| // SPDX-License-Identifier: GPL-2.0 |
| /* Marvell GTI Watchdog driver |
| * |
| * Copyright (C) 2023 Marvell. |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/of.h> |
| #include <linux/watchdog.h> |
| |
| /* |
| * Hardware supports following mode of operation: |
| * 1) Interrupt Only: |
| * This will generate the interrupt to arm core whenever timeout happens. |
| * |
| * 2) Interrupt + del3t (Interrupt to firmware (SCP processor)). |
| * This will generate interrupt to arm core on 1st timeout happens |
| * This will generate interrupt to SCP processor on 2nd timeout happens |
| * |
| * 3) Interrupt + Interrupt to SCP processor (called delt3t) + reboot. |
| * This will generate interrupt to arm core on 1st timeout happens |
| * Will generate interrupt to SCP processor on 2nd timeout happens, |
| * if interrupt is configured. |
| * Reboot on 3rd timeout. |
| * |
| * Driver will use hardware in mode-3 above so that system can reboot in case |
| * a hardware hang. Also h/w is configured not to generate SCP interrupt, so |
| * effectively 2nd timeout is ignored within hardware. |
| * |
| * First timeout is effectively watchdog pretimeout. |
| */ |
| |
| /* GTI CWD Watchdog (GTI_CWD_WDOG) Register */ |
| #define GTI_CWD_WDOG(reg_offset) (0x8 * (reg_offset)) |
| #define GTI_CWD_WDOG_MODE_INT_DEL3T_RST 0x3 |
| #define GTI_CWD_WDOG_MODE_MASK GENMASK_ULL(1, 0) |
| #define GTI_CWD_WDOG_LEN_SHIFT 4 |
| #define GTI_CWD_WDOG_LEN_MASK GENMASK_ULL(19, 4) |
| #define GTI_CWD_WDOG_CNT_SHIFT 20 |
| #define GTI_CWD_WDOG_CNT_MASK GENMASK_ULL(43, 20) |
| |
| /* GTI CWD Watchdog Interrupt (GTI_CWD_INT) Register */ |
| #define GTI_CWD_INT 0x200 |
| #define GTI_CWD_INT_PENDING_STATUS(bit) BIT_ULL(bit) |
| |
| /* GTI CWD Watchdog Interrupt Enable Clear (GTI_CWD_INT_ENA_CLR) Register */ |
| #define GTI_CWD_INT_ENA_CLR 0x210 |
| #define GTI_CWD_INT_ENA_CLR_VAL(bit) BIT_ULL(bit) |
| |
| /* GTI CWD Watchdog Interrupt Enable Set (GTI_CWD_INT_ENA_SET) Register */ |
| #define GTI_CWD_INT_ENA_SET 0x218 |
| #define GTI_CWD_INT_ENA_SET_VAL(bit) BIT_ULL(bit) |
| |
| /* GTI CWD Watchdog Poke (GTI_CWD_POKE) Registers */ |
| #define GTI_CWD_POKE(reg_offset) (0x10000 + 0x8 * (reg_offset)) |
| #define GTI_CWD_POKE_VAL 1 |
| |
| struct gti_match_data { |
| u32 gti_num_timers; |
| }; |
| |
| static const struct gti_match_data match_data_octeontx2 = { |
| .gti_num_timers = 54, |
| }; |
| |
| static const struct gti_match_data match_data_cn10k = { |
| .gti_num_timers = 64, |
| }; |
| |
| struct gti_wdt_priv { |
| struct watchdog_device wdev; |
| void __iomem *base; |
| u32 clock_freq; |
| struct clk *sclk; |
| /* wdt_timer_idx used for timer to be used for system watchdog */ |
| u32 wdt_timer_idx; |
| const struct gti_match_data *data; |
| }; |
| |
| static irqreturn_t gti_wdt_interrupt(int irq, void *data) |
| { |
| struct watchdog_device *wdev = data; |
| struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev); |
| |
| /* Clear Interrupt Pending Status */ |
| writeq(GTI_CWD_INT_PENDING_STATUS(priv->wdt_timer_idx), |
| priv->base + GTI_CWD_INT); |
| |
| watchdog_notify_pretimeout(wdev); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int gti_wdt_ping(struct watchdog_device *wdev) |
| { |
| struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev); |
| |
| writeq(GTI_CWD_POKE_VAL, |
| priv->base + GTI_CWD_POKE(priv->wdt_timer_idx)); |
| |
| return 0; |
| } |
| |
| static int gti_wdt_start(struct watchdog_device *wdev) |
| { |
| struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev); |
| u64 regval; |
| |
| if (!wdev->pretimeout) |
| return -EINVAL; |
| |
| set_bit(WDOG_HW_RUNNING, &wdev->status); |
| |
| /* Clear any pending interrupt */ |
| writeq(GTI_CWD_INT_PENDING_STATUS(priv->wdt_timer_idx), |
| priv->base + GTI_CWD_INT); |
| |
| /* Enable Interrupt */ |
| writeq(GTI_CWD_INT_ENA_SET_VAL(priv->wdt_timer_idx), |
| priv->base + GTI_CWD_INT_ENA_SET); |
| |
| /* Set (Interrupt + SCP interrupt (DEL3T) + core domain reset) Mode */ |
| regval = readq(priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx)); |
| regval |= GTI_CWD_WDOG_MODE_INT_DEL3T_RST; |
| writeq(regval, priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx)); |
| |
| return 0; |
| } |
| |
| static int gti_wdt_stop(struct watchdog_device *wdev) |
| { |
| struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev); |
| u64 regval; |
| |
| /* Disable Interrupt */ |
| writeq(GTI_CWD_INT_ENA_CLR_VAL(priv->wdt_timer_idx), |
| priv->base + GTI_CWD_INT_ENA_CLR); |
| |
| /* Set GTI_CWD_WDOG.Mode = 0 to stop the timer */ |
| regval = readq(priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx)); |
| regval &= ~GTI_CWD_WDOG_MODE_MASK; |
| writeq(regval, priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx)); |
| |
| return 0; |
| } |
| |
| static int gti_wdt_settimeout(struct watchdog_device *wdev, |
| unsigned int timeout) |
| { |
| struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev); |
| u64 timeout_wdog, regval; |
| |
| /* Update new timeout */ |
| wdev->timeout = timeout; |
| |
| /* Pretimeout is 1/3 of timeout */ |
| wdev->pretimeout = timeout / 3; |
| |
| /* Get clock cycles from pretimeout */ |
| timeout_wdog = (u64)priv->clock_freq * wdev->pretimeout; |
| |
| /* Watchdog counts in 1024 cycle steps */ |
| timeout_wdog = timeout_wdog >> 10; |
| |
| /* GTI_CWD_WDOG.CNT: reload counter is 16-bit */ |
| timeout_wdog = (timeout_wdog + 0xff) >> 8; |
| if (timeout_wdog >= 0x10000) |
| timeout_wdog = 0xffff; |
| |
| /* |
| * GTI_CWD_WDOG.LEN is 24bit, lower 8-bits should be zero and |
| * upper 16-bits are same as GTI_CWD_WDOG.CNT |
| */ |
| regval = readq(priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx)); |
| regval &= GTI_CWD_WDOG_MODE_MASK; |
| regval |= (timeout_wdog << (GTI_CWD_WDOG_CNT_SHIFT + 8)) | |
| (timeout_wdog << GTI_CWD_WDOG_LEN_SHIFT); |
| writeq(regval, priv->base + GTI_CWD_WDOG(priv->wdt_timer_idx)); |
| |
| return 0; |
| } |
| |
| static int gti_wdt_set_pretimeout(struct watchdog_device *wdev, |
| unsigned int timeout) |
| { |
| struct gti_wdt_priv *priv = watchdog_get_drvdata(wdev); |
| struct watchdog_device *wdog_dev = &priv->wdev; |
| |
| if (!timeout) { |
| /* Disable Interrupt */ |
| writeq(GTI_CWD_INT_ENA_CLR_VAL(priv->wdt_timer_idx), |
| priv->base + GTI_CWD_INT_ENA_CLR); |
| return 0; |
| } |
| |
| /* pretimeout should 1/3 of max_timeout */ |
| if (timeout * 3 <= wdog_dev->max_timeout) |
| return gti_wdt_settimeout(wdev, timeout * 3); |
| |
| return -EINVAL; |
| } |
| |
| static void gti_clk_disable_unprepare(void *data) |
| { |
| clk_disable_unprepare(data); |
| } |
| |
| static int gti_wdt_get_cntfrq(struct platform_device *pdev, |
| struct gti_wdt_priv *priv) |
| { |
| int err; |
| |
| priv->sclk = devm_clk_get_enabled(&pdev->dev, NULL); |
| if (IS_ERR(priv->sclk)) |
| return PTR_ERR(priv->sclk); |
| |
| err = devm_add_action_or_reset(&pdev->dev, |
| gti_clk_disable_unprepare, priv->sclk); |
| if (err) |
| return err; |
| |
| priv->clock_freq = clk_get_rate(priv->sclk); |
| if (!priv->clock_freq) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static const struct watchdog_info gti_wdt_ident = { |
| .identity = "Marvell GTI watchdog", |
| .options = WDIOF_SETTIMEOUT | WDIOF_PRETIMEOUT | WDIOF_KEEPALIVEPING | |
| WDIOF_MAGICCLOSE | WDIOF_CARDRESET, |
| }; |
| |
| static const struct watchdog_ops gti_wdt_ops = { |
| .owner = THIS_MODULE, |
| .start = gti_wdt_start, |
| .stop = gti_wdt_stop, |
| .ping = gti_wdt_ping, |
| .set_timeout = gti_wdt_settimeout, |
| .set_pretimeout = gti_wdt_set_pretimeout, |
| }; |
| |
| static int gti_wdt_probe(struct platform_device *pdev) |
| { |
| struct gti_wdt_priv *priv; |
| struct device *dev = &pdev->dev; |
| struct watchdog_device *wdog_dev; |
| u64 max_pretimeout; |
| u32 wdt_idx; |
| int irq; |
| int err; |
| |
| priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
| if (!priv) |
| return -ENOMEM; |
| |
| priv->base = devm_platform_ioremap_resource(pdev, 0); |
| if (IS_ERR(priv->base)) |
| return dev_err_probe(&pdev->dev, PTR_ERR(priv->base), |
| "reg property not valid/found\n"); |
| |
| err = gti_wdt_get_cntfrq(pdev, priv); |
| if (err) |
| return dev_err_probe(&pdev->dev, err, |
| "GTI clock frequency not valid/found"); |
| |
| priv->data = of_device_get_match_data(dev); |
| |
| /* default use last timer for watchdog */ |
| priv->wdt_timer_idx = priv->data->gti_num_timers - 1; |
| |
| err = of_property_read_u32(dev->of_node, "marvell,wdt-timer-index", |
| &wdt_idx); |
| if (!err) { |
| if (wdt_idx >= priv->data->gti_num_timers) |
| return dev_err_probe(&pdev->dev, -EINVAL, |
| "GTI wdog timer index not valid"); |
| |
| priv->wdt_timer_idx = wdt_idx; |
| } |
| |
| wdog_dev = &priv->wdev; |
| wdog_dev->info = >i_wdt_ident; |
| wdog_dev->ops = >i_wdt_ops; |
| wdog_dev->parent = dev; |
| /* |
| * Watchdog counter is 24 bit where lower 8 bits are zeros |
| * This counter decrements every 1024 clock cycles. |
| */ |
| max_pretimeout = (GTI_CWD_WDOG_CNT_MASK >> GTI_CWD_WDOG_CNT_SHIFT); |
| max_pretimeout &= ~0xFFUL; |
| max_pretimeout = (max_pretimeout * 1024) / priv->clock_freq; |
| wdog_dev->pretimeout = max_pretimeout; |
| |
| /* Maximum timeout is 3 times the pretimeout */ |
| wdog_dev->max_timeout = max_pretimeout * 3; |
| wdog_dev->max_hw_heartbeat_ms = max_pretimeout * 1000; |
| /* Minimum first timeout (pretimeout) is 1, so min_timeout as 3 */ |
| wdog_dev->min_timeout = 3; |
| wdog_dev->timeout = wdog_dev->pretimeout; |
| |
| watchdog_set_drvdata(wdog_dev, priv); |
| platform_set_drvdata(pdev, priv); |
| gti_wdt_settimeout(wdog_dev, wdog_dev->timeout); |
| watchdog_stop_on_reboot(wdog_dev); |
| watchdog_stop_on_unregister(wdog_dev); |
| |
| err = devm_watchdog_register_device(dev, wdog_dev); |
| if (err) |
| return err; |
| |
| irq = platform_get_irq(pdev, 0); |
| if (irq < 0) |
| return irq; |
| |
| err = devm_request_irq(dev, irq, gti_wdt_interrupt, 0, |
| pdev->name, &priv->wdev); |
| if (err) |
| return dev_err_probe(dev, err, "Failed to register interrupt handler\n"); |
| |
| dev_info(dev, "Watchdog enabled (timeout=%d sec)\n", wdog_dev->timeout); |
| return 0; |
| } |
| |
| static const struct of_device_id gti_wdt_of_match[] = { |
| { .compatible = "marvell,cn9670-wdt", .data = &match_data_octeontx2}, |
| { .compatible = "marvell,cn10624-wdt", .data = &match_data_cn10k}, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(of, gti_wdt_of_match); |
| |
| static struct platform_driver gti_wdt_driver = { |
| .driver = { |
| .name = "gti-wdt", |
| .of_match_table = gti_wdt_of_match, |
| }, |
| .probe = gti_wdt_probe, |
| }; |
| module_platform_driver(gti_wdt_driver); |
| |
| MODULE_AUTHOR("Bharat Bhushan <bbhushan2@marvell.com>"); |
| MODULE_DESCRIPTION("Marvell GTI watchdog driver"); |
| MODULE_LICENSE("GPL"); |