reset: Add Sunplus SP7021 reset driver

Add reset driver for Sunplus SP7021 SoC.

Signed-off-by: Qin Jian <qinjian@cqplus1.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/MAINTAINERS b/MAINTAINERS
index d24ef0b..db00f5e 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2832,6 +2832,7 @@ 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/sunplus,sp7021-reset.h
 
 ARM/Synaptics SoC support

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 93c8d07..48d9464 100644 (file)
--- 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 holds 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 a80a9c4..3ff378f 100644 (file)
--- 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 (file)
index 0000000..2f23eca
--- /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);