phy: qcom: Introduce new eDP PHY driver

Many recent Qualcomm platforms comes with native DP and eDP support.
This consists of a controller in the MDSS and a QMP-like PHY.

While similar to the well known QMP block, the eDP PHY only has TX lanes
and the programming sequences are slightly different. Rather than
continuing the trend of parameterize the QMP driver to pieces, this
introduces the support as a new driver.

The registration of link and pixel clocks are borrowed from the QMP
driver. The non-DP link frequencies are omitted for now.

The eDP PHY is very similar to the dedicated (non-USB) DP PHY, but only
the prior is supported for now.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20211103234410.1352424-2-bjorn.andersson@linaro.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/qualcomm/Kconfig

@@ -18,6 +18,16 @@ config PHY_QCOM_APQ8064_SATA
 	depends on OF
 	select GENERIC_PHY
 
+config PHY_QCOM_EDP
+	tristate "Qualcomm eDP PHY driver"
+	depends on ARCH_QCOM || COMPILE_TEST
+	depends on OF
+	depends on COMMON_CLK
+	select GENERIC_PHY
+	help
+	  Enable this driver to support the Qualcomm eDP PHY found in various
+	  Qualcomm chipsets.
+
 config PHY_QCOM_IPQ4019_USB
 	tristate "Qualcomm IPQ4019 USB PHY driver"
 	depends on OF && (ARCH_QCOM || COMPILE_TEST)

drivers/phy/qualcomm/Makefile

 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_PHY_ATH79_USB)		+= phy-ath79-usb.o
 obj-$(CONFIG_PHY_QCOM_APQ8064_SATA)	+= phy-qcom-apq8064-sata.o
+obj-$(CONFIG_PHY_QCOM_EDP)		+= phy-qcom-edp.o
 obj-$(CONFIG_PHY_QCOM_IPQ4019_USB)	+= phy-qcom-ipq4019-usb.o
 obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA)	+= phy-qcom-ipq806x-sata.o
 obj-$(CONFIG_PHY_QCOM_PCIE2)		+= phy-qcom-pcie2.o

drivers/phy/qualcomm/phy-qcom-qmp.h

@@ -551,6 +551,7 @@
 /* Only for QMP V4 PHY - QSERDES COM registers */
 #define QSERDES_V4_COM_BG_TIMER				0x00c
 #define QSERDES_V4_COM_SSC_EN_CENTER			0x010
+#define QSERDES_V4_COM_SSC_ADJ_PER1			0x014
 #define QSERDES_V4_COM_SSC_PER1				0x01c
 #define QSERDES_V4_COM_SSC_PER2				0x020
 #define QSERDES_V4_COM_SSC_STEP_SIZE1_MODE0		0x024