[PATCH v2] ARC: reset: introduce HSDKv1 reset driver
Eugeniy Paltsev
Eugeniy.Paltsev at synopsys.com
Wed Jul 19 11:45:11 PDT 2017
The HSDK v1 periphery IPs can be reset by accessing some registers
from the CGU block.
The list of available reset lines is documented in the DT bindings.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com>
---
Changes v1 -> v2:
- Remove defines of the unused registers.
- Map io memory only for single CGU_SYS_RST_CTRL register instead
of CGU_SYS_*_CTRL, as we use only CGU_SYS_RST_CTRL.
.../bindings/reset/snps,hsdk-v1-reset.txt | 28 +++++
MAINTAINERS | 7 ++
drivers/reset/Kconfig | 6 +
drivers/reset/Makefile | 1 +
drivers/reset/reset-hsdk-v1.c | 137 +++++++++++++++++++++
include/dt-bindings/reset/snps,hsdk-v1-reset.h | 17 +++
6 files changed, 196 insertions(+)
create mode 100644 Documentation/devicetree/bindings/reset/snps,hsdk-v1-reset.txt
create mode 100644 drivers/reset/reset-hsdk-v1.c
create mode 100644 include/dt-bindings/reset/snps,hsdk-v1-reset.h
diff --git a/Documentation/devicetree/bindings/reset/snps,hsdk-v1-reset.txt b/Documentation/devicetree/bindings/reset/snps,hsdk-v1-reset.txt
new file mode 100644
index 0000000..6a68146
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/snps,hsdk-v1-reset.txt
@@ -0,0 +1,28 @@
+Binding for the HSDK v1 reset controller
+
+This binding uses the common reset binding[1].
+
+[1] Documentation/devicetree/bindings/reset/reset.txt
+
+Required properties:
+- compatible: should be "snps,hsdk-v1.0-reset".
+- reg: should always contain 2 pairs address - length: first for reset
+ configuration register and second for corresponding SW reset and status bits
+ register.
+- #reset-cells: from common reset binding; Should always be set to 1.
+
+Example:
+ reset: reset at 880 {
+ compatible = "snps,hsdk-v1.0-reset";
+ #reset-cells = <1>;
+ reg = <0x8A0 0x4>, <0xFF0 0x4>;
+ };
+
+Specifying reset lines connected to IP modules:
+ ethernet at .... {
+ ....
+ resets = <&reset HSDK_V1_ETH_RESET>;
+ ....
+ };
+
+The index could be found in <dt-bindings/reset/snps,hsdk-v1-reset.h>
diff --git a/MAINTAINERS b/MAINTAINERS
index 09b5ab6..99deabb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11307,6 +11307,13 @@ L: linux-mmc at vger.kernel.org
S: Maintained
F: drivers/mmc/host/dw_mmc*
+SYNOPSYS HSDK RESET CONTROLLER DRIVER
+M: Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com>
+S: Supported
+F: drivers/reset/reset-hsdk-v1.c
+F: include/dt-bindings/reset/snps,hsdk-v1-reset.h
+F: Documentation/devicetree/bindings/reset/snps,hsdk-v1-reset.txt
+
SYSTEM TRACE MODULE CLASS
M: Alexander Shishkin <alexander.shishkin at linux.intel.com>
S: Maintained
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index d21c07c..cb13f0d 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -34,6 +34,12 @@ config RESET_BERLIN
help
This enables the reset controller driver for Marvell Berlin SoCs.
+config RESET_HSDK_V1
+ bool "HSDK v1 Reset Driver"
+ default n
+ help
+ This enables the reset controller driver for HSDK v1.
+
config RESET_IMX7
bool "i.MX7 Reset Driver" if COMPILE_TEST
default SOC_IMX7D
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 02a74db..772e5f2 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_ARCH_TEGRA) += tegra/
obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o
obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
+obj-$(CONFIG_RESET_HSDK_V1) += reset-hsdk-v1.o
obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
obj-$(CONFIG_RESET_MESON) += reset-meson.o
diff --git a/drivers/reset/reset-hsdk-v1.c b/drivers/reset/reset-hsdk-v1.c
new file mode 100644
index 0000000..bca13e4
--- /dev/null
+++ b/drivers/reset/reset-hsdk-v1.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2017 Synopsys.
+ *
+ * Synopsys HSDKv1 SDP reset driver.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define to_hsdkv1_rst(p) container_of((p), struct hsdkv1_rst, rcdev)
+
+struct hsdkv1_rst {
+ void __iomem *regs_ctl;
+ void __iomem *regs_rst;
+ spinlock_t lock;
+ struct reset_controller_dev rcdev;
+};
+
+static const u32 rst_map[] = {
+ BIT(16), /* APB_RST */
+ BIT(17), /* AXI_RST */
+ BIT(18), /* ETH_RST */
+ BIT(19), /* USB_RST */
+ BIT(20), /* SDIO_RST */
+ BIT(21), /* HDMI_RST */
+ BIT(22), /* GFX_RST */
+ BIT(25), /* DMAC_RST */
+ BIT(31), /* EBI_RST */
+};
+
+#define HSDK_MAX_RESETS ARRAY_SIZE(rst_map)
+
+#define CGU_SYS_RST_CTRL 0x0
+#define CGU_IP_SW_RESET 0x0
+#define CGU_IP_SW_RESET_DELAY_SHIFT 16
+#define CGU_IP_SW_RESET_DELAY_MASK GENMASK(31, CGU_IP_SW_RESET_DELAY_SHIFT)
+#define CGU_IP_SW_RESET_DELAY 0
+#define CGU_IP_SW_RESET_RESET BIT(0)
+#define SW_RESET_TIMEOUT 10000
+
+static void hsdkv1_reset_config(struct hsdkv1_rst *rst, unsigned long id)
+{
+ writel(rst_map[id], rst->regs_ctl + CGU_SYS_RST_CTRL);
+}
+
+static int hsdkv1_reset_do(struct hsdkv1_rst *rst)
+{
+ u32 reg;
+
+ reg = readl(rst->regs_rst + CGU_IP_SW_RESET);
+ reg &= ~CGU_IP_SW_RESET_DELAY_MASK;
+ reg |= CGU_IP_SW_RESET_DELAY << CGU_IP_SW_RESET_DELAY_SHIFT;
+ reg |= CGU_IP_SW_RESET_RESET;
+ writel(reg, rst->regs_rst + CGU_IP_SW_RESET);
+
+ /* wait till reset bit is back to 0 */
+ return readl_poll_timeout_atomic(rst->regs_rst + CGU_IP_SW_RESET, reg,
+ !(reg & CGU_IP_SW_RESET_RESET), 5, SW_RESET_TIMEOUT);
+}
+
+static int hsdkv1_reset_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct hsdkv1_rst *rst = to_hsdkv1_rst(rcdev);
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&rst->lock, flags);
+ hsdkv1_reset_config(rst, id);
+ ret = hsdkv1_reset_do(rst);
+ spin_unlock_irqrestore(&rst->lock, flags);
+
+ return ret;
+}
+
+static const struct reset_control_ops hsdkv1_reset_ops = {
+ .reset = hsdkv1_reset_reset,
+};
+
+static int hsdkv1_reset_probe(struct platform_device *pdev)
+{
+ struct hsdkv1_rst *rst;
+ struct resource *mem;
+
+ rst = devm_kzalloc(&pdev->dev, sizeof(*rst), GFP_KERNEL);
+ if (!rst)
+ return -ENOMEM;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ rst->regs_ctl = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(rst->regs_ctl))
+ return PTR_ERR(rst->regs_ctl);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ rst->regs_rst = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(rst->regs_rst))
+ return PTR_ERR(rst->regs_rst);
+
+ spin_lock_init(&rst->lock);
+
+ rst->rcdev.owner = THIS_MODULE;
+ rst->rcdev.ops = &hsdkv1_reset_ops;
+ rst->rcdev.of_node = pdev->dev.of_node;
+ rst->rcdev.nr_resets = HSDK_MAX_RESETS;
+ rst->rcdev.of_reset_n_cells = 1;
+
+ return reset_controller_register(&rst->rcdev);
+}
+
+static const struct of_device_id hsdkv1_reset_dt_match[] = {
+ { .compatible = "snps,hsdk-v1.0-reset" },
+ { },
+};
+
+static struct platform_driver hsdkv1_reset_driver = {
+ .probe = hsdkv1_reset_probe,
+ .driver = {
+ .name = "hsdk-v1.0-reset",
+ .of_match_table = hsdkv1_reset_dt_match,
+ },
+};
+builtin_platform_driver(hsdkv1_reset_driver);
+
+MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev at synopsys.com>");
+MODULE_DESCRIPTION("Synopsys HSDKv1 SDP reset driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/dt-bindings/reset/snps,hsdk-v1-reset.h b/include/dt-bindings/reset/snps,hsdk-v1-reset.h
new file mode 100644
index 0000000..d898c89
--- /dev/null
+++ b/include/dt-bindings/reset/snps,hsdk-v1-reset.h
@@ -0,0 +1,17 @@
+/**
+ * This header provides index for the HSDK v1 reset controller.
+ */
+#ifndef _DT_BINDINGS_RESET_CONTROLLER_HSDK_V1
+#define _DT_BINDINGS_RESET_CONTROLLER_HSDK_V1
+
+#define HSDK_V1_APB_RESET 0
+#define HSDK_V1_AXI_RESET 1
+#define HSDK_V1_ETH_RESET 2
+#define HSDK_V1_USB_RESET 3
+#define HSDK_V1_SDIO_RESET 4
+#define HSDK_V1_HDMI_RESET 5
+#define HSDK_V1_GFX_RESET 6
+#define HSDK_V1_DMAC_RESET 7
+#define HSDK_V1_EBI_RESET 8
+
+#endif /*_DT_BINDINGS_RESET_CONTROLLER_HSDK_V1*/
--
2.9.3
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