit
>>    * @clk:        Pointer to struct clk
>>    * @clk_rate_change_nb:    Notifier block for clock rate changes
>> + * @reset:        Reset control for the device
>>    * @quirks:        flag for broken hold bit usage in r1p10
>>    * @ctrl_reg:        Cached value of the control register.
>>    * @ctrl_reg_diva_divb: value of fields DIV_A and DIV_B from CR 
>> register
>> @@ -204,6 +206,7 @@ struct cdns_i2c {
>>       unsigned int bus_hold_flag;
>>       struct clk *clk;
>>       struct notifier_block clk_rate_change_nb;
>> +    struct reset_control *reset;
>>       u32 quirks;
>>       u32 ctrl_reg;
>>       struct i2c_bus_recovery_info rinfo;
>> @@ -1325,10 +1328,22 @@ static int cdns_i2c_probe(struct 
>> platform_device *pdev)
>>           return dev_err_probe(&pdev->dev, PTR_ERR(id->clk),
>>                        "input clock not found.\n");
>>   +    id->reset = devm_reset_control_get_optional_shared(&pdev->dev, 
>> NULL);
>> +    if (IS_ERR(id->reset))
>> +        return dev_err_probe(&pdev->dev, PTR_ERR(id->reset),
>> +                             "Failed to request reset.\n");
>
> incorrect alignment.
>
>> +
>>       ret = clk_prepare_enable(id->clk);
>>       if (ret)
>>           dev_err(&pdev->dev, "Unable to enable clock.\n");
>>   +    ret = reset_control_deassert(id->reset);
>> +    if (ret) {
>> +        dev_err_probe(&pdev->dev, ret,
>> +                      "Failed to de-assert reset.\n");
>
> incorrect alignment
Wrong tabstop, that's embarrassing. Will fix.