1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Intel CE4100 platform specific setup code
4 *
5 * (C) Copyright 2010 Intel Corporation
6 */
7 #include <linux/init.h>
8 #include <linux/kernel.h>
9 #include <linux/irq.h>
10 #include <linux/reboot.h>
11 #include <linux/serial_reg.h>
12 #include <linux/serial_8250.h>
13
14 #include <asm/ce4100.h>
15 #include <asm/prom.h>
16 #include <asm/setup.h>
17 #include <asm/i8259.h>
18 #include <asm/io.h>
19 #include <asm/io_apic.h>
20 #include <asm/emergency-restart.h>
21
22 /*
23 * The CE4100 platform has an internal 8051 Microcontroller which is
24 * responsible for signaling to the external Power Management Unit the
25 * intention to reset, reboot or power off the system. This 8051 device has
26 * its command register mapped at I/O port 0xcf9 and the value 0x4 is used
27 * to power off the system.
28 */
29 static void ce4100_power_off(void)
30 {
31 outb(0x4, 0xcf9);
32 }
33
34 #ifdef CONFIG_SERIAL_8250
35
36 static unsigned int mem_serial_in(struct uart_port *p, int offset)
37 {
38 offset = offset << p->regshift;
39 return readl(p->membase + offset);
40 }
41
42 /*
43 * The UART Tx interrupts are not set under some conditions and therefore serial
44 * transmission hangs. This is a silicon issue and has not been root caused. The
45 * workaround for this silicon issue checks UART_LSR_THRE bit and UART_LSR_TEMT
46 * bit of LSR register in interrupt handler to see whether at least one of these
47 * two bits is set, if so then process the transmit request. If this workaround
48 * is not applied, then the serial transmission may hang. This workaround is for
49 * errata number 9 in Errata - B step.
50 */
51
52 static unsigned int ce4100_mem_serial_in(struct uart_port *p, int offset)
53 {
54 unsigned int ret, ier, lsr;
55
56 if (offset == UART_IIR) {
57 offset = offset << p->regshift;
58 ret = readl(p->membase + offset);
59 if (ret & UART_IIR_NO_INT) {
60 /* see if the TX interrupt should have really set */
61 ier = mem_serial_in(p, UART_IER);
62 /* see if the UART's XMIT interrupt is enabled */
63 if (ier & UART_IER_THRI) {
64 lsr = mem_serial_in(p, UART_LSR);
65 /* now check to see if the UART should be
66 generating an interrupt (but isn't) */
67 if (lsr & (UART_LSR_THRE | UART_LSR_TEMT))
68 ret &= ~UART_IIR_NO_INT;
69 }
70 }
71 } else
72 ret = mem_serial_in(p, offset);
73 return ret;
74 }
75
76 static void ce4100_mem_serial_out(struct uart_port *p, int offset, int value)
77 {
78 offset = offset << p->regshift;
79 writel(value, p->membase + offset);
80 }
81
82 static void ce4100_serial_fixup(int port, struct uart_port *up,
83 u32 *capabilities)
84 {
85 #ifdef CONFIG_EARLY_PRINTK
86 /*
87 * Over ride the legacy port configuration that comes from
88 * asm/serial.h. Using the ioport driver then switching to the
89 * PCI memmaped driver hangs the IOAPIC
90 */
91 if (up->iotype != UPIO_MEM32) {
92 up->uartclk = 14745600;
93 up->mapbase = 0xdffe0200;
94 set_fixmap_nocache(FIX_EARLYCON_MEM_BASE,
95 up->mapbase & PAGE_MASK);
96 up->membase =
97 (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
98 up->membase += up->mapbase & ~PAGE_MASK;
99 up->mapbase += port * 0x100;
100 up->membase += port * 0x100;
101 up->iotype = UPIO_MEM32;
102 up->regshift = 2;
103 up->irq = 4;
104 }
105 #endif
106 up->iobase = 0;
107 up->serial_in = ce4100_mem_serial_in;
108 up->serial_out = ce4100_mem_serial_out;
109
110 *capabilities |= (1 << 12);
111 }
112
113 static __init void sdv_serial_fixup(void)
114 {
115 serial8250_set_isa_configurator(ce4100_serial_fixup);
116 }
117
118 #else
119 static inline void sdv_serial_fixup(void) {};
120 #endif
121
122 static void __init sdv_arch_setup(void)
123 {
124 sdv_serial_fixup();
125 }
126
127 static void sdv_pci_init(void)
128 {
129 x86_of_pci_init();
130 }
131
132 /*
133 * CE4100 specific x86_init function overrides and early setup
134 * calls.
135 */
136 void __init x86_ce4100_early_setup(void)
137 {
138 x86_init.oem.arch_setup = sdv_arch_setup;
139 x86_init.resources.probe_roms = x86_init_noop;
140 x86_init.mpparse.find_mptable = x86_init_noop;
141 x86_init.mpparse.early_parse_smp_cfg = x86_init_noop;
142 x86_init.pci.init = ce4100_pci_init;
143 x86_init.pci.init_irq = sdv_pci_init;
144
145 /*
146 * By default, the reboot method is ACPI which is supported by the
147 * CE4100 bootloader CEFDK using FADT.ResetReg Address and ResetValue
148 * the bootloader will however issue a system power off instead of
149 * reboot. By using BOOT_KBD we ensure proper system reboot as
150 * expected.
151 */
152 reboot_type = BOOT_KBD;
153
154 pm_power_off = ce4100_power_off;
155 }
156
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