Re: [RFC 1/3] usb: typec: tps6598x: handle block writes separately with plain-I2C adapters

[Guenter Roeck <linux@roeck-us.net>]

On Wed, Feb 27, 2019 at 12:38:08AM +0900, Suwan Kim wrote:
> From: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>
> 
> Commit 1a2f474d328f handles block _reads_ separately with plain-I2C
> adapters, but the problem described with regmap-i2c not handling
> SMBus block transfers (i.e. read and writes) correctly also exists
> with writes.
> 
> As workaround, this patch adds a block write function the same way
> 1a2f474d328f adds a block read function.
> 
> Fixes: 1a2f474d328f ("usb: typec: tps6598x: handle block reads separately with plain-I2C adapters")
> Fixes: 0a4c005bd171 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers")
> Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>
> Cc: stable <stable@vger.kernel.org>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Sorry, I am lost. What is this about ?

Guenter

> ---
>  drivers/usb/typec/tps6598x.c | 26 ++++++++++++++++++++------
>  1 file changed, 20 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c
> index 9947c87d2a1e..c674abe3cf99 100644
> --- a/drivers/usb/typec/tps6598x.c
> +++ b/drivers/usb/typec/tps6598x.c
> @@ -126,6 +126,20 @@ tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, size_t len)
>  	return 0;
>  }
>  
> +static int tps6598x_block_write(struct tps6598x *tps, u8 reg,
> +				void *val, size_t len)
> +{
> +	u8 data[TPS_MAX_LEN + 1];
> +
> +	if (!tps->i2c_protocol)
> +		return regmap_raw_write(tps->regmap, reg, val, len);
> +
> +	data[0] = len;
> +	memcpy(&data[1], val, len);
> +
> +	return regmap_raw_write(tps->regmap, reg, data, sizeof(data));
> +}
> +
>  static inline int tps6598x_read16(struct tps6598x *tps, u8 reg, u16 *val)
>  {
>  	return tps6598x_block_read(tps, reg, val, sizeof(u16));
> @@ -143,23 +157,23 @@ static inline int tps6598x_read64(struct tps6598x *tps, u8 reg, u64 *val)
>  
>  static inline int tps6598x_write16(struct tps6598x *tps, u8 reg, u16 val)
>  {
> -	return regmap_raw_write(tps->regmap, reg, &val, sizeof(u16));
> +	return tps6598x_block_write(tps, reg, &val, sizeof(u16));
>  }
>  
>  static inline int tps6598x_write32(struct tps6598x *tps, u8 reg, u32 val)
>  {
> -	return regmap_raw_write(tps->regmap, reg, &val, sizeof(u32));
> +	return tps6598x_block_write(tps, reg, &val, sizeof(u32));
>  }
>  
>  static inline int tps6598x_write64(struct tps6598x *tps, u8 reg, u64 val)
>  {
> -	return regmap_raw_write(tps->regmap, reg, &val, sizeof(u64));
> +	return tps6598x_block_write(tps, reg, &val, sizeof(u64));
>  }
>  
>  static inline int
>  tps6598x_write_4cc(struct tps6598x *tps, u8 reg, const char *val)
>  {
> -	return regmap_raw_write(tps->regmap, reg, &val, sizeof(u32));
> +	return tps6598x_block_write(tps, reg, &val, sizeof(u32));
>  }
>  
>  static int tps6598x_read_partner_identity(struct tps6598x *tps)
> @@ -245,8 +259,8 @@ static int tps6598x_exec_cmd(struct tps6598x *tps, const char *cmd,
>  		return -EBUSY;
>  
>  	if (in_len) {
> -		ret = regmap_raw_write(tps->regmap, TPS_REG_DATA1,
> -				       in_data, in_len);
> +		ret = tps6598x_block_write(tps, TPS_REG_DATA1,
> +					   in_data, in_len);
>  		if (ret)
>  			return ret;
>  	}
> -- 
> 2.20.1
>