Re: [PATCHv3] usb: typec: tps6598x: handle block writes separately with plain-I2C adapters

[Guenter Roeck]

On 2/20/19 7:35 AM, Guenter Roeck wrote:
> On 2/20/19 7:11 AM, Nikolaus Voss wrote:
> > From: Nikolaus Voss <nikolaus.voss@xxxxxxxxxxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxxxxxxxxxxxx>
>
> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>
> Note that tps6598x_exec_cmd() is only called with in_len == out_len == 0
> and NULL data pointers. It might make sense to simplify the function and
> drop the unused parameters as well as the associated code.
Clarification: That would be a separate patch.

Guenter

> Guenter
>
> > ---
> > v2: fix tps6598x_exec_cmd also
> > v3: use fixed length for stack buffer
> > ---
> > Â drivers/usb/typec/tps6598x.c | 26 ++++++++++++++++++++------
> > Â 1 file changed, 20 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/usb/typec/tps6598x.c b/drivers/usb/typec/tps6598x.c
> > index c84c8c189e90..eb8046f87a54 100644
> > --- a/drivers/usb/typec/tps6598x.c
> > +++ b/drivers/usb/typec/tps6598x.c
> > @@ -110,6 +110,20 @@ tps6598x_block_read(struct tps6598x *tps, u8 reg, void *val, size_t len)
> > ÂÂÂÂÂ return 0;
> > Â }
> > +static int tps6598x_block_write(struct tps6598x *tps, u8 reg,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ void *val, size_t len)
> > +{
> > +ÂÂÂ u8 data[TPS_MAX_LEN + 1];
> > +
> > +ÂÂÂ if (!tps->i2c_protocol)
> > +ÂÂÂÂÂÂÂ return regmap_raw_write(tps->regmap, reg, val, len);
> > +
> > +ÂÂÂ data[0] = len;
> > +ÂÂÂ memcpy(&data[1], val, len);
> > +
> > +ÂÂÂ return regmap_raw_write(tps->regmap, reg, data, sizeof(data));
> > +}
> > +
> > Â static inline int tps6598x_read16(struct tps6598x *tps, u8 reg, u16 *val)
> > Â {
> > ÂÂÂÂÂ return tps6598x_block_read(tps, reg, val, sizeof(u16));
> > @@ -127,23 +141,23 @@ static inline int tps6598x_read64(struct tps6598x *tps, u8 reg, u64 *val)
> > Â static inline int tps6598x_write16(struct tps6598x *tps, u8 reg, u16 val)
> > Â {
> > -ÂÂÂ return regmap_raw_write(tps->regmap, reg, &val, sizeof(u16));
> > +ÂÂÂ return tps6598x_block_write(tps, reg, &val, sizeof(u16));
> > Â }
> > Â static inline int tps6598x_write32(struct tps6598x *tps, u8 reg, u32 val)
> > Â {
> > -ÂÂÂ return regmap_raw_write(tps->regmap, reg, &val, sizeof(u32));
> > +ÂÂÂ return tps6598x_block_write(tps, reg, &val, sizeof(u32));
> > Â }
> > Â static inline int tps6598x_write64(struct tps6598x *tps, u8 reg, u64 val)
> > Â {
> > -ÂÂÂ return regmap_raw_write(tps->regmap, reg, &val, sizeof(u64));
> > +ÂÂÂ return tps6598x_block_write(tps, reg, &val, sizeof(u64));
> > Â }
> > Â static inline int
> > Â tps6598x_write_4cc(struct tps6598x *tps, u8 reg, const char *val)
> > Â {
> > -ÂÂÂ return regmap_raw_write(tps->regmap, reg, &val, sizeof(u32));
> > +ÂÂÂ return tps6598x_block_write(tps, reg, &val, sizeof(u32));
> > Â }
> > Â static int tps6598x_read_partner_identity(struct tps6598x *tps)
> > @@ -229,8 +243,8 @@ static int tps6598x_exec_cmd(struct tps6598x *tps, const char *cmd,
> > ÂÂÂÂÂÂÂÂÂ return -EBUSY;
> > ÂÂÂÂÂ if (in_len) {
> > -ÂÂÂÂÂÂÂ ret = regmap_raw_write(tps->regmap, TPS_REG_DATA1,
> > -ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ in_data, in_len);
> > +ÂÂÂÂÂÂÂ ret = tps6598x_block_write(tps, TPS_REG_DATA1,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ in_data, in_len);
> > ÂÂÂÂÂÂÂÂÂ if (ret)
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂ return ret;
> > ÂÂÂÂÂ }