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/gpio.h> 16 #include <linux/kernel.h> 17 #include <linux/spinlock.h> 18 #include <linux/of_platform.h> 19 #include <linux/of_gpio.h> 20 #include <linux/export.h> 21 #include <asm/io.h> 22 #include <asm/prom.h> 23 #include <asm/mpc52xx.h> 24 25 /* MPC5200 device tree match tables */ 26 static const struct of_device_id mpc52xx_xlb_ids[] __initconst = { 27 { .compatible = "fsl,mpc5200-xlb", }, 28 { .compatible = "mpc5200-xlb", }, 29 {} 30 }; 31 static const struct of_device_id mpc52xx_bus_ids[] __initconst = { 32 { .compatible = "fsl,mpc5200-immr", }, 33 { .compatible = "fsl,mpc5200b-immr", }, 34 { .compatible = "simple-bus", }, 35 36 /* depreciated matches; shouldn't be used in new device trees */ 37 { .compatible = "fsl,lpb", }, 38 { .type = "builtin", .compatible = "mpc5200", }, /* efika */ 39 { .type = "soc", .compatible = "mpc5200", }, /* lite5200 */ 40 {} 41 }; 42 43 /* 44 * This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart(). 45 * Permanent mapping is required because mpc52xx_restart() can be called 46 * from interrupt context while node mapping (which calls ioremap()) 47 * cannot be used at such point. 48 */ 49 static DEFINE_SPINLOCK(mpc52xx_lock); 50 static struct mpc52xx_gpt __iomem *mpc52xx_wdt; 51 static struct mpc52xx_cdm __iomem *mpc52xx_cdm; 52 53 /* 54 * Configure the XLB arbiter settings to match what Linux expects. 55 */ 56 void __init 57 mpc5200_setup_xlb_arbiter(void) 58 { 59 struct device_node *np; 60 struct mpc52xx_xlb __iomem *xlb; 61 62 np = of_find_matching_node(NULL, mpc52xx_xlb_ids); 63 xlb = of_iomap(np, 0); 64 of_node_put(np); 65 if (!xlb) { 66 printk(KERN_ERR __FILE__ ": " 67 "Error mapping XLB in mpc52xx_setup_cpu(). " 68 "Expect some abnormal behavior\n"); 69 return; 70 } 71 72 /* Configure the XLB Arbiter priorities */ 73 out_be32(&xlb->master_pri_enable, 0xff); 74 out_be32(&xlb->master_priority, 0x11111111); 75 76 /* 77 * Disable XLB pipelining 78 * (cfr errate 292. We could do this only just before ATA PIO 79 * transaction and re-enable it afterwards ...) 80 * Not needed on MPC5200B. 81 */ 82 if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR) 83 out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS); 84 85 iounmap(xlb); 86 } 87 88 /* 89 * This variable is mapped in mpc52xx_map_common_devices and 90 * used in mpc5200_psc_ac97_gpio_reset(). 91 */ 92 static DEFINE_SPINLOCK(gpio_lock); 93 struct mpc52xx_gpio __iomem *simple_gpio; 94 struct mpc52xx_gpio_wkup __iomem *wkup_gpio; 95 96 /** 97 * mpc52xx_declare_of_platform_devices: register internal devices and children 98 * of the localplus bus to the of_platform 99 * bus. 100 */ 101 void __init mpc52xx_declare_of_platform_devices(void) 102 { 103 /* Find all the 'platform' devices and register them. */ 104 if (of_platform_populate(NULL, mpc52xx_bus_ids, NULL, NULL)) 105 pr_err(__FILE__ ": Error while populating devices from DT\n"); 106 } 107 108 /* 109 * match tables used by mpc52xx_map_common_devices() 110 */ 111 static const struct of_device_id mpc52xx_gpt_ids[] __initconst = { 112 { .compatible = "fsl,mpc5200-gpt", }, 113 { .compatible = "mpc5200-gpt", }, /* old */ 114 {} 115 }; 116 static const struct of_device_id mpc52xx_cdm_ids[] __initconst = { 117 { .compatible = "fsl,mpc5200-cdm", }, 118 { .compatible = "mpc5200-cdm", }, /* old */ 119 {} 120 }; 121 static const struct of_device_id mpc52xx_gpio_simple[] __initconst = { 122 { .compatible = "fsl,mpc5200-gpio", }, 123 {} 124 }; 125 static const struct of_device_id mpc52xx_gpio_wkup[] __initconst = { 126 { .compatible = "fsl,mpc5200-gpio-wkup", }, 127 {} 128 }; 129 130 131 /** 132 * mpc52xx_map_common_devices: iomap devices required by common code 133 */ 134 void __init 135 mpc52xx_map_common_devices(void) 136 { 137 struct device_node *np; 138 139 /* mpc52xx_wdt is mapped here and used in mpc52xx_restart, 140 * possibly from a interrupt context. wdt is only implement 141 * on a gpt0, so check has-wdt property before mapping. 142 */ 143 for_each_matching_node(np, mpc52xx_gpt_ids) { 144 if (of_get_property(np, "fsl,has-wdt", NULL) || 145 of_get_property(np, "has-wdt", NULL)) { 146 mpc52xx_wdt = of_iomap(np, 0); 147 of_node_put(np); 148 break; 149 } 150 } 151 152 /* Clock Distribution Module, used by PSC clock setting function */ 153 np = of_find_matching_node(NULL, mpc52xx_cdm_ids); 154 mpc52xx_cdm = of_iomap(np, 0); 155 of_node_put(np); 156 157 /* simple_gpio registers */ 158 np = of_find_matching_node(NULL, mpc52xx_gpio_simple); 159 simple_gpio = of_iomap(np, 0); 160 of_node_put(np); 161 162 /* wkup_gpio registers */ 163 np = of_find_matching_node(NULL, mpc52xx_gpio_wkup); 164 wkup_gpio = of_iomap(np, 0); 165 of_node_put(np); 166 } 167 168 /** 169 * mpc52xx_set_psc_clkdiv: Set clock divider in the CDM for PSC ports 170 * 171 * @psc_id: id of psc port; must be 1,2,3 or 6 172 * @clkdiv: clock divider value to put into CDM PSC register. 173 */ 174 int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv) 175 { 176 unsigned long flags; 177 u16 __iomem *reg; 178 u32 val; 179 u32 mask; 180 u32 mclken_div; 181 182 if (!mpc52xx_cdm) 183 return -ENODEV; 184 185 mclken_div = 0x8000 | (clkdiv & 0x1FF); 186 switch (psc_id) { 187 case 1: reg = &mpc52xx_cdm->mclken_div_psc1; mask = 0x20; break; 188 case 2: reg = &mpc52xx_cdm->mclken_div_psc2; mask = 0x40; break; 189 case 3: reg = &mpc52xx_cdm->mclken_div_psc3; mask = 0x80; break; 190 case 6: reg = &mpc52xx_cdm->mclken_div_psc6; mask = 0x10; break; 191 default: 192 return -ENODEV; 193 } 194 195 /* Set the rate and enable the clock */ 196 spin_lock_irqsave(&mpc52xx_lock, flags); 197 out_be16(reg, mclken_div); 198 val = in_be32(&mpc52xx_cdm->clk_enables); 199 out_be32(&mpc52xx_cdm->clk_enables, val | mask); 200 spin_unlock_irqrestore(&mpc52xx_lock, flags); 201 202 return 0; 203 } 204 EXPORT_SYMBOL(mpc52xx_set_psc_clkdiv); 205 206 /** 207 * mpc52xx_get_xtal_freq - Get SYS_XTAL_IN frequency for a device 208 * 209 * @node: device node 210 * 211 * Returns the frequency of the external oscillator clock connected 212 * to the SYS_XTAL_IN pin, or 0 if it cannot be determined. 213 */ 214 unsigned int mpc52xx_get_xtal_freq(struct device_node *node) 215 { 216 u32 val; 217 unsigned int freq; 218 219 if (!mpc52xx_cdm) 220 return 0; 221 222 freq = mpc5xxx_get_bus_frequency(node); 223 if (!freq) 224 return 0; 225 226 if (in_8(&mpc52xx_cdm->ipb_clk_sel) & 0x1) 227 freq *= 2; 228 229 val = in_be32(&mpc52xx_cdm->rstcfg); 230 if (val & (1 << 5)) 231 freq *= 8; 232 else 233 freq *= 4; 234 if (val & (1 << 6)) 235 freq /= 12; 236 else 237 freq /= 16; 238 239 return freq; 240 } 241 EXPORT_SYMBOL(mpc52xx_get_xtal_freq); 242 243 /** 244 * mpc52xx_restart: ppc_md->restart hook for mpc5200 using the watchdog timer 245 */ 246 void __noreturn mpc52xx_restart(char *cmd) 247 { 248 local_irq_disable(); 249 250 /* Turn on the watchdog and wait for it to expire. 251 * It effectively does a reset. */ 252 if (mpc52xx_wdt) { 253 out_be32(&mpc52xx_wdt->mode, 0x00000000); 254 out_be32(&mpc52xx_wdt->count, 0x000000ff); 255 out_be32(&mpc52xx_wdt->mode, 0x00009004); 256 } else 257 printk(KERN_ERR __FILE__ ": " 258 "mpc52xx_restart: Can't access wdt. " 259 "Restart impossible, system halted.\n"); 260 261 while (1); 262 } 263 264 #define PSC1_RESET 0x1 265 #define PSC1_SYNC 0x4 266 #define PSC1_SDATA_OUT 0x1 267 #define PSC2_RESET 0x2 268 #define PSC2_SYNC (0x4<<4) 269 #define PSC2_SDATA_OUT (0x1<<4) 270 #define MPC52xx_GPIO_PSC1_MASK 0x7 271 #define MPC52xx_GPIO_PSC2_MASK (0x7<<4) 272 273 /** 274 * mpc5200_psc_ac97_gpio_reset: Use gpio pins to reset the ac97 bus 275 * 276 * @psc: psc number to reset (only psc 1 and 2 support ac97) 277 */ 278 int mpc5200_psc_ac97_gpio_reset(int psc_number) 279 { 280 unsigned long flags; 281 u32 gpio; 282 u32 mux; 283 int out; 284 int reset; 285 int sync; 286 287 if ((!simple_gpio) || (!wkup_gpio)) 288 return -ENODEV; 289 290 switch (psc_number) { 291 case 0: 292 reset = PSC1_RESET; /* AC97_1_RES */ 293 sync = PSC1_SYNC; /* AC97_1_SYNC */ 294 out = PSC1_SDATA_OUT; /* AC97_1_SDATA_OUT */ 295 gpio = MPC52xx_GPIO_PSC1_MASK; 296 break; 297 case 1: 298 reset = PSC2_RESET; /* AC97_2_RES */ 299 sync = PSC2_SYNC; /* AC97_2_SYNC */ 300 out = PSC2_SDATA_OUT; /* AC97_2_SDATA_OUT */ 301 gpio = MPC52xx_GPIO_PSC2_MASK; 302 break; 303 default: 304 pr_err(__FILE__ ": Unable to determine PSC, no ac97 " 305 "cold-reset will be performed\n"); 306 return -ENODEV; 307 } 308 309 spin_lock_irqsave(&gpio_lock, flags); 310 311 /* Reconfiure pin-muxing to gpio */ 312 mux = in_be32(&simple_gpio->port_config); 313 out_be32(&simple_gpio->port_config, mux & (~gpio)); 314 315 /* enable gpio pins for output */ 316 setbits8(&wkup_gpio->wkup_gpioe, reset); 317 setbits32(&simple_gpio->simple_gpioe, sync | out); 318 319 setbits8(&wkup_gpio->wkup_ddr, reset); 320 setbits32(&simple_gpio->simple_ddr, sync | out); 321 322 /* Assert cold reset */ 323 clrbits32(&simple_gpio->simple_dvo, sync | out); 324 clrbits8(&wkup_gpio->wkup_dvo, reset); 325 326 /* wait for 1 us */ 327 udelay(1); 328 329 /* Deassert reset */ 330 setbits8(&wkup_gpio->wkup_dvo, reset); 331 332 /* wait at least 200ns */ 333 /* 7 ~= (200ns * timebase) / ns2sec */ 334 __delay(7); 335 336 /* Restore pin-muxing */ 337 out_be32(&simple_gpio->port_config, mux); 338 339 spin_unlock_irqrestore(&gpio_lock, flags); 340 341 return 0; 342 } 343 EXPORT_SYMBOL(mpc5200_psc_ac97_gpio_reset); 344