Add support for hardware watchdog timer for Amlogic SoCs. This driver has been heavily inspired by his Linux equivalent (meson_gxbb_wdt.c).
Reviewed-by: Jerome Brunet jbrunet@baylibre.com Reviewed-by: Neil Armstrong narmstrong@baylibre.com
Signed-off-by: Philippe Boos pboos@baylibre.com
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Your recommendations have been implemented. I let you check this version 2. The reset works well when triggered by the wdt command in u-boot.
This watchdog driver has been tested on a GXL libretech-cc board and also on a custom G12a board. I did the following test cases: * boot with a faulty boot command, then we reach watchdog reset successfully, * boot a Linux kernel with and without watchdog support, and check if it is working as expected.
MAINTAINERS | 1 + doc/board/amlogic/index.rst | 2 + drivers/watchdog/Kconfig | 7 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/meson_gxbb_wdt.c | 136 ++++++++++++++++++++++++++++++ 5 files changed, 147 insertions(+) create mode 100644 drivers/watchdog/meson_gxbb_wdt.c
diff --git a/MAINTAINERS b/MAINTAINERS index 28e4d38238..ab3ef041f7 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -160,6 +160,7 @@ F: drivers/spi/meson_spifc.c F: drivers/pinctrl/meson/ F: drivers/power/domain/meson-gx-pwrc-vpu.c F: drivers/video/meson/ +F: drivers/watchdog/meson_gxbb_wdt.c F: include/configs/meson64.h F: include/configs/meson64_android.h F: doc/board/amlogic/ diff --git a/doc/board/amlogic/index.rst b/doc/board/amlogic/index.rst index 9c7fadf2c0..cc2ba50889 100644 --- a/doc/board/amlogic/index.rst +++ b/doc/board/amlogic/index.rst @@ -73,6 +73,8 @@ This matrix concerns the actual source code version. +-------------------------------+-----------+-----------------+--------------+-------------+------------+-------------+--------------+ | PCIe (+NVMe) | *N/A* | *N/A* | *N/A* | **Yes** | **Yes** | **Yes** | **Yes** | +-------------------------------+-----------+-----------------+--------------+-------------+------------+-------------+--------------+ +| Watchdog | *N/A* | **Yes** | *N/A* | *N/A* | *N/A* | *N/A* | *N/A* | ++-------------------------------+-----------+-----------------+--------------+-------------+------------+-------------+--------------+
Boot Documentation ------------------ diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index c3eb8a8aec..da0fa5396f 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -175,6 +175,13 @@ config WDT_MAX6370 help Select this to enable max6370 watchdog timer.
+config WDT_MESON_GXBB + bool "Amlogic watchdog timer support" + depends on WDT + help + Select this to enable Meson watchdog timer, + which can be found on some Amlogic platforms. + config WDT_MPC8xx bool "MPC8xx watchdog timer support" depends on WDT && MPC8xx diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 1f6199beca..0e2f582a5f 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_WDT_ORION) += orion_wdt.o obj-$(CONFIG_WDT_CDNS) += cdns_wdt.o obj-$(CONFIG_WDT_GPIO) += gpio_wdt.o obj-$(CONFIG_WDT_MAX6370) += max6370_wdt.o +obj-$(CONFIG_WDT_MESON_GXBB) += meson_gxbb_wdt.o obj-$(CONFIG_WDT_MPC8xx) += mpc8xx_wdt.o obj-$(CONFIG_WDT_MT7620) += mt7620_wdt.o obj-$(CONFIG_WDT_MT7621) += mt7621_wdt.o diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c new file mode 100644 index 0000000000..6ab005813f --- /dev/null +++ b/drivers/watchdog/meson_gxbb_wdt.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2022 BayLibre, SAS. + */ + +#include <clk.h> +#include <dm.h> +#include <dm/device_compat.h> +#include <reset.h> +#include <wdt.h> +#include <asm/io.h> +#include <linux/bitops.h> + +#define GXBB_WDT_CTRL_REG 0x0 +#define GXBB_WDT_TCNT_REG 0x8 +#define GXBB_WDT_RSET_REG 0xc + +#define GXBB_WDT_CTRL_SYS_RESET_NOW BIT(26) +#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25) +#define GXBB_WDT_CTRL_CLK_EN BIT(24) +#define GXBB_WDT_CTRL_EE_RESET BIT(21) +#define GXBB_WDT_CTRL_EN BIT(18) + +#define GXBB_WDT_CTRL_DIV_MASK GENMASK(17, 0) +#define GXBB_WDT_TCNT_SETUP_MASK GENMASK(15, 0) + + +struct amlogic_wdt_priv { + void __iomem *reg_base; +}; + +static int amlogic_wdt_set_timeout(struct udevice *dev, u64 timeout_ms) +{ + struct amlogic_wdt_priv *data = dev_get_priv(dev); + + if (timeout_ms > GXBB_WDT_TCNT_SETUP_MASK) { + dev_warn(dev, "%s: timeout_ms=%llu: maximum watchdog timeout exceeded\n", + __func__, timeout_ms); + timeout_ms = GXBB_WDT_TCNT_SETUP_MASK; + } + + writel(timeout_ms, data->reg_base + GXBB_WDT_TCNT_REG); + + return 0; +} + +static int amlogic_wdt_stop(struct udevice *dev) +{ + struct amlogic_wdt_priv *data = dev_get_priv(dev); + + writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN, + data->reg_base + GXBB_WDT_CTRL_REG); + + return 0; +} + +static int amlogic_wdt_start(struct udevice *dev, u64 time_ms, ulong flags) +{ + struct amlogic_wdt_priv *data = dev_get_priv(dev); + + writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN, + data->reg_base + GXBB_WDT_CTRL_REG); + + return amlogic_wdt_set_timeout(dev, time_ms); +} + +static int amlogic_wdt_reset(struct udevice *dev) +{ + struct amlogic_wdt_priv *data = dev_get_priv(dev); + + writel(0, data->reg_base + GXBB_WDT_RSET_REG); + + return 0; +} + +static int amlogic_wdt_expire_now(struct udevice *dev, ulong flags) +{ + struct amlogic_wdt_priv *data = dev_get_priv(dev); + + writel(0, data->reg_base + GXBB_WDT_CTRL_SYS_RESET_NOW); + + return 0; +} + +static int amlogic_wdt_probe(struct udevice *dev) +{ + struct amlogic_wdt_priv *data = dev_get_priv(dev); + int ret; + + data->reg_base = dev_remap_addr(dev); + if (!data->reg_base) + return -EINVAL; + + struct clk clk; + + ret = clk_get_by_index(dev, 0, &clk); + if (ret) + return ret; + + ret = clk_enable(&clk); + if (ret) { + clk_free(&clk); + return ret; + } + + /* Setup with 1ms timebase */ + writel(((clk_get_rate(&clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) | + GXBB_WDT_CTRL_EE_RESET | + GXBB_WDT_CTRL_CLK_EN | + GXBB_WDT_CTRL_CLKDIV_EN, + data->reg_base + GXBB_WDT_CTRL_REG); + + return 0; +} + +static const struct wdt_ops amlogic_wdt_ops = { + .start = amlogic_wdt_start, + .reset = amlogic_wdt_reset, + .stop = amlogic_wdt_stop, + .expire_now = amlogic_wdt_expire_now, +}; + +static const struct udevice_id amlogic_wdt_ids[] = { + { .compatible = "amlogic,meson-gxbb-wdt" }, + {} +}; + +U_BOOT_DRIVER(amlogic_wdt) = { + .name = "amlogic_wdt", + .id = UCLASS_WDT, + .of_match = amlogic_wdt_ids, + .priv_auto = sizeof(struct amlogic_wdt_priv), + .probe = amlogic_wdt_probe, + .ops = &amlogic_wdt_ops, + .flags = DM_FLAG_PRE_RELOC, +};