diff options
Diffstat (limited to 'drivers/watchdog/imx7ulp_wdt.c')
| -rw-r--r-- | drivers/watchdog/imx7ulp_wdt.c | 212 |
1 files changed, 168 insertions, 44 deletions
diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c index 922b60374295..2897902090b3 100644 --- a/drivers/watchdog/imx7ulp_wdt.c +++ b/drivers/watchdog/imx7ulp_wdt.c @@ -9,12 +9,15 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/reboot.h> #include <linux/watchdog.h> #define WDOG_CS 0x0 +#define WDOG_CS_FLG BIT(14) #define WDOG_CS_CMD32EN BIT(13) +#define WDOG_CS_PRES BIT(12) #define WDOG_CS_ULK BIT(11) #define WDOG_CS_RCS BIT(10) #define LPO_CLK 0x1 @@ -39,60 +42,105 @@ #define DEFAULT_TIMEOUT 60 #define MAX_TIMEOUT 128 #define WDOG_CLOCK_RATE 1000 -#define WDOG_WAIT_TIMEOUT 20 +#define WDOG_ULK_WAIT_TIMEOUT 1000 +#define WDOG_RCS_WAIT_TIMEOUT 10000 +#define WDOG_RCS_POST_WAIT 3000 + +#define RETRY_MAX 5 static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0000); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +struct imx_wdt_hw_feature { + bool prescaler_enable; + u32 wdog_clock_rate; +}; + struct imx7ulp_wdt_device { struct watchdog_device wdd; void __iomem *base; struct clk *clk; + bool post_rcs_wait; + const struct imx_wdt_hw_feature *hw; }; -static int imx7ulp_wdt_wait(void __iomem *base, u32 mask) +static int imx7ulp_wdt_wait_ulk(void __iomem *base) { u32 val = readl(base + WDOG_CS); - if (!(val & mask) && readl_poll_timeout_atomic(base + WDOG_CS, val, - val & mask, 0, - WDOG_WAIT_TIMEOUT)) + if (!(val & WDOG_CS_ULK) && + readl_poll_timeout_atomic(base + WDOG_CS, val, + val & WDOG_CS_ULK, 0, + WDOG_ULK_WAIT_TIMEOUT)) return -ETIMEDOUT; return 0; } -static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) +static int imx7ulp_wdt_wait_rcs(struct imx7ulp_wdt_device *wdt) { - struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); + int ret = 0; + u32 val = readl(wdt->base + WDOG_CS); + u64 timeout = (val & WDOG_CS_PRES) ? + WDOG_RCS_WAIT_TIMEOUT * 256 : WDOG_RCS_WAIT_TIMEOUT; + unsigned long wait_min = (val & WDOG_CS_PRES) ? + WDOG_RCS_POST_WAIT * 256 : WDOG_RCS_POST_WAIT; + + if (!(val & WDOG_CS_RCS) && + readl_poll_timeout(wdt->base + WDOG_CS, val, val & WDOG_CS_RCS, 100, + timeout)) + ret = -ETIMEDOUT; + + /* Wait 2.5 clocks after RCS done */ + if (wdt->post_rcs_wait) + usleep_range(wait_min, wait_min + 2000); + + return ret; +} +static int _imx7ulp_wdt_enable(struct imx7ulp_wdt_device *wdt, bool enable) +{ u32 val = readl(wdt->base + WDOG_CS); int ret; local_irq_disable(); writel(UNLOCK, wdt->base + WDOG_CNT); - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); + ret = imx7ulp_wdt_wait_ulk(wdt->base); if (ret) goto enable_out; if (enable) writel(val | WDOG_CS_EN, wdt->base + WDOG_CS); else writel(val & ~WDOG_CS_EN, wdt->base + WDOG_CS); - imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); -enable_out: local_irq_enable(); + ret = imx7ulp_wdt_wait_rcs(wdt); return ret; + +enable_out: + local_irq_enable(); + return ret; } -static bool imx7ulp_wdt_is_enabled(void __iomem *base) +static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) { - u32 val = readl(base + WDOG_CS); + struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); + int ret; + u32 val; + u32 loop = RETRY_MAX; + + do { + ret = _imx7ulp_wdt_enable(wdt, enable); + val = readl(wdt->base + WDOG_CS); + } while (--loop > 0 && ((!!(val & WDOG_CS_EN)) != enable || ret)); - return val & WDOG_CS_EN; + if (loop == 0) + return -EBUSY; + + return ret; } static int imx7ulp_wdt_ping(struct watchdog_device *wdog) @@ -114,26 +162,44 @@ static int imx7ulp_wdt_stop(struct watchdog_device *wdog) return imx7ulp_wdt_enable(wdog, false); } -static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, - unsigned int timeout) +static int _imx7ulp_wdt_set_timeout(struct imx7ulp_wdt_device *wdt, + unsigned int toval) { - struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); - u32 val = WDOG_CLOCK_RATE * timeout; int ret; local_irq_disable(); writel(UNLOCK, wdt->base + WDOG_CNT); - ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); + ret = imx7ulp_wdt_wait_ulk(wdt->base); if (ret) goto timeout_out; - writel(val, wdt->base + WDOG_TOVAL); - imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); - - wdog->timeout = timeout; + writel(toval, wdt->base + WDOG_TOVAL); + local_irq_enable(); + ret = imx7ulp_wdt_wait_rcs(wdt); + return ret; timeout_out: local_irq_enable(); + return ret; +} +static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, + unsigned int timeout) +{ + struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); + u32 toval = wdt->hw->wdog_clock_rate * timeout; + u32 val; + int ret; + u32 loop = RETRY_MAX; + + do { + ret = _imx7ulp_wdt_set_timeout(wdt, toval); + val = readl(wdt->base + WDOG_TOVAL); + } while (--loop > 0 && (val != toval || ret)); + + if (loop == 0) + return -EBUSY; + + wdog->timeout = timeout; return ret; } @@ -173,29 +239,62 @@ static const struct watchdog_info imx7ulp_wdt_info = { WDIOF_MAGICCLOSE, }; -static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout) +static int _imx7ulp_wdt_init(struct imx7ulp_wdt_device *wdt, unsigned int timeout, unsigned int cs) { u32 val; int ret; local_irq_disable(); - /* unlock the wdog for reconfiguration */ - writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT); - writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT); - ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK); + + val = readl(wdt->base + WDOG_CS); + if (val & WDOG_CS_CMD32EN) { + writel(UNLOCK, wdt->base + WDOG_CNT); + } else { + mb(); + /* unlock the wdog for reconfiguration */ + writel_relaxed(UNLOCK_SEQ0, wdt->base + WDOG_CNT); + writel_relaxed(UNLOCK_SEQ1, wdt->base + WDOG_CNT); + mb(); + } + + ret = imx7ulp_wdt_wait_ulk(wdt->base); if (ret) goto init_out; /* set an initial timeout value in TOVAL */ - writel(timeout, base + WDOG_TOVAL); - /* enable 32bit command sequence and reconfigure */ - val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE | - WDOG_CS_WAIT | WDOG_CS_STOP; - writel(val, base + WDOG_CS); - imx7ulp_wdt_wait(base, WDOG_CS_RCS); + writel(timeout, wdt->base + WDOG_TOVAL); + writel(cs, wdt->base + WDOG_CS); + local_irq_enable(); + ret = imx7ulp_wdt_wait_rcs(wdt); + + return ret; init_out: local_irq_enable(); + return ret; +} + +static int imx7ulp_wdt_init(struct imx7ulp_wdt_device *wdt, unsigned int timeout) +{ + /* enable 32bit command sequence and reconfigure */ + u32 val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE | + WDOG_CS_WAIT | WDOG_CS_STOP; + u32 cs, toval; + int ret; + u32 loop = RETRY_MAX; + + if (wdt->hw->prescaler_enable) + val |= WDOG_CS_PRES; + + do { + ret = _imx7ulp_wdt_init(wdt, timeout, val); + toval = readl(wdt->base + WDOG_TOVAL); + cs = readl(wdt->base + WDOG_CS); + cs &= ~(WDOG_CS_FLG | WDOG_CS_ULK | WDOG_CS_RCS); + } while (--loop > 0 && (cs != val || toval != timeout || ret)); + + if (loop == 0) + return -EBUSY; return ret; } @@ -228,6 +327,15 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev) return PTR_ERR(imx7ulp_wdt->clk); } + imx7ulp_wdt->post_rcs_wait = true; + if (of_device_is_compatible(dev->of_node, + "fsl,imx8ulp-wdt")) { + dev_info(dev, "imx8ulp wdt probe\n"); + imx7ulp_wdt->post_rcs_wait = false; + } else { + dev_info(dev, "imx7ulp wdt probe\n"); + } + ret = clk_prepare_enable(imx7ulp_wdt->clk); if (ret) return ret; @@ -248,14 +356,16 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev) watchdog_stop_on_reboot(wdog); watchdog_stop_on_unregister(wdog); watchdog_set_drvdata(wdog, imx7ulp_wdt); - ret = imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE); + + imx7ulp_wdt->hw = of_device_get_match_data(dev); + ret = imx7ulp_wdt_init(imx7ulp_wdt, wdog->timeout * imx7ulp_wdt->hw->wdog_clock_rate); if (ret) return ret; return devm_watchdog_register_device(dev, wdog); } -static int __maybe_unused imx7ulp_wdt_suspend(struct device *dev) +static int __maybe_unused imx7ulp_wdt_suspend_noirq(struct device *dev) { struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev); @@ -267,30 +377,44 @@ static int __maybe_unused imx7ulp_wdt_suspend(struct device *dev) return 0; } -static int __maybe_unused imx7ulp_wdt_resume(struct device *dev) +static int __maybe_unused imx7ulp_wdt_resume_noirq(struct device *dev) { struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev); - u32 timeout = imx7ulp_wdt->wdd.timeout * WDOG_CLOCK_RATE; + u32 timeout = imx7ulp_wdt->wdd.timeout * imx7ulp_wdt->hw->wdog_clock_rate; int ret; ret = clk_prepare_enable(imx7ulp_wdt->clk); if (ret) return ret; - if (imx7ulp_wdt_is_enabled(imx7ulp_wdt->base)) - imx7ulp_wdt_init(imx7ulp_wdt->base, timeout); - - if (watchdog_active(&imx7ulp_wdt->wdd)) + if (watchdog_active(&imx7ulp_wdt->wdd)) { + imx7ulp_wdt_init(imx7ulp_wdt, timeout); imx7ulp_wdt_start(&imx7ulp_wdt->wdd); + imx7ulp_wdt_ping(&imx7ulp_wdt->wdd); + } return 0; } -static SIMPLE_DEV_PM_OPS(imx7ulp_wdt_pm_ops, imx7ulp_wdt_suspend, - imx7ulp_wdt_resume); +static const struct dev_pm_ops imx7ulp_wdt_pm_ops = { + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx7ulp_wdt_suspend_noirq, + imx7ulp_wdt_resume_noirq) +}; + +static const struct imx_wdt_hw_feature imx7ulp_wdt_hw = { + .prescaler_enable = false, + .wdog_clock_rate = 1000, +}; + +static const struct imx_wdt_hw_feature imx93_wdt_hw = { + .prescaler_enable = true, + .wdog_clock_rate = 125, +}; static const struct of_device_id imx7ulp_wdt_dt_ids[] = { - { .compatible = "fsl,imx7ulp-wdt", }, + { .compatible = "fsl,imx8ulp-wdt", .data = &imx7ulp_wdt_hw, }, + { .compatible = "fsl,imx7ulp-wdt", .data = &imx7ulp_wdt_hw, }, + { .compatible = "fsl,imx93-wdt", .data = &imx93_wdt_hw, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, imx7ulp_wdt_dt_ids); |