From: Ashok Reddy Soma ashok.reddy.soma@xilinx.com
Add support for Xilinx window watchdog, which can be found on Versal platforms.
Signed-off-by: Ashok Reddy Soma ashok.reddy.soma@xilinx.com Signed-off-by: Michal Simek michal.simek@xilinx.com ---
Changes in v2: - Reverse subject prefixes - Convert to regmap as was asked - Rename WWDT_XILINX to WDT_XILINX
MAINTAINERS | 1 + drivers/watchdog/Kconfig | 9 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/xilinx_wwdt.c | 179 +++++++++++++++++++++++++++++++++ 4 files changed, 190 insertions(+) create mode 100644 drivers/watchdog/xilinx_wwdt.c
diff --git a/MAINTAINERS b/MAINTAINERS index 92dda40a85df..b14d83475d7c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -447,6 +447,7 @@ M: Michal Simek michal.simek@xilinx.com S: Maintained T: git https://gitlab.denx.de/u-boot/custodians/u-boot-microblaze.git F: arch/arm/mach-versal/ +F: drivers/watchdog/xilinx_wwdt.c N: (?<!uni)versal
ARM VERSATILE EXPRESS DRIVERS diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index cb4da2e3cf88..6cafd243e049 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -185,6 +185,15 @@ config XILINX_TB_WATCHDOG Select this to enable Xilinx Axi watchdog timer, which can be found on some Xilinx Microblaze Platforms.
+config WDT_XILINX + bool "Xilinx window watchdog timer support" + depends on WDT && ARCH_VERSAL + select REGMAP + imply WATCHDOG + help + Select this to enable Xilinx window watchdog timer, which can be found on + Xilinx Versal Platforms. + config WDT_TANGIER bool "Intel Tangier watchdog timer support" depends on WDT && INTEL_MID diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 87f92a43b14e..519bbd3a40fc 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -30,3 +30,4 @@ obj-$(CONFIG_WDT_OMAP3) += omap_wdt.o obj-$(CONFIG_WDT_SP805) += sp805_wdt.o obj-$(CONFIG_WDT_STM32MP) += stm32mp_wdt.o obj-$(CONFIG_WDT_TANGIER) += tangier_wdt.o +obj-$(CONFIG_WDT_XILINX) += xilinx_wwdt.o diff --git a/drivers/watchdog/xilinx_wwdt.c b/drivers/watchdog/xilinx_wwdt.c new file mode 100644 index 000000000000..d8a585a48306 --- /dev/null +++ b/drivers/watchdog/xilinx_wwdt.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Xilinx window watchdog timer driver. + * + * Author(s): Michal Simek michal.simek@xilinx.com + * Ashok Reddy Soma ashokred@xilinx.com + * + * Copyright (c) 2020, Xilinx Inc. + */ + +#include <clk.h> +#include <common.h> +#include <dm.h> +#include <regmap.h> +#include <wdt.h> +#include <linux/compat.h> +#include <linux/io.h> + +/* Refresh Register Masks */ +#define XWT_WWREF_GWRR_MASK BIT(0) /* Refresh and start new period */ + +/* Generic Control/Status Register Masks */ +#define XWT_WWCSR_GWEN_MASK BIT(0) /* Enable Bit */ + +/* Register offsets for the Wdt device */ +#define XWT_WWREF_OFFSET 0x1000 /* Refresh Register */ +#define XWT_WWCSR_OFFSET 0x2000 /* Control/Status Register */ +#define XWT_WWOFF_OFFSET 0x2008 /* Offset Register */ +#define XWT_WWCMP0_OFFSET 0x2010 /* Compare Value Register0 */ +#define XWT_WWCMP1_OFFSET 0x2014 /* Compare Value Register1 */ +#define XWT_WWWRST_OFFSET 0x2FD0 /* Warm Reset Register */ + +struct xlnx_wwdt_priv { + bool enable_once; + struct regmap *regs; + struct clk clk; +}; + +struct xlnx_wwdt_platdata { + bool enable_once; +}; + +static int xlnx_wwdt_reset(struct udevice *dev) +{ + struct xlnx_wwdt_priv *wdt = dev_get_priv(dev); + + regmap_write(wdt->regs, XWT_WWREF_OFFSET, XWT_WWREF_GWRR_MASK); + + return 0; +} + +static int xlnx_wwdt_stop(struct udevice *dev) +{ + u32 csr; + struct xlnx_wwdt_priv *wdt = dev_get_priv(dev); + + if (wdt->enable_once) { + dev_warn(dev, "Can't stop Xilinx watchdog.\n"); + return -EBUSY; + } + + /* Disable the generic watchdog timer */ + regmap_read(wdt->regs, XWT_WWCSR_OFFSET, &csr); + csr &= ~(XWT_WWCSR_GWEN_MASK); + regmap_write(wdt->regs, XWT_WWCSR_OFFSET, csr); + + clk_disable(&wdt->clk); + + dev_dbg(dev, "Watchdog disabled!\n"); + + return 0; +} + +static int xlnx_wwdt_start(struct udevice *dev, u64 timeout, ulong flags) +{ + int ret; + u32 csr; + u64 count; + unsigned long clock_f; + struct xlnx_wwdt_priv *wdt = dev_get_priv(dev); + + clock_f = clk_get_rate(&wdt->clk); + if (IS_ERR_VALUE(clock_f)) { + dev_err(dev, "failed to get rate\n"); + return clock_f; + } + + dev_dbg(dev, "%s: CLK %ld\n", __func__, clock_f); + + /* Calculate timeout count */ + count = timeout * clock_f; + + /* clk_enable will return -ENOSYS when it is not implemented */ + ret = clk_enable(&wdt->clk); + if (ret && ret != -ENOSYS) { + dev_err(dev, "failed to enable clock\n"); + return ret; + } + + /* + * Timeout count is half as there are two windows + * first window overflow is ignored (interrupt), + * reset is only generated at second window overflow + */ + count = count >> 1; + + /* Disable the generic watchdog timer */ + regmap_read(wdt->regs, XWT_WWCSR_OFFSET, &csr); + csr &= ~(XWT_WWCSR_GWEN_MASK); + regmap_write(wdt->regs, XWT_WWCSR_OFFSET, csr); + + /* Set compare and offset registers for generic watchdog timeout */ + regmap_write(wdt->regs, XWT_WWCMP0_OFFSET, (u32)count); + regmap_write(wdt->regs, XWT_WWCMP1_OFFSET, 0); + regmap_write(wdt->regs, XWT_WWOFF_OFFSET, (u32)count); + + /* Enable the generic watchdog timer */ + regmap_read(wdt->regs, XWT_WWCSR_OFFSET, &csr); + csr |= (XWT_WWCSR_GWEN_MASK); + regmap_write(wdt->regs, XWT_WWCSR_OFFSET, csr); + + return 0; +} + +static int xlnx_wwdt_probe(struct udevice *dev) +{ + int ret; + struct xlnx_wwdt_platdata *platdata = dev_get_platdata(dev); + struct xlnx_wwdt_priv *wdt = dev_get_priv(dev); + + dev_dbg(dev, "%s: Probing wdt%u\n", __func__, dev->seq); + + ret = regmap_init_mem(dev_ofnode(dev), &wdt->regs); + if (ret) { + dev_dbg(dev, "failed to get regbase of wwdt\n"); + return ret; + } + + wdt->enable_once = platdata->enable_once; + + ret = clk_get_by_index(dev, 0, &wdt->clk); + if (ret < 0) + dev_err(dev, "failed to get clock\n"); + + return ret; +} + +static int xlnx_wwdt_ofdata_to_platdata(struct udevice *dev) +{ + struct xlnx_wwdt_platdata *platdata = dev_get_platdata(dev); + + platdata->enable_once = dev_read_u32_default(dev, + "xlnx,wdt-enable-once", 0); + dev_dbg(dev, "wdt-enable-once %d\n", platdata->enable_once); + + return 0; +} + +static const struct wdt_ops xlnx_wwdt_ops = { + .start = xlnx_wwdt_start, + .reset = xlnx_wwdt_reset, + .stop = xlnx_wwdt_stop, +}; + +static const struct udevice_id xlnx_wwdt_ids[] = { + { .compatible = "xlnx,versal-wwdt-1.0", }, + {}, +}; + +U_BOOT_DRIVER(xlnx_wwdt) = { + .name = "xlnx_wwdt", + .id = UCLASS_WDT, + .of_match = xlnx_wwdt_ids, + .probe = xlnx_wwdt_probe, + .priv_auto_alloc_size = sizeof(struct xlnx_wwdt_priv), + .platdata_auto_alloc_size = sizeof(struct xlnx_wwdt_platdata), + .ofdata_to_platdata = xlnx_wwdt_ofdata_to_platdata, + .ops = &xlnx_wwdt_ops, +};