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Subject[PATCH v3 2/2] scsi: ufs: Add UFS platform driver for Cadence UFS
Date
This patch adds a device tree platform driver for
Cadence UFS Host Controller.
It can be enabled with SCSI_UFS_CDNS_PLATFORM Kconfig option.

Signed-off-by: Jan Kotas <jank@cadence.com>
---
drivers/scsi/ufs/Kconfig | 8 +++
drivers/scsi/ufs/Makefile | 1 +
drivers/scsi/ufs/cdns-pltfrm.c | 147 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 156 insertions(+)
create mode 100644 drivers/scsi/ufs/cdns-pltfrm.c

diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index e27b4d4e..44cb90a0 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -80,6 +80,14 @@ config SCSI_UFSHCD_PLATFORM

If unsure, say N.

+config SCSI_UFS_CDNS_PLATFORM
+ tristate "Cadence UFS Controller platform driver"
+ depends on SCSI_UFSHCD_PLATFORM
+ help
+ This selects the Cadence specific additions to UFSHCD platform driver.
+
+ If unsure, say N.
+
config SCSI_UFS_DWC_TC_PLATFORM
tristate "DesignWare platform support using a G210 Test Chip"
depends on SCSI_UFSHCD_PLATFORM
diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index 918f5791..dcddc7a4 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -2,6 +2,7 @@
# UFSHCD makefile
obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o tc-dwc-g210.o
obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-dwc-g210.o
+obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
ufshcd-core-objs := ufshcd.o ufs-sysfs.o
diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
new file mode 100644
index 00000000..5d9e4875
--- /dev/null
+++ b/drivers/scsi/ufs/cdns-pltfrm.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Platform UFS Host driver for Cadence controller
+ *
+ * Copyright (C) 2018 Cadence Design Systems, Inc.
+ *
+ * Authors:
+ * Jan Kotas <jank@cadence.com>
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/time.h>
+
+#include "ufshcd-pltfrm.h"
+
+#define CDNS_UFS_REG_HCLKDIV 0xFC
+
+/**
+ * Sets HCLKDIV register value based on the core_clk
+ * @hba: host controller instance
+ *
+ * Return zero for success and non-zero for failure
+ */
+static int cdns_ufs_set_hclkdiv(struct ufs_hba *hba)
+{
+ struct ufs_clk_info *clki;
+ struct list_head *head = &hba->clk_list_head;
+ unsigned long core_clk_rate = 0;
+ u32 core_clk_div = 0;
+
+ if (list_empty(head))
+ return 0;
+
+ list_for_each_entry(clki, head, list) {
+ if (IS_ERR_OR_NULL(clki->clk))
+ continue;
+ if (!strcmp(clki->name, "core_clk"))
+ core_clk_rate = clk_get_rate(clki->clk);
+ }
+
+ if (!core_clk_rate) {
+ dev_err(hba->dev, "%s: unable to find core_clk rate\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ core_clk_div = core_clk_rate / USEC_PER_SEC;
+
+ ufshcd_writel(hba, core_clk_div, CDNS_UFS_REG_HCLKDIV);
+ /* Make sure the register was updated */
+ mb();
+
+ return 0;
+}
+
+/**
+ * Sets clocks used by the controller
+ * @hba: host controller instance
+ * @on: if true, enable clocks, otherwise disable
+ * @status: notify stage (pre, post change)
+ *
+ * Return zero for success and non-zero for failure
+ */
+static int cdns_ufs_setup_clocks(struct ufs_hba *hba, bool on,
+ enum ufs_notify_change_status status)
+{
+ if ((!on) || (status == PRE_CHANGE))
+ return 0;
+
+ return cdns_ufs_set_hclkdiv(hba);
+}
+
+static struct ufs_hba_variant_ops cdns_pltfm_hba_vops = {
+ .name = "cdns-ufs-pltfm",
+ .setup_clocks = cdns_ufs_setup_clocks,
+};
+
+/**
+ * cdns_ufs_pltfrm_probe - probe routine of the driver
+ * @pdev: pointer to platform device handle
+ *
+ * Return zero for success and non-zero for failure
+ */
+static int cdns_ufs_pltfrm_probe(struct platform_device *pdev)
+{
+ int err;
+ struct device *dev = &pdev->dev;
+
+ /* Perform generic probe */
+ err = ufshcd_pltfrm_init(pdev, &cdns_pltfm_hba_vops);
+ if (err)
+ dev_err(dev, "ufshcd_pltfrm_init() failed %d\n", err);
+
+ return err;
+}
+
+/**
+ * cdns_ufs_pltfrm_remove - set driver_data of the device to NULL
+ * @pdev: pointer to platform device handle
+ *
+ * Always returns 0
+ */
+static int cdns_ufs_pltfrm_remove(struct platform_device *pdev)
+{
+ struct ufs_hba *hba = platform_get_drvdata(pdev);
+
+ pm_runtime_get_sync(&(pdev)->dev);
+ ufshcd_remove(hba);
+ return 0;
+}
+
+static const struct of_device_id cdns_ufs_of_match[] = {
+ { .compatible = "cdns,ufshc" },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, cdns_ufs_of_match);
+
+static const struct dev_pm_ops cdns_ufs_dev_pm_ops = {
+ .suspend = ufshcd_pltfrm_suspend,
+ .resume = ufshcd_pltfrm_resume,
+ .runtime_suspend = ufshcd_pltfrm_runtime_suspend,
+ .runtime_resume = ufshcd_pltfrm_runtime_resume,
+ .runtime_idle = ufshcd_pltfrm_runtime_idle,
+};
+
+static struct platform_driver cdns_ufs_pltfrm_driver = {
+ .probe = cdns_ufs_pltfrm_probe,
+ .remove = cdns_ufs_pltfrm_remove,
+ .driver = {
+ .name = "cdns-ufshcd",
+ .owner = THIS_MODULE,
+ .pm = &cdns_ufs_dev_pm_ops,
+ .of_match_table = cdns_ufs_of_match,
+ },
+};
+
+module_platform_driver(cdns_ufs_pltfrm_driver);
+
+MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
+MODULE_DESCRIPTION("Cadence UFS host controller platform driver");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(UFSHCD_DRIVER_VERSION);
--
2.15.0

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