On Tue, Feb 2, 2021 at 1:17 PM Tobias Waldekranz <tob...@waldekranz.com> wrote:
[snip]
>
> George, have you used the chip in I2C mode with the code that is on
> net-next now? I was not able to get the driver to even read the ID
> register correctly.
I wrote the i2c driver before I had any hardware in hand thinking I
was going to get a board with the switch connected via i2c. When the
board arrived it turned out it was connected via mdio so I wrote that
driver as well. I looked it over quite carefully but I guess the
documentation was wrong and I had the register addresses shifted off
by one. I never ended up with hardware to test the i2c.
>
> drivers/net/dsa/xrs700x/xrs700x_i2c.c | 31 ++++++++++++---------------
> 1 file changed, 14 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/dsa/xrs700x/xrs700x_i2c.c
> b/drivers/net/dsa/xrs700x/xrs700x_i2c.c
> index a5f8883af829..16a46a78a037 100644
> --- a/drivers/net/dsa/xrs700x/xrs700x_i2c.c
> +++ b/drivers/net/dsa/xrs700x/xrs700x_i2c.c
> @@ -10,33 +10,34 @@
> #include "xrs700x.h"
> #include "xrs700x_reg.h"
>
> +struct xrs700x_i2c_cmd {
> + __be32 reg;
> + __be16 val;
> +} __packed;
> +
> static int xrs700x_i2c_reg_read(void *context, unsigned int reg,
> unsigned int *val)
> {
> struct device *dev = context;
> struct i2c_client *i2c = to_i2c_client(dev);
> - unsigned char buf[4];
> + struct xrs700x_i2c_cmd cmd;
> int ret;
>
> - buf[0] = reg >> 23 & 0xff;
> - buf[1] = reg >> 15 & 0xff;
> - buf[2] = reg >> 7 & 0xff;
> - buf[3] = (reg & 0x7f) << 1;
> + cmd.reg = cpu_to_be32(reg | 1);
>
> - ret = i2c_master_send(i2c, buf, sizeof(buf));
> + ret = i2c_master_send(i2c, (char *)&cmd.reg, sizeof(cmd.reg));
> if (ret < 0) {
> dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
> return ret;
> }
>
> - ret = i2c_master_recv(i2c, buf, 2);
> + ret = i2c_master_recv(i2c, (char *)&cmd.val, sizeof(cmd.val));
> if (ret < 0) {
> dev_err(dev, "xrs i2c_master_recv returned %d\n", ret);
> return ret;
> }
>
> - *val = buf[0] << 8 | buf[1];
> -
> + *val = be16_to_cpu(cmd.val);
> return 0;
> }
>
> @@ -45,17 +46,13 @@ static int xrs700x_i2c_reg_write(void *context, unsigned
> int reg,
> {
> struct device *dev = context;
> struct i2c_client *i2c = to_i2c_client(dev);
> - unsigned char buf[6];
> + struct xrs700x_i2c_cmd cmd;
> int ret;
>
> - buf[0] = reg >> 23 & 0xff;
> - buf[1] = reg >> 15 & 0xff;
> - buf[2] = reg >> 7 & 0xff;
> - buf[3] = (reg & 0x7f) << 1 | 1;
> - buf[4] = val >> 8 & 0xff;
> - buf[5] = val & 0xff;
> + cmd.reg = cpu_to_be32(reg);
> + cmd.val = cpu_to_be16(val);
>
> - ret = i2c_master_send(i2c, buf, sizeof(buf));
> + ret = i2c_master_send(i2c, (char *)&cmd, sizeof(cmd));
> if (ret < 0) {
> dev_err(dev, "xrs i2c_master_send returned %d\n", ret);
> return ret;
> --
> 2.17.1
>
Reviewed-by: George McCollister <george.mccollis...@gmail.com>
