Re: [PATCH v5] usb: dwc3: enable CCI support for AMD-xilinx DWC3 controller

[Thinh Nguyen]

On Tue, Jul 09, 2024, Radhey Shyam Pandey 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.
> 
> To program GSBUSCFG0 cache bits create a software node property
> in AMD-xilinx dwc3 glue driver and pass it to dwc3 core. The core
> then reads this property value and configures it in dwc3_core_init()
> sequence.
> 
> Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxx>
> ---
> Changes for v5:
> - Remove linux/of_address.h include from core.c
> - Move dwc3_get_properties() implementation above dwc3_get_properties().
> - Rename DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED.
> 
> Changes for v4:
> - Pass swnode GSBUSCFG0 cache property from glue driver based on
>   dma-coherent flag.
> - Introduce function dwc3_get_software_properties().
> - Rename DWC3_GSBUSCFG0_REQINFO_MASK.
> - Use DWC3_GSBUSCFG0_REQINFO(n) and get rid of mask shift define.
> - Rename dwc3 member gsbuscfg0_reqinfo and change it type to u32
>   and define 0xffffffff as unspecified.
> - In comment dwc3_get_software_properties() description also mention
>   "non-DT (non-ABI) properties".
> 
> Changes for v3:
> - In v2 review as suggested by Thinh Nguyen, switch to swnode
>   implementation for passing GSBUSCFG0 cache bits from AMD-xilinx
>   dwc3 glue driver to core driver.
> 
> Changes for v2:
> - Make GSBUSCFG0 configuration specific to AMD-xilinx platform.
>   Taken reference from existing commit ec5eb43813a4 ("usb: dwc3: core:
>   add support for realtek SoCs custom's global register start address")
> 
> v1 link:
>   https://urldefense.com/v3/__https://lore.kernel.org/all/20231013053448.11056-1-piyush.mehta@amd.com__;!!A4F2R9G_pg!Z4XtbxfxX768N7nydthP0wLAvHOE4X-AWbdjJfUvQgPnmGh8zcV9U44Mlippmbgpzf-yPN3XYFqZ5tF9t75xMe4yACzM7w$ 
> ---
>  drivers/usb/dwc3/core.c        | 37 ++++++++++++++++++++++++++++++++++
>  drivers/usb/dwc3/core.h        |  8 ++++++++
>  drivers/usb/dwc3/dwc3-xilinx.c | 29 ++++++++++++++++++++++++++
>  3 files changed, 74 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index cb82557678dd..ebb3f6eb191f 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -599,6 +599,18 @@ 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 (dwc->gsbuscfg0_reqinfo != DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED) {
> +		u32 reg;
> +
> +		reg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
> +		reg &= ~DWC3_GSBUSCFG0_REQINFO(~0);
> +		reg |= DWC3_GSBUSCFG0_REQINFO(dwc->gsbuscfg0_reqinfo);
> +		dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, reg);
> +	}
> +}
> +
>  static int dwc3_core_ulpi_init(struct dwc3 *dwc)
>  {
>  	int intf;
> @@ -1338,6 +1350,8 @@ 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;
> @@ -1576,6 +1590,27 @@ static void dwc3_core_exit_mode(struct dwc3 *dwc)
>  	dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
>  }
>  
> +static void dwc3_get_software_properties(struct dwc3 *dwc)
> +{
> +	struct device *tmpdev;
> +	u16 gsbuscfg0_reqinfo;
> +	int ret;
> +
> +	dwc->gsbuscfg0_reqinfo = DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED;
> +
> +	/*
> +	 * Iterate over all parent nodes for finding swnode properties
> +	 * and non-DT (non-ABI) properties.
> +	 */
> +	for (tmpdev = dwc->dev; tmpdev; tmpdev = tmpdev->parent) {
> +		ret = device_property_read_u16(tmpdev,
> +					       "snps,gsbuscfg0-reqinfo",
> +					       &gsbuscfg0_reqinfo);
> +		if (!ret)
> +			dwc->gsbuscfg0_reqinfo = gsbuscfg0_reqinfo;
> +	}
> +}
> +
>  static void dwc3_get_properties(struct dwc3 *dwc)
>  {
>  	struct device		*dev = dwc->dev;
> @@ -2090,6 +2125,8 @@ static int dwc3_probe(struct platform_device *pdev)
>  
>  	dwc3_get_properties(dwc);
>  
> +	dwc3_get_software_properties(dwc);
> +
>  	dwc->reset = devm_reset_control_array_get_optional_shared(dev);
>  	if (IS_ERR(dwc->reset)) {
>  		ret = PTR_ERR(dwc->reset);
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 3781c736c1a1..1e561fd8b86e 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -194,6 +194,10 @@
>  #define DWC3_GSBUSCFG0_INCRBRSTENA	(1 << 0) /* undefined length enable */
>  #define DWC3_GSBUSCFG0_INCRBRST_MASK	0xff
>  
> +/* Global SoC Bus Configuration Register: AHB-prot/AXI-cache/OCP-ReqInfo */
> +#define DWC3_GSBUSCFG0_REQINFO(n)	(((n) & 0xffff) << 16)
> +#define DWC3_GSBUSCFG0_REQINFO_UNSPECIFIED	0xffffffff
> +
>  /* Global Debug LSP MUX Select */
>  #define DWC3_GDBGLSPMUX_ENDBC		BIT(15)	/* Host only */
>  #define DWC3_GDBGLSPMUX_HOSTSELECT(n)	((n) & 0x3fff)
> @@ -1153,6 +1157,9 @@ struct dwc3_scratchpad_array {
>   * @num_ep_resized: carries the current number endpoints which have had its tx
>   *		    fifo resized.
>   * @debug_root: root debugfs directory for this device to put its files in.
> + * @gsbuscfg0_reqinfo: store GSBUSCFG0.DATRDREQINFO, DESRDREQINFO,
> + *		       DATWRREQINFO, and DESWRREQINFO value passed from
> + *		       glue driver.
>   */
>  struct dwc3 {
>  	struct work_struct	drd_work;
> @@ -1380,6 +1387,7 @@ struct dwc3 {
>  	int			last_fifo_depth;
>  	int			num_ep_resized;
>  	struct dentry		*debug_root;
> +	u32			gsbuscfg0_reqinfo;
>  };
>  
>  #define INCRX_BURST_MODE 0
> diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c
> index 6095f4dee6ce..bb4d894c16e9 100644
> --- a/drivers/usb/dwc3/dwc3-xilinx.c
> +++ b/drivers/usb/dwc3/dwc3-xilinx.c
> @@ -246,6 +246,31 @@ static const struct of_device_id dwc3_xlnx_of_match[] = {
>  };
>  MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);
>  
> +static int dwc3_set_swnode(struct device *dev)
> +{
> +	struct device_node *np = dev->of_node, *dwc3_np;
> +	struct property_entry props[2];
> +	int prop_idx = 0, ret = 0;
> +
> +	dwc3_np = of_get_compatible_child(np, "snps,dwc3");
> +	if (!dwc3_np) {
> +		ret = -ENODEV;
> +		dev_err(dev, "failed to find dwc3 core child\n");
> +		return ret;
> +	}
> +
> +	memset(props, 0, sizeof(struct property_entry) * ARRAY_SIZE(props));
> +	if (of_dma_is_coherent(dwc3_np))
> +		props[prop_idx++] = PROPERTY_ENTRY_U16("snps,gsbuscfg0-reqinfo",
> +						       0xffff);
> +	of_node_put(dwc3_np);
> +
> +	if (prop_idx)
> +		ret = device_create_managed_software_node(dev, props, NULL);
> +
> +	return ret;
> +}
> +
>  static int dwc3_xlnx_probe(struct platform_device *pdev)
>  {
>  	struct dwc3_xlnx		*priv_data;
> @@ -288,6 +313,10 @@ static int dwc3_xlnx_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto err_clk_put;
>  
> +	ret = dwc3_set_swnode(dev);
> +	if (ret)
> +		goto err_clk_put;
> +
>  	ret = of_platform_populate(np, NULL, NULL, dev);
>  	if (ret)
>  		goto err_clk_put;
> 
> base-commit: 34afb82a3c67f869267a26f593b6f8fc6bf35905
> -- 
> 2.34.1
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

Thanks,
Thinh