reset: reset-zynqmp: Adding support for Xilinx zynqmp reset controller.

Add a reset controller driver for Xilinx Zynq UltraScale+ MPSoC.
The zynqmp reset-controller has the ability to reset lines
connected to different blocks and peripheral in the Soc.

Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

2 files changed, 115 insertions, 0 deletions

diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index d08e8b90046a..380602d9c9b4 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -25,4 +25,5 @@ obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
 obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
 obj-$(CONFIG_RESET_UNIPHIER_USB3) += reset-uniphier-usb3.o
 obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o
+obj-$(CONFIG_ARCH_ZYNQMP) += reset-zynqmp.o
 
diff --git a/drivers/reset/reset-zynqmp.c b/drivers/reset/reset-zynqmp.c
new file mode 100644
index 000000000000..2ef1f13aa47b
--- /dev/null
+++ b/drivers/reset/reset-zynqmp.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Xilinx, Inc.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/firmware/xlnx-zynqmp.h>
+
+#define ZYNQMP_NR_RESETS (ZYNQMP_PM_RESET_END - ZYNQMP_PM_RESET_START)
+#define ZYNQMP_RESET_ID ZYNQMP_PM_RESET_START
+
+struct zynqmp_reset_data {
+        struct reset_controller_dev rcdev;
+        const struct zynqmp_eemi_ops *eemi_ops;
+};
+
+static inline struct zynqmp_reset_data *
+to_zynqmp_reset_data(struct reset_controller_dev *rcdev)
+{
+        return container_of(rcdev, struct zynqmp_reset_data, rcdev);
+}
+
+static int zynqmp_reset_assert(struct reset_controller_dev *rcdev,
+                               unsigned long id)
+{
+        struct zynqmp_reset_data *priv = to_zynqmp_reset_data(rcdev);
+
+        return priv->eemi_ops->reset_assert(ZYNQMP_RESET_ID + id,
+                                            PM_RESET_ACTION_ASSERT);
+}
+
+static int zynqmp_reset_deassert(struct reset_controller_dev *rcdev,
+                                 unsigned long id)
+{
+        struct zynqmp_reset_data *priv = to_zynqmp_reset_data(rcdev);
+
+        return priv->eemi_ops->reset_assert(ZYNQMP_RESET_ID + id,
+                                            PM_RESET_ACTION_RELEASE);
+}
+
+static int zynqmp_reset_status(struct reset_controller_dev *rcdev,
+                               unsigned long id)
+{
+        struct zynqmp_reset_data *priv = to_zynqmp_reset_data(rcdev);
+        int val, err;
+
+        err = priv->eemi_ops->reset_get_status(ZYNQMP_RESET_ID + id, &val);
+        if (err)
+                return err;
+
+        return val;
+}
+
+static int zynqmp_reset_reset(struct reset_controller_dev *rcdev,
+                              unsigned long id)
+{
+        struct zynqmp_reset_data *priv = to_zynqmp_reset_data(rcdev);
+
+        return priv->eemi_ops->reset_assert(ZYNQMP_RESET_ID + id,
+                                            PM_RESET_ACTION_PULSE);
+}
+
+static struct reset_control_ops zynqmp_reset_ops = {
+        .reset = zynqmp_reset_reset,
+        .assert = zynqmp_reset_assert,
+        .deassert = zynqmp_reset_deassert,
+        .status = zynqmp_reset_status,
+};
+
+static int zynqmp_reset_probe(struct platform_device *pdev)
+{
+        struct zynqmp_reset_data *priv;
+
+        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, priv);
+
+        priv->eemi_ops = zynqmp_pm_get_eemi_ops();
+        if (!priv->eemi_ops)
+                return -ENXIO;
+
+        priv->rcdev.ops = &zynqmp_reset_ops;
+        priv->rcdev.owner = THIS_MODULE;
+        priv->rcdev.of_node = pdev->dev.of_node;
+        priv->rcdev.nr_resets = ZYNQMP_NR_RESETS;
+
+        return devm_reset_controller_register(&pdev->dev, &priv->rcdev);
+}
+
+static const struct of_device_id zynqmp_reset_dt_ids[] = {
+        { .compatible = "xlnx,zynqmp-reset", },
+        { /* sentinel */ },
+};
+
+static struct platform_driver zynqmp_reset_driver = {
+        .probe  = zynqmp_reset_probe,
+        .driver = {
+                .name           = KBUILD_MODNAME,
+                .of_match_table = zynqmp_reset_dt_ids,
+        },
+};
+
+static int __init zynqmp_reset_init(void)
+{
+        return platform_driver_register(&zynqmp_reset_driver);
+}
+
+arch_initcall(zynqmp_reset_init);