This patch set adds reset controller support
for the Nuvoton NPCM Baseboard Management Controller (BMC).
Apart of controlling all NPCM BMC reset module lines the NPCM reset driver
support NPCM BMC software reset to restarting the NPCM BMC.
Supporting NPCM USB-PHY reset as follow:
NPCM BMC USB-PHY connected to two modules USB device (UDC) and USB host.
If we will restart the USB-PHY at the UDC probe and later the
USB host probe will restart USB-PHY again it will disable the UDC
and vice versa.
The solution is to reset the USB-PHY at the reset probe stage before
the UDC and the USB host are initializing.
NPCM reset driver tested on NPCM750 evaluation board.
Addressed comments from:.
- Philipp Zabel : https://lkml.org/lkml/2019/10/29/712
https://lkml.org/lkml/2019/10/29/713
https://lkml.org/lkml/2019/10/29/731
- kbuild test robot : https://lkml.org/lkml/2019/10/30/29
Changes since version 2:
- Remove unnecessary details in the dt-binding documentation.
- Modify device tree binding constants.
- initialize gcr_regmap parameter to NULL.
- Add of_xlate support.
- Enable NPCM reset driver by default.
- Remove unused header include.
- Using devm_platform_ioremap_resource instead of_address_to_resource
and devm_ioremap_resource.
- Modify number of resets.
- Using devm_reset_controller_register instead reset_controller_register.
- Remove unnecessary probe print.
Changes since version 1:
- Check if gcr_regmap parameter initialized before using it.
Tomer Maimon (3):
dt-binding: reset: add NPCM reset controller documentation
dt-bindings: reset: Add binding constants for NPCM7xx reset controller
reset: npcm: add NPCM reset controller driver
.../bindings/reset/nuvoton,npcm-reset.txt | 32 ++
drivers/reset/Kconfig | 7 +
drivers/reset/Makefile | 1 +
drivers/reset/reset-npcm.c | 281 ++++++++++++++++++
.../dt-bindings/reset/nuvoton,npcm7xx-reset.h | 91 ++++++
5 files changed, 412 insertions(+)
create mode 100644 Documentation/devicetree/bindings/reset/nuvoton,npcm-reset.txt
create mode 100644 drivers/reset/reset-npcm.c
create mode 100644 include/dt-bindings/reset/nuvoton,npcm7xx-reset.h
--
2.22.0
===========================================================================================
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Add Nuvoton NPCM BMC reset controller driver.
Signed-off-by: Tomer Maimon <[email protected]>
---
drivers/reset/Kconfig | 7 +
drivers/reset/Makefile | 1 +
drivers/reset/reset-npcm.c | 281 +++++++++++++++++++++++++++++++++++++
3 files changed, 289 insertions(+)
create mode 100644 drivers/reset/reset-npcm.c
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 7b07281aa0ae..9e3eac30e7db 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -89,6 +89,13 @@ config RESET_MESON_AUDIO_ARB
This enables the reset driver for Audio Memory Arbiter of
Amlogic's A113 based SoCs
+config RESET_NPCM
+ bool "NPCM BMC Reset Driver" if COMPILE_TEST
+ default ARCH_NPCM
+ help
+ This enables the reset controller driver for Nuvoton NPCM
+ BMC SoCs.
+
config RESET_OXNAS
bool
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index cf60ce526064..00767c03f5f2 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
obj-$(CONFIG_RESET_MESON) += reset-meson.o
obj-$(CONFIG_RESET_MESON_AUDIO_ARB) += reset-meson-audio-arb.o
+obj-$(CONFIG_RESET_NPCM) += reset-npcm.o
obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o
diff --git a/drivers/reset/reset-npcm.c b/drivers/reset/reset-npcm.c
new file mode 100644
index 000000000000..ad09d466d7f9
--- /dev/null
+++ b/drivers/reset/reset-npcm.c
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Nuvoton Technology corporation.
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/reset-controller.h>
+#include <linux/spinlock.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/of_address.h>
+
+/* NPCM7xx GCR registers */
+#define NPCM_MDLR_OFFSET 0x7C
+#define NPCM_MDLR_USBD0 BIT(9)
+#define NPCM_MDLR_USBD1 BIT(8)
+#define NPCM_MDLR_USBD2_4 BIT(21)
+#define NPCM_MDLR_USBD5_9 BIT(22)
+
+#define NPCM_USB1PHYCTL_OFFSET 0x140
+#define NPCM_USB2PHYCTL_OFFSET 0x144
+#define NPCM_USBXPHYCTL_RS BIT(28)
+
+/* NPCM7xx Reset registers */
+#define NPCM_SWRSTR 0x14
+#define NPCM_SWRST BIT(2)
+
+#define NPCM_IPSRST1 0x20
+#define NPCM_IPSRST1_USBD1 BIT(5)
+#define NPCM_IPSRST1_USBD2 BIT(8)
+#define NPCM_IPSRST1_USBD3 BIT(25)
+#define NPCM_IPSRST1_USBD4 BIT(22)
+#define NPCM_IPSRST1_USBD5 BIT(23)
+#define NPCM_IPSRST1_USBD6 BIT(24)
+
+#define NPCM_IPSRST2 0x24
+#define NPCM_IPSRST2_USB_HOST BIT(26)
+
+#define NPCM_IPSRST3 0x34
+#define NPCM_IPSRST3_USBD0 BIT(4)
+#define NPCM_IPSRST3_USBD7 BIT(5)
+#define NPCM_IPSRST3_USBD8 BIT(6)
+#define NPCM_IPSRST3_USBD9 BIT(7)
+#define NPCM_IPSRST3_USBPHY1 BIT(24)
+#define NPCM_IPSRST3_USBPHY2 BIT(25)
+
+#define NPCM_RC_RESETS_PER_REG 32
+#define NPCM_MASK_RESETS GENMASK(4, 0)
+
+struct npcm_rc_data {
+ struct reset_controller_dev rcdev;
+ struct notifier_block restart_nb;
+ u32 sw_reset_number;
+ void __iomem *base;
+ spinlock_t lock;
+};
+
+#define to_rc_data(p) container_of(p, struct npcm_rc_data, rcdev)
+
+static int npcm_rc_restart(struct notifier_block *nb, unsigned long mode,
+ void *cmd)
+{
+ struct npcm_rc_data *rc = container_of(nb, struct npcm_rc_data,
+ restart_nb);
+
+ writel(NPCM_SWRST << rc->sw_reset_number, rc->base + NPCM_SWRSTR);
+ mdelay(1000);
+
+ pr_emerg("%s: unable to restart system\n", __func__);
+
+ return NOTIFY_DONE;
+}
+
+static int npcm_rc_setclear_reset(struct reset_controller_dev *rcdev,
+ unsigned long id, bool set)
+{
+ struct npcm_rc_data *rc = to_rc_data(rcdev);
+ unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
+ unsigned int ctrl_offset = id >> 8;
+ unsigned long flags;
+ u32 stat;
+
+ spin_lock_irqsave(&rc->lock, flags);
+ stat = readl(rc->base + ctrl_offset);
+ if (set)
+ writel(stat | rst_bit, rc->base + ctrl_offset);
+ else
+ writel(stat & ~rst_bit, rc->base + ctrl_offset);
+ spin_unlock_irqrestore(&rc->lock, flags);
+
+ return 0;
+}
+
+static int npcm_rc_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+ return npcm_rc_setclear_reset(rcdev, id, true);
+}
+
+static int npcm_rc_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return npcm_rc_setclear_reset(rcdev, id, false);
+}
+
+static int npcm_rc_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct npcm_rc_data *rc = to_rc_data(rcdev);
+ unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
+ unsigned int ctrl_offset = id >> 8;
+
+ return (readl(rc->base + ctrl_offset) & rst_bit);
+}
+
+/*
+ * The following procedure should be observed in USB PHY, USB device and
+ * USB host initialization at BMC boot
+ */
+static int npcm_usb_reset(struct platform_device *pdev, struct npcm_rc_data *rc)
+{
+ struct device_node *np = pdev->dev.of_node;
+ u32 mdlr, iprst1, iprst2, iprst3;
+ struct regmap *gcr_regmap = NULL;
+ u32 ipsrst1_bits = 0;
+ u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
+ u32 ipsrst3_bits = 0;
+
+ if (of_device_is_compatible(np, "nuvoton,npcm750-reset")) {
+ gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
+ if (IS_ERR(gcr_regmap)) {
+ dev_err(&pdev->dev, "Failed to find nuvoton,npcm750-gcr\n");
+ return PTR_ERR(gcr_regmap);
+ }
+ }
+ if (!gcr_regmap)
+ return -ENXIO;
+
+ /* checking which USB device is enabled */
+ regmap_read(gcr_regmap, NPCM_MDLR_OFFSET, &mdlr);
+ if (!(mdlr & NPCM_MDLR_USBD0))
+ ipsrst3_bits |= NPCM_IPSRST3_USBD0;
+ if (!(mdlr & NPCM_MDLR_USBD1))
+ ipsrst1_bits |= NPCM_IPSRST1_USBD1;
+ if (!(mdlr & NPCM_MDLR_USBD2_4))
+ ipsrst1_bits |= (NPCM_IPSRST1_USBD2 |
+ NPCM_IPSRST1_USBD3 |
+ NPCM_IPSRST1_USBD4);
+ if (!(mdlr & NPCM_MDLR_USBD0)) {
+ ipsrst1_bits |= (NPCM_IPSRST1_USBD5 |
+ NPCM_IPSRST1_USBD6);
+ ipsrst3_bits |= (NPCM_IPSRST3_USBD7 |
+ NPCM_IPSRST3_USBD8 |
+ NPCM_IPSRST3_USBD9);
+ }
+
+ /* assert reset USB PHY and USB devices */
+ iprst1 = readl(rc->base + NPCM_IPSRST1);
+ iprst2 = readl(rc->base + NPCM_IPSRST2);
+ iprst3 = readl(rc->base + NPCM_IPSRST3);
+
+ iprst1 |= ipsrst1_bits;
+ iprst2 |= ipsrst2_bits;
+ iprst3 |= (ipsrst3_bits | NPCM_IPSRST3_USBPHY1 |
+ NPCM_IPSRST3_USBPHY2);
+
+ writel(iprst1, rc->base + NPCM_IPSRST1);
+ writel(iprst2, rc->base + NPCM_IPSRST2);
+ writel(iprst3, rc->base + NPCM_IPSRST3);
+
+ /* clear USB PHY RS bit */
+ regmap_update_bits(gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
+ NPCM_USBXPHYCTL_RS, 0);
+ regmap_update_bits(gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
+ NPCM_USBXPHYCTL_RS, 0);
+
+ /* deassert reset USB PHY */
+ iprst3 &= ~(NPCM_IPSRST3_USBPHY1 | NPCM_IPSRST3_USBPHY2);
+ writel(iprst3, rc->base + NPCM_IPSRST3);
+
+ udelay(50);
+
+ /* set USB PHY RS bit */
+ regmap_update_bits(gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
+ NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
+ regmap_update_bits(gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
+ NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
+
+ /* deassert reset USB devices*/
+ iprst1 &= ~ipsrst1_bits;
+ iprst2 &= ~ipsrst2_bits;
+ iprst3 &= ~ipsrst3_bits;
+
+ writel(iprst1, rc->base + NPCM_IPSRST1);
+ writel(iprst2, rc->base + NPCM_IPSRST2);
+ writel(iprst3, rc->base + NPCM_IPSRST3);
+
+ return 0;
+}
+
+static int npcm_reset_xlate(struct reset_controller_dev *rcdev,
+ const struct of_phandle_args *reset_spec)
+{
+ unsigned int offset, bit;
+
+ offset = reset_spec->args[0];
+ bit = reset_spec->args[1];
+
+ return (offset << 8) | bit;
+}
+
+static const struct reset_control_ops npcm_rc_ops = {
+ .assert = npcm_rc_assert,
+ .deassert = npcm_rc_deassert,
+ .status = npcm_rc_status,
+};
+
+static int npcm_rc_probe(struct platform_device *pdev)
+{
+ struct npcm_rc_data *rc;
+ int ret;
+
+ rc = devm_kzalloc(&pdev->dev, sizeof(*rc), GFP_KERNEL);
+ if (!rc)
+ return -ENOMEM;
+
+ rc->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(rc->base))
+ return PTR_ERR(rc->base);
+
+ spin_lock_init(&rc->lock);
+
+ rc->rcdev.owner = THIS_MODULE;
+ rc->rcdev.nr_resets = NPCM_RC_RESETS_PER_REG;
+ rc->rcdev.ops = &npcm_rc_ops;
+ rc->rcdev.of_node = pdev->dev.of_node;
+ rc->rcdev.of_reset_n_cells = 2;
+ rc->rcdev.of_xlate = npcm_reset_xlate;
+
+ platform_set_drvdata(pdev, rc);
+
+ ret = devm_reset_controller_register(&pdev->dev, &rc->rcdev);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to register device\n");
+ return ret;
+ }
+
+ if (npcm_usb_reset(pdev, rc))
+ dev_warn(&pdev->dev, "NPCM USB reset failed, can cause issues with UDC and USB host\n");
+
+ if (!of_property_read_u32(pdev->dev.of_node, "nuvoton,sw-reset-number",
+ &rc->sw_reset_number)) {
+ if (rc->sw_reset_number && rc->sw_reset_number < 5) {
+ rc->restart_nb.priority = 192,
+ rc->restart_nb.notifier_call = npcm_rc_restart,
+ ret = register_restart_handler(&rc->restart_nb);
+ if (ret)
+ dev_warn(&pdev->dev, "failed to register restart handler\n");
+ }
+ }
+
+ return ret;
+}
+
+static const struct of_device_id npcm_rc_match[] = {
+ { .compatible = "nuvoton,npcm750-reset" },
+ { }
+};
+
+static struct platform_driver npcm_rc_driver = {
+ .probe = npcm_rc_probe,
+ .driver = {
+ .name = "npcm-reset",
+ .of_match_table = npcm_rc_match,
+ .suppress_bind_attrs = true,
+ },
+};
+builtin_platform_driver(npcm_rc_driver);
--
2.22.0
===========================================================================================
The privileged confidential information contained in this email is intended for use only by the addressees as indicated by the original sender of this email. If you are not the addressee indicated in this email or are not responsible for delivery of the email to such a person, please kindly reply to the sender indicating this fact and delete all copies of it from your computer and network server immediately. Your cooperation is highly appreciated. It is advised that any unauthorized use of confidential information of Nuvoton is strictly prohibited; and any information in this email irrelevant to the official business of Nuvoton shall be deemed as neither given nor endorsed by Nuvoton.