diff options
Diffstat (limited to 'drivers/reset/reset-npcm.c')
| -rw-r--r-- | drivers/reset/reset-npcm.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/reset/reset-npcm.c b/drivers/reset/reset-npcm.c new file mode 100644 index 000000000000..2ea4d3136e15 --- /dev/null +++ b/drivers/reset/reset-npcm.c @@ -0,0 +1,291 @@ +// 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/of_device.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); +} + +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]; + if (offset != NPCM_IPSRST1 && offset != NPCM_IPSRST2 && + offset != NPCM_IPSRST3) { + dev_err(rcdev->dev, "Error reset register (0x%x)\n", offset); + return -EINVAL; + } + bit = reset_spec->args[1]; + if (bit >= NPCM_RC_RESETS_PER_REG) { + dev_err(rcdev->dev, "Error reset number (%d)\n", bit); + return -EINVAL; + } + + return (offset << 8) | bit; +} + +static const struct of_device_id npcm_rc_match[] = { + { .compatible = "nuvoton,npcm750-reset", + .data = (void *)"nuvoton,npcm750-gcr" }, + { } +}; + +/* + * 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) +{ + u32 mdlr, iprst1, iprst2, iprst3; + struct device *dev = &pdev->dev; + struct regmap *gcr_regmap; + u32 ipsrst1_bits = 0; + u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST; + u32 ipsrst3_bits = 0; + const char *gcr_dt; + + gcr_dt = (const char *) + of_match_device(dev->driver->of_match_table, dev)->data; + + gcr_regmap = syscon_regmap_lookup_by_compatible(gcr_dt); + if (IS_ERR(gcr_regmap)) { + dev_err(&pdev->dev, "Failed to find %s\n", gcr_dt); + return PTR_ERR(gcr_regmap); + } + + /* 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 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.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 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); |