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

Wolfram Sang wsa at the-dreams.de
Sat Mar 24 15:43:32 PDT 2018


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 at gmail.com>
> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret at 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).

> ---
>   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
> 
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