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 ---
MAINTAINERS | 1 + drivers/watchdog/Kconfig | 8 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/xilinx_wwdt.c | 185 +++++++++++++++++++++++++++++++++ 4 files changed, 195 insertions(+) create mode 100644 drivers/watchdog/xilinx_wwdt.c
diff --git a/MAINTAINERS b/MAINTAINERS index 37ff21a037b4..7cb1bc0957a3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -433,6 +433,7 @@ 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 d24c1e48353f..b3911cf346ed 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -185,6 +185,14 @@ config XILINX_TB_WATCHDOG Select this to enable Xilinx Axi watchdog timer, which can be found on some Xilinx Microblaze Platforms.
+config WWDT_XILINX + bool "Xilinx window watchdog timer support" + depends on WDT && ARCH_VERSAL + 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..dc25560dbadf 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_WWDT_XILINX) += xilinx_wwdt.o diff --git a/drivers/watchdog/xilinx_wwdt.c b/drivers/watchdog/xilinx_wwdt.c new file mode 100644 index 000000000000..34018e2b2b34 --- /dev/null +++ b/drivers/watchdog/xilinx_wwdt.c @@ -0,0 +1,185 @@ +// 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 <wdt.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 */ + +struct wwdt_regs { + u32 reserved0[1024]; + u32 refresh; /* Refresh Register [0x1000] */ + u32 reserved1[1023]; + u32 csr; /* Control/Status Register [0x2000] */ + u32 reserved2; + u32 offset; /* Offset Register [0x2008] */ + u32 reserved3; + u32 cmp0; /* Compare Value Register0 [0x2010] */ + u32 cmp1; /* Compare Value Register1 [0x2014] */ + u32 reserved4[1006]; + u32 warmrst; /* Warm Reset Register [0x2FD0] */ +}; + +struct xlnx_wwdt_priv { + bool enable_once; + struct wwdt_regs *regs; + struct clk clk; +}; + +struct xlnx_wwdt_platdata { + bool enable_once; + phys_addr_t iobase; +}; + +static int xlnx_wwdt_reset(struct udevice *dev) +{ + struct xlnx_wwdt_priv *wdt = dev_get_priv(dev); + + dev_dbg(dev, "%s ", __func__); + + writel(XWT_WWREF_GWRR_MASK, &wdt->regs->refresh); + + 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 */ + csr = readl(&wdt->regs->csr); + csr &= ~(XWT_WWCSR_GWEN_MASK); + writel(csr, &wdt->regs->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); + + dev_dbg(dev, "%s:\n", __func__); + + 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 */ + csr = readl(&wdt->regs->csr); + csr &= ~(XWT_WWCSR_GWEN_MASK); + writel(csr, &wdt->regs->csr); + + /* Set compare and offset registers for generic watchdog timeout */ + writel((u32)count, &wdt->regs->cmp0); + writel((u32)0, &wdt->regs->cmp1); + writel((u32)count, &wdt->regs->offset); + + /* Enable the generic watchdog timer */ + csr = readl(&wdt->regs->csr); + csr |= (XWT_WWCSR_GWEN_MASK); + writel(csr, &wdt->regs->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); + + wdt->regs = (struct wwdt_regs *)ioremap(platdata->iobase, + sizeof(struct wwdt_regs)); + 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->iobase = dev_read_addr(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, +};