I will send two more patches in sometime.
Patch 1: Define i2c_adapter_quirks to let i2c core check msg's order,
type and length
As of now this driver itself is doing this sanity.
Patch 2: Add support for GPIO functionality
On Tue, Mar 10, 2020 at 5:59 PM Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
>
>
> > + if (num == 1) {
> > + if (msgs->flags & I2C_M_RD) {
> > + ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA,
> > + 0, 0, NULL);
> > + } else {
> > + ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1);
> > + }
> > + if (ret)
> > + goto exit;
> > + ret = num;
> > + } else if (num == 2) {
> > + /* Ex transaction; send reg address and read its contents */
> > + if (msgs[0].addr == msgs[1].addr &&
> > + !(msgs[0].flags & I2C_M_RD) &&
> > + (msgs[1].flags & I2C_M_RD)) {
> > +
> > + ret = mcp_i2c_write(mcp, &msgs[0],
> > + MCP2221_I2C_WR_NO_STOP, 0);
> > + if (ret)
> > + goto exit;
> > +
> > + ret = mcp_i2c_smbus_read(mcp, &msgs[1],
> > + MCP2221_I2C_RD_RPT_START,
> > + 0, 0, NULL);
> > + if (ret)
> > + goto exit;
> > + ret = num;
> > + } else {
> > + dev_err(&adapter->dev,
> > + "unsupported multi-msg i2c transaction\n");
> > + ret = -EOPNOTSUPP;
> > + }
> > + } else {
> > + dev_err(&adapter->dev,
> > + "unsupported multi-msg i2c transaction\n");
> > + ret = -EOPNOTSUPP;
> > + }
>
> Have a look at struct i2c_adapter_quirks and especially the flags to let
> the I2C core do the sanity checks from here.
>
