1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PowerPC 476FPE board specific routines
4  *
5  * Copyright © 2013 Tony Breeds IBM Corporation
6  * Copyright © 2013 Alistair Popple IBM Corporation
7  *
8  * Based on earlier code:
9  *    Matt Porter <mporter@kernel.crashing.org>
10  *    Copyright 2002-2005 MontaVista Software Inc.
11  *
12  *    Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
13  *    Copyright (c) 2003-2005 Zultys Technologies
14  *
15  *    Rewritten and ported to the merged powerpc tree:
16  *    Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
17  *    Copyright © 2011 David Kliekamp IBM Corporation
18  */
19 
20 #include <linux/init.h>
21 #include <linux/of.h>
22 #include <linux/of_platform.h>
23 #include <linux/rtc.h>
24 
25 #include <asm/machdep.h>
26 #include <asm/prom.h>
27 #include <asm/udbg.h>
28 #include <asm/time.h>
29 #include <asm/uic.h>
30 #include <asm/ppc4xx.h>
31 #include <asm/mpic.h>
32 #include <asm/mmu.h>
33 #include <asm/swiotlb.h>
34 
35 #include <linux/pci.h>
36 #include <linux/i2c.h>
37 
38 static const struct of_device_id ppc47x_of_bus[] __initconst = {
39 	{ .compatible = "ibm,plb4", },
40 	{ .compatible = "ibm,plb6", },
41 	{ .compatible = "ibm,opb", },
42 	{ .compatible = "ibm,ebc", },
43 	{},
44 };
45 
46 /* The EEPROM is missing and the default values are bogus.  This forces USB in
47  * to EHCI mode */
48 static void quirk_ppc_currituck_usb_fixup(struct pci_dev *dev)
49 {
50 	if (of_machine_is_compatible("ibm,currituck")) {
51 		pci_write_config_dword(dev, 0xe0, 0x0114231f);
52 		pci_write_config_dword(dev, 0xe4, 0x00006c40);
53 	}
54 }
55 DECLARE_PCI_FIXUP_HEADER(0x1033, 0x0035, quirk_ppc_currituck_usb_fixup);
56 
57 /* Akebono has an AVR microcontroller attached to the I2C bus
58  * which is used to power off/reset the system. */
59 
60 /* AVR I2C Commands */
61 #define AVR_PWRCTL_CMD (0x26)
62 
63 /* Flags for the power control I2C commands */
64 #define AVR_PWRCTL_PWROFF (0x01)
65 #define AVR_PWRCTL_RESET (0x02)
66 
67 static struct i2c_client *avr_i2c_client;
68 static void __noreturn avr_halt_system(int pwrctl_flags)
69 {
70 	/* Request the AVR to reset the system */
71 	i2c_smbus_write_byte_data(avr_i2c_client,
72 				  AVR_PWRCTL_CMD, pwrctl_flags);
73 
74 	/* Wait for system to be reset */
75 	while (1)
76 		;
77 }
78 
79 static void avr_power_off_system(void)
80 {
81 	avr_halt_system(AVR_PWRCTL_PWROFF);
82 }
83 
84 static void __noreturn avr_reset_system(char *cmd)
85 {
86 	avr_halt_system(AVR_PWRCTL_RESET);
87 }
88 
89 static int avr_probe(struct i2c_client *client)
90 {
91 	avr_i2c_client = client;
92 	ppc_md.restart = avr_reset_system;
93 	pm_power_off = avr_power_off_system;
94 	return 0;
95 }
96 
97 static const struct i2c_device_id avr_id[] = {
98 	{ "akebono-avr", 0 },
99 	{ }
100 };
101 
102 static struct i2c_driver avr_driver = {
103 	.driver = {
104 		.name = "akebono-avr",
105 	},
106 	.probe_new = avr_probe,
107 	.id_table = avr_id,
108 };
109 
110 static int __init ppc47x_device_probe(void)
111 {
112 	i2c_add_driver(&avr_driver);
113 	of_platform_bus_probe(NULL, ppc47x_of_bus, NULL);
114 
115 	return 0;
116 }
117 machine_device_initcall(ppc47x, ppc47x_device_probe);
118 
119 static void __init ppc47x_init_irq(void)
120 {
121 	struct device_node *np;
122 
123 	/* Find top level interrupt controller */
124 	for_each_node_with_property(np, "interrupt-controller") {
125 		if (of_get_property(np, "interrupts", NULL) == NULL)
126 			break;
127 	}
128 	if (np == NULL)
129 		panic("Can't find top level interrupt controller");
130 
131 	/* Check type and do appropriate initialization */
132 	if (of_device_is_compatible(np, "chrp,open-pic")) {
133 		/* The MPIC driver will get everything it needs from the
134 		 * device-tree, just pass 0 to all arguments
135 		 */
136 		struct mpic *mpic =
137 			mpic_alloc(np, 0, MPIC_NO_RESET, 0, 0, " MPIC     ");
138 		BUG_ON(mpic == NULL);
139 		mpic_init(mpic);
140 		ppc_md.get_irq = mpic_get_irq;
141 	} else
142 		panic("Unrecognized top level interrupt controller");
143 }
144 
145 #ifdef CONFIG_SMP
146 static void smp_ppc47x_setup_cpu(int cpu)
147 {
148 	mpic_setup_this_cpu();
149 }
150 
151 static int smp_ppc47x_kick_cpu(int cpu)
152 {
153 	struct device_node *cpunode = of_get_cpu_node(cpu, NULL);
154 	const u64 *spin_table_addr_prop;
155 	u32 *spin_table;
156 	extern void start_secondary_47x(void);
157 
158 	BUG_ON(cpunode == NULL);
159 
160 	/* Assume spin table. We could test for the enable-method in
161 	 * the device-tree but currently there's little point as it's
162 	 * our only supported method
163 	 */
164 	spin_table_addr_prop =
165 		of_get_property(cpunode, "cpu-release-addr", NULL);
166 
167 	if (spin_table_addr_prop == NULL) {
168 		pr_err("CPU%d: Can't start, missing cpu-release-addr !\n",
169 		       cpu);
170 		return 1;
171 	}
172 
173 	/* Assume it's mapped as part of the linear mapping. This is a bit
174 	 * fishy but will work fine for now
175 	 *
176 	 * XXX: Is there any reason to assume differently?
177 	 */
178 	spin_table = (u32 *)__va(*spin_table_addr_prop);
179 	pr_debug("CPU%d: Spin table mapped at %p\n", cpu, spin_table);
180 
181 	spin_table[3] = cpu;
182 	smp_wmb();
183 	spin_table[1] = __pa(start_secondary_47x);
184 	mb();
185 
186 	return 0;
187 }
188 
189 static struct smp_ops_t ppc47x_smp_ops = {
190 	.probe		= smp_mpic_probe,
191 	.message_pass	= smp_mpic_message_pass,
192 	.setup_cpu	= smp_ppc47x_setup_cpu,
193 	.kick_cpu	= smp_ppc47x_kick_cpu,
194 	.give_timebase	= smp_generic_give_timebase,
195 	.take_timebase	= smp_generic_take_timebase,
196 };
197 
198 static void __init ppc47x_smp_init(void)
199 {
200 	if (mmu_has_feature(MMU_FTR_TYPE_47x))
201 		smp_ops = &ppc47x_smp_ops;
202 }
203 
204 #else /* CONFIG_SMP */
205 static void __init ppc47x_smp_init(void) { }
206 #endif /* CONFIG_SMP */
207 
208 static void __init ppc47x_setup_arch(void)
209 {
210 
211 	/* No need to check the DMA config as we /know/ our windows are all of
212 	 * RAM.  Lets hope that doesn't change */
213 	swiotlb_detect_4g();
214 
215 	ppc47x_smp_init();
216 }
217 
218 static int board_rev = -1;
219 static int __init ppc47x_get_board_rev(void)
220 {
221 	int reg;
222 	u8 *fpga;
223 	struct device_node *np = NULL;
224 
225 	if (of_machine_is_compatible("ibm,currituck")) {
226 		np = of_find_compatible_node(NULL, NULL, "ibm,currituck-fpga");
227 		reg = 0;
228 	} else if (of_machine_is_compatible("ibm,akebono")) {
229 		np = of_find_compatible_node(NULL, NULL, "ibm,akebono-fpga");
230 		reg = 2;
231 	}
232 
233 	if (!np)
234 		goto fail;
235 
236 	fpga = (u8 *) of_iomap(np, 0);
237 	of_node_put(np);
238 	if (!fpga)
239 		goto fail;
240 
241 	board_rev = ioread8(fpga + reg) & 0x03;
242 	pr_info("%s: Found board revision %d\n", __func__, board_rev);
243 	iounmap(fpga);
244 	return 0;
245 
246 fail:
247 	pr_info("%s: Unable to find board revision\n", __func__);
248 	return 0;
249 }
250 machine_arch_initcall(ppc47x, ppc47x_get_board_rev);
251 
252 /* Use USB controller should have been hardware swizzled but it wasn't :( */
253 static void ppc47x_pci_irq_fixup(struct pci_dev *dev)
254 {
255 	if (dev->vendor == 0x1033 && (dev->device == 0x0035 ||
256 				      dev->device == 0x00e0)) {
257 		if (board_rev == 0) {
258 			dev->irq = irq_create_mapping(NULL, 47);
259 			pr_info("%s: Mapping irq %d\n", __func__, dev->irq);
260 		} else if (board_rev == 2) {
261 			dev->irq = irq_create_mapping(NULL, 49);
262 			pr_info("%s: Mapping irq %d\n", __func__, dev->irq);
263 		} else {
264 			pr_alert("%s: Unknown board revision\n", __func__);
265 		}
266 	}
267 }
268 
269 /*
270  * Called very early, MMU is off, device-tree isn't unflattened
271  */
272 static int __init ppc47x_probe(void)
273 {
274 	if (of_machine_is_compatible("ibm,akebono"))
275 		return 1;
276 
277 	if (of_machine_is_compatible("ibm,currituck")) {
278 		ppc_md.pci_irq_fixup = ppc47x_pci_irq_fixup;
279 		return 1;
280 	}
281 
282 	return 0;
283 }
284 
285 define_machine(ppc47x) {
286 	.name			= "PowerPC 47x",
287 	.probe			= ppc47x_probe,
288 	.progress		= udbg_progress,
289 	.init_IRQ		= ppc47x_init_irq,
290 	.setup_arch		= ppc47x_setup_arch,
291 	.restart		= ppc4xx_reset_system,
292 	.calibrate_decr		= generic_calibrate_decr,
293 };
294