[RFC PATCH v2 3/3] reset: reset-zynqmp: Adding support for Xilinx zynqmp reset controller.

From: Nava kishore Manne
Date: Wed Sep 05 2018 - 02:41:21 EST


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@xxxxxxxxxx>
---
Changes for v2:
-Moved eemi_ops into a priv struct as suggested
by philipp.

drivers/reset/Makefile | 1 +
drivers/reset/reset-zynqmp.c | 115 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 116 insertions(+)
create mode 100644 drivers/reset/reset-zynqmp.c

diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index c1261dc..27e4a33 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -21,4 +21,5 @@ obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
obj-$(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 0000000..f908492
--- /dev/null
+++ b/drivers/reset/reset-zynqmp.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Xilinx, Inc.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/module.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 - 2)
+#define ZYNQMP_RESET_ID (ZYNQMP_PM_RESET_START + 1)
+
+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 -EINVAL;
+
+ 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", },
+ { },
+};
+
+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);
--
2.7.4