soc/soc/intel: Add UFS device with ref-clk-freq property

UFS storage devices require the bRefClkFreq attribute to be set to
operate correctly in high speed mode. The correct value is determined by
what the SoC / board supports. For the ADL UFS controller, it is
19.2 MHz.

a) Introduce a new ACPI property "ref-clk-freq".
b) Add support to configure this property using an SoC Kconfig.

Kernel patch:
https://web.archive.org/web/20220801060732/https://lore.kernel.org/all/
20220715210230.1.I365d113d275117dee8fd055ce4fc7e6aebd0bce9@changeid/

BUG=b:238262674
TEST=Build,boot Nirwen and dump SSDT entries and check that the kernel
correctly parses ref-clk-freq as 19.2 MHz.

Scope (\_SB.PCI0)
    {
        Device (UFS)
        {
            Name (_ADR, 0x0000000000120007)  // _ADR: Address
            Name (_DDN, "UFS Controller")  // _DDN: DOS Device Name
            Name (_DSD, Package (0x02)  // _DSD: Device-Specific Data
            {
                ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301")
                /* Device Properties for _DSD */,
                Package (0x01)
                {
                    Package (0x02)
                    {
                        "ref-clk-freq",
                        0x0124F800
                    }
                }
            })
        }
    }

Signed-off-by: Meera Ravindranath <meera.ravindranath@intel.com>
Signed-off-by: Reka Norman <rekanorman@chromium.org>
Change-Id: I80c338a8a61f161b0feb6c5a3ca00cf5e0cfb36c
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66051
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Ronak Kanabar <ronak.kanabar@intel.com>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>

src/soc/intel/alderlake/Kconfig

@@ -295,6 +295,10 @@ config SOC_INTEL_COMMON_BLOCK_GSPI_CLOCK_MHZ
 config CPU_XTAL_HZ
 	default 38400000
 
+config SOC_INTEL_UFS_CLK_FREQ_HZ
+	int
+	default 19200000
+
 config DRIVERS_I2C_DESIGNWARE_CLOCK_MHZ
 	int
 	default 133

src/soc/intel/common/block/scs/Kconfig

@@ -19,3 +19,10 @@ config SOC_INTEL_COMMON_MMC_OVERRIDE
 	help
 	  Override the MMC settings after FSP-S.
 	  It should be used only when there is no FSP UPDs for certain setting.
+
+config SOC_INTEL_COMMON_UFS_SUPPORT
+	bool
+	default n
+	help
+	  Enable UFS support. Should be enabled when a particular SoC supports
+	  boot from UFS.

src/soc/intel/common/block/scs/Makefile.inc

@@ -2,4 +2,5 @@ ifneq ($(CONFIG_SOC_INTEL_ALDERLAKE_PCH_N),y)
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_SCS) += sd.c
 endif
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_SCS) += mmc.c
+ramstage-$(CONFIG_SOC_INTEL_COMMON_UFS_SUPPORT) += ufs.c
 romstage-$(CONFIG_SOC_INTEL_COMMON_EARLY_MMC_WAKE) += early_mmc.c

src/soc/intel/common/block/scs/ufs.c

@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <acpi/acpi_device.h>
+#include <acpi/acpigen.h>
+#include <acpi/acpigen_pci.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+
+#if CONFIG(HAVE_ACPI_TABLES)
+static void ufs_fill_ssdt(const struct device *dev)
+{
+	struct acpi_dp *dsd;
+
+	const char *scope = acpi_device_scope(dev);
+
+	acpigen_write_scope(scope);
+	acpigen_write_device("UFS");
+	acpigen_write_ADR_pci_device(dev);
+	acpigen_write_name_string("_DDN", "UFS Controller");
+
+	dsd = acpi_dp_new_table("_DSD");
+	acpi_dp_add_integer(dsd, "ref-clk-freq", CONFIG_SOC_INTEL_UFS_CLK_FREQ_HZ);
+	acpi_dp_write(dsd);
+	acpigen_write_device_end();
+	acpigen_pop_len();
+}
+#endif
+
+static struct device_operations dev_ops = {
+	.read_resources		= pci_dev_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_dev_enable_resources,
+#if CONFIG(HAVE_ACPI_TABLES)
+	.acpi_fill_ssdt		= ufs_fill_ssdt,
+#endif
+	.ops_pci		= &pci_dev_ops_pci,
+};
+
+static const unsigned short pci_device_ids[] = {
+	PCI_DID_INTEL_ADP_UFS,
+	0
+};
+
+static const struct pci_driver pch_ufs __pci_driver = {
+	.ops		= &dev_ops,
+	.vendor		= PCI_VID_INTEL,
+	.devices	= pci_device_ids
+};