root/arch/powerpc/platforms/52xx/mpc52xx_common.c

DEFINITIONS

1. mpc5200_setup_xlb_arbiter
2. mpc52xx_declare_of_platform_devices
3. mpc52xx_map_common_devices
4. mpc52xx_set_psc_clkdiv
5. mpc52xx_get_xtal_freq
6. mpc52xx_restart
7. mpc5200_psc_ac97_gpio_reset

   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);