usb: phy: tegra: Program new PHY parameters
authorTuomas Tynkkynen <ttynkkynen@nvidia.com>
Mon, 12 Aug 2013 13:06:53 +0000 (16:06 +0300)
committerFelipe Balbi <balbi@ti.com>
Mon, 12 Aug 2013 18:29:52 +0000 (13:29 -0500)
commite497a24d8e18af510879b2ae059ee20a4a58eae8
tree43e213a25bd02b22194b8fa1409a27feeb25fccb
parent91e66700029d71d2938e1341172331c58b6bd8b3
usb: phy: tegra: Program new PHY parameters

The Tegra30 TRM recommends configuration of certain PHY parameters for
optimal quality. Program the following registers based on device tree
parameters:

- UTMIP_XCVR_HSSLEW: HS slew rate control.
- UTMIP_HSSQUELCH_LEVEL: HS squelch detector level
- UTMIP_HSDISCON_LEVEL: HS disconnect detector level.

These registers exist in Tegra20, but programming them hasn't been
necessary, so these parameters won't be set on Tegra20 to keep the
device trees backward compatible.

Additionally, the UTMIP_XCVR_SETUP parameter can be set from fuses
instead of a software-programmed value, as the optimal value can
vary between invidual boards. The boolean property
nvidia,xcvr-setup-use-fuses can be used to enable this behaviour.

Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
drivers/usb/phy/phy-tegra-usb.c
include/linux/usb/tegra_usb_phy.h