usb: dwc3: make LPM configurable in DT

This patch removes "Enable USB3 LPM Capability" option from Kconfig
and adds snps,usb3_lpm_capable devicetree property instead of it.

USB3 LPM (Link Power Management) capability is hardware property, and
it's platform dependent, so if our hardware supports this feature, we
want rather to configure it in devicetree than having it as Kconfig option.

Signed-off-by: Robert Baldyga <[e-mail]>
Signed-off-by: Felipe Balbi <[e-mail]>

Documentation/devicetree/bindings/usb/dwc3.txt

···
  - phys: from the *Generic PHY* bindings
  - phy-names: from the *Generic PHY* bindings
  - tx-fifo-resize: determines if the FIFO *has* to be reallocated.
+ - snps,usb3_lpm_capable: determines if platform is USB3 LPM capable
  - snps,disable_scramble_quirk: true when SW should disable data scrambling.
 	Only really useful for FPGA builds.
  - snps,has-lpm-erratum: true when DWC3 was configured with LPM Erratum enabled

drivers/usb/dwc3/Kconfig

···
 	help
 	  Say Y here to enable debugging messages on DWC3 Driver.
 
-config DWC3_HOST_USB3_LPM_ENABLE
-	bool "Enable USB3 LPM Capability"
-	depends on USB_DWC3_HOST=y || USB_DWC3_DUAL_ROLE=y
-	default n
-	help
-	  Select this when you want to enable USB3 LPM with dwc3 xhci host.
-
 endif

drivers/usb/dwc3/core.c

···
 				"snps,is-utmi-l1-suspend");
 		of_property_read_u8(node, "snps,hird-threshold",
 				&hird_threshold);
+		dwc->usb3_lpm_capable = of_property_read_bool(node,
+				"snps,usb3_lpm_capable");
 
 		dwc->needs_fifo_resize = of_property_read_bool(node,
 				"tx-fifo-resize");
···
 			hird_threshold = pdata->hird_threshold;
 
 		dwc->needs_fifo_resize = pdata->tx_fifo_resize;
+		dwc->usb3_lpm_capable = pdata->usb3_lpm_capable;
 		dwc->dr_mode = pdata->dr_mode;
 
 		dwc->disable_scramble_quirk = pdata->disable_scramble_quirk;

drivers/usb/dwc3/core.h

···
  * @setup_packet_pending: true when there's a Setup Packet in FIFO. Workaround
  * @start_config_issued: true when StartConfig command has been issued
  * @three_stage_setup: set if we perform a three phase setup
+ * @usb3_lpm_capable: set if hadrware supports Link Power Management
  * @disable_scramble_quirk: set if we enable the disable scramble quirk
  * @u2exit_lfps_quirk: set if we enable u2exit lfps quirk
  * @u2ss_inp3_quirk: set if we enable P3 OK for U2/SS Inactive quirk
···
 	unsigned		setup_packet_pending:1;
 	unsigned		start_config_issued:1;
 	unsigned		three_stage_setup:1;
+	unsigned		usb3_lpm_capable:1;
 
 	unsigned		disable_scramble_quirk:1;
 	unsigned		u2exit_lfps_quirk:1;

drivers/usb/dwc3/host.c

···
 
 	memset(&pdata, 0, sizeof(pdata));
 
-#ifdef CONFIG_DWC3_HOST_USB3_LPM_ENABLE
-	pdata.usb3_lpm_capable = 1;
-#endif
+	pdata.usb3_lpm_capable = dwc->usb3_lpm_capable;
 
 	ret = platform_device_add_data(xhci, &pdata, sizeof(pdata));
 	if (ret) {

drivers/usb/dwc3/platform_data.h

···
 	enum usb_device_speed maximum_speed;
 	enum usb_dr_mode dr_mode;
 	bool tx_fifo_resize;
+	bool usb3_lpm_capable;
 
 	unsigned is_utmi_l1_suspend:1;
 	u8 hird_threshold;