Re: [PATCH v7 3/9] usb: dwc3: core: Access XHCI address space temporarily to read port info
From: Krishna Kurapati PSSNV
Date: Thu May 04 2023 - 00:06:02 EST
On 5/4/2023 3:19 AM, Thinh Nguyen wrote:
On Wed, May 03, 2023, Krishna Kurapati PSSNV wrote:
On 5/3/2023 3:11 AM, Thinh Nguyen wrote:
Hi,
On Mon, May 01, 2023, Krishna Kurapati wrote:
Currently host-only capable DWC3 controllers support Multiport.
Temporarily map XHCI address space for host-only controllers and parse
XHCI Extended Capabilities registers to read number of usb2 ports and
usb3 ports present on multiport controller. Each USB Port is at least HS
capable.
The port info for usb2 and usb3 phy are identified as num_usb2_ports
and num_usb3_ports. The intention is as follows:
Wherever we need to perform phy operations like:
LOOP_OVER_NUMBER_OF_AVAILABLE_PORTS()
{
phy_set_mode(dwc->usb2_generic_phy[i], PHY_MODE_USB_HOST);
phy_set_mode(dwc->usb3_generic_phy[i], PHY_MODE_USB_HOST);
}
If number of usb2 ports is 3, loop can go from index 0-2 for
usb2_generic_phy. If number of usb3-ports is 2, we don't know for sure,
if the first 2 ports are SS capable or some other ports like (2 and 3)
are SS capable. So instead, num_usb2_ports is used to loop around all
phy's (both hs and ss) for performing phy operations. If any
usb3_generic_phy turns out to be NULL, phy operation just bails out.
num_usb3_ports is used to modify GUSB3PIPECTL registers while setting up
phy's as we need to know how many SS capable ports are there for this.
Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
---
drivers/usb/dwc3/core.c | 68 +++++++++++++++++++++++++++++++++++++++++
drivers/usb/dwc3/core.h | 58 +++++++++++++++++++++++++++++++++++
2 files changed, 126 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 0beaab932e7d..b8ac7bcee391 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1767,6 +1767,59 @@ static int dwc3_get_clocks(struct dwc3 *dwc)
return 0;
}
+static int dwc3_read_port_info(struct dwc3 *dwc)
+{
+ void __iomem *regs;
+ u32 offset;
+ u32 temp;
+ u8 major_revision;
+ int ret = 0;
+
+ /*
+ * Remap xHCI address space to access XHCI ext cap regs,
+ * since it is needed to get port info.
+ */
+ regs = ioremap(dwc->xhci_resources[0].start,
+ resource_size(&dwc->xhci_resources[0]));
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+
+ offset = dwc3_xhci_find_next_ext_cap(regs, 0,
+ XHCI_EXT_CAPS_PROTOCOL);
+ while (offset) {
+ temp = readl(regs + offset);
+ major_revision = XHCI_EXT_PORT_MAJOR(temp);
+
+ temp = readl(regs + offset + 0x08);
+ if (major_revision == 0x03) {
+ dwc->num_usb3_ports += XHCI_EXT_PORT_COUNT(temp);
+ } else if (major_revision <= 0x02) {
+ dwc->num_usb2_ports += XHCI_EXT_PORT_COUNT(temp);
+ } else {
+ dev_err(dwc->dev, "port revision seems wrong\n");
Can we print this instead:
dev_err(dwc->dev, "Unrecognized port major revision %d\n", major_revision);
+ ret = -EINVAL;
+ goto unmap_reg;
+ }
+
+ offset = dwc3_xhci_find_next_ext_cap(regs, offset,
+ XHCI_EXT_CAPS_PROTOCOL);
+ }
+
+ temp = readl(regs + DWC3_XHCI_HCSPARAMS1);
+ if (HCS_MAX_PORTS(temp) != (dwc->num_usb3_ports + dwc->num_usb2_ports)) {
+ dev_err(dwc->dev, "inconsistency in port info\n");
Can we print this instead:
dev_err(dwc->dev, "Mismatched reported MAXPORTS (%d)\n", HCS_MAX_PORTS(temp));
+ ret = -EINVAL;
+ goto unmap_reg;
+ }
+
+ dev_dbg(dwc->dev,
+ "hs-ports: %d ss-ports: %d\n", dwc->num_usb2_ports, dwc->num_usb3_ports);
+
+unmap_reg:
+ iounmap(regs);
+ return ret;
+}
+
static int dwc3_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -1774,6 +1827,7 @@ static int dwc3_probe(struct platform_device *pdev)
void __iomem *regs;
struct dwc3 *dwc;
int ret;
+ unsigned int hw_mode;
dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
if (!dwc)
@@ -1843,6 +1897,20 @@ static int dwc3_probe(struct platform_device *pdev)
goto err_disable_clks;
}
+ /*
+ * Currently DWC3 controllers that are host-only capable
+ * support Multiport
+ */
+ hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
+ if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST) {
+ ret = dwc3_read_port_info(dwc);
+ if (ret)
+ goto err_disable_clks;
+ } else {
+ dwc->num_usb2_ports = 1;
+ dwc->num_usb3_ports = 1;
+ }
+
spin_lock_init(&dwc->lock);
mutex_init(&dwc->mutex);
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index d56457c02996..21312703e053 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -35,6 +35,17 @@
#define DWC3_MSG_MAX 500
+/* Define XHCI Extcap register offsets for getting multiport info */
+#define XHCI_HCC_PARAMS_OFFSET 0x10
+#define DWC3_XHCI_HCSPARAMS1 0x04
+#define XHCI_EXT_CAPS_PROTOCOL 2
+#define XHCI_HCC_EXT_CAPS(x) (((x) >> 16) & 0xffff)
+#define XHCI_EXT_CAPS_ID(x) (((x) >> 0) & 0xff)
+#define XHCI_EXT_CAPS_NEXT(x) (((x) >> 8) & 0xff)
+#define XHCI_EXT_PORT_MAJOR(x) (((x) >> 24) & 0xff)
+#define XHCI_EXT_PORT_COUNT(x) (((x) >> 8) & 0xff)
+#define HCS_MAX_PORTS(x) (((x) >> 24) & 0x7f)
+
/* Global constants */
#define DWC3_PULL_UP_TIMEOUT 500 /* ms */
#define DWC3_BOUNCE_SIZE 1024 /* size of a superspeed bulk */
@@ -1025,6 +1036,8 @@ struct dwc3_scratchpad_array {
* @usb_psy: pointer to power supply interface.
* @usb2_phy: pointer to USB2 PHY
* @usb3_phy: pointer to USB3 PHY
+ * @num_usb2_ports: number of usb2 ports.
+ * @num_usb3_ports: number of usb3 ports.
* @usb2_generic_phy: pointer to USB2 PHY
* @usb3_generic_phy: pointer to USB3 PHY
* @phys_ready: flag to indicate that PHYs are ready
@@ -1162,6 +1175,9 @@ struct dwc3 {
struct usb_phy *usb2_phy;
struct usb_phy *usb3_phy;
+ u32 num_usb2_ports;
+ u32 num_usb3_ports;
can we use u8?
+
struct phy *usb2_generic_phy;
struct phy *usb3_generic_phy;
@@ -1650,4 +1666,46 @@ static inline void dwc3_ulpi_exit(struct dwc3 *dwc)
{ }
#endif
+/**
+ * dwc3_xhci_find_next_ext_cap - Find the offset of the extended capabilities
+ * with capability ID id.
+ *
+ * @base PCI MMIO registers base address.
+ * @start address at which to start looking, (0 or HCC_PARAMS to start at
+ * beginning of list)
+ * @id Extended capability ID to search for, or 0 for the next
+ * capability
I know that this is a duplicate from the xhci driver, but can we fix the
kerneldoc style as in other places if we're going to keep it?
Hi Thinh,
Isn't this same as other functions ?
/**
* <function name> - description
* @params
*
*/
I missed the function name in comments last time, but added it in this
version.
Checkpatch too didn't give any errors/warnings other than alignment. Can you
help point out any other mistake in this function doc/comments so that I can
fix it in next version.
It's missing ":" after @params.
You can use the kernel-doc script to check for documentation's
errors/warnings.
Here's the output if you run the following command:
# <KERNEL_SRC>/scripts/kernel-doc -none -Werror -function dwc3_xhci_find_next_ext_cap drivers/usb/dwc3/core.h
drivers/usb/dwc3/core.h:1684: warning: Function parameter or member 'base' not described in 'dwc3_xhci_find_next_ext_cap'
drivers/usb/dwc3/core.h:1684: warning: Function parameter or member 'start' not described in 'dwc3_xhci_find_next_ext_cap'
drivers/usb/dwc3/core.h:1684: warning: Function parameter or member 'id' not described in 'dwc3_xhci_find_next_ext_cap'
3 warnings as Errors
This is a minor style issue. While I don't think it's strictly needed to
follow the kerneldoc style for a non-api function. But if we do follow
it, we should do it correctly.
Thanks,
Thinh
Thanks Thinh for pointing it out. Will fix this in the next version.
Regards,
Krishna,