Hi!
Sorry for the late review.
On 2020-11-18 15:44, Vadim Pasternak wrote:
> Allow to extend mux number supported by driver.
> Currently it is limited by eight, which is not enough for new coming
> Mellanox modular system with line cards, which require up to 64 mux
> support.
>
> Signed-off-by: Vadim Pasternak <vadimp@xxxxxxxxxx>
> Reviewed-by: Michael Shych <michaelsh@xxxxxxxxxx>
> ---
> drivers/i2c/muxes/i2c-mux-mlxcpld.c | 17 +++++------------
> include/linux/platform_data/mlxcpld.h | 3 +++
> 2 files changed, 8 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/i2c/muxes/i2c-mux-mlxcpld.c b/drivers/i2c/muxes/i2c-mux-mlxcpld.c
> index c76180919fc3..760636b507fa 100644
> --- a/drivers/i2c/muxes/i2c-mux-mlxcpld.c
> +++ b/drivers/i2c/muxes/i2c-mux-mlxcpld.c
> @@ -15,8 +15,6 @@
> #include <linux/platform_device.h>
> #include <linux/slab.h>
>
> -#define CPLD_MUX_MAX_NCHANS 8
> -
> /* mlxcpld_mux - mux control structure:
> * @last_chan - last register value
> * @client - I2C device client
> @@ -24,7 +22,7 @@
> * @sel_buf: I2C message buffer for mux select 16 bits transactions
> */
> struct mlxcpld_mux {
> - u8 last_chan;
> + int last_chan;
> struct i2c_client *client;
> struct mlxcpld_mux_plat_data pdata;
> u8 sel_buf[3];
> @@ -94,7 +92,6 @@ static int mlxcpld_mux_select_chan(struct i2c_mux_core *muxc, u32 chan)
> int err = 0;
>
> /* Only select the channel if its different from the last channel */
> - chan++;
This breaks a property of _deselect which previously always triggered a write to the
register. It's also a subtle change without any motivation. How is this connected to
extending the mux channel count?
> if (mux->last_chan != chan) {
> err = mlxcpld_mux_reg_write(muxc->parent, mux, chan);
> mux->last_chan = err < 0 ? 0 : chan;
> @@ -143,7 +140,7 @@ static int mlxcpld_mux_probe(struct platform_device *pdev)
> if (!i2c_check_functionality(client->adapter, func))
> return -ENODEV;
>
> - muxc = i2c_mux_alloc(client->adapter, &pdev->dev, CPLD_MUX_MAX_NCHANS,
> + muxc = i2c_mux_alloc(client->adapter, &pdev->dev, pdata->num_adaps,
> sizeof(*data), 0, mlxcpld_mux_select_chan,
> mlxcpld_mux_deselect);
> if (!muxc)
> @@ -158,13 +155,9 @@ static int mlxcpld_mux_probe(struct platform_device *pdev)
> data->last_chan = 0; /* force the first selection */
>
> /* Create an adapter for each channel. */
> - for (num = 0; num < CPLD_MUX_MAX_NCHANS; num++) {
> - if (num >= pdata->num_adaps)
> - /* discard unconfigured channels */
> - break;
> -
> - force = pdata->adap_ids[num];
> -
> + for (num = 0; num < pdata->num_adaps; num++) {
> + force = pdata->base_nr ? (pdata->base_nr +
> + pdata->adap_ids[num]) : pdata->adap_ids[num];
> err = i2c_mux_add_adapter(muxc, force, num, 0);
> if (err)
> goto virt_reg_failed;
> diff --git a/include/linux/platform_data/mlxcpld.h b/include/linux/platform_data/mlxcpld.h
> index da4f7e8f5721..ea88817b3b35 100644
> --- a/include/linux/platform_data/mlxcpld.h
> +++ b/include/linux/platform_data/mlxcpld.h
> @@ -11,12 +11,15 @@
> /* Platform data for the CPLD I2C multiplexers */
>
> /* mlxcpld_mux_plat_data - per mux data, used with i2c_register_board_info
> + * @base_nr: base I2C bus number to number adapters from or zero for setting
> + * to adap_ids vector
> * @adap_ids - adapter array
> * @num_adaps - number of adapters
> * @sel_reg_addr - mux select register offset in CPLD space
> * @reg_size: register size in bytes (default 0 - 1 byte data, 1 - 2 bytes data
> */
> struct mlxcpld_mux_plat_data {
> + int base_nr;
The changes related to adding a base is not mentioned in the commit message. It's
totally unrelated to extending the number of supported channels, AFAICT.
Cheers,
Peter
> int *adap_ids;
> int num_adaps;
> int sel_reg_addr;
>
