ufs: add support for DesignWare Controller

This patch has the goal to add support for DesignWare UFS Controller
specific operations.

This is based on linux kernel commit:
"drivers/scsi/ufs/ufshcd-dwc.c: ufs: add support for DesignWare
Controller" (sha1: 4b9ffb5a353bdee49f1f477ffe2b95ab3f9cbc0c)
It is ported from linux kernel 6.11-rc1.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240920041651.18173-2-venkatesh.abbarapu@amd.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

drivers/ufs/ufshcd-dwc.c

@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * UFS Host driver for Synopsys Designware Core
+ *
+ * Copyright (C) 2015-2016 Synopsys, Inc. (www.synopsys.com)
+ *
+ */
+#include <clk.h>
+#include <dm.h>
+#include <ufs.h>
+#include <asm/io.h>
+#include <dm/device_compat.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/time.h>
+
+#include "ufs.h"
+#include "ufshci-dwc.h"
+#include "ufshcd-dwc.h"
+
+int ufshcd_dwc_dme_set_attrs(struct ufs_hba *hba,
+			     const struct ufshcd_dme_attr_val *v, int n)
+{
+	int ret = 0;
+	int attr_node = 0;
+
+	for (attr_node = 0; attr_node < n; attr_node++) {
+		ret = ufshcd_dme_set_attr(hba, v[attr_node].attr_sel,
+					  ATTR_SET_NOR, v[attr_node].mib_val, v[attr_node].peer);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * ufshcd_dwc_program_clk_div() - program clock divider.
+ * @hba: Private Structure pointer
+ * @divider_val: clock divider value to be programmed
+ *
+ */
+static void ufshcd_dwc_program_clk_div(struct ufs_hba *hba, u32 divider_val)
+{
+	ufshcd_writel(hba, divider_val, DWC_UFS_REG_HCLKDIV);
+}
+
+/**
+ * ufshcd_dwc_link_is_up() - check if link is up.
+ * @hba: private structure pointer
+ *
+ * Return: 0 on success, non-zero value on failure.
+ */
+static int ufshcd_dwc_link_is_up(struct ufs_hba *hba)
+{
+	int dme_result = 0;
+
+	ufshcd_dme_get(hba, UIC_ARG_MIB(VS_POWERSTATE), &dme_result);
+
+	if (dme_result == UFSHCD_LINK_IS_UP)
+		return 0;
+
+	return 1;
+}
+
+/**
+ * ufshcd_dwc_connection_setup() - configure unipro attributes.
+ * @hba: pointer to drivers private data
+ *
+ * This function configures both the local side (host) and the peer side
+ * (device) unipro attributes to establish the connection to application/
+ * cport.
+ * This function is not required if the hardware is properly configured to
+ * have this connection setup on reset. But invoking this function does no
+ * harm and should be fine even working with any ufs device.
+ *
+ * Return: 0 on success non-zero value on failure.
+ */
+static int ufshcd_dwc_connection_setup(struct ufs_hba *hba)
+{
+	static const struct ufshcd_dme_attr_val setup_attrs[] = {
+		{ UIC_ARG_MIB(T_CONNECTIONSTATE), 0, DME_LOCAL },
+		{ UIC_ARG_MIB(N_DEVICEID), 0, DME_LOCAL },
+		{ UIC_ARG_MIB(N_DEVICEID_VALID), 0, DME_LOCAL },
+		{ UIC_ARG_MIB(T_PEERDEVICEID), 1, DME_LOCAL },
+		{ UIC_ARG_MIB(T_PEERCPORTID), 0, DME_LOCAL },
+		{ UIC_ARG_MIB(T_TRAFFICCLASS), 0, DME_LOCAL },
+		{ UIC_ARG_MIB(T_CPORTFLAGS), 0x6, DME_LOCAL },
+		{ UIC_ARG_MIB(T_CPORTMODE), 1, DME_LOCAL },
+		{ UIC_ARG_MIB(T_CONNECTIONSTATE), 1, DME_LOCAL },
+		{ UIC_ARG_MIB(T_CONNECTIONSTATE), 0, DME_PEER },
+		{ UIC_ARG_MIB(N_DEVICEID), 1, DME_PEER },
+		{ UIC_ARG_MIB(N_DEVICEID_VALID), 1, DME_PEER },
+		{ UIC_ARG_MIB(T_PEERDEVICEID), 1, DME_PEER },
+		{ UIC_ARG_MIB(T_PEERCPORTID), 0, DME_PEER },
+		{ UIC_ARG_MIB(T_TRAFFICCLASS), 0, DME_PEER },
+		{ UIC_ARG_MIB(T_CPORTFLAGS), 0x6, DME_PEER },
+		{ UIC_ARG_MIB(T_CPORTMODE), 1, DME_PEER },
+		{ UIC_ARG_MIB(T_CONNECTIONSTATE), 1, DME_PEER }
+	};
+	return ufshcd_dwc_dme_set_attrs(hba, setup_attrs, ARRAY_SIZE(setup_attrs));
+}
+
+/**
+ * ufshcd_dwc_link_startup_notify() - program clock divider.
+ * @hba: private structure pointer
+ * @status: Callback notify status
+ *
+ * Return: 0 on success, non-zero value on failure.
+ */
+int ufshcd_dwc_link_startup_notify(struct ufs_hba *hba,
+				   enum ufs_notify_change_status status)
+{
+	int err = 0;
+
+	if (status == PRE_CHANGE) {
+		ufshcd_dwc_program_clk_div(hba, DWC_UFS_REG_HCLKDIV_DIV_125);
+	} else { /* POST_CHANGE */
+		err = ufshcd_dwc_link_is_up(hba);
+		if (err) {
+			dev_err(hba->dev, "Link is not up\n");
+			return err;
+		}
+
+		err = ufshcd_dwc_connection_setup(hba);
+		if (err)
+			dev_err(hba->dev, "Connection setup failed (%d)\n",
+				err);
+	}
+
+	return err;
+}

drivers/ufs/ufshcd-dwc.h

@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * UFS Host driver for Synopsys Designware Core
+ *
+ * Copyright (C) 2015-2016 Synopsys, Inc. (www.synopsys.com)
+ *
+ * Authors: Joao Pinto <jpinto@synopsys.com>
+ */
+
+#ifndef _UFSHCD_DWC_H
+#define _UFSHCD_DWC_H
+
+struct ufshcd_dme_attr_val {
+	u32 attr_sel;
+	u32 mib_val;
+	u8 peer;
+};
+
+int ufshcd_dwc_link_startup_notify(struct ufs_hba *hba,
+				   enum ufs_notify_change_status status);
+int ufshcd_dwc_dme_set_attrs(struct ufs_hba *hba,
+			     const struct ufshcd_dme_attr_val *v, int n);
+#endif /* End of Header */

drivers/ufs/ufshci-dwc.h

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * UFS Host driver for Synopsys Designware Core
+ *
+ * Copyright (C) 2015-2016 Synopsys, Inc. (www.synopsys.com)
+ *
+ * Authors: Joao Pinto <jpinto@synopsys.com>
+ */
+
+#ifndef _UFSHCI_DWC_H
+#define _UFSHCI_DWC_H
+
+/* DWC HC UFSHCI specific Registers */
+enum dwc_specific_registers {
+	DWC_UFS_REG_HCLKDIV	= 0xFC,
+};
+
+/* Clock Divider Values: Hex equivalent of frequency in MHz */
+enum clk_div_values {
+	DWC_UFS_REG_HCLKDIV_DIV_62_5	= 0x3e,
+	DWC_UFS_REG_HCLKDIV_DIV_125	= 0x7d,
+	DWC_UFS_REG_HCLKDIV_DIV_200	= 0xc8,
+};
+
+/* Selector Index */
+enum selector_index {
+	SELIND_LN0_TX	= 0x00,
+	SELIND_LN1_TX	= 0x01,
+	SELIND_LN0_RX	= 0x04,
+	SELIND_LN1_RX	= 0x05,
+};
+#endif