Merge commit 'gcl/next' into next
[deliverable/linux.git] / arch / powerpc / platforms / 52xx / mpc52xx_common.c
1 /*
2 *
3 * Utility functions for the Freescale MPC52xx.
4 *
5 * Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com>
6 *
7 * This file is licensed under the terms of the GNU General Public License
8 * version 2. This program is licensed "as is" without any warranty of any
9 * kind, whether express or implied.
10 *
11 */
12
13 #undef DEBUG
14
15 #include <linux/kernel.h>
16 #include <linux/spinlock.h>
17 #include <linux/of_platform.h>
18 #include <asm/io.h>
19 #include <asm/prom.h>
20 #include <asm/mpc52xx.h>
21
22 /* MPC5200 device tree match tables */
23 static struct of_device_id mpc52xx_xlb_ids[] __initdata = {
24 { .compatible = "fsl,mpc5200-xlb", },
25 { .compatible = "mpc5200-xlb", },
26 {}
27 };
28 static struct of_device_id mpc52xx_bus_ids[] __initdata = {
29 { .compatible = "fsl,mpc5200-immr", },
30 { .compatible = "fsl,mpc5200b-immr", },
31 { .compatible = "simple-bus", },
32
33 /* depreciated matches; shouldn't be used in new device trees */
34 { .compatible = "fsl,lpb", },
35 { .type = "builtin", .compatible = "mpc5200", }, /* efika */
36 { .type = "soc", .compatible = "mpc5200", }, /* lite5200 */
37 {}
38 };
39
40 /*
41 * This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart().
42 * Permanent mapping is required because mpc52xx_restart() can be called
43 * from interrupt context while node mapping (which calls ioremap())
44 * cannot be used at such point.
45 */
46 static DEFINE_SPINLOCK(mpc52xx_lock);
47 static struct mpc52xx_gpt __iomem *mpc52xx_wdt;
48 static struct mpc52xx_cdm __iomem *mpc52xx_cdm;
49
50 /**
51 * mpc52xx_find_ipb_freq - Find the IPB bus frequency for a device
52 * @node: device node
53 *
54 * Returns IPB bus frequency, or 0 if the bus frequency cannot be found.
55 */
56 unsigned int
57 mpc52xx_find_ipb_freq(struct device_node *node)
58 {
59 struct device_node *np;
60 const unsigned int *p_ipb_freq = NULL;
61
62 of_node_get(node);
63 while (node) {
64 p_ipb_freq = of_get_property(node, "bus-frequency", NULL);
65 if (p_ipb_freq)
66 break;
67
68 np = of_get_parent(node);
69 of_node_put(node);
70 node = np;
71 }
72 if (node)
73 of_node_put(node);
74
75 return p_ipb_freq ? *p_ipb_freq : 0;
76 }
77 EXPORT_SYMBOL(mpc52xx_find_ipb_freq);
78
79
80 /*
81 * Configure the XLB arbiter settings to match what Linux expects.
82 */
83 void __init
84 mpc5200_setup_xlb_arbiter(void)
85 {
86 struct device_node *np;
87 struct mpc52xx_xlb __iomem *xlb;
88
89 np = of_find_matching_node(NULL, mpc52xx_xlb_ids);
90 xlb = of_iomap(np, 0);
91 of_node_put(np);
92 if (!xlb) {
93 printk(KERN_ERR __FILE__ ": "
94 "Error mapping XLB in mpc52xx_setup_cpu(). "
95 "Expect some abnormal behavior\n");
96 return;
97 }
98
99 /* Configure the XLB Arbiter priorities */
100 out_be32(&xlb->master_pri_enable, 0xff);
101 out_be32(&xlb->master_priority, 0x11111111);
102
103 /*
104 * Disable XLB pipelining
105 * (cfr errate 292. We could do this only just before ATA PIO
106 * transaction and re-enable it afterwards ...)
107 * Not needed on MPC5200B.
108 */
109 if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR)
110 out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
111
112 iounmap(xlb);
113 }
114
115 /**
116 * mpc52xx_declare_of_platform_devices: register internal devices and children
117 * of the localplus bus to the of_platform
118 * bus.
119 */
120 void __init
121 mpc52xx_declare_of_platform_devices(void)
122 {
123 /* Find every child of the SOC node and add it to of_platform */
124 if (of_platform_bus_probe(NULL, mpc52xx_bus_ids, NULL))
125 printk(KERN_ERR __FILE__ ": "
126 "Error while probing of_platform bus\n");
127 }
128
129 /*
130 * match tables used by mpc52xx_map_common_devices()
131 */
132 static struct of_device_id mpc52xx_gpt_ids[] __initdata = {
133 { .compatible = "fsl,mpc5200-gpt", },
134 { .compatible = "mpc5200-gpt", }, /* old */
135 {}
136 };
137 static struct of_device_id mpc52xx_cdm_ids[] __initdata = {
138 { .compatible = "fsl,mpc5200-cdm", },
139 { .compatible = "mpc5200-cdm", }, /* old */
140 {}
141 };
142
143 /**
144 * mpc52xx_map_common_devices: iomap devices required by common code
145 */
146 void __init
147 mpc52xx_map_common_devices(void)
148 {
149 struct device_node *np;
150
151 /* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
152 * possibly from a interrupt context. wdt is only implement
153 * on a gpt0, so check has-wdt property before mapping.
154 */
155 for_each_matching_node(np, mpc52xx_gpt_ids) {
156 if (of_get_property(np, "fsl,has-wdt", NULL) ||
157 of_get_property(np, "has-wdt", NULL)) {
158 mpc52xx_wdt = of_iomap(np, 0);
159 of_node_put(np);
160 break;
161 }
162 }
163
164 /* Clock Distribution Module, used by PSC clock setting function */
165 np = of_find_matching_node(NULL, mpc52xx_cdm_ids);
166 mpc52xx_cdm = of_iomap(np, 0);
167 of_node_put(np);
168 }
169
170 /**
171 * mpc52xx_set_psc_clkdiv: Set clock divider in the CDM for PSC ports
172 *
173 * @psc_id: id of psc port; must be 1,2,3 or 6
174 * @clkdiv: clock divider value to put into CDM PSC register.
175 */
176 int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv)
177 {
178 unsigned long flags;
179 u16 __iomem *reg;
180 u32 val;
181 u32 mask;
182 u32 mclken_div;
183
184 if (!mpc52xx_cdm)
185 return -ENODEV;
186
187 mclken_div = 0x8000 | (clkdiv & 0x1FF);
188 switch (psc_id) {
189 case 1: reg = &mpc52xx_cdm->mclken_div_psc1; mask = 0x20; break;
190 case 2: reg = &mpc52xx_cdm->mclken_div_psc2; mask = 0x40; break;
191 case 3: reg = &mpc52xx_cdm->mclken_div_psc3; mask = 0x80; break;
192 case 6: reg = &mpc52xx_cdm->mclken_div_psc6; mask = 0x10; break;
193 default:
194 return -ENODEV;
195 }
196
197 /* Set the rate and enable the clock */
198 spin_lock_irqsave(&mpc52xx_lock, flags);
199 out_be16(reg, mclken_div);
200 val = in_be32(&mpc52xx_cdm->clk_enables);
201 out_be32(&mpc52xx_cdm->clk_enables, val | mask);
202 spin_unlock_irqrestore(&mpc52xx_lock, flags);
203
204 return 0;
205 }
206 EXPORT_SYMBOL(mpc52xx_set_psc_clkdiv);
207
208 /**
209 * mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer
210 */
211 void
212 mpc52xx_restart(char *cmd)
213 {
214 local_irq_disable();
215
216 /* Turn on the watchdog and wait for it to expire.
217 * It effectively does a reset. */
218 if (mpc52xx_wdt) {
219 out_be32(&mpc52xx_wdt->mode, 0x00000000);
220 out_be32(&mpc52xx_wdt->count, 0x000000ff);
221 out_be32(&mpc52xx_wdt->mode, 0x00009004);
222 } else
223 printk(KERN_ERR __FILE__ ": "
224 "mpc52xx_restart: Can't access wdt. "
225 "Restart impossible, system halted.\n");
226
227 while (1);
228 }
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