[PATCH v3] usb: dwc3: enable CCI support for AMD-xilinx DWC3 controller

Thinh Nguyen Thinh.Nguyen at synopsys.com
Fri Jun 7 17:08:36 PDT 2024


Hi,

On Thu, Jun 06, 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 at amd.com>
> ---
> 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!cOoWxmacxPeYVCxDfg3-xlQLhKm8MIEgwWx45cLQjgwRWA4e4QyY_kGVVHo2m_dcRbpBQEFpB9JsYP6nzasK2AIAsyefjQ$ 
> ---
>  drivers/usb/dwc3/core.c        | 24 ++++++++++++++++++++++++
>  drivers/usb/dwc3/core.h        |  8 ++++++++
>  drivers/usb/dwc3/dwc3-xilinx.c | 18 +++++++++++++++++-
>  3 files changed, 49 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 7ee61a89520b..159d21b25629 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>
> @@ -599,6 +600,19 @@ 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)) {

This can be applicable outside of of_node, do we need this if case?

> +		u32 reg;
> +
> +		reg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
> +		reg &= ~DWC3_GSBUSCFG0_DAT_DES_RD_WR_REQINFO_MASK;
> +		reg |= (dwc->acache_data_rd_wr_info <<

What if the user doesn't specify this property? We should not
automatically write 0 by default.

> +			DWC3_GSBUSCFG0_DAT_DES_RD_WR_REQINFO_SHIFT);
> +		dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, reg);
> +	}
> +}
> +
>  static int dwc3_core_ulpi_init(struct dwc3 *dwc)
>  {
>  	int intf;
> @@ -1320,6 +1334,8 @@ 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;
> @@ -1574,6 +1590,7 @@ static void dwc3_get_properties(struct dwc3 *dwc)
>  	u8			tx_max_burst_prd = 0;
>  	u8			tx_fifo_resize_max_num;
>  	const char		*usb_psy_name;
> +	struct device		*tmpdev;
>  	int			ret;
>  
>  	/* default to highest possible threshold */
> @@ -1716,6 +1733,13 @@ static void dwc3_get_properties(struct dwc3 *dwc)
>  	dwc->dis_split_quirk = device_property_read_bool(dev,
>  				"snps,dis-split-quirk");
>  
> +	/* Iterate over all parent nodes for finding swnode properties */
> +	for (tmpdev = dwc->dev; tmpdev; tmpdev = tmpdev->parent) {
> +		device_property_read_u16(tmpdev,
> +					 "snps,acache-data-rd-wr-info",
> +					  &dwc->acache_data_rd_wr_info);
> +	}
> +

Please split this to a separate function and name it as
dwc3_get_software_properties(). For now, just the new property you
create is fine. We can introduce new patches to move all the software
defined properties (ie. non ABI/DS) there such as sysdev_is_parent.

>  	dwc->lpm_nyet_threshold = lpm_nyet_threshold;
>  	dwc->tx_de_emphasis = tx_de_emphasis;
>  
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 3781c736c1a1..57b3cb739353 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_DAT_DES_RD_WR_REQINFO_MASK	GENMASK(31, 16)

Can we rename this to DWC3_GSBUSCFG0_REQINFO_MASK

> +#define DWC3_GSBUSCFG0_DAT_DES_RD_WR_REQINFO_SHIFT	16

We don't need a shift value. Either define DWC3_GSBUSCFG0_REQINFO(n) or
use FIELD_PREP and the mask.

> +
>  /* 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.
> + * @acache_data_rd_wr_info: 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;
> +	u16			acache_data_rd_wr_info;

If we do need to keep this field around, please define the default
for unspecified value. Also rename this to 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..f3757bfbd650 100644
> --- a/drivers/usb/dwc3/dwc3-xilinx.c
> +++ b/drivers/usb/dwc3/dwc3-xilinx.c
> @@ -47,6 +47,15 @@ struct dwc3_xlnx {
>  	struct phy			*usb3_phy;
>  };
>  
> +static const struct property_entry dwc3_xilinx_properties[] = {
> +	PROPERTY_ENTRY_U16("snps,acache-data-rd-wr-info", 0xffff),
> +	{},
> +};
> +
> +static const struct software_node dwc3_xilinx_swnode = {
> +	.properties = dwc3_xilinx_properties,
> +};
> +
>  static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool mask)
>  {
>  	u32 reg;
> @@ -288,10 +297,14 @@ static int dwc3_xlnx_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto err_clk_put;
>  
> -	ret = of_platform_populate(np, NULL, NULL, dev);
> +	ret = device_add_software_node(dev, &dwc3_xilinx_swnode);
>  	if (ret)
>  		goto err_clk_put;
>  
> +	ret = of_platform_populate(np, NULL, NULL, dev);
> +	if (ret)
> +		goto err_remove_swnode;
> +
>  	pm_runtime_set_active(dev);
>  	ret = devm_pm_runtime_enable(dev);
>  	if (ret < 0)
> @@ -303,6 +316,9 @@ static int dwc3_xlnx_probe(struct platform_device *pdev)
>  err_pm_set_suspended:
>  	pm_runtime_set_suspended(dev);
>  
> +err_remove_swnode:
> +	device_remove_software_node(dev);
> +
>  err_clk_put:
>  	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);
>  
> -- 
> 2.34.1
> 

Thanks,
Thinh


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