> -----Original Message-----
> From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
> Sent: Saturday, June 8, 2024 5:39 AM
> To: Pandey, Radhey Shyam <radhey.shyam.pandey@xxxxxxx>
> Cc: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>;
> gregkh@xxxxxxxxxxxxxxxxxxx; Simek, Michal <michal.simek@xxxxxxx>;
> robh+dt@xxxxxxxxxx; krzysztof.kozlowski@xxxxxxxxxx; linux-
> usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; git (AMD-Xilinx) <git@xxxxxxx>
> Subject: Re: [PATCH v3] usb: dwc3: enable CCI support for AMD-xilinx DWC3
> controller
>
> 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@xxxxxxx>
> > ---
> > 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/20231013053448.11
> 056-1-piyush.mehta@amd.com__;!!A4F2R9G_pg!cOoWxmacxPeYVCxDfg3-
> xlQLhKm8MIEgwWx45cLQjgwRWA4e4QyY_kGVVHo2m_dcRbpBQEFpB9JsYP6
> nzasK2AIAsyefjQ$
> > ---
> > 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?
This of_dma_is_coherent detect presence of dma-coherent property
in dwc3 node and then if propery is present we program
GSBUSCFG0_REQINFO.
Alternatively glue driver can also read/detect DWC3 node dma-coherent
property and then override snps,acache-data-rd-wr-info value only
if dma-coherent property is present.
Or do you mean we should support presence of dma-coherent
property in either parent node ("xlnx,zynqmp-dwc3") or child
node(snps,dwc3)?
>
> > + 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.
USB3 3.30a core configured for 2.0 I see reset value for
GSBUSCFG0 [31:16] bits are 0. Will cross-check it for other
versions.
>
> > +
> 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.
Sure , will split it to separate patch.
>
> > 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
Yes, will do it in next version.
>
> > +#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.
Yes, will fix it in next version.
>
> > +
> > /* 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.
Sure. will define default (likely 0 ) and rename it to gsbuscfg0_reqinfo
in next version.
>
> > };
> >
> > #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
