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 * Configure the XLB arbiter settings to match what Linux expects. 52 */ 53 void __init 54 mpc5200_setup_xlb_arbiter(void) 55 { 56 struct device_node *np; 57 struct mpc52xx_xlb __iomem *xlb; 58 59 np = of_find_matching_node(NULL, mpc52xx_xlb_ids); 60 xlb = of_iomap(np, 0); 61 of_node_put(np); 62 if (!xlb) { 63 printk(KERN_ERR __FILE__ ": " 64 "Error mapping XLB in mpc52xx_setup_cpu(). " 65 "Expect some abnormal behavior\n"); 66 return; 67 } 68 69 /* Configure the XLB Arbiter priorities */ 70 out_be32(&xlb->master_pri_enable, 0xff); 71 out_be32(&xlb->master_priority, 0x11111111); 72 73 /* 74 * Disable XLB pipelining 75 * (cfr errate 292. We could do this only just before ATA PIO 76 * transaction and re-enable it afterwards ...) 77 * Not needed on MPC5200B. 78 */ 79 if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR) 80 out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS); 81 82 iounmap(xlb); 83 } 84 85 /** 86 * mpc52xx_declare_of_platform_devices: register internal devices and children 87 * of the localplus bus to the of_platform 88 * bus. 89 */ 90 void __init 91 mpc52xx_declare_of_platform_devices(void) 92 { 93 /* Find every child of the SOC node and add it to of_platform */ 94 if (of_platform_bus_probe(NULL, mpc52xx_bus_ids, NULL)) 95 printk(KERN_ERR __FILE__ ": " 96 "Error while probing of_platform bus\n"); 97 } 98 99 /* 100 * match tables used by mpc52xx_map_common_devices() 101 */ 102 static struct of_device_id mpc52xx_gpt_ids[] __initdata = { 103 { .compatible = "fsl,mpc5200-gpt", }, 104 { .compatible = "mpc5200-gpt", }, /* old */ 105 {} 106 }; 107 static struct of_device_id mpc52xx_cdm_ids[] __initdata = { 108 { .compatible = "fsl,mpc5200-cdm", }, 109 { .compatible = "mpc5200-cdm", }, /* old */ 110 {} 111 }; 112 113 /** 114 * mpc52xx_map_common_devices: iomap devices required by common code 115 */ 116 void __init 117 mpc52xx_map_common_devices(void) 118 { 119 struct device_node *np; 120 121 /* mpc52xx_wdt is mapped here and used in mpc52xx_restart, 122 * possibly from a interrupt context. wdt is only implement 123 * on a gpt0, so check has-wdt property before mapping. 124 */ 125 for_each_matching_node(np, mpc52xx_gpt_ids) { 126 if (of_get_property(np, "fsl,has-wdt", NULL) || 127 of_get_property(np, "has-wdt", NULL)) { 128 mpc52xx_wdt = of_iomap(np, 0); 129 of_node_put(np); 130 break; 131 } 132 } 133 134 /* Clock Distribution Module, used by PSC clock setting function */ 135 np = of_find_matching_node(NULL, mpc52xx_cdm_ids); 136 mpc52xx_cdm = of_iomap(np, 0); 137 of_node_put(np); 138 } 139 140 /** 141 * mpc52xx_set_psc_clkdiv: Set clock divider in the CDM for PSC ports 142 * 143 * @psc_id: id of psc port; must be 1,2,3 or 6 144 * @clkdiv: clock divider value to put into CDM PSC register. 145 */ 146 int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv) 147 { 148 unsigned long flags; 149 u16 __iomem *reg; 150 u32 val; 151 u32 mask; 152 u32 mclken_div; 153 154 if (!mpc52xx_cdm) 155 return -ENODEV; 156 157 mclken_div = 0x8000 | (clkdiv & 0x1FF); 158 switch (psc_id) { 159 case 1: reg = &mpc52xx_cdm->mclken_div_psc1; mask = 0x20; break; 160 case 2: reg = &mpc52xx_cdm->mclken_div_psc2; mask = 0x40; break; 161 case 3: reg = &mpc52xx_cdm->mclken_div_psc3; mask = 0x80; break; 162 case 6: reg = &mpc52xx_cdm->mclken_div_psc6; mask = 0x10; break; 163 default: 164 return -ENODEV; 165 } 166 167 /* Set the rate and enable the clock */ 168 spin_lock_irqsave(&mpc52xx_lock, flags); 169 out_be16(reg, mclken_div); 170 val = in_be32(&mpc52xx_cdm->clk_enables); 171 out_be32(&mpc52xx_cdm->clk_enables, val | mask); 172 spin_unlock_irqrestore(&mpc52xx_lock, flags); 173 174 return 0; 175 } 176 EXPORT_SYMBOL(mpc52xx_set_psc_clkdiv); 177 178 /** 179 * mpc52xx_get_xtal_freq - Get SYS_XTAL_IN frequency for a device 180 * 181 * @node: device node 182 * 183 * Returns the frequency of the external oscillator clock connected 184 * to the SYS_XTAL_IN pin, or 0 if it cannot be determined. 185 */ 186 unsigned int mpc52xx_get_xtal_freq(struct device_node *node) 187 { 188 u32 val; 189 unsigned int freq; 190 191 if (!mpc52xx_cdm) 192 return 0; 193 194 freq = mpc5xxx_get_bus_frequency(node); 195 if (!freq) 196 return 0; 197 198 if (in_8(&mpc52xx_cdm->ipb_clk_sel) & 0x1) 199 freq *= 2; 200 201 val = in_be32(&mpc52xx_cdm->rstcfg); 202 if (val & (1 << 5)) 203 freq *= 8; 204 else 205 freq *= 4; 206 if (val & (1 << 6)) 207 freq /= 12; 208 else 209 freq /= 16; 210 211 return freq; 212 } 213 EXPORT_SYMBOL(mpc52xx_get_xtal_freq); 214 215 /** 216 * mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer 217 */ 218 void 219 mpc52xx_restart(char *cmd) 220 { 221 local_irq_disable(); 222 223 /* Turn on the watchdog and wait for it to expire. 224 * It effectively does a reset. */ 225 if (mpc52xx_wdt) { 226 out_be32(&mpc52xx_wdt->mode, 0x00000000); 227 out_be32(&mpc52xx_wdt->count, 0x000000ff); 228 out_be32(&mpc52xx_wdt->mode, 0x00009004); 229 } else 230 printk(KERN_ERR __FILE__ ": " 231 "mpc52xx_restart: Can't access wdt. " 232 "Restart impossible, system halted.\n"); 233 234 while (1); 235 } 236