Re: [PATCH v3 2/2] usb: dwc3: Add cache type configuration support
From: Peter Chen
Date: Thu Nov 21 2019 - 04:54:07 EST
On 19-11-21 10:42:06, Ran Wang wrote:
> This feature is telling how to configure cache type on 4 different
> transfer types: Data Read, Desc Read, Data Write and Desc write. For each
> treasfer type, controller has a 4-bit register field to enable different
%s/treasfer/transfer
> cache type. Quoted from DWC3 data book Table 6-5 Cache Type Bit Assignments:
> ----------------------------------------------------------------
> MBUS_TYPE| bit[3] |bit[2] |bit[1] |bit[0]
> ----------------------------------------------------------------
> AHB |Cacheable |Bufferable |Privilegge |Data
> AXI3 |Write Allocate|Read Allocate|Cacheable |Bufferable
> AXI4 |Allocate Other|Allocate |Modifiable |Bufferable
> AXI4 |Other Allocate|Allocate |Modifiable |Bufferable
> Native |Same as AXI |Same as AXI |Same as AXI|Same as AXI
> ----------------------------------------------------------------
> Note: The AHB, AXI3, AXI4, and PCIe busses use different names for certain
> signals, which have the same meaning:
> Bufferable = Posted
> Cacheable = Modifiable = Snoop (negation of No Snoop)
>
> In most cases, driver support is not required unless the default values of
> registers are not correct *and* DWC3 node has enabled dma-coherent. So far we
> have observed USB device detect failure on some Layerscape platforms if this
> programming was not applied.
>
> Related struct:
> struct dwc3_cache_type {
> u8 transfer_type_datard;
> u8 transfer_type_descrd;
> u8 transfer_type_datawr;
> u8 transfer_type_descwr;
> };
>
> Signed-off-by: Ran Wang <ran.wang_1@xxxxxxx>
> ---
> Change in v3:
> - Replace cache type sub-node parsing with chip-specifc data parsing.
If it is SoC implementation specific, you may move the implementation to
dwc3-of-simmple.c, and change your dts accordingly.
Feplie, what do you think?
Peter
>
> Change in v2:
> - Change most program logic to meet new DTS property define.
> - Rename related register address macros.
> - Rename function dwc3_enable_snooping() to dwc3_set_cache_type().
>
> drivers/usb/dwc3/core.c | 67 ++++++++++++++++++++++++++++++++++++++++++++-----
> drivers/usb/dwc3/core.h | 15 +++++++++++
> 2 files changed, 76 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 97d6ae3..0baa972 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -894,6 +894,53 @@ static void dwc3_set_incr_burst_type(struct dwc3 *dwc)
> dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, cfg);
> }
>
> +#ifdef CONFIG_OF
> +struct dwc3_cache_type {
> + u8 transfer_type_datard;
> + u8 transfer_type_descrd;
> + u8 transfer_type_datawr;
> + u8 transfer_type_descwr;
> +};
> +
> +static const struct dwc3_cache_type ls1088a_dwc3_cache_type = {
> + .transfer_type_datard = 2,
> + .transfer_type_descrd = 2,
> + .transfer_type_datawr = 2,
> + .transfer_type_descwr = 2,
> +};
> +
> +/**
> + * dwc3_set_cache_type - Configure cache type registers
> + * @dwc: Pointer to our controller context structure
> + */
> +static void dwc3_set_cache_type(struct dwc3 *dwc)
> +{
> + u32 tmp, reg;
> + const struct dwc3_cache_type *cache_type =
> + device_get_match_data(dwc->dev);
> +
> + if (cache_type) {
> + reg = dwc3_readl(dwc->regs, DWC3_GSBUSCFG0);
> + tmp = reg;
> +
> + reg &= ~DWC3_GSBUSCFG0_DATARD(~0);
> + reg |= DWC3_GSBUSCFG0_DATARD(cache_type->transfer_type_datard);
> +
> + reg &= ~DWC3_GSBUSCFG0_DESCRD(~0);
> + reg |= DWC3_GSBUSCFG0_DESCRD(cache_type->transfer_type_descrd);
> +
> + reg &= ~DWC3_GSBUSCFG0_DATAWR(~0);
> + reg |= DWC3_GSBUSCFG0_DATAWR(cache_type->transfer_type_datawr);
> +
> + reg &= ~DWC3_GSBUSCFG0_DESCWR(~0);
> + reg |= DWC3_GSBUSCFG0_DESCWR(cache_type->transfer_type_descwr);
> +
> + if (tmp != reg)
> + dwc3_writel(dwc->regs, DWC3_GSBUSCFG0, reg);
> + }
> +}
> +#endif
> +
> /**
> * dwc3_core_init - Low-level initialization of DWC3 Core
> * @dwc: Pointer to our controller context structure
> @@ -952,6 +999,10 @@ static int dwc3_core_init(struct dwc3 *dwc)
>
> dwc3_set_incr_burst_type(dwc);
>
> +#ifdef CONFIG_OF
> + dwc3_set_cache_type(dwc);
> +#endif
> +
> usb_phy_set_suspend(dwc->usb2_phy, 0);
> usb_phy_set_suspend(dwc->usb3_phy, 0);
> ret = phy_power_on(dwc->usb2_generic_phy);
> @@ -1837,12 +1888,16 @@ static const struct dev_pm_ops dwc3_dev_pm_ops = {
>
> #ifdef CONFIG_OF
> static const struct of_device_id of_dwc3_match[] = {
> - {
> - .compatible = "snps,dwc3"
> - },
> - {
> - .compatible = "synopsys,dwc3"
> - },
> + { .compatible = "fsl,ls1012a-dwc3", .data = &ls1088a_dwc3_cache_type, },
> + { .compatible = "fsl,ls1021a-dwc3", .data = &ls1088a_dwc3_cache_type, },
> + { .compatible = "fsl,ls1028a-dwc3", .data = &ls1088a_dwc3_cache_type, },
> + { .compatible = "fsl,ls1043a-dwc3", .data = &ls1088a_dwc3_cache_type, },
> + { .compatible = "fsl,ls1046a-dwc3", .data = &ls1088a_dwc3_cache_type, },
> + { .compatible = "fsl,ls1088a-dwc3", .data = &ls1088a_dwc3_cache_type, },
> + { .compatible = "fsl,ls2088a-dwc3", .data = &ls1088a_dwc3_cache_type, },
> + { .compatible = "fsl,lx2160a-dwc3", .data = &ls1088a_dwc3_cache_type, },
> + { .compatible = "snps,dwc3" },
> + { .compatible = "synopsys,dwc3" },
> { },
> };
> MODULE_DEVICE_TABLE(of, of_dwc3_match);
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 1c8b3493..ac51dfe 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -165,6 +165,21 @@
> /* Bit fields */
>
> /* Global SoC Bus Configuration INCRx Register 0 */
> +#ifdef CONFIG_OF
> +#define DWC3_GSBUSCFG0_DATARD_SHIFT 28
> +#define DWC3_GSBUSCFG0_DATARD(n) (((n) & 0xf) \
> + << DWC3_GSBUSCFG0_DATARD_SHIFT)
> +#define DWC3_GSBUSCFG0_DESCRD_SHIFT 24
> +#define DWC3_GSBUSCFG0_DESCRD(n) (((n) & 0xf) \
> + << DWC3_GSBUSCFG0_DESCRD_SHIFT)
> +#define DWC3_GSBUSCFG0_DATAWR_SHIFT 20
> +#define DWC3_GSBUSCFG0_DATAWR(n) (((n) & 0xf) \
> + << DWC3_GSBUSCFG0_DATAWR_SHIFT)
> +#define DWC3_GSBUSCFG0_DESCWR_SHIFT 16
> +#define DWC3_GSBUSCFG0_DESCWR(n) (((n) & 0xf) \
> + << DWC3_GSBUSCFG0_DESCWR_SHIFT)
> +#endif
> +
> #define DWC3_GSBUSCFG0_INCR256BRSTENA (1 << 7) /* INCR256 burst */
> #define DWC3_GSBUSCFG0_INCR128BRSTENA (1 << 6) /* INCR128 burst */
> #define DWC3_GSBUSCFG0_INCR64BRSTENA (1 << 5) /* INCR64 burst */
> --
> 2.7.4
>
--
Thanks,
Peter Chen