[PATCH v2] arm: rockchip-rk3568-evb: add hardware id detection

[Ahmad Fatoum]

On 05.07.21 18:04, Michael Riesch wrote:
> The RK3568 EVB uses a voltage divider to determine the hardware ID of
> the board. At the moment, the voltage levels for seven EVB variants are
> defined. This commit adds a late_initcall to the board code that reads
> out the voltage and populates the hardware ID as environment variable.
> 
> Signed-off-by: Michael Riesch <michael.riesch at wolfvision.net>

Reviewed-by: Ahmad Fatoum <a.fatoum at pengutronix.de>

I just sent out a fixup that Sascha can squash if both patches
are ok with him.

> ---
> v2:
> - add compatible check
> - return early in case the voltage cannot be read
> - populate hardware ID as environment variable
> 
>  arch/arm/boards/rockchip-rk3568-evb/board.c | 56 +++++++++++++++++++++
>  1 file changed, 56 insertions(+)
> 
> diff --git a/arch/arm/boards/rockchip-rk3568-evb/board.c b/arch/arm/boards/rockchip-rk3568-evb/board.c
> index 57c24ed3c..f8b257e57 100644
> --- a/arch/arm/boards/rockchip-rk3568-evb/board.c
> +++ b/arch/arm/boards/rockchip-rk3568-evb/board.c
> @@ -2,7 +2,13 @@
>  #include <common.h>
>  #include <init.h>
>  #include <mach/bbu.h>
> +#include <aiodev.h>
>  #include <bootsource.h>
> +#include <environment.h>
> +#include <globalvar.h>
> +#include <magicvar.h>
> +
> +static bool machine_is_rk3568_evb = false;
>  
>  static int rk3568_evb_probe(struct device_d *dev)
>  {
> @@ -11,6 +17,7 @@ static int rk3568_evb_probe(struct device_d *dev)
>  
>  	barebox_set_model("Rockchip RK3568 EVB");
>  	barebox_set_hostname("rk3568-evb");
> +	machine_is_rk3568_evb = true;
>  
>  	if (bootsource == BOOTSOURCE_MMC && instance == 1)
>  		of_device_enable_path("/chosen/environment-sd");
> @@ -34,3 +41,52 @@ static struct driver_d rk3568_evb_board_driver = {
>  	.of_compatible = rk3568_evb_of_match,
>  };
>  coredevice_platform_driver(rk3568_evb_board_driver);
> +
> +static int rk3568_evb_detect_hwid(void)
> +{
> +	int ret;
> +	int evb_hwid_voltage;
> +	struct aiochannel *evb_hwid_chan;
> +	char *evb_hwid;
> +
> +	if (!machine_is_rk3568_evb)
> +		return 0;
> +
> +	evb_hwid_chan = aiochannel_by_name("aiodev0.in_value1_mV");
> +	if (IS_ERR(evb_hwid_chan)) {
> +		ret = PTR_ERR(evb_hwid_chan);
> +		goto err_hwid;
> +	}
> +
> +	ret = aiochannel_get_value(evb_hwid_chan, &evb_hwid_voltage);
> +	if (ret)
> +		goto err_hwid;
> +
> +	if (evb_hwid_voltage > 1650) {
> +		evb_hwid = "1";
> +	} else if (evb_hwid_voltage > 1350) {
> +		evb_hwid = "2";
> +	} else if (evb_hwid_voltage > 1050) {
> +		evb_hwid = "3";
> +	} else if (evb_hwid_voltage > 750) {
> +		evb_hwid = "4";
> +	} else if (evb_hwid_voltage > 450) {
> +		evb_hwid = "5";
> +	} else if (evb_hwid_voltage > 150) {
> +		evb_hwid = "6";
> +	} else {
> +		evb_hwid = "7";
> +	}
> +	pr_info("Detected RK3568 EVB%s\n", evb_hwid);
> +
> +	globalvar_add_simple("board.hwid", evb_hwid);
> +
> +	return 0;
> +
> +err_hwid:
> +	pr_err("couldn't retrieve hardware ID");
> +	return ret;
> +}
> +late_initcall(rk3568_evb_detect_hwid);
> +
> +BAREBOX_MAGICVAR(global.board.hwid, "The board hardware ID");
> 

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