[PATCH] rockchip: i2c: fix switch to new implementation for rk3188

[Alexander Kochetkov]

To make clear, there is kernel driver i2c-rk3x.c.
For rk3066 it write bits in the GRF word at offset 0x154. See [1] and [2].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/i2c/busses/i2c-rk3x.c#n1236
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/i2c/busses/i2c-rk3x.c#n1137

In u-boot there is include file cru_rk3036.h [3]. If this include file valid for rk3066, than offset 0x154 correspond
to soc_con3 register. But all documentation I found for 30xx SoC clarify that I2C switch bits located in the
soc_con1 registers.

So I don’t know correct location for I2C switch bits.

[3] https://github.com/u-boot/u-boot/blob/master/arch/arm/include/asm/arch-rockchip/cru_rk3036.h


> 27 июня 2020 г., в 17:17, Kever Yang <kever.yang at rock-chips.com> написал(а):
> 
> +David,
> 
> Hi David,
> 
>     Could you help to commend on this?
> 
> 
> Hi Alex,
> 
>     Thanks for your patch.
> 
> On 2020/6/22 下午9:06, Alexander Kochetkov wrote:
>> The commit e7ae4cf27a6d 'pinctrl: rockchip: Add common rockchip
>> pinctrl driver' dropped rk3188_pinctrl_request operation, that
>> did switching to new implementation.
>> 
>> This commit implement switching to new implementation using
>> writing bits to GRF.
>> 
>> I don't have rk3060
> rk3066
>>  board to test, so switching implemented
>> as a stub returning -ENOSYS.
>> 
>> Signed-off-by: Alexander Kochetkov <al.kochet at gmail.com>
>> ---
>>  drivers/i2c/rk_i2c.c | 42 +++++++++++++++++++++++++++++++-----------
>>  1 file changed, 31 insertions(+), 11 deletions(-)
>> 
>> diff --git a/drivers/i2c/rk_i2c.c b/drivers/i2c/rk_i2c.c
>> index 32b2ee8578..ad3c66843b 100644
>> --- a/drivers/i2c/rk_i2c.c
>> +++ b/drivers/i2c/rk_i2c.c
>> @@ -15,6 +15,8 @@
>>  #include <asm/arch-rockchip/clock.h>
>>  #include <asm/arch-rockchip/i2c.h>
>>  #include <asm/arch-rockchip/periph.h>
>> +#include <asm/arch-rockchip/grf_rk3188.h>
>> +#include <syscon.h>
>>  #include <dm/pinctrl.h>
>>  #include <linux/sizes.h>
>>  @@ -41,6 +43,7 @@ enum {
>>   */
>>  struct rk_i2c_soc_data {
>>  	int controller_type;
>> +	int (*switch_to_new_type)(int bus_nr);
>>  };
>>    static inline void rk_i2c_get_div(int div, int *divh, int *divl)
>> @@ -388,11 +391,33 @@ static int rockchip_i2c_ofdata_to_platdata(struct udevice *bus)
>>  	return 0;
>>  }
>>  +static int rockchip_i2c_switch_to_new_type_rk3066(int bus_nr)
>> +{
>> +	return -ENOSYS;
>> +}
>> +
>> +static int rockchip_i2c_switch_to_new_type_rk3188(int bus_nr)
>> +{
>> +	struct rk3188_grf *grf = syscon_get_first_range(ROCKCHIP_SYSCON_GRF);
>> +
>> +	if (grf == NULL)
>> +		return -ENOSYS;
>> +
>> +	if (bus_nr < 0 || bus_nr > (RKI2C4_SEL_SHIFT - RKI2C0_SEL_SHIFT))
>> +		return -EINVAL;
>> +
>> +	/* enable new i2c controller */
>> +	rk_clrsetreg(&grf->soc_con1,
>> +		     1 << (RKI2C0_SEL_SHIFT + bus_nr),
>> +		     1 << (RKI2C0_SEL_SHIFT + bus_nr));
>> +
>> +	return 0;
>> +}
>> +
>>  static int rockchip_i2c_probe(struct udevice *bus)
>>  {
>>  	struct rk_i2c *priv = dev_get_priv(bus);
>>  	struct rk_i2c_soc_data *soc_data;
>> -	struct udevice *pinctrl;
>>  	int bus_nr;
>>  	int ret;
>>  @@ -408,17 +433,10 @@ static int rockchip_i2c_probe(struct udevice *bus)
>>  			return ret;
>>  		}
>>  -		ret = uclass_get_device(UCLASS_PINCTRL, 0, &pinctrl);
>> -		if (ret) {
>> -			debug("%s: Cannot find pinctrl device\n", __func__);
>> -			return ret;
>> -		}
>> -
>> -		/* pinctrl will switch I2C to new type */
>> -		ret = pinctrl_request_noflags(pinctrl, PERIPH_ID_I2C0 + bus_nr);
>> -		if (ret) {
>> +		ret = soc_data->switch_to_new_type(bus_nr);
>> +		if (ret < 0) {
>>  			debug("%s: Failed to switch I2C to new type %s: %d\n",
>> -				__func__, bus->name, ret);
>> +			 __func__, bus->name, ret);
>>  			return ret;
>>  		}
>>  	}
>> @@ -433,10 +451,12 @@ static const struct dm_i2c_ops rockchip_i2c_ops = {
>>    static const struct rk_i2c_soc_data rk3066_soc_data = {
>>  	.controller_type = RK_I2C_LEGACY,
>> +	.switch_to_new_type = rockchip_i2c_switch_to_new_type_rk3066,
>>  };
>>    static const struct rk_i2c_soc_data rk3188_soc_data = {
>>  	.controller_type = RK_I2C_LEGACY,
>> +	.switch_to_new_type = rockchip_i2c_switch_to_new_type_rk3188,
>>  };
>>    static const struct rk_i2c_soc_data rk3228_soc_data = {
> 
>