[PATCH v13 3/9] reset: Add Sunplus SP7021 reset driver

Qin Jian
2022-04-11T06:57:41Z

Add reset driver for Sunplus SP7021 SoC.

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Qin Jian <qinjian@cqplus1.com>
---
Move HW mapping from dt-binding header to driver.
---
MAINTAINERS | 1 +
drivers/reset/Kconfig | 9 ++
drivers/reset/Makefile | 1 +
drivers/reset/reset-sunplus.c | 212 ++++++++++++++++++++++++++++++++++
4 files changed, 223 insertions(+)
create mode 100644 drivers/reset/reset-sunplus.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a8be86b25..26066f199 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2745,6 +2745,7 @@ S: Maintained
W: https://sunplus-tibbo.atlassian.net/wiki/spaces/doc/overview
F: Documentation/devicetree/bindings/arm/sunplus,sp7021.yaml
F: Documentation/devicetree/bindings/reset/sunplus,reset.yaml
+F: drivers/reset/reset-sunplus.c
F: include/dt-bindings/reset/sp-sp7021.h

ARM/Synaptics SoC support
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 6f8ba0ddc..36825787e 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -231,6 +231,15 @@ config RESET_STARFIVE_JH7100
help
This enables the reset controller driver for the StarFive JH7100 SoC.

+config RESET_SUNPLUS
+ bool "Sunplus SoCs Reset Driver" if COMPILE_TEST
+ default ARCH_SUNPLUS
+ help
+ This enables the reset driver support for Sunplus SoCs.
+ The reset lines that can be asserted and deasserted by toggling bits
+ in a contiguous, exclusive register space. The register is HIWORD_MASKED,
+ which means each register hold 16 reset lines.
+
config RESET_SUNXI
bool "Allwinner SoCs Reset Driver" if COMPILE_TEST && !ARCH_SUNXI
default ARCH_SUNXI
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index bd0a97be1..cadc46d3e 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_RESET_SCMI) += reset-scmi.o
obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o
obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
obj-$(CONFIG_RESET_STARFIVE_JH7100) += reset-starfive-jh7100.o
+obj-$(CONFIG_RESET_SUNPLUS) += reset-sunplus.o
obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
diff --git a/drivers/reset/reset-sunplus.c b/drivers/reset/reset-sunplus.c
new file mode 100644
index 000000000..2f23ecaa7
--- /dev/null
+++ b/drivers/reset/reset-sunplus.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/*
+ * SP7021 reset driver
+ *
+ * Copyright (C) Sunplus Technology Co., Ltd.
+ * All rights reserved.
+ */
+
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/reboot.h>
+
+/* HIWORD_MASK_REG BITS */
+#define BITS_PER_HWM_REG 16
+
+/* resets HW info: reg_index_shift */
+static const u32 sp_resets[] = {
+/* SP7021: mo_reset0 ~ mo_reset9 */
+ 0x00,
+ 0x02,
+ 0x03,
+ 0x04,
+ 0x05,
+ 0x06,
+ 0x07,
+ 0x08,
+ 0x09,
+ 0x0a,
+ 0x0b,
+ 0x0d,
+ 0x0e,
+ 0x0f,
+ 0x10,
+ 0x12,
+ 0x14,
+ 0x15,
+ 0x16,
+ 0x17,
+ 0x18,
+ 0x19,
+ 0x1a,
+ 0x1b,
+ 0x1c,
+ 0x1d,
+ 0x1e,
+ 0x1f,
+ 0x20,
+ 0x21,
+ 0x22,
+ 0x23,
+ 0x24,
+ 0x25,
+ 0x26,
+ 0x2a,
+ 0x2b,
+ 0x2d,
+ 0x2e,
+ 0x30,
+ 0x31,
+ 0x32,
+ 0x33,
+ 0x3d,
+ 0x3e,
+ 0x3f,
+ 0x42,
+ 0x44,
+ 0x4b,
+ 0x4c,
+ 0x4d,
+ 0x4e,
+ 0x4f,
+ 0x50,
+ 0x55,
+ 0x60,
+ 0x61,
+ 0x6a,
+ 0x6f,
+ 0x70,
+ 0x73,
+ 0x74,
+ 0x86,
+ 0x8a,
+ 0x8b,
+ 0x8d,
+ 0x8e,
+ 0x8f,
+ 0x90,
+ 0x92,
+ 0x93,
+ 0x94,
+ 0x95,
+ 0x96,
+ 0x97,
+ 0x98,
+ 0x99,
+};
+
+struct sp_reset {
+ struct reset_controller_dev rcdev;
+ struct notifier_block notifier;
+ void __iomem *base;
+};
+
+static inline struct sp_reset *to_sp_reset(struct reset_controller_dev *rcdev)
+{
+ return container_of(rcdev, struct sp_reset, rcdev);
+}
+
+static int sp_reset_update(struct reset_controller_dev *rcdev,
+ unsigned long id, bool assert)
+{
+ struct sp_reset *reset = to_sp_reset(rcdev);
+ int index = sp_resets[id] / BITS_PER_HWM_REG;
+ int shift = sp_resets[id] % BITS_PER_HWM_REG;
+ u32 val;
+
+ val = (1 << (16 + shift)) | (assert << shift);
+ writel(val, reset->base + (index * 4));
+
+ return 0;
+}
+
+static int sp_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return sp_reset_update(rcdev, id, true);
+}
+
+static int sp_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return sp_reset_update(rcdev, id, false);
+}
+
+static int sp_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct sp_reset *reset = to_sp_reset(rcdev);
+ int index = sp_resets[id] / BITS_PER_HWM_REG;
+ int shift = sp_resets[id] % BITS_PER_HWM_REG;
+ u32 reg;
+
+ reg = readl(reset->base + (index * 4));
+
+ return !!(reg & BIT(shift));
+}
+
+static const struct reset_control_ops sp_reset_ops = {
+ .assert = sp_reset_assert,
+ .deassert = sp_reset_deassert,
+ .status = sp_reset_status,
+};
+
+static int sp_restart(struct notifier_block *nb, unsigned long mode,
+ void *cmd)
+{
+ struct sp_reset *reset = container_of(nb, struct sp_reset, notifier);
+
+ sp_reset_assert(&reset->rcdev, 0);
+ sp_reset_deassert(&reset->rcdev, 0);
+
+ return NOTIFY_DONE;
+}
+
+static int sp_reset_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct sp_reset *reset;
+ struct resource *res;
+ int ret;
+
+ reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL);
+ if (!reset)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ reset->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(reset->base))
+ return PTR_ERR(reset->base);
+
+ reset->rcdev.ops = &sp_reset_ops;
+ reset->rcdev.owner = THIS_MODULE;
+ reset->rcdev.of_node = dev->of_node;
+ reset->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_HWM_REG;
+
+ ret = devm_reset_controller_register(dev, &reset->rcdev);
+ if (ret)
+ return ret;
+
+ reset->notifier.notifier_call = sp_restart;
+ reset->notifier.priority = 192;
+
+ return register_restart_handler(&reset->notifier);
+}
+
+static const struct of_device_id sp_reset_dt_ids[] = {
+ {.compatible = "sunplus,sp7021-reset",},
+ { /* sentinel */ },
+};
+
+static struct platform_driver sp_reset_driver = {
+ .probe = sp_reset_probe,
+ .driver = {
+ .name = "sunplus-reset",
+ .of_match_table = sp_reset_dt_ids,
+ .suppress_bind_attrs = true,
+ },
+};
+builtin_platform_driver(sp_reset_driver);
--
2.33.1