ufs: Add Support for Cadence platform UFS driver

Add Support for the platform driver for the Cadence device present on
TI's J721e device.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>

drivers/ufs/Kconfig

@@ -6,4 +6,12 @@ config UFS
 	help
 	  This selects support for Universal Flash Subsystem (UFS).
 	  Say Y here if you want UFS Support.
+
+config CADENCE_UFS
+	bool "Cadence platform driver for UFS"
+	depends on UFS
+        help
+	  This selects the platform driver for the Cadence UFS host
+	  controller present on present TI's J721e devices.
+
 endmenu

drivers/ufs/Makefile

@@ -4,3 +4,4 @@
 #
 
 obj-$(CONFIG_UFS) += ufs.o ufs-uclass.o
+obj-$(CONFIG_CADENCE_UFS) += cdns-platform.o

drivers/ufs/cdns-platform.c

@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0+
+/**
+ * cdns-platform.c - Platform driver for Cadence UFSHCI device
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com
+ */
+
+#include <clk.h>
+#include <common.h>
+#include <dm.h>
+#include <ufs.h>
+
+#include "ufs.h"
+
+#define USEC_PER_SEC	1000000L
+
+#define CDNS_UFS_REG_HCLKDIV	0xFC
+#define CDNS_UFS_REG_PHY_XCFGD1	0x113C
+
+static int cdns_ufs_link_startup_notify(struct ufs_hba *hba,
+					enum ufs_notify_change_status status)
+{
+	hba->quirks |= UFSHCD_QUIRK_BROKEN_LCC;
+	switch (status) {
+	case PRE_CHANGE:
+		return ufshcd_dme_set(hba,
+				      UIC_ARG_MIB(PA_LOCAL_TX_LCC_ENABLE),
+				      0);
+	case POST_CHANGE:
+	;
+	}
+
+	return 0;
+}
+
+static int cdns_ufs_set_hclkdiv(struct ufs_hba *hba)
+{
+	struct clk clk;
+	unsigned long core_clk_rate = 0;
+	u32 core_clk_div = 0;
+	int ret;
+
+	ret = clk_get_by_name(hba->dev, "core_clk", &clk);
+	if (ret) {
+		dev_err(hba->dev, "failed to get core_clk clock\n");
+		return ret;
+	}
+
+	core_clk_rate = clk_get_rate(&clk);
+	if (IS_ERR_VALUE(core_clk_rate)) {
+		dev_err(hba->dev, "%s: unable to find core_clk rate\n",
+			__func__);
+		return core_clk_rate;
+	}
+
+	core_clk_div = core_clk_rate / USEC_PER_SEC;
+	ufshcd_writel(hba, core_clk_div, CDNS_UFS_REG_HCLKDIV);
+
+	return 0;
+}
+
+static int cdns_ufs_hce_enable_notify(struct ufs_hba *hba,
+				      enum ufs_notify_change_status status)
+{
+	switch (status) {
+	case PRE_CHANGE:
+		return cdns_ufs_set_hclkdiv(hba);
+	case POST_CHANGE:
+	;
+	}
+
+	return 0;
+}
+
+static int cdns_ufs_init(struct ufs_hba *hba)
+{
+	u32 data;
+
+	/* Increase RX_Advanced_Min_ActivateTime_Capability */
+	data = ufshcd_readl(hba, CDNS_UFS_REG_PHY_XCFGD1);
+	data |= BIT(24);
+	ufshcd_writel(hba, data, CDNS_UFS_REG_PHY_XCFGD1);
+
+	return 0;
+}
+
+static struct ufs_hba_ops cdns_pltfm_hba_ops = {
+	.init = cdns_ufs_init,
+	.hce_enable_notify = cdns_ufs_hce_enable_notify,
+	.link_startup_notify = cdns_ufs_link_startup_notify,
+};
+
+static int cdns_ufs_pltfm_probe(struct udevice *dev)
+{
+	int err = ufshcd_probe(dev, &cdns_pltfm_hba_ops);
+	if (err)
+		dev_err(dev, "ufshcd_probe() failed %d\n", err);
+
+	return err;
+}
+
+static int cdns_ufs_pltfm_bind(struct udevice *dev)
+{
+	struct udevice *scsi_dev;
+
+	return ufs_scsi_bind(dev, &scsi_dev);
+}
+
+static const struct udevice_id cdns_ufs_pltfm_ids[] = {
+	{
+		.compatible = "cdns,ufshc-m31-16nm",
+	},
+	{},
+};
+
+U_BOOT_DRIVER(cdns_ufs_pltfm) = {
+	.name		= "cdns-ufs-pltfm",
+	.id		=  UCLASS_UFS,
+	.of_match	= cdns_ufs_pltfm_ids,
+	.probe		= cdns_ufs_pltfm_probe,
+	.bind		= cdns_ufs_pltfm_bind,
+};