[PATCH v8 4/6] reset: Add Delta TN48M CPLD reset controller

From: Robert Marko
Date: Fri Nov 05 2021 - 07:39:21 EST


Delta TN48M CPLD exposes resets for the following:
* 88F7040 SoC
* 88F6820 SoC
* 98DX3265 switch MAC-s
* 88E1680 PHY-s
* 88E1512 PHY
* PoE PSE controller

Controller supports only self clearing resets.

Signed-off-by: Robert Marko <robert.marko@xxxxxxxxxx>
Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
---
Changes in v8:
* Drop of.h and include mod_devicetable.h per Andys comment
* Mark the units used in timeout and sleep defines for the timeout poller

Changes in v5:
* Allow COMPILE_TEST as well
* Default to MFD_TN48M_CPLD

Changes in v4:
* Drop assert and deassert as only self-clearing
resets are support by the HW
* Make sure that reset is cleared before returning
from reset.
---
drivers/reset/Kconfig | 10 +++
drivers/reset/Makefile | 1 +
drivers/reset/reset-tn48m.c | 128 ++++++++++++++++++++++++++++++++++++
3 files changed, 139 insertions(+)
create mode 100644 drivers/reset/reset-tn48m.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 5656cac04b4c..e76aba5f4c84 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -243,6 +243,16 @@ config RESET_TI_SYSCON
you wish to use the reset framework for such memory-mapped devices,
say Y here. Otherwise, say N.

+config RESET_TN48M_CPLD
+ tristate "Delta Networks TN48M switch CPLD reset controller"
+ depends on MFD_TN48M_CPLD || COMPILE_TEST
+ default MFD_TN48M_CPLD
+ help
+ This enables the reset controller driver for the Delta TN48M CPLD.
+ It provides reset signals for Armada 7040 and 385 SoC-s, Alleycat 3X
+ switch MAC-s, Alaska OOB ethernet PHY, Quad Alaska ethernet PHY-s and
+ Microchip PD69200 PoE PSE controller.
+
config RESET_UNIPHIER
tristate "Reset controller driver for UniPhier SoCs"
depends on ARCH_UNIPHIER || COMPILE_TEST
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index ea8b8d9ca565..79beab92324f 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
+obj-$(CONFIG_RESET_TN48M_CPLD) += reset-tn48m.o
obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
obj-$(CONFIG_RESET_UNIPHIER_GLUE) += reset-uniphier-glue.o
obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o
diff --git a/drivers/reset/reset-tn48m.c b/drivers/reset/reset-tn48m.c
new file mode 100644
index 000000000000..6889e9173577
--- /dev/null
+++ b/drivers/reset/reset-tn48m.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Delta TN48M CPLD reset driver
+ *
+ * Copyright (C) 2021 Sartura Ltd.
+ *
+ * Author: Robert Marko <robert.marko@xxxxxxxxxx>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+
+#include <dt-bindings/reset/delta,tn48m-reset.h>
+
+#define TN48M_RESET_REG 0x10
+
+#define TN48M_RESET_TIMEOUT_US 125000
+#define TN48M_RESET_SLEEP_US 10
+
+struct tn48_reset_map {
+ u8 bit;
+};
+
+struct tn48_reset_data {
+ struct reset_controller_dev rcdev;
+ struct regmap *regmap;
+};
+
+static const struct tn48_reset_map tn48m_resets[] = {
+ [CPU_88F7040_RESET] = {0},
+ [CPU_88F6820_RESET] = {1},
+ [MAC_98DX3265_RESET] = {2},
+ [PHY_88E1680_RESET] = {4},
+ [PHY_88E1512_RESET] = {6},
+ [POE_RESET] = {7},
+};
+
+static inline struct tn48_reset_data *to_tn48_reset_data(
+ struct reset_controller_dev *rcdev)
+{
+ return container_of(rcdev, struct tn48_reset_data, rcdev);
+}
+
+static int tn48m_control_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct tn48_reset_data *data = to_tn48_reset_data(rcdev);
+ unsigned int val;
+
+ regmap_update_bits(data->regmap, TN48M_RESET_REG,
+ BIT(tn48m_resets[id].bit), 0);
+
+ return regmap_read_poll_timeout(data->regmap,
+ TN48M_RESET_REG,
+ val,
+ val & BIT(tn48m_resets[id].bit),
+ TN48M_RESET_SLEEP_US,
+ TN48M_RESET_TIMEOUT_US);
+}
+
+static int tn48m_control_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct tn48_reset_data *data = to_tn48_reset_data(rcdev);
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(data->regmap, TN48M_RESET_REG, &regval);
+ if (ret < 0)
+ return ret;
+
+ if (BIT(tn48m_resets[id].bit) & regval)
+ return 0;
+ else
+ return 1;
+}
+
+static const struct reset_control_ops tn48_reset_ops = {
+ .reset = tn48m_control_reset,
+ .status = tn48m_control_status,
+};
+
+static int tn48m_reset_probe(struct platform_device *pdev)
+{
+ struct tn48_reset_data *data;
+ struct regmap *regmap;
+
+ regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!regmap)
+ return -ENODEV;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->regmap = regmap;
+
+ data->rcdev.owner = THIS_MODULE;
+ data->rcdev.ops = &tn48_reset_ops;
+ data->rcdev.nr_resets = ARRAY_SIZE(tn48m_resets);
+ data->rcdev.of_node = pdev->dev.of_node;
+
+ return devm_reset_controller_register(&pdev->dev, &data->rcdev);
+}
+
+static const struct of_device_id tn48m_reset_of_match[] = {
+ { .compatible = "delta,tn48m-reset", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, tn48m_reset_of_match);
+
+static struct platform_driver tn48m_reset_driver = {
+ .driver = {
+ .name = "delta-tn48m-reset",
+ .of_match_table = tn48m_reset_of_match,
+ },
+ .probe = tn48m_reset_probe,
+};
+module_platform_driver(tn48m_reset_driver);
+
+MODULE_AUTHOR("Robert Marko <robert.marko@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Delta TN48M CPLD reset driver");
+MODULE_LICENSE("GPL");
--
2.33.1