diff options
| -rw-r--r-- | src/sys/acpi/acpi_init.c | 6 | ||||
| -rw-r--r-- | src/sys/arch/amd64/io/hpet.c | 161 | ||||
| -rw-r--r-- | src/sys/include/arch/amd64/hpet.h | 40 |
3 files changed, 207 insertions, 0 deletions
diff --git a/src/sys/acpi/acpi_init.c b/src/sys/acpi/acpi_init.c index bb98ff4..e931b36 100644 --- a/src/sys/acpi/acpi_init.c +++ b/src/sys/acpi/acpi_init.c @@ -32,6 +32,9 @@ #include <sys/syslog.h> #include <acpi/acpi.h> #include <acpi/tables.h> +#if defined(__x86_64__) +#include <machine/hpet.h> +#endif #include <vm/vm.h> static size_t root_sdt_len = 0; @@ -83,5 +86,8 @@ acpi_early_init(void) } root_sdt_len = (root_sdt->hdr.length - sizeof(root_sdt->hdr)) / 4; +#if defined(__x86_64__) + hpet_init(); +#endif return 0; } diff --git a/src/sys/arch/amd64/io/hpet.c b/src/sys/arch/amd64/io/hpet.c new file mode 100644 index 0000000..7b7ea35 --- /dev/null +++ b/src/sys/arch/amd64/io/hpet.c @@ -0,0 +1,161 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and L5 engineers + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/* + * Description: IA-PC HPET timer driver + * Author: Ian Marco Moffett + */ + +#include <sys/types.h> +#include <sys/errno.h> +#include <sys/param.h> +#include <sys/syslog.h> +#include <os/mmio.h> +#include <acpi/acpi.h> +#include <acpi/tables.h> +#include <machine/hpet.h> + +#define HPET_REG_CAPS 0x00 +#define HPET_GENERAL_CONFIG 0x10 +#define HPET_REG_MAIN_COUNTER 0xF0 + +#define CAP_REV_ID(caps) (caps & 0xFF) +#define CAP_NUM_TIM(caps) (caps >> 8) & 0x1F +#define CAP_CLK_PERIOD(caps) (caps >> 32) + +static void *hpet_base = NULL; + +/* + * Read from HPET register space. + * + * @reg: Register to read from. + */ +static inline uint64_t +hpet_read(uint32_t reg) +{ + void *addr; + + addr = PTR_OFFSET(hpet_base, reg); + return mmio_read64(addr); +} + +/* + * Write to HPET register space. + * + * @reg: Register to write to. + * @val: Value to write. + */ +static inline void +hpet_write(uint32_t reg, uint64_t val) +{ + void *addr; + + addr = PTR_OFFSET(hpet_base, reg); + mmio_write64(addr, val); +} + +/* + * Sleep for 'n' amount of 'units' + * + * @n: Number of 'units' to sleep + * @units: Units per 'n' + * + * Returns zero on success, otherwise a less than zero + * value. + */ +static int +hpet_sleep(uint64_t n, uint64_t units) +{ + uint64_t caps; + uint32_t period; + uint64_t counter_val; + volatile size_t ticks; + + caps = hpet_read(HPET_REG_CAPS); + period = CAP_CLK_PERIOD(caps); + counter_val = hpet_read(HPET_REG_MAIN_COUNTER); + + ticks = counter_val + (n * (units / period)); + + while (hpet_read(HPET_REG_MAIN_COUNTER) < ticks) { + __ASMV("rep; nop"); + } + + return 0; +} + +static int +hpet_msleep(size_t ms) +{ + return hpet_sleep(ms, 1000000000000); +} + +/* + * Initialize the HPET + */ +int +hpet_init(void) +{ + struct acpi_gas *gas; + struct acpi_hpet *hpet; + uint64_t caps; + + hpet = acpi_query("HPET"); + if (hpet == NULL) { + return -ENODEV; + } + + gas = &hpet->gas; + hpet_base = (void *)gas->address; + + caps = hpet_read(HPET_REG_CAPS); + if (CAP_REV_ID(caps) == 0) { + printf("hpet_init: bad revision HPET ID\n"); + return -1; + } + + /* + * The spec states this counter clk period must + * be <= 0x05F5E100. So we'll consider it as bogus + * if it exceeds this value + */ + if (CAP_CLK_PERIOD(caps) > 0x05F5E100) { + printf("hpet_init: bad COUNTER_CLK_PERIOD\n"); + return -1; + } + + /* + * Clear the counter and enable the HPET via + * the ENABLE_CNF bit in general_config + */ + hpet_write(HPET_REG_MAIN_COUNTER, 0); + hpet_write(HPET_GENERAL_CONFIG, 1); + printf("hpet: HPET initialized and enabled\n"); + return 0; +} diff --git a/src/sys/include/arch/amd64/hpet.h b/src/sys/include/arch/amd64/hpet.h new file mode 100644 index 0000000..7913b4c --- /dev/null +++ b/src/sys/include/arch/amd64/hpet.h @@ -0,0 +1,40 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and L5 engineers + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _MACHINE_HPET_H_ +#define _MACHINE_HPET_H_ + +#include <sys/types.h> + +/* + * Initialize the HPET into a basic state + */ +int hpet_init(void); + +#endif /* !_MACHINE_HPET_H_ */ |