[PATCH v4 0/5] usb: host: dwc2: use driver model for PHY and CLOCK

[Patrick Delaunay]

In this serie I update the DWC2 host driver to use the device tree
information and the associated PHY and CLOCK drivers when they are
availables.

The V4 is rebased on latest master (v2020.04-rc2).
CI-Tavis build is OK:
    https://travis-ci.org/patrickdelaunay/u-boot/builds/651479714

NB: CI-Travis build was OK for all target after V3:
    https://travis-ci.org/patrickdelaunay/u-boot/builds/609496187
    As in V2, I cause the warnings for some boards:
    drivers/usb/host/built-in.o: In function `dwc2_usb_remove':
    drivers/usb/host/dwc2.c:1441: undefined reference to `clk_disable_bulk'

I test this serie on stm32mp157c-ev1 board, with PHY and CLK
support

The U-CLASS are provided by:
- PHY by USBPHYC driver = ./drivers/phy/phy-stm32-usbphyc.c
- CLOCK by RCC clock driver = drivers/clk/clk_stm32mp1.c
- RESET by RCC reset driver = drivers/reset/stm32-reset.c

And I activate the configuration
+CONFIG_USB_DWC2=y

PS: it is not the default configuration to avoid conflict with gadget
    driver

To solve a binding issue, I also deactivate the gadget support:
by default only one driver is bound to the usbotg_hs node with "snps,dwc2"
compatible, and today it is the device one (the first in the driver list).

I also need to deactivate hnp-srp support with:

&usbotg_hs {
	/* need to disable ONLY for HOST support */
	hnp-srp-disable;
};

WARNING: OTG with device or host support is not correctly handle by DWC2
         driver (see example for dynamic OTG role in DWC3 driver).

The tests executed on the stm32mp157c-ev1 target:

STM32MP> usb start
starting USB...
Bus usb-otg at 49000000: USB DWC2
Bus usbh-ehci at 5800d000: USB EHCI 1.00
scanning bus usb-otg at 49000000 for devices... 2 USB Device(s) found
scanning bus usbh-ehci at 5800d000 for devices... 3 USB Device(s) found
       scanning usb for storage devices... 2 Storage Device(s) found
STM32MP> usb tree
USB device tree:
  1  Hub (480 Mb/s, 0mA)
  |   U-Boot Root Hub
  |
  +-2  Mass Storage (480 Mb/s, 300mA)
       Verbatim STORE N GO 070731C8ACD7EE97

  1  Hub (480 Mb/s, 0mA)
  |  u-boot EHCI Host Controller
  |
  +-2  Hub (480 Mb/s, 2mA)

STM32MP> ls usb 0
<DIR>       4096 .
<DIR>       4096 ..
<DIR>      16384 lost+found
<DIR>       4096 record
         1490212 xipImage
        21058006 vmlinux

STM32MP> load usb 0 0xC0000000 vmlinux
21058006 bytes read in 10851 ms (1.9 MiB/s)


Changes in v4:
- Add stub for all functions using 'struct clk' or 'struct clk_bulk'
  after remarks on v3

Changes in v3:
- Add stub for clk_disable_bulk

Changes in v2:
- update dev_err
- update commit message
- change dev_err to dev_dbg for PHY function call
- treat dwc2_shutdown_phy error
- add clk_disable_bulk in dwc2_usb_remove

Patrick Delaunay (5):
  dm: clk: add stub when CONFIG_CLK is desactivated
  usb: host: dwc2: add phy support
  usb: host: dwc2: add clk support
  usb: host: dwc2: force reset assert
  usb: host: dwc2: add trace to have clean usb start

 drivers/usb/host/dwc2.c | 100 ++++++++++++++++++++++++++++++++++++++-
 include/clk.h           | 101 ++++++++++++++++++++++++++++++++++------
 2 files changed, 187 insertions(+), 14 deletions(-)

-- 
2.17.1