[PATCH 08/13] reset: Add a reset controller driver for the Lantiq XWAY based SoCs
Hauke Mehrtens
hauke at hauke-m.de
Mon Apr 17 12:29:37 PDT 2017
From: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
The reset controllers (on xRX200 and newer SoCs have two of them) are
provided by the RCU module. This was initially implemented as a simple
reset controller. However, the RCU module provides more functionality
(ethernet GPHYs, USB PHY, etc.), which makes it a MFD device.
The old reset controller driver implementation from
arch/mips/lantiq/xway/reset.c did not honor this fact.
For some devices the request and the status bits are different.
Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
.../devicetree/bindings/reset/lantiq,rcu-reset.txt | 43 ++++
arch/mips/lantiq/xway/reset.c | 68 ------
drivers/reset/Kconfig | 6 +
drivers/reset/Makefile | 1 +
drivers/reset/reset-lantiq-rcu.c | 231 +++++++++++++++++++++
5 files changed, 281 insertions(+), 68 deletions(-)
create mode 100644 Documentation/devicetree/bindings/reset/lantiq,rcu-reset.txt
create mode 100644 drivers/reset/reset-lantiq-rcu.c
diff --git a/Documentation/devicetree/bindings/reset/lantiq,rcu-reset.txt b/Documentation/devicetree/bindings/reset/lantiq,rcu-reset.txt
new file mode 100644
index 000000000000..7f097d16bbb7
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/lantiq,rcu-reset.txt
@@ -0,0 +1,43 @@
+Lantiq XWAY SoC RCU reset controller binding
+============================================
+
+This binding describes a reset-controller found on the RCU module on Lantiq
+XWAY SoCs.
+
+
+-------------------------------------------------------------------------------
+Required properties (controller (parent) node):
+- compatible : Should be "lantiq,rcu-reset"
+- lantiq,rcu-syscon : A phandle to the RCU syscon, the reset register
+ offset and the status register offset.
+- #reset-cells : Specifies the number of cells needed to encode the
+ reset line, should be 1.
+
+Optional properties:
+- reset-status : The request status bit. For some bits the request bit
+ and the status bit are different. This is depending
+ on the SoC. If the reset-status bit does not match
+ the reset-request bit, put the reset number into the
+ reset-request property and the status bit at the same
+ index into the reset-status property. If no
+ reset-request bit is given here, the driver assume
+ status and request bit are the same.
+- reset-request : The reset request bit, to map it to the reset-status
+ bit.
+
+
+-------------------------------------------------------------------------------
+Example for the reset-controllers on the xRX200 SoCs:
+ rcu_reset0: rcu_reset {
+ compatible = "lantiq,rcu-reset";
+ lantiq,rcu-syscon = <&rcu0 0x10 0x14>;
+ #reset-cells = <1>;
+ reset-request = <31>, <29>, <21>, <19>, <16>, <12>;
+ reset-status = <30>, <28>, <16>, <25>, <5>, <24>;
+ };
+
+ rcu_reset1: rcu_reset {
+ compatible = "lantiq,rcu-reset";
+ lantiq,rcu-syscon = <&rcu0 0x48 0x24>;
+ #reset-cells = <1>;
+ };
diff --git a/arch/mips/lantiq/xway/reset.c b/arch/mips/lantiq/xway/reset.c
index 2dedcf939901..5cb9309b0047 100644
--- a/arch/mips/lantiq/xway/reset.c
+++ b/arch/mips/lantiq/xway/reset.c
@@ -194,74 +194,6 @@ int xrx200_gphy_boot(struct device *dev, unsigned int id, dma_addr_t dev_addr)
return 0;
}
-/* reset a io domain for u micro seconds */
-void ltq_reset_once(unsigned int module, ulong u)
-{
- ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) | module, RCU_RST_REQ);
- udelay(u);
- ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) & ~module, RCU_RST_REQ);
-}
-
-static int ltq_assert_device(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- u32 val;
-
- if (id < 8)
- return -1;
-
- val = ltq_rcu_r32(RCU_RST_REQ);
- val |= BIT(id);
- ltq_rcu_w32(val, RCU_RST_REQ);
-
- return 0;
-}
-
-static int ltq_deassert_device(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- u32 val;
-
- if (id < 8)
- return -1;
-
- val = ltq_rcu_r32(RCU_RST_REQ);
- val &= ~BIT(id);
- ltq_rcu_w32(val, RCU_RST_REQ);
-
- return 0;
-}
-
-static int ltq_reset_device(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- ltq_assert_device(rcdev, id);
- return ltq_deassert_device(rcdev, id);
-}
-
-static const struct reset_control_ops reset_ops = {
- .reset = ltq_reset_device,
- .assert = ltq_assert_device,
- .deassert = ltq_deassert_device,
-};
-
-static struct reset_controller_dev reset_dev = {
- .ops = &reset_ops,
- .owner = THIS_MODULE,
- .nr_resets = 32,
- .of_reset_n_cells = 1,
-};
-
-void ltq_rst_init(void)
-{
- reset_dev.of_node = of_find_compatible_node(NULL, NULL,
- "lantiq,xway-reset");
- if (!reset_dev.of_node)
- pr_err("Failed to find reset controller node");
- else
- reset_controller_register(&reset_dev);
-}
-
static void ltq_machine_restart(char *command)
{
u32 val = ltq_rcu_r32(RCU_RST_REQ);
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index f4cdfe94b9ec..8962ba44248c 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -27,6 +27,12 @@ config RESET_BERLIN
help
This enables the reset controller driver for Marvell Berlin SoCs.
+config RESET_LANTIQ_RCU
+ bool "Lantiq XWAY Reset Driver" if COMPILE_TEST
+ default SOC_TYPE_XWAY
+ help
+ This enables the reset controller driver for Lantiq / Intel XWAY SoCs.
+
config RESET_LPC18XX
bool "LPC18xx/43xx Reset Driver" if COMPILE_TEST
default ARCH_LPC18XX
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 2cd3f6c45165..97b0a844b849 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_ARCH_STI) += sti/
obj-$(CONFIG_ARCH_TEGRA) += tegra/
obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
+obj-$(CONFIG_RESET_LANTIQ_RCU) += reset-lantiq-rcu.o
obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
obj-$(CONFIG_RESET_MESON) += reset-meson.o
obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
diff --git a/drivers/reset/reset-lantiq-rcu.c b/drivers/reset/reset-lantiq-rcu.c
new file mode 100644
index 000000000000..6178112ca5b4
--- /dev/null
+++ b/drivers/reset/reset-lantiq-rcu.c
@@ -0,0 +1,231 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * Copyright (C) 2010 John Crispin <blogic at openwrt.org>
+ * Copyright (C) 2013-2015 Lantiq Beteiligungs-GmbH & Co.KG
+ * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl at googlemail.com>
+ * Copyright (C) 2017 Hauke Mehrtens <hauke at hauke-m.de>
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+#include <linux/of_platform.h>
+
+#define LANTIQ_RCU_RESET_TIMEOUT 1000000
+
+struct lantiq_rcu_reset_translation {
+ int request;
+ int status;
+};
+
+struct lantiq_rcu_reset_priv {
+ struct reset_controller_dev rcdev;
+ struct device *dev;
+ struct regmap *regmap;
+ u32 reset_offset;
+ u32 status_offset;
+ int trans_number;
+ struct lantiq_rcu_reset_translation *trans;
+};
+
+static struct lantiq_rcu_reset_priv *to_lantiq_rcu_reset_priv(
+ struct reset_controller_dev *rcdev)
+{
+ return container_of(rcdev, struct lantiq_rcu_reset_priv, rcdev);
+}
+
+static int lantiq_rcu_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct lantiq_rcu_reset_priv *priv = to_lantiq_rcu_reset_priv(rcdev);
+ u32 val;
+ int ret, i;
+
+ if (id >= rcdev->nr_resets)
+ return -EINVAL;
+
+ for (i = 0; i < priv->trans_number; i++) {
+ if (id == priv->trans[i].request) {
+ id = priv->trans[i].status;
+ break;
+ }
+ }
+
+ ret = regmap_read(priv->regmap, priv->status_offset, &val);
+ if (ret)
+ return ret;
+
+ return !!(val & BIT(id));
+}
+
+static int lantiq_rcu_reset_update(struct reset_controller_dev *rcdev,
+ unsigned long id, bool assert)
+{
+ struct lantiq_rcu_reset_priv *priv = to_lantiq_rcu_reset_priv(rcdev);
+ u32 val;
+ int ret, retry = LANTIQ_RCU_RESET_TIMEOUT;
+
+ if (id >= rcdev->nr_resets)
+ return -EINVAL;
+
+ if (assert)
+ val = BIT(id);
+ else
+ val = 0;
+
+ ret = regmap_update_bits(priv->regmap, priv->reset_offset, BIT(id),
+ val);
+ if (ret) {
+ dev_err(priv->dev, "Failed to set reset bit %lu\n", id);
+ return ret;
+ }
+
+ do {} while (--retry && lantiq_rcu_reset_status(rcdev, id) != assert);
+ if (!retry) {
+ dev_err(priv->dev, "Failed to %s bit %lu\n",
+ assert ? "assert" : "deassert", id);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int lantiq_rcu_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return lantiq_rcu_reset_update(rcdev, id, true);
+}
+
+static int lantiq_rcu_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return lantiq_rcu_reset_update(rcdev, id, false);
+}
+
+static int lantiq_rcu_reset_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ int ret;
+
+ ret = lantiq_rcu_reset_assert(rcdev, id);
+ if (ret)
+ return ret;
+
+ return lantiq_rcu_reset_deassert(rcdev, id);
+}
+
+static struct reset_control_ops lantiq_rcu_reset_ops = {
+ .assert = lantiq_rcu_reset_assert,
+ .deassert = lantiq_rcu_reset_deassert,
+ .status = lantiq_rcu_reset_status,
+ .reset = lantiq_rcu_reset_reset,
+};
+
+static int lantiq_rcu_reset_of_probe(struct platform_device *pdev,
+ struct lantiq_rcu_reset_priv *priv)
+{
+ struct device_node *np = pdev->dev.of_node;
+ int cnt, i, ret;
+
+ priv->regmap = syscon_regmap_lookup_by_phandle(np,
+ "lantiq,rcu-syscon");
+ if (IS_ERR(priv->regmap)) {
+ dev_err(&pdev->dev, "Failed to lookup RCU regmap\n");
+ return PTR_ERR(priv->regmap);
+ }
+
+ if (of_property_read_u32_index(np, "lantiq,rcu-syscon", 1,
+ &priv->reset_offset)) {
+ dev_err(&pdev->dev, "Failed to get RCU reset offset\n");
+ return -EINVAL;
+ }
+
+ if (of_property_read_u32_index(np, "lantiq,rcu-syscon", 2,
+ &priv->status_offset)) {
+ dev_err(&pdev->dev, "Failed to get RCU status offset\n");
+ return -EINVAL;
+ }
+
+ cnt = of_property_count_elems_of_size(np, "reset-request", sizeof(u32));
+ if (cnt <= 0)
+ return 0;
+
+ priv->trans = devm_kmalloc_array(&pdev->dev, cnt, sizeof(*priv->trans),
+ GFP_KERNEL);
+ if (!priv->trans)
+ return -ENOMEM;
+
+ for (i = 0; i < cnt; i++) {
+ ret = of_property_read_u32_index(np, "reset-request", i,
+ &priv->trans[i].request);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Failed to get reset-request at index %i\n",
+ i);
+ return ret;
+ }
+ ret = of_property_read_u32_index(np, "reset-status", i,
+ &priv->trans[i].status);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Failed to get reset-status at index %i\n",
+ i);
+ return ret;
+ }
+ }
+ priv->trans_number = cnt;
+
+ return 0;
+}
+
+static int lantiq_rcu_reset_probe(struct platform_device *pdev)
+{
+ struct lantiq_rcu_reset_priv *priv;
+ int err;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = &pdev->dev;
+ platform_set_drvdata(pdev, priv);
+
+ err = lantiq_rcu_reset_of_probe(pdev, priv);
+ if (err)
+ return err;
+
+ priv->rcdev.ops = &lantiq_rcu_reset_ops;
+ priv->rcdev.owner = THIS_MODULE;
+ priv->rcdev.of_node = pdev->dev.of_node;
+ priv->rcdev.of_reset_n_cells = 1;
+ priv->rcdev.nr_resets = 32;
+
+ err = reset_controller_register(&priv->rcdev);
+ if (err)
+ return err;
+
+ return 0;
+}
+
+static const struct of_device_id lantiq_rcu_reset_dt_ids[] = {
+ { .compatible = "lantiq,rcu-reset", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, lantiq_rcu_reset_dt_ids);
+
+static struct platform_driver lantiq_rcu_reset_driver = {
+ .probe = lantiq_rcu_reset_probe,
+ .driver = {
+ .name = "lantiq-rcu-reset",
+ .of_match_table = lantiq_rcu_reset_dt_ids,
+ },
+};
+module_platform_driver(lantiq_rcu_reset_driver);
+
+MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl at googlemail.com>");
+MODULE_DESCRIPTION("Lantiq XWAY RCU Reset Controller Driver");
+MODULE_LICENSE("GPL");
--
2.11.0
More information about the linux-mtd
mailing list