Hi Farouk,
Before jumping into the review, who is going to take this and the
previous patch?
Peter shall I take it?
Now to the review :-)
On Mon, Sep 02, 2024 at 06:38:15PM GMT, Farouk Bouabid wrote:
> Theobroma Systems Mule is an MCU that emulates a set of I2C devices,
> among which an amc6821 and devices that are reachable through an I2C-mux.
> The devices on the mux can be selected by writing the appropriate device
> number to an I2C config register (amc6821 reg 0xff).
>
> This driver is expected to be probed as a platform device with amc6821
> as its parent i2c device.
>
> Add support for the mule-i2c-mux platform driver. The amc6821 driver
Along the driver I expressed some concern about the prefixes.
You should avoid prefixes such as mux_* or MUX_* because they
don't belong to your driver. You should always use your driver's
name:
1. mule_*
2. mule_mux_*
3. mule_i2c_mux_*
You have used the 3rd, I'd rather prefer the 1st. Because when
you are in i2c/muxex/ it's implied that you are an i2c mux
device. But it's a matter of personal taste.
Other than this, there is still, one major error down below.
> support for the mux will be added in a later commit.
>
> Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Farouk Bouabid <farouk.bouabid@xxxxxxxxx>
...
> +#include <linux/i2c-mux.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +
> +#define MUX_CONFIG_REG 0xff
> +#define MUX_DEFAULT_DEV 0x0
Please define these as MULE_I2C_MUX_*
> +
> +struct mule_i2c_reg_mux {
> + struct regmap *regmap;
> +};
> +
> +static int mux_select(struct i2c_mux_core *muxc, u32 dev)
> +{
> + struct mule_i2c_reg_mux *mux = muxc->priv;
> +
> + return regmap_write(mux->regmap, MUX_CONFIG_REG, dev);
> +}
> +
> +static int mux_deselect(struct i2c_mux_core *muxc, u32 dev)
> +{
> + return mux_select(muxc, MUX_DEFAULT_DEV);
> +}
> +
> +static void mux_remove(void *data)
Please call these mule_i2c_mux_*(), the mux_ prefix doesn't
belong to this driver.
> +{
> + struct i2c_mux_core *muxc = data;
> +
> + i2c_mux_del_adapters(muxc);
> +
> + mux_deselect(muxc, MUX_DEFAULT_DEV);
> +}
...
> + /* Create device adapters */
> + for_each_child_of_node(mux_dev->of_node, dev) {
> + u32 reg;
> +
> + ret = of_property_read_u32(dev, "reg", ®);
> + if (ret)
> + return dev_err_probe(mux_dev, ret,
> + "No reg property found for %s\n",
> + of_node_full_name(dev));
> +
> + if (old_fw && reg != 0) {
> + dev_warn(mux_dev,
> + "Mux is not supported, please update Mule FW\n");
> + continue;
> + }
> +
> + ret = mux_select(muxc, reg);
> + if (ret) {
> + dev_warn(mux_dev,
> + "Device %d not supported, please update Mule FW\n", reg);
> + continue;
> + }
> +
> + ret = i2c_mux_add_adapter(muxc, 0, reg);
> + if (ret)
> + return ret;
do we need to delete the adapters we added in previous cycles?
> + }
> +
> + mux_deselect(muxc, MUX_DEFAULT_DEV);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id mule_i2c_mux_of_match[] = {
> + {.compatible = "tsd,mule-i2c-mux",},
if you are going to resend, can you leave one space after the
'{' and before the '}'
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, mule_i2c_mux_of_match);
> +
> +static struct platform_driver mule_i2c_mux_driver = {
> + .driver = {
I don't see the need for this '\t' here, the alignment is too
far. It just looks bad. Your choice, though.
Thanks,
Andi
> + .name = "mule-i2c-mux",
> + .of_match_table = mule_i2c_mux_of_match,
> + },
> + .probe = mule_i2c_mux_probe,
> +};
> +
> +module_platform_driver(mule_i2c_mux_driver);
> +
> +MODULE_AUTHOR("Farouk Bouabid <farouk.bouabid@xxxxxxxxx>");
> +MODULE_DESCRIPTION("I2C mux driver for Theobroma Systems Mule");
> +MODULE_LICENSE("GPL");
>
> --
> 2.34.1
>
