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1 /*
2  * PowerPC 476FPE board specific routines
3  *
4  * Copyright © 2013 Tony Breeds IBM Corporation
5  * Copyright © 2013 Alistair Popple IBM Corporation
6  *
7  * Based on earlier code:
8  *    Matt Porter <mporter@kernel.crashing.org>
9  *    Copyright 2002-2005 MontaVista Software Inc.
10  *
11  *    Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
12  *    Copyright (c) 2003-2005 Zultys Technologies
13  *
14  *    Rewritten and ported to the merged powerpc tree:
15  *    Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
16  *    Copyright © 2011 David Kliekamp IBM Corporation
17  *
18  * This program is free software; you can redistribute  it and/or modify it
19  * under  the terms of  the GNU General  Public License as published by the
20  * Free Software Foundation;  either version 2 of the  License, or (at your
21  * option) any later version.
22  */
23 
24 #include <linux/init.h>
25 #include <linux/of.h>
26 #include <linux/of_platform.h>
27 #include <linux/rtc.h>
28 
29 #include <asm/machdep.h>
30 #include <asm/prom.h>
31 #include <asm/udbg.h>
32 #include <asm/time.h>
33 #include <asm/uic.h>
34 #include <asm/ppc4xx.h>
35 #include <asm/mpic.h>
36 #include <asm/mmu.h>
37 
38 #include <linux/pci.h>
39 #include <linux/i2c.h>
40 
41 static const struct of_device_id ppc47x_of_bus[] __initconst = {
42 	{ .compatible = "ibm,plb4", },
43 	{ .compatible = "ibm,plb6", },
44 	{ .compatible = "ibm,opb", },
45 	{ .compatible = "ibm,ebc", },
46 	{},
47 };
48 
49 /* The EEPROM is missing and the default values are bogus.  This forces USB in
50  * to EHCI mode */
quirk_ppc_currituck_usb_fixup(struct pci_dev * dev)51 static void quirk_ppc_currituck_usb_fixup(struct pci_dev *dev)
52 {
53 	if (of_machine_is_compatible("ibm,currituck")) {
54 		pci_write_config_dword(dev, 0xe0, 0x0114231f);
55 		pci_write_config_dword(dev, 0xe4, 0x00006c40);
56 	}
57 }
58 DECLARE_PCI_FIXUP_HEADER(0x1033, 0x0035, quirk_ppc_currituck_usb_fixup);
59 
60 /* Akebono has an AVR microcontroller attached to the I2C bus
61  * which is used to power off/reset the system. */
62 
63 /* AVR I2C Commands */
64 #define AVR_PWRCTL_CMD (0x26)
65 
66 /* Flags for the power control I2C commands */
67 #define AVR_PWRCTL_PWROFF (0x01)
68 #define AVR_PWRCTL_RESET (0x02)
69 
70 static struct i2c_client *avr_i2c_client;
avr_halt_system(int pwrctl_flags)71 static void avr_halt_system(int pwrctl_flags)
72 {
73 	/* Request the AVR to reset the system */
74 	i2c_smbus_write_byte_data(avr_i2c_client,
75 				  AVR_PWRCTL_CMD, pwrctl_flags);
76 
77 	/* Wait for system to be reset */
78 	while (1)
79 		;
80 }
81 
avr_power_off_system(void)82 static void avr_power_off_system(void)
83 {
84 	avr_halt_system(AVR_PWRCTL_PWROFF);
85 }
86 
avr_reset_system(char * cmd)87 static void avr_reset_system(char *cmd)
88 {
89 	avr_halt_system(AVR_PWRCTL_RESET);
90 }
91 
avr_probe(struct i2c_client * client,const struct i2c_device_id * id)92 static int avr_probe(struct i2c_client *client,
93 			    const struct i2c_device_id *id)
94 {
95 	avr_i2c_client = client;
96 	ppc_md.restart = avr_reset_system;
97 	ppc_md.power_off = avr_power_off_system;
98 	return 0;
99 }
100 
101 static const struct i2c_device_id avr_id[] = {
102 	{ "akebono-avr", 0 },
103 	{ }
104 };
105 
106 static struct i2c_driver avr_driver = {
107 	.driver = {
108 		.name = "akebono-avr",
109 	},
110 	.probe = avr_probe,
111 	.id_table = avr_id,
112 };
113 
ppc47x_device_probe(void)114 static int __init ppc47x_device_probe(void)
115 {
116 	i2c_add_driver(&avr_driver);
117 	of_platform_bus_probe(NULL, ppc47x_of_bus, NULL);
118 
119 	return 0;
120 }
121 machine_device_initcall(ppc47x, ppc47x_device_probe);
122 
ppc47x_init_irq(void)123 static void __init ppc47x_init_irq(void)
124 {
125 	struct device_node *np;
126 
127 	/* Find top level interrupt controller */
128 	for_each_node_with_property(np, "interrupt-controller") {
129 		if (of_get_property(np, "interrupts", NULL) == NULL)
130 			break;
131 	}
132 	if (np == NULL)
133 		panic("Can't find top level interrupt controller");
134 
135 	/* Check type and do appropriate initialization */
136 	if (of_device_is_compatible(np, "chrp,open-pic")) {
137 		/* The MPIC driver will get everything it needs from the
138 		 * device-tree, just pass 0 to all arguments
139 		 */
140 		struct mpic *mpic =
141 			mpic_alloc(np, 0, MPIC_NO_RESET, 0, 0, " MPIC     ");
142 		BUG_ON(mpic == NULL);
143 		mpic_init(mpic);
144 		ppc_md.get_irq = mpic_get_irq;
145 	} else
146 		panic("Unrecognized top level interrupt controller");
147 }
148 
149 #ifdef CONFIG_SMP
smp_ppc47x_setup_cpu(int cpu)150 static void smp_ppc47x_setup_cpu(int cpu)
151 {
152 	mpic_setup_this_cpu();
153 }
154 
smp_ppc47x_kick_cpu(int cpu)155 static int smp_ppc47x_kick_cpu(int cpu)
156 {
157 	struct device_node *cpunode = of_get_cpu_node(cpu, NULL);
158 	const u64 *spin_table_addr_prop;
159 	u32 *spin_table;
160 	extern void start_secondary_47x(void);
161 
162 	BUG_ON(cpunode == NULL);
163 
164 	/* Assume spin table. We could test for the enable-method in
165 	 * the device-tree but currently there's little point as it's
166 	 * our only supported method
167 	 */
168 	spin_table_addr_prop =
169 		of_get_property(cpunode, "cpu-release-addr", NULL);
170 
171 	if (spin_table_addr_prop == NULL) {
172 		pr_err("CPU%d: Can't start, missing cpu-release-addr !\n",
173 		       cpu);
174 		return 1;
175 	}
176 
177 	/* Assume it's mapped as part of the linear mapping. This is a bit
178 	 * fishy but will work fine for now
179 	 *
180 	 * XXX: Is there any reason to assume differently?
181 	 */
182 	spin_table = (u32 *)__va(*spin_table_addr_prop);
183 	pr_debug("CPU%d: Spin table mapped at %p\n", cpu, spin_table);
184 
185 	spin_table[3] = cpu;
186 	smp_wmb();
187 	spin_table[1] = __pa(start_secondary_47x);
188 	mb();
189 
190 	return 0;
191 }
192 
193 static struct smp_ops_t ppc47x_smp_ops = {
194 	.probe		= smp_mpic_probe,
195 	.message_pass	= smp_mpic_message_pass,
196 	.setup_cpu	= smp_ppc47x_setup_cpu,
197 	.kick_cpu	= smp_ppc47x_kick_cpu,
198 	.give_timebase	= smp_generic_give_timebase,
199 	.take_timebase	= smp_generic_take_timebase,
200 };
201 
ppc47x_smp_init(void)202 static void __init ppc47x_smp_init(void)
203 {
204 	if (mmu_has_feature(MMU_FTR_TYPE_47x))
205 		smp_ops = &ppc47x_smp_ops;
206 }
207 
208 #else /* CONFIG_SMP */
ppc47x_smp_init(void)209 static void __init ppc47x_smp_init(void) { }
210 #endif /* CONFIG_SMP */
211 
ppc47x_setup_arch(void)212 static void __init ppc47x_setup_arch(void)
213 {
214 
215 	/* No need to check the DMA config as we /know/ our windows are all of
216 	 * RAM.  Lets hope that doesn't change */
217 	swiotlb_detect_4g();
218 
219 	ppc47x_smp_init();
220 }
221 
222 static int board_rev = -1;
ppc47x_get_board_rev(void)223 static int __init ppc47x_get_board_rev(void)
224 {
225 	int reg;
226 	u8 *fpga;
227 	struct device_node *np = NULL;
228 
229 	if (of_machine_is_compatible("ibm,currituck")) {
230 		np = of_find_compatible_node(NULL, NULL, "ibm,currituck-fpga");
231 		reg = 0;
232 	} else if (of_machine_is_compatible("ibm,akebono")) {
233 		np = of_find_compatible_node(NULL, NULL, "ibm,akebono-fpga");
234 		reg = 2;
235 	}
236 
237 	if (!np)
238 		goto fail;
239 
240 	fpga = (u8 *) of_iomap(np, 0);
241 	of_node_put(np);
242 	if (!fpga)
243 		goto fail;
244 
245 	board_rev = ioread8(fpga + reg) & 0x03;
246 	pr_info("%s: Found board revision %d\n", __func__, board_rev);
247 	iounmap(fpga);
248 	return 0;
249 
250 fail:
251 	pr_info("%s: Unable to find board revision\n", __func__);
252 	return 0;
253 }
254 machine_arch_initcall(ppc47x, ppc47x_get_board_rev);
255 
256 /* Use USB controller should have been hardware swizzled but it wasn't :( */
ppc47x_pci_irq_fixup(struct pci_dev * dev)257 static void ppc47x_pci_irq_fixup(struct pci_dev *dev)
258 {
259 	if (dev->vendor == 0x1033 && (dev->device == 0x0035 ||
260 				      dev->device == 0x00e0)) {
261 		if (board_rev == 0) {
262 			dev->irq = irq_create_mapping(NULL, 47);
263 			pr_info("%s: Mapping irq %d\n", __func__, dev->irq);
264 		} else if (board_rev == 2) {
265 			dev->irq = irq_create_mapping(NULL, 49);
266 			pr_info("%s: Mapping irq %d\n", __func__, dev->irq);
267 		} else {
268 			pr_alert("%s: Unknown board revision\n", __func__);
269 		}
270 	}
271 }
272 
273 /*
274  * Called very early, MMU is off, device-tree isn't unflattened
275  */
ppc47x_probe(void)276 static int __init ppc47x_probe(void)
277 {
278 	unsigned long root = of_get_flat_dt_root();
279 
280 	if (of_flat_dt_is_compatible(root, "ibm,akebono"))
281 		return 1;
282 
283 	if (of_flat_dt_is_compatible(root, "ibm,currituck")) {
284 		ppc_md.pci_irq_fixup = ppc47x_pci_irq_fixup;
285 		return 1;
286 	}
287 
288 	return 0;
289 }
290 
define_machine(ppc47x)291 define_machine(ppc47x) {
292 	.name			= "PowerPC 47x",
293 	.probe			= ppc47x_probe,
294 	.progress		= udbg_progress,
295 	.init_IRQ		= ppc47x_init_irq,
296 	.setup_arch		= ppc47x_setup_arch,
297 	.restart		= ppc4xx_reset_system,
298 	.calibrate_decr		= generic_calibrate_decr,
299 };
300