3 * Utility functions for the Freescale MPC52xx.
5 * Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com>
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.
15 #include <linux/kernel.h>
16 #include <linux/spinlock.h>
17 #include <linux/of_platform.h>
20 #include <asm/mpc52xx.h>
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", },
28 static struct of_device_id mpc52xx_bus_ids[] __initdata = {
29 { .compatible = "fsl,mpc5200-immr", },
30 { .compatible = "fsl,mpc5200b-immr", },
31 { .compatible = "fsl,lpb", },
33 /* depreciated matches; shouldn't be used in new device trees */
34 { .type = "builtin", .compatible = "mpc5200", }, /* efika */
35 { .type = "soc", .compatible = "mpc5200", }, /* lite5200 */
40 * This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart().
41 * Permanent mapping is required because mpc52xx_restart() can be called
42 * from interrupt context while node mapping (which calls ioremap())
43 * cannot be used at such point.
45 static spinlock_t mpc52xx_lock = SPIN_LOCK_UNLOCKED;
46 static struct mpc52xx_gpt __iomem *mpc52xx_wdt;
47 static struct mpc52xx_cdm __iomem *mpc52xx_cdm;
50 * mpc52xx_find_ipb_freq - Find the IPB bus frequency for a device
53 * Returns IPB bus frequency, or 0 if the bus frequency cannot be found.
56 mpc52xx_find_ipb_freq(struct device_node *node)
58 struct device_node *np;
59 const unsigned int *p_ipb_freq = NULL;
63 p_ipb_freq = of_get_property(node, "bus-frequency", NULL);
67 np = of_get_parent(node);
74 return p_ipb_freq ? *p_ipb_freq : 0;
76 EXPORT_SYMBOL(mpc52xx_find_ipb_freq);
80 * Configure the XLB arbiter settings to match what Linux expects.
83 mpc5200_setup_xlb_arbiter(void)
85 struct device_node *np;
86 struct mpc52xx_xlb __iomem *xlb;
88 np = of_find_matching_node(NULL, mpc52xx_xlb_ids);
89 xlb = of_iomap(np, 0);
92 printk(KERN_ERR __FILE__ ": "
93 "Error mapping XLB in mpc52xx_setup_cpu(). "
94 "Expect some abnormal behavior\n");
98 /* Configure the XLB Arbiter priorities */
99 out_be32(&xlb->master_pri_enable, 0xff);
100 out_be32(&xlb->master_priority, 0x11111111);
102 /* Disable XLB pipelining
103 * (cfr errate 292. We could do this only just before ATA PIO
104 * transaction and re-enable it afterwards ...)
106 out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
112 * mpc52xx_declare_of_platform_devices: register internal devices and children
113 * of the localplus bus to the of_platform
117 mpc52xx_declare_of_platform_devices(void)
119 /* Find every child of the SOC node and add it to of_platform */
120 if (of_platform_bus_probe(NULL, mpc52xx_bus_ids, NULL))
121 printk(KERN_ERR __FILE__ ": "
122 "Error while probing of_platform bus\n");
126 * match tables used by mpc52xx_map_common_devices()
128 static struct of_device_id mpc52xx_gpt_ids[] __initdata = {
129 { .compatible = "fsl,mpc5200-gpt", },
130 { .compatible = "mpc5200-gpt", }, /* old */
133 static struct of_device_id mpc52xx_cdm_ids[] __initdata = {
134 { .compatible = "fsl,mpc5200-cdm", },
135 { .compatible = "mpc5200-cdm", }, /* old */
140 * mpc52xx_map_common_devices: iomap devices required by common code
143 mpc52xx_map_common_devices(void)
145 struct device_node *np;
147 /* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
148 * possibly from a interrupt context. wdt is only implement
149 * on a gpt0, so check has-wdt property before mapping.
151 for_each_matching_node(np, mpc52xx_gpt_ids) {
152 if (of_get_property(np, "fsl,has-wdt", NULL) ||
153 of_get_property(np, "has-wdt", NULL)) {
154 mpc52xx_wdt = of_iomap(np, 0);
160 /* Clock Distribution Module, used by PSC clock setting function */
161 np = of_find_matching_node(NULL, mpc52xx_cdm_ids);
162 mpc52xx_cdm = of_iomap(np, 0);
167 * mpc52xx_set_psc_clkdiv: Set clock divider in the CDM for PSC ports
169 * @psc_id: id of psc port; must be 1,2,3 or 6
170 * @clkdiv: clock divider value to put into CDM PSC register.
172 int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv)
183 mclken_div = 0x8000 | (clkdiv & 0x1FF);
185 case 1: reg = &mpc52xx_cdm->mclken_div_psc1; mask = 0x20; break;
186 case 2: reg = &mpc52xx_cdm->mclken_div_psc2; mask = 0x40; break;
187 case 3: reg = &mpc52xx_cdm->mclken_div_psc3; mask = 0x80; break;
188 case 6: reg = &mpc52xx_cdm->mclken_div_psc6; mask = 0x10; break;
193 /* Set the rate and enable the clock */
194 spin_lock_irqsave(&mpc52xx_lock, flags);
195 out_be16(reg, mclken_div);
196 val = in_be32(&mpc52xx_cdm->clk_enables);
197 out_be32(&mpc52xx_cdm->clk_enables, val | mask);
198 spin_unlock_irqrestore(&mpc52xx_lock, flags);
202 EXPORT_SYMBOL(mpc52xx_set_psc_clkdiv);
205 * mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer
208 mpc52xx_restart(char *cmd)
212 /* Turn on the watchdog and wait for it to expire.
213 * It effectively does a reset. */
215 out_be32(&mpc52xx_wdt->mode, 0x00000000);
216 out_be32(&mpc52xx_wdt->count, 0x000000ff);
217 out_be32(&mpc52xx_wdt->mode, 0x00009004);
219 printk(KERN_ERR __FILE__ ": "
220 "mpc52xx_restart: Can't access wdt. "
221 "Restart impossible, system halted.\n");