reset: zx2967: add reset controller driver for ZTE's zx2967 family

This patch adds reset controller driver for ZTE's zx2967 family.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Reviewed-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 172dc966a01fb087c87d014e8f6f7d7299c09aff..f4cdfe94b9ec0b4124b3f9680b23c283d546f867 100644 (file)
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -86,6 +86,12 @@ config RESET_UNIPHIER
          Say Y if you want to control reset signals provided by System Control
          block, Media I/O block, Peripheral Block.
 
+config RESET_ZX2967
+       bool "ZTE ZX2967 Reset Driver"
+       depends on ARCH_ZX || COMPILE_TEST
+       help
+         This enables the reset controller driver for ZTE's zx2967 family.
+
 config RESET_ZYNQ
        bool "ZYNQ Reset Driver" if COMPILE_TEST
        default ARCH_ZYNQ

diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 13b346e03d84b5b924100e96ad99f5f9f0c7a4b8..2cd3f6c45165a8f4a3a1e5c31c92e7f2fa69a8f8 100644 (file)
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -13,4 +13,5 @@ obj-$(CONFIG_RESET_STM32) += reset-stm32.o
 obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_TI_SYSCON_RESET) += reset-ti-syscon.o
 obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
+obj-$(CONFIG_RESET_ZX2967) += reset-zx2967.o
 obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o

diff --git a/drivers/reset/reset-zx2967.c b/drivers/reset/reset-zx2967.c
new file mode 100644 (file)
index 0000000..5d82151
--- /dev/null
+++ b/drivers/reset/reset-zx2967.c
@@ -0,0 +1,106 @@
+/*
+ * ZTE's zx2967 family reset controller driver
+ *
+ * Copyright (C) 2017 ZTE Ltd.
+ *
+ * Author: Baoyou Xie <baoyou.xie@linaro.org>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+
+struct zx2967_reset {
+       void __iomem                    *reg_base;
+       spinlock_t                      lock;
+       struct reset_controller_dev     rcdev;
+};
+
+static int zx2967_reset_act(struct reset_controller_dev *rcdev,
+                           unsigned long id, bool assert)
+{
+       struct zx2967_reset *reset = NULL;
+       int bank = id / 32;
+       int offset = id % 32;
+       u32 reg;
+       unsigned long flags;
+
+       reset = container_of(rcdev, struct zx2967_reset, rcdev);
+
+       spin_lock_irqsave(&reset->lock, flags);
+
+       reg = readl_relaxed(reset->reg_base + (bank * 4));
+       if (assert)
+               reg &= ~BIT(offset);
+       else
+               reg |= BIT(offset);
+       writel_relaxed(reg, reset->reg_base + (bank * 4));
+
+       spin_unlock_irqrestore(&reset->lock, flags);
+
+       return 0;
+}
+
+static int zx2967_reset_assert(struct reset_controller_dev *rcdev,
+                              unsigned long id)
+{
+       return zx2967_reset_act(rcdev, id, true);
+}
+
+static int zx2967_reset_deassert(struct reset_controller_dev *rcdev,
+                                unsigned long id)
+{
+       return zx2967_reset_act(rcdev, id, false);
+}
+
+static struct reset_control_ops zx2967_reset_ops = {
+       .assert         = zx2967_reset_assert,
+       .deassert       = zx2967_reset_deassert,
+};
+
+static int zx2967_reset_probe(struct platform_device *pdev)
+{
+       struct zx2967_reset *reset;
+       struct resource *res;
+
+       reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL);
+       if (!reset)
+               return -ENOMEM;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       reset->reg_base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(reset->reg_base))
+               return PTR_ERR(reset->reg_base);
+
+       spin_lock_init(&reset->lock);
+
+       reset->rcdev.owner = THIS_MODULE;
+       reset->rcdev.nr_resets = resource_size(res) * 8;
+       reset->rcdev.ops = &zx2967_reset_ops;
+       reset->rcdev.of_node = pdev->dev.of_node;
+
+       return devm_reset_controller_register(&pdev->dev, &reset->rcdev);
+}
+
+static const struct of_device_id zx2967_reset_dt_ids[] = {
+        { .compatible = "zte,zx296718-reset", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, zx2967_reset_dt_ids);
+
+static struct platform_driver zx2967_reset_driver = {
+       .probe  = zx2967_reset_probe,
+       .driver = {
+               .name           = "zx2967-reset",
+               .of_match_table = zx2967_reset_dt_ids,
+       },
+};
+
+builtin_platform_driver(zx2967_reset_driver);
+
+MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>");
+MODULE_DESCRIPTION("ZTE zx2967 Reset Controller Driver");
+MODULE_LICENSE("GPL");