[PATCH v2 1/6] i2c: i2c-stm32f7: Add 10-bit address support

Pierre Yves MORDRET
2018-03-26T07:56:40Z

On 03/24/2018 11:43 PM, Wolfram Sang wrote:
> On Wed, Mar 21, 2018 at 05:48:55PM +0100, Pierre-Yves MORDRET wrote:
>> This patch adds support for 10-bit device address for STM32F7 I2C
>>
>> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
>> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
>
> Out of curiosity: how did you test this patch? I never managed to find a
> 10-bit client (except for an SoC with 10-bit slave mode).

I don't have a 10-bit device either. For testing 10-bit I'm using 2 I2C
instances from the SoC, one in master mode and the other in slave mode.

>
>> ---
>> Version history:
>> v1:
>> * Initial
>> v2:
>> ---
>> ---
>> drivers/i2c/busses/i2c-stm32f7.c | 22 +++++++++++++++++-----
>> 1 file changed, 17 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
>> index f273e28..ae0d15c 100644
>> --- a/drivers/i2c/busses/i2c-stm32f7.c
>> +++ b/drivers/i2c/busses/i2c-stm32f7.c
>> @@ -65,7 +65,12 @@
>> #define STM32F7_I2C_CR2_NACK BIT(15)
>> #define STM32F7_I2C_CR2_STOP BIT(14)
>> #define STM32F7_I2C_CR2_START BIT(13)
>> +#define STM32F7_I2C_CR2_HEAD10R BIT(12)
>> +#define STM32F7_I2C_CR2_ADD10 BIT(11)
>> #define STM32F7_I2C_CR2_RD_WRN BIT(10)
>> +#define STM32F7_I2C_CR2_SADD10_MASK GENMASK(9, 0)
>> +#define STM32F7_I2C_CR2_SADD10(n) (((n) & \
>> + STM32F7_I2C_CR2_SADD10_MASK))
>> #define STM32F7_I2C_CR2_SADD7_MASK GENMASK(7, 1)
>> #define STM32F7_I2C_CR2_SADD7(n) (((n) & 0x7f) << 1)
>>
>> @@ -176,14 +181,14 @@ struct stm32f7_i2c_timings {
>>
>> /**
>> * struct stm32f7_i2c_msg - client specific data
>> - * @addr: 8-bit slave addr, including r/w bit
>> + * @addr: 8-bit or 10-bit slave addr, including r/w bit
>> * @count: number of bytes to be transferred
>> * @buf: data buffer
>> * @result: result of the transfer
>> * @stop: last I2C msg to be sent, i.e. STOP to be generated
>> */
>> struct stm32f7_i2c_msg {
>> - u8 addr;
>> + u16 addr;
>> u32 count;
>> u8 *buf;
>> int result;
>> @@ -629,8 +634,15 @@ static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
>> cr2 |= STM32F7_I2C_CR2_RD_WRN;
>>
>> /* Set slave address */
>> - cr2 &= ~STM32F7_I2C_CR2_SADD7_MASK;
>> - cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
>> + cr2 &= ~(STM32F7_I2C_CR2_HEAD10R | STM32F7_I2C_CR2_ADD10);
>> + if (msg->flags & I2C_M_TEN) {
>> + cr2 &= ~STM32F7_I2C_CR2_SADD10_MASK;
>> + cr2 |= STM32F7_I2C_CR2_SADD10(f7_msg->addr);
>> + cr2 |= STM32F7_I2C_CR2_ADD10;
>> + } else {
>> + cr2 &= ~STM32F7_I2C_CR2_SADD7_MASK;
>> + cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
>> + }
>>
>> /* Set nb bytes to transfer and reload if needed */
>> cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
>> @@ -798,7 +810,7 @@ static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
>>
>> static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
>> {
>> - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
>> + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
>> }
>>
>> static struct i2c_algorithm stm32f7_i2c_algo = {
>> --
>> 2.7.4
>>