Re: [PATCH] usb: dwc3: core: enable CCI support

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Fri, Oct 13, 2023, Piyush Mehta wrote:
> The GSBUSCFG0 register bits [31:16] are used to configure the cache type
> settings of the descriptor and data write/read transfers (Cacheable,
> Bufferable/ Posted). When CCI is enabled in the design, DWC3 core GSBUSCFG0
> cache bits must be updated to support CCI enabled transfers in USB.
> 
> Signed-off-by: Piyush Mehta <piyush.mehta@amd.com>
> ---
> DWC3 Register Map Link:
> https://urldefense.com/v3/__https://docs.xilinx.com/r/en-US/ug1087-zynq-ultrascale-registers/GSBUSCFG0-USB3_XHCI-Register__;!!A4F2R9G_pg!cbLbYLk9xu54DZMkiTQzMhdCaPA4gmIVInes4ZeNb28AI2pgesEvHNYtjoZfWvE_t7wlUdZvYn-Pio8WjA55ekal$ 
> Register Name	GSBUSCFG0
> Description	Global SoC Bus Configuration Register 0
> 
> GSBUSCFG0 (USB3_XHCI) Register Bit-Field:
> DATRDREQINFO	31:28
> DESRDREQINFO	27:24
> DATWRREQINFO	23:20
> DESWRREQINFO	19:16
> ---
>  drivers/usb/dwc3/core.c | 17 +++++++++++++++++
>  drivers/usb/dwc3/core.h |  5 +++++
>  2 files changed, 22 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 9c6bf054f15d..fc6892c63abf 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -23,6 +23,7 @@
>  #include <linux/delay.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/of.h>
> +#include <linux/of_address.h>
>  #include <linux/of_graph.h>
>  #include <linux/acpi.h>
>  #include <linux/pinctrl/consumer.h>
> @@ -559,6 +560,20 @@ static void dwc3_cache_hwparams(struct dwc3 *dwc)
>  		parms->hwparams9 = dwc3_readl(dwc->regs, DWC3_GHWPARAMS9);
>  }
>  
> +static void dwc3_config_soc_bus(struct dwc3 *dwc)
> +{
> +	if (of_dma_is_coherent(dwc->dev->of_node)) {
> +		u32 reg;
> +
> +		reg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
> +		reg |= DWC3_GSBUSCFG0_DATRDREQINFO_MASK |
> +			DWC3_GSBUSCFG0_DESRDREQINFO_MASK |
> +			DWC3_GSBUSCFG0_DATWRREQINFO_MASK |
> +			DWC3_GSBUSCFG0_DESWRREQINFO_MASK;
> +		dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, reg);
> +	}
> +}
> +

You're overwriting default values for all platforms. Don't do that. Not
every platform supports this setting. Only apply these specific settings
to your platform.

BR,
Thinh

>  static int dwc3_core_ulpi_init(struct dwc3 *dwc)
>  {
>  	int intf;
> @@ -1137,6 +1152,8 @@ static int dwc3_core_init(struct dwc3 *dwc)
>  
>  	dwc3_set_incr_burst_type(dwc);
>  
> +	dwc3_config_soc_bus(dwc);
> +
>  	ret = dwc3_phy_power_on(dwc);
>  	if (ret)
>  		goto err_exit_phy;
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index a69ac67d89fe..bd937025ce05 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -173,6 +173,11 @@
>  #define DWC3_OSTS		0xcc10
>  
>  /* Bit fields */
> +/* Global SoC Bus Configuration Register: AHB-prot/AXI-cache/OCP-ReqInfo */
> +#define DWC3_GSBUSCFG0_DATRDREQINFO_MASK	GENMASK(31, 28)
> +#define DWC3_GSBUSCFG0_DESRDREQINFO_MASK	GENMASK(27, 24)
> +#define DWC3_GSBUSCFG0_DATWRREQINFO_MASK	GENMASK(23, 20)
> +#define DWC3_GSBUSCFG0_DESWRREQINFO_MASK	GENMASK(19, 16)
>  
>  /* Global SoC Bus Configuration INCRx Register 0 */
>  #define DWC3_GSBUSCFG0_INCR256BRSTENA	(1 << 7) /* INCR256 burst */
> -- 
> 2.17.1
>