Hi, Andi,
On Tue, 2023-09-05 at 12:22 +0200, Andi Shyti wrote:
> Hi Aryan,
>
> In the title, please leave a space after the ':'
>
> i2c: octeon: Add block-mode r/w
>
> Please check with "git log drivers..." to see what's the rule in
> a particular community.
>
> I guess Wolfram can fix this, though, before pushing.
>
> [...]
>
Done
> > +/* high-level-controller composite block write+read, msg0=addr,
> > msg1=data */
>
> I think this comment is fine and great to have it, but it's
> missing a bit of clarity, can you please expand the concept?
>
Done, let me know if you want me to add more here.
> > +static int octeon_i2c_hlc_block_comp_read(struct octeon_i2c *i2c,
> > struct i2c_msg *msgs)
> > +{
> > + int i, j, len, ret = 0;
> > + u64 cmd = 0, rd = 0;
>
> can please you move rd, j inside the for loop? The basic common
> sense is to have all variable declared in the innermost section
> in order to avoid confusion.
>
> It's a nitpick though, not a strong comment and, afaik, not a
> real rule.
>
> Same comment for the function below.
>
Done, I agree they should be defined within loop. I was just trying to
match the other hlc r/w.
> > +
> > + octeon_i2c_hlc_enable(i2c);
> > + octeon_i2c_block_enable(i2c);
> > +
> > + /* Write (size - 1) into block control register */
> > + len = msgs[1].len - 1;
> > + octeon_i2c_writeq_flush((u64)(len), i2c->twsi_base +
> > TWSI_BLOCK_CTL(i2c));
> > +
> > + /* Prepare core command */
> > + cmd = SW_TWSI_V | SW_TWSI_R | SW_TWSI_SOVR;
> > + cmd |= (u64)(msgs[0].addr & 0x7full) << SW_TWSI_ADDR_SHIFT;
> > +
> > + if (msgs[0].flags & I2C_M_TEN)
> > + cmd |= SW_TWSI_OP_10_IA;
> > + else
> > + cmd |= SW_TWSI_OP_7_IA;
> > +No, but this doesnt really matter as the internal j loop will take
> > care of the remaining bytes.
> >
> > e.g. if the len is 9, then we will do
> > 0-7 in the first, then i = 8, which is < len, and then the internal
> > loop will do 8-17.
> > + if (msgs[0].len == 2) {
> > + u64 ext = 0;
> > +
> > + cmd |= SW_TWSI_EIA;
> > + ext = (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
> > + cmd |= (u64)msgs[0].buf[1] << SW_TWSI_IA_SHIFT;
> > + octeon_i2c_writeq_flush(ext, i2c->twsi_base +
> > SW_TWSI_EXT(i2c));
> > + } else {
> > + cmd |= (u64)msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
> > + }
>
> This first part is basically a copy/paste with the write()
> function... can we put them together in a common function?
>
> Can we put as much as we can in a single function?
>
Done. Could not make a common for the write+writes, as they way we
insert data into buffers for writing are significantly different,
and don't occur after the core command send (i.e. the core command is
sent with/concurrently with the write data). Unlike the read, which
sends almost identical core commands and reads the buffer differently
afterwards. Though if would like it I could mangle together a function
for these as well.
> > + /* Send command to core (send data to FIFO) */
> > + octeon_i2c_hlc_int_clear(i2c);
> > + octeon_i2c_writeq_flush(cmd, i2c->twsi_base + SW_TWSI(i2c));
> > +
> > + /* Wait for transaction to complete */
> > + ret = octeon_i2c_hlc_wait(i2c);
> > + if (ret)
> > + return ret;
> > +
> > + cmd = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
> > + if ((cmd & SW_TWSI_R) == 0)
> > + return octeon_i2c_check_status(i2c, false);
> > +
> > + /* read data in FIFO */
> > + octeon_i2c_writeq_flush(TWSI_BLOCK_STS_RESET_PTR, i2c-
> > >twsi_base + TWSI_BLOCK_STS(i2c));
> > + for (i = 0; i < len; i += 8) {
> > + rd = __raw_readq(i2c->twsi_base +
> > TWSI_BLOCK_FIFO(i2c));
> > + for (j = 7; j >= 0; j--)
>
> is len always a multiple of 8?
>
> > + msgs[1].buf[i + (7 - j)] = (rd >> (8 * j)) &
> > 0xff;
> > + }
> > +
> > + octeon_i2c_block_disable(i2c);
> > + return ret;
> > +}
>
> [...]
No, but this doesnt really matter as the internal j loop will take care
of the remaining bytes.
e.g. if the len is 9, then we will do
0-7 in the first, then i = 8, which is < len, and then the internal
loop will do 8-17.
>
> > - msgs[1].len > 0 && msgs[1].len <= 8 &&
> > + msgs[1].len > 0 &&
> > msgs[0].addr == msgs[1].addr) {
> > - if (msgs[1].flags & I2C_M_RD)
> > - ret = octeon_i2c_hlc_comp_read(i2c,
> > msgs);
> > - else
> > - ret = octeon_i2c_hlc_comp_write(i2c,
> > msgs);
> > - goto out;
> > + if (msgs[1].len <= 8) {
> > + if (msgs[1].flags & I2C_M_RD)
> > + ret =
> > octeon_i2c_hlc_comp_read(i2c, msgs);
> > + else
> > + ret =
> > octeon_i2c_hlc_comp_write(i2c, msgs);
> > + goto out;
> > + } else if (msgs[1].len <= 1024 &&
> > TWSI_BLOCK_CTL(i2c)) {
> > + if (msgs[1].flags & I2C_M_RD)
> > + ret =
> > octeon_i2c_hlc_block_comp_read(i2c, msgs);
> > + else
> > + ret =
> > octeon_i2c_hlc_block_comp_write(i2c, msgs);
> > + goto out;
> > + }
>
> the rest looks good...
>
> Thanks,
> Andi
Thanks,
Aryan
