^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Implement 'Simple Boot Flag Specification 2.0'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/acpi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <asm/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/mc146818rtc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #define SBF_RESERVED (0x78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #define SBF_PNPOS (1<<0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #define SBF_BOOTING (1<<1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #define SBF_DIAG (1<<2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #define SBF_PARITY (1<<7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) int sbf_port __initdata = -1; /* set via acpi_boot_init() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) static int __init parity(u8 v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) int x = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) for (i = 0; i < 8; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) x ^= (v & 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) v >>= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) return x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static void __init sbf_write(u8 v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) if (sbf_port != -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) v &= ~SBF_PARITY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) if (!parity(v))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) v |= SBF_PARITY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) printk(KERN_INFO "Simple Boot Flag at 0x%x set to 0x%x\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) sbf_port, v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) spin_lock_irqsave(&rtc_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) CMOS_WRITE(v, sbf_port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) spin_unlock_irqrestore(&rtc_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) static u8 __init sbf_read(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) u8 v;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) if (sbf_port == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) spin_lock_irqsave(&rtc_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) v = CMOS_READ(sbf_port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) spin_unlock_irqrestore(&rtc_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) return v;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) static int __init sbf_value_valid(u8 v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) if (v & SBF_RESERVED) /* Reserved bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) if (!parity(v))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) static int __init sbf_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) u8 v;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) if (sbf_port == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) v = sbf_read();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) if (!sbf_value_valid(v)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) printk(KERN_WARNING "Simple Boot Flag value 0x%x read from "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) "CMOS RAM was invalid\n", v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) v &= ~SBF_RESERVED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) v &= ~SBF_BOOTING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) v &= ~SBF_DIAG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) #if defined(CONFIG_ISAPNP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) v |= SBF_PNPOS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) sbf_write(v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) arch_initcall(sbf_init);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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