diff options
| author | Green Wan <green.wan@sifive.com> | 2021-07-13 11:23:45 +0800 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2021-07-17 14:12:07 +0530 |
| commit | e3d6919d10d73ff97cfe583cc78fc01c7beaf4b5 (patch) | |
| tree | 07e84a394080af03f315a24a08337938ef4e0ad5 | |
| parent | 4c3df2ab96be2ae513b80ee96d1db7b97155d231 (diff) | |
lib: utils/reset: Add generic GPIO reset driver
We add generic GPIO reset driver inspired from gpio-restart
and gpio-poweroff drivers of Linux kernel.
Signed-off-by: Green Wan <green.wan@sifive.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
| -rw-r--r-- | lib/utils/reset/fdt_reset.c | 2 | ||||
| -rw-r--r-- | lib/utils/reset/fdt_reset_gpio.c | 141 | ||||
| -rw-r--r-- | lib/utils/reset/objects.mk | 1 |
3 files changed, 144 insertions, 0 deletions
diff --git a/lib/utils/reset/fdt_reset.c b/lib/utils/reset/fdt_reset.c index 48a49fb..aa5f59f 100644 --- a/lib/utils/reset/fdt_reset.c +++ b/lib/utils/reset/fdt_reset.c @@ -12,11 +12,13 @@ #include <sbi_utils/fdt/fdt_helper.h> #include <sbi_utils/reset/fdt_reset.h> +extern struct fdt_reset fdt_reset_gpio; extern struct fdt_reset fdt_reset_sifive_test; extern struct fdt_reset fdt_reset_htif; extern struct fdt_reset fdt_reset_thead; static struct fdt_reset *reset_drivers[] = { + &fdt_reset_gpio, &fdt_reset_sifive_test, &fdt_reset_htif, &fdt_reset_thead, diff --git a/lib/utils/reset/fdt_reset_gpio.c b/lib/utils/reset/fdt_reset_gpio.c new file mode 100644 index 0000000..7e0eb74 --- /dev/null +++ b/lib/utils/reset/fdt_reset_gpio.c @@ -0,0 +1,141 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2021 SiFive + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * + * Authors: + * Green Wan <green.wan@sifive.com> + * Anup Patel <anup.patel@wdc.com> + */ + +#include <libfdt.h> +#include <sbi/sbi_console.h> +#include <sbi/sbi_ecall_interface.h> +#include <sbi/sbi_hart.h> +#include <sbi/sbi_system.h> +#include <sbi_utils/fdt/fdt_helper.h> +#include <sbi_utils/gpio/fdt_gpio.h> +#include <sbi_utils/reset/fdt_reset.h> + +struct gpio_reset { + struct gpio_pin pin; + u32 active_delay; + u32 inactive_delay; +}; + +static struct gpio_reset poweroff = { + .active_delay = 100, + .inactive_delay = 100 +}; + +static struct gpio_reset restart = { + .active_delay = 100, + .inactive_delay = 100 +}; + +/* Custom mdelay function until we have a generic mdelay() API */ +static void gpio_mdelay(unsigned long msecs) +{ + volatile int i; + while (msecs--) + for (i = 0; i < 100000; i++) ; +} + +static int gpio_system_reset_check(u32 type, u32 reason) +{ + switch (type) { + case SBI_SRST_RESET_TYPE_SHUTDOWN: + case SBI_SRST_RESET_TYPE_COLD_REBOOT: + case SBI_SRST_RESET_TYPE_WARM_REBOOT: + return 1; + } + + return 0; +} + +static void gpio_system_reset(u32 type, u32 reason) +{ + struct gpio_reset *reset = NULL; + + switch (type) { + case SBI_SRST_RESET_TYPE_SHUTDOWN: + reset = &poweroff; + break; + case SBI_SRST_RESET_TYPE_COLD_REBOOT: + case SBI_SRST_RESET_TYPE_WARM_REBOOT: + reset = &restart; + break; + } + + if (reset) { + if (!reset->pin.chip) { + sbi_printf("%s: gpio pin not available\n", __func__); + goto skip_reset; + } + + /* drive it active, also inactive->active edge */ + gpio_direction_output(&reset->pin, 1); + gpio_mdelay(reset->active_delay); + + /* drive inactive, also active->inactive edge */ + gpio_set(&reset->pin, 0); + gpio_mdelay(reset->inactive_delay); + + /* drive it active, also inactive->active edge */ + gpio_set(&reset->pin, 1); + +skip_reset: + /* hang !!! */ + sbi_hart_hang(); + } +} + +static struct sbi_system_reset_device gpio_reset = { + .name = "gpio-reset", + .system_reset_check = gpio_system_reset_check, + .system_reset = gpio_system_reset +}; + +static int gpio_reset_init(void *fdt, int nodeoff, + const struct fdt_match *match) +{ + int rc, len; + const fdt32_t *val; + bool is_restart = (ulong)match->data; + const char *dir_prop = (is_restart) ? "open-source" : "input"; + struct gpio_reset *reset = (is_restart) ? &restart : &poweroff; + + rc = fdt_gpio_pin_get(fdt, nodeoff, 0, &reset->pin); + if (rc) + return rc; + + if (fdt_getprop(fdt, nodeoff, dir_prop, &len)) { + rc = gpio_direction_input(&reset->pin); + if (rc) + return rc; + } + + val = fdt_getprop(fdt, nodeoff, "active-delay-ms", &len); + if (len > 0) + reset->active_delay = fdt32_to_cpu(*val); + + val = fdt_getprop(fdt, nodeoff, "inactive-delay-ms", &len); + if (len > 0) + reset->inactive_delay = fdt32_to_cpu(*val); + + sbi_system_reset_set_device(&gpio_reset); + + return 0; +} + +static const struct fdt_match gpio_reset_match[] = { + { .compatible = "gpio-poweroff", .data = (void *)FALSE }, + { .compatible = "gpio-restart", .data = (void *)TRUE }, + { }, +}; + +struct fdt_reset fdt_reset_gpio = { + .match_table = gpio_reset_match, + .init = gpio_reset_init, +}; diff --git a/lib/utils/reset/objects.mk b/lib/utils/reset/objects.mk index 672aad9..4215396 100644 --- a/lib/utils/reset/objects.mk +++ b/lib/utils/reset/objects.mk @@ -8,6 +8,7 @@ # libsbiutils-objs-y += reset/fdt_reset.o +libsbiutils-objs-y += reset/fdt_reset_gpio.o libsbiutils-objs-y += reset/fdt_reset_htif.o libsbiutils-objs-y += reset/fdt_reset_thead.o libsbiutils-objs-y += reset/fdt_reset_thead_asm.o |