1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2016 Imagination Technologies
4 * Author: Paul Burton <paul.burton@mips.com>
5 */
6
7 #define pr_fmt(fmt) "sead3: " fmt
8
9 #include <linux/errno.h>
10 #include <linux/libfdt.h>
11 #include <linux/printk.h>
12 #include <linux/sizes.h>
13
14 #include <asm/fw/fw.h>
15 #include <asm/io.h>
16 #include <asm/machine.h>
17 #include <asm/yamon-dt.h>
18
19 #define SEAD_CONFIG CKSEG1ADDR(0x1b100110)
20 #define SEAD_CONFIG_GIC_PRESENT BIT(1)
21
22 #define MIPS_REVISION CKSEG1ADDR(0x1fc00010)
23 #define MIPS_REVISION_MACHINE (0xf << 4)
24 #define MIPS_REVISION_MACHINE_SEAD3 (0x4 << 4)
25
26 /*
27 * Maximum 384MB RAM at physical address 0, preceding any I/O.
28 */
29 static struct yamon_mem_region mem_regions[] __initdata = {
30 /* start size */
31 { 0, SZ_256M + SZ_128M },
32 {}
33 };
34
sead3_detect(void)35 static __init bool sead3_detect(void)
36 {
37 uint32_t rev;
38
39 rev = __raw_readl((void *)MIPS_REVISION);
40 return (rev & MIPS_REVISION_MACHINE) == MIPS_REVISION_MACHINE_SEAD3;
41 }
42
append_memory(void * fdt)43 static __init int append_memory(void *fdt)
44 {
45 return yamon_dt_append_memory(fdt, mem_regions);
46 }
47
remove_gic(void * fdt)48 static __init int remove_gic(void *fdt)
49 {
50 const unsigned int cpu_ehci_int = 2;
51 const unsigned int cpu_uart_int = 4;
52 const unsigned int cpu_eth_int = 6;
53 int gic_off, cpu_off, uart_off, eth_off, ehci_off, err;
54 uint32_t cfg, cpu_phandle;
55
56 /* leave the GIC node intact if a GIC is present */
57 cfg = __raw_readl((uint32_t *)SEAD_CONFIG);
58 if (cfg & SEAD_CONFIG_GIC_PRESENT)
59 return 0;
60
61 gic_off = fdt_node_offset_by_compatible(fdt, -1, "mti,gic");
62 if (gic_off < 0) {
63 pr_err("unable to find DT GIC node: %d\n", gic_off);
64 return gic_off;
65 }
66
67 err = fdt_nop_node(fdt, gic_off);
68 if (err) {
69 pr_err("unable to nop GIC node\n");
70 return err;
71 }
72
73 cpu_off = fdt_node_offset_by_compatible(fdt, -1,
74 "mti,cpu-interrupt-controller");
75 if (cpu_off < 0) {
76 pr_err("unable to find CPU intc node: %d\n", cpu_off);
77 return cpu_off;
78 }
79
80 cpu_phandle = fdt_get_phandle(fdt, cpu_off);
81 if (!cpu_phandle) {
82 pr_err("unable to get CPU intc phandle\n");
83 return -EINVAL;
84 }
85
86 uart_off = fdt_node_offset_by_compatible(fdt, -1, "ns16550a");
87 while (uart_off >= 0) {
88 err = fdt_setprop_u32(fdt, uart_off, "interrupt-parent",
89 cpu_phandle);
90 if (err) {
91 pr_warn("unable to set UART interrupt-parent: %d\n",
92 err);
93 return err;
94 }
95
96 err = fdt_setprop_u32(fdt, uart_off, "interrupts",
97 cpu_uart_int);
98 if (err) {
99 pr_err("unable to set UART interrupts property: %d\n",
100 err);
101 return err;
102 }
103
104 uart_off = fdt_node_offset_by_compatible(fdt, uart_off,
105 "ns16550a");
106 }
107 if (uart_off != -FDT_ERR_NOTFOUND) {
108 pr_err("error searching for UART DT node: %d\n", uart_off);
109 return uart_off;
110 }
111
112 eth_off = fdt_node_offset_by_compatible(fdt, -1, "smsc,lan9115");
113 if (eth_off < 0) {
114 pr_err("unable to find ethernet DT node: %d\n", eth_off);
115 return eth_off;
116 }
117
118 err = fdt_setprop_u32(fdt, eth_off, "interrupt-parent", cpu_phandle);
119 if (err) {
120 pr_err("unable to set ethernet interrupt-parent: %d\n", err);
121 return err;
122 }
123
124 err = fdt_setprop_u32(fdt, eth_off, "interrupts", cpu_eth_int);
125 if (err) {
126 pr_err("unable to set ethernet interrupts property: %d\n", err);
127 return err;
128 }
129
130 ehci_off = fdt_node_offset_by_compatible(fdt, -1, "generic-ehci");
131 if (ehci_off < 0) {
132 pr_err("unable to find EHCI DT node: %d\n", ehci_off);
133 return ehci_off;
134 }
135
136 err = fdt_setprop_u32(fdt, ehci_off, "interrupt-parent", cpu_phandle);
137 if (err) {
138 pr_err("unable to set EHCI interrupt-parent: %d\n", err);
139 return err;
140 }
141
142 err = fdt_setprop_u32(fdt, ehci_off, "interrupts", cpu_ehci_int);
143 if (err) {
144 pr_err("unable to set EHCI interrupts property: %d\n", err);
145 return err;
146 }
147
148 return 0;
149 }
150
151 static const struct mips_fdt_fixup sead3_fdt_fixups[] __initconst = {
152 { yamon_dt_append_cmdline, "append command line" },
153 { append_memory, "append memory" },
154 { remove_gic, "remove GIC when not present" },
155 { yamon_dt_serial_config, "append serial configuration" },
156 { },
157 };
158
sead3_fixup_fdt(const void * fdt,const void * match_data)159 static __init const void *sead3_fixup_fdt(const void *fdt,
160 const void *match_data)
161 {
162 static unsigned char fdt_buf[16 << 10] __initdata;
163 int err;
164
165 if (fdt_check_header(fdt))
166 panic("Corrupt DT");
167
168 /* if this isn't SEAD3, something went wrong */
169 BUG_ON(fdt_node_check_compatible(fdt, 0, "mti,sead-3"));
170
171 fw_init_cmdline();
172
173 err = apply_mips_fdt_fixups(fdt_buf, sizeof(fdt_buf),
174 fdt, sead3_fdt_fixups);
175 if (err)
176 panic("Unable to fixup FDT: %d", err);
177
178 return fdt_buf;
179 }
180
sead3_measure_hpt_freq(void)181 static __init unsigned int sead3_measure_hpt_freq(void)
182 {
183 void __iomem *status_reg = (void __iomem *)0xbf000410;
184 unsigned int freq, orig, tick = 0;
185 unsigned long flags;
186
187 local_irq_save(flags);
188
189 orig = readl(status_reg) & 0x2; /* get original sample */
190 /* wait for transition */
191 while ((readl(status_reg) & 0x2) == orig)
192 ;
193 orig = orig ^ 0x2; /* flip the bit */
194
195 write_c0_count(0);
196
197 /* wait 1 second (the sampling clock transitions every 10ms) */
198 while (tick < 100) {
199 /* wait for transition */
200 while ((readl(status_reg) & 0x2) == orig)
201 ;
202 orig = orig ^ 0x2; /* flip the bit */
203 tick++;
204 }
205
206 freq = read_c0_count();
207
208 local_irq_restore(flags);
209
210 return freq;
211 }
212
213 extern char __dtb_sead3_begin[];
214
215 MIPS_MACHINE(sead3) = {
216 .fdt = __dtb_sead3_begin,
217 .detect = sead3_detect,
218 .fixup_fdt = sead3_fixup_fdt,
219 .measure_hpt_freq = sead3_measure_hpt_freq,
220 };
221