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Signed-off-by: Lad Prabhakar Reviewed-by: Conor Dooley Reviewed-by: Guenter Roeck Reviewed-by: Geert Uytterhoeven --- v4->v5 - Updated commit description - Collated RB tags from Geert and Guenter v3->v4 - No change v2->v3 - No change v1->v2 - Included RB tag --- .../bindings/watchdog/renesas,wdt.yaml | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml b/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml index eba454d1680f..29ada89fdcdc 100644 --- a/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml +++ b/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml @@ -75,6 +75,8 @@ properties: - renesas,r8a779h0-wdt # R-Car V4M - const: renesas,rcar-gen4-wdt # R-Car Gen4 + - const: renesas,r9a09g057-wdt # RZ/V2H(P) + reg: maxItems: 1 @@ -113,7 +115,6 @@ properties: required: - compatible - reg - - interrupts - clocks allOf: @@ -137,6 +138,7 @@ allOf: compatible: contains: enum: + - renesas,r9a09g057-wdt - renesas,rzg2l-wdt - renesas,rzv2m-wdt then: @@ -171,6 +173,19 @@ allOf: interrupts: maxItems: 1 + - if: + properties: + compatible: + contains: + const: renesas,r9a09g057-wdt + then: + properties: + interrupts: false + interrupt-names: false + else: + required: + - interrupts + additionalProperties: false examples: From patchwork Thu Aug 29 19:38:31 2024 Content-Type: text/plain; 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Signed-off-by: Lad Prabhakar Reviewed-by: Guenter Roeck --- v4->v5 - Collated RB tag from Guenter v3->v4 - Turn on the clocks first before reset operation in start & restart callbacks - Added checks in restart callback before turning ON clocks/resets - Dropped udelay after every ping operation - Added comments - Simplified calculation of max_hw_heartbeat_ms v2->v3 - Fixed dependency, ARCH_R9A09G011->ARCH_R9A09G057 - Added dependency for PM - Added delay after de-assert operation as clks are halted temporarily after de-assert operation - clearing WDTSR register v1->v2 - Stopped using PM runtime calls in restart handler - Dropped rstc deassert from probe --- drivers/watchdog/Kconfig | 9 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/rzv2h_wdt.c | 272 +++++++++++++++++++++++++++++++++++ 3 files changed, 282 insertions(+) create mode 100644 drivers/watchdog/rzv2h_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index bae1d97cce89..684b9fe84fff 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -953,6 +953,15 @@ config RENESAS_RZG2LWDT This driver adds watchdog support for the integrated watchdogs in the Renesas RZ/G2L SoCs. These watchdogs can be used to reset a system. +config RENESAS_RZV2HWDT + tristate "Renesas RZ/V2H(P) WDT Watchdog" + depends on ARCH_R9A09G057 || COMPILE_TEST + depends on PM || COMPILE_TEST + select WATCHDOG_CORE + help + This driver adds watchdog support for the integrated watchdogs in the + Renesas RZ/V2H(P) SoCs. These watchdogs can be used to reset a system. + config ASPEED_WATCHDOG tristate "Aspeed BMC watchdog support" depends on ARCH_ASPEED || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index b51030f035a6..ab6f2b41e38e 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -86,6 +86,7 @@ obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o obj-$(CONFIG_RENESAS_RZAWDT) += rza_wdt.o obj-$(CONFIG_RENESAS_RZN1WDT) += rzn1_wdt.o obj-$(CONFIG_RENESAS_RZG2LWDT) += rzg2l_wdt.o +obj-$(CONFIG_RENESAS_RZV2HWDT) += rzv2h_wdt.o obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o diff --git a/drivers/watchdog/rzv2h_wdt.c b/drivers/watchdog/rzv2h_wdt.c new file mode 100644 index 000000000000..2da7a631fb2a --- /dev/null +++ b/drivers/watchdog/rzv2h_wdt.c @@ -0,0 +1,272 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/V2H(P) WDT Watchdog Driver + * + * Copyright (C) 2024 Renesas Electronics Corporation. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define WDTRR 0x00 /* WDT Refresh Register RW, 8 */ +#define WDTCR 0x02 /* WDT Control Register RW, 16 */ +#define WDTSR 0x04 /* WDT Status Register RW, 16 */ +#define WDTRCR 0x06 /* WDT Reset Control Register RW, 8 */ + +#define WDTCR_TOPS_1024 0x00 +#define WDTCR_TOPS_16384 0x03 + +#define WDTCR_CKS_CLK_1 0x00 +#define WDTCR_CKS_CLK_256 0x50 + +#define WDTCR_RPES_0 0x300 +#define WDTCR_RPES_75 0x000 + +#define WDTCR_RPSS_25 0x00 +#define WDTCR_RPSS_100 0x3000 + +#define WDTRCR_RSTIRQS BIT(7) + +#define MAX_TIMEOUT_CYCLES 16384 +#define CLOCK_DIV_BY_256 256 + +#define WDT_DEFAULT_TIMEOUT 60U + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +struct rzv2h_wdt_priv { + void __iomem *base; + struct clk *pclk; + struct clk *oscclk; + struct reset_control *rstc; + struct watchdog_device wdev; +}; + +static int rzv2h_wdt_ping(struct watchdog_device *wdev) +{ + struct rzv2h_wdt_priv *priv = watchdog_get_drvdata(wdev); + + /* + * The down-counter is refreshed and starts counting operation on + * a write of the values 00h and FFh to the WDTRR register. + */ + writeb(0x0, priv->base + WDTRR); + writeb(0xFF, priv->base + WDTRR); + + return 0; +} + +static void rzv2h_wdt_setup(struct watchdog_device *wdev, u16 wdtcr) +{ + struct rzv2h_wdt_priv *priv = watchdog_get_drvdata(wdev); + + /* Configure the timeout, clock division ratio, and window start and end positions. */ + writew(wdtcr, priv->base + WDTCR); + + /* Enable interrupt output to the ICU. */ + writeb(0, priv->base + WDTRCR); + + /* Clear underflow flag and refresh error flag. */ + writew(0, priv->base + WDTSR); +} + +static int rzv2h_wdt_start(struct watchdog_device *wdev) +{ + struct rzv2h_wdt_priv *priv = watchdog_get_drvdata(wdev); + int ret; + + ret = pm_runtime_resume_and_get(wdev->parent); + if (ret) + return ret; + + ret = reset_control_deassert(priv->rstc); + if (ret) { + pm_runtime_put(wdev->parent); + return ret; + } + + /* delay to handle clock halt after de-assert operation */ + udelay(3); + + /* + * WDTCR + * - CKS[7:4] - Clock Division Ratio Select - 0101b: oscclk/256 + * - RPSS[13:12] - Window Start Position Select - 11b: 100% + * - RPES[9:8] - Window End Position Select - 11b: 0% + * - TOPS[1:0] - Timeout Period Select - 11b: 16384 cycles (3FFFh) + */ + rzv2h_wdt_setup(wdev, WDTCR_CKS_CLK_256 | WDTCR_RPSS_100 | + WDTCR_RPES_0 | WDTCR_TOPS_16384); + + /* + * Down counting starts after writing the sequence 00h -> FFh to the + * WDTRR register. Hence, call the ping operation after loading the counter. + */ + rzv2h_wdt_ping(wdev); + + return 0; +} + +static int rzv2h_wdt_stop(struct watchdog_device *wdev) +{ + struct rzv2h_wdt_priv *priv = watchdog_get_drvdata(wdev); + int ret; + + ret = reset_control_assert(priv->rstc); + if (ret) + return ret; + + ret = pm_runtime_put(wdev->parent); + if (ret < 0) + return ret; + + return 0; +} + +static const struct watchdog_info rzv2h_wdt_ident = { + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, + .identity = "Renesas RZ/V2H WDT Watchdog", +}; + +static int rzv2h_wdt_restart(struct watchdog_device *wdev, + unsigned long action, void *data) +{ + struct rzv2h_wdt_priv *priv = watchdog_get_drvdata(wdev); + int ret; + + if (!watchdog_active(wdev)) { + ret = clk_enable(priv->pclk); + if (ret) + return ret; + + ret = clk_enable(priv->oscclk); + if (ret) { + clk_disable(priv->pclk); + return ret; + } + + ret = reset_control_deassert(priv->rstc); + if (ret) { + clk_disable(priv->oscclk); + clk_disable(priv->pclk); + return ret; + } + } else { + /* + * Writing to the WDT Control Register (WDTCR) or WDT Reset + * Control Register (WDTRCR) is possible once between the + * release from the reset state and the first refresh operation. + * Therefore, issue a reset if the watchdog is active. + */ + ret = reset_control_reset(priv->rstc); + if (ret) + return ret; + } + + /* delay to handle clock halt after de-assert operation */ + udelay(3); + + /* + * WDTCR + * - CKS[7:4] - Clock Division Ratio Select - 0000b: oscclk/1 + * - RPSS[13:12] - Window Start Position Select - 00b: 25% + * - RPES[9:8] - Window End Position Select - 00b: 75% + * - TOPS[1:0] - Timeout Period Select - 00b: 1024 cycles (03FFh) + */ + rzv2h_wdt_setup(wdev, WDTCR_CKS_CLK_1 | WDTCR_RPSS_25 | + WDTCR_RPES_75 | WDTCR_TOPS_1024); + + rzv2h_wdt_ping(wdev); + + /* wait for underflow to trigger... */ + udelay(5); + + return 0; +} + +static const struct watchdog_ops rzv2h_wdt_ops = { + .owner = THIS_MODULE, + .start = rzv2h_wdt_start, + .stop = rzv2h_wdt_stop, + .ping = rzv2h_wdt_ping, + .restart = rzv2h_wdt_restart, +}; + +static int rzv2h_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rzv2h_wdt_priv *priv; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->pclk = devm_clk_get_prepared(&pdev->dev, "pclk"); + if (IS_ERR(priv->pclk)) + return dev_err_probe(&pdev->dev, PTR_ERR(priv->pclk), "no pclk"); + + priv->oscclk = devm_clk_get_prepared(&pdev->dev, "oscclk"); + if (IS_ERR(priv->oscclk)) + return dev_err_probe(&pdev->dev, PTR_ERR(priv->oscclk), "no oscclk"); + + priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); + if (IS_ERR(priv->rstc)) + return dev_err_probe(&pdev->dev, PTR_ERR(priv->rstc), + "failed to get cpg reset"); + + priv->wdev.max_hw_heartbeat_ms = (MILLI * MAX_TIMEOUT_CYCLES * CLOCK_DIV_BY_256) / + clk_get_rate(priv->oscclk); + dev_dbg(dev, "max hw timeout of %dms\n", priv->wdev.max_hw_heartbeat_ms); + + ret = devm_pm_runtime_enable(&pdev->dev); + if (ret) + return ret; + + priv->wdev.min_timeout = 1; + priv->wdev.timeout = WDT_DEFAULT_TIMEOUT; + priv->wdev.info = &rzv2h_wdt_ident; + priv->wdev.ops = &rzv2h_wdt_ops; + priv->wdev.parent = dev; + watchdog_set_drvdata(&priv->wdev, priv); + watchdog_set_nowayout(&priv->wdev, nowayout); + watchdog_stop_on_unregister(&priv->wdev); + + ret = watchdog_init_timeout(&priv->wdev, 0, dev); + if (ret) + dev_warn(dev, "Specified timeout invalid, using default"); + + return devm_watchdog_register_device(&pdev->dev, &priv->wdev); +} + +static const struct of_device_id rzv2h_wdt_ids[] = { + { .compatible = "renesas,r9a09g057-wdt", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, rzv2h_wdt_ids); + +static struct platform_driver rzv2h_wdt_driver = { + .driver = { + .name = "rzv2h_wdt", + .of_match_table = rzv2h_wdt_ids, + }, + .probe = rzv2h_wdt_probe, +}; +module_platform_driver(rzv2h_wdt_driver); +MODULE_AUTHOR("Lad Prabhakar "); +MODULE_DESCRIPTION("Renesas RZ/V2H(P) WDT Watchdog Driver");