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_address.h> 19 #include <linux/of_platform.h> 20 #include <linux/of_gpio.h> 21 #include <linux/export.h> 22 #include <asm/io.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_restart: ppc_md->restart hook for mpc5200 using the watchdog timer 208 */ 209 void __noreturn mpc52xx_restart(char *cmd) 210 { 211 local_irq_disable(); 212 213 /* Turn on the watchdog and wait for it to expire. 214 * It effectively does a reset. */ 215 if (mpc52xx_wdt) { 216 out_be32(&mpc52xx_wdt->mode, 0x00000000); 217 out_be32(&mpc52xx_wdt->count, 0x000000ff); 218 out_be32(&mpc52xx_wdt->mode, 0x00009004); 219 } else 220 printk(KERN_ERR __FILE__ ": " 221 "mpc52xx_restart: Can't access wdt. " 222 "Restart impossible, system halted.\n"); 223 224 while (1); 225 } 226 227 #define PSC1_RESET 0x1 228 #define PSC1_SYNC 0x4 229 #define PSC1_SDATA_OUT 0x1 230 #define PSC2_RESET 0x2 231 #define PSC2_SYNC (0x4<<4) 232 #define PSC2_SDATA_OUT (0x1<<4) 233 #define MPC52xx_GPIO_PSC1_MASK 0x7 234 #define MPC52xx_GPIO_PSC2_MASK (0x7<<4) 235 236 /** 237 * mpc5200_psc_ac97_gpio_reset: Use gpio pins to reset the ac97 bus 238 * 239 * @psc: psc number to reset (only psc 1 and 2 support ac97) 240 */ 241 int mpc5200_psc_ac97_gpio_reset(int psc_number) 242 { 243 unsigned long flags; 244 u32 gpio; 245 u32 mux; 246 int out; 247 int reset; 248 int sync; 249 250 if ((!simple_gpio) || (!wkup_gpio)) 251 return -ENODEV; 252 253 switch (psc_number) { 254 case 0: 255 reset = PSC1_RESET; /* AC97_1_RES */ 256 sync = PSC1_SYNC; /* AC97_1_SYNC */ 257 out = PSC1_SDATA_OUT; /* AC97_1_SDATA_OUT */ 258 gpio = MPC52xx_GPIO_PSC1_MASK; 259 break; 260 case 1: 261 reset = PSC2_RESET; /* AC97_2_RES */ 262 sync = PSC2_SYNC; /* AC97_2_SYNC */ 263 out = PSC2_SDATA_OUT; /* AC97_2_SDATA_OUT */ 264 gpio = MPC52xx_GPIO_PSC2_MASK; 265 break; 266 default: 267 pr_err(__FILE__ ": Unable to determine PSC, no ac97 " 268 "cold-reset will be performed\n"); 269 return -ENODEV; 270 } 271 272 spin_lock_irqsave(&gpio_lock, flags); 273 274 /* Reconfigure pin-muxing to gpio */ 275 mux = in_be32(&simple_gpio->port_config); 276 out_be32(&simple_gpio->port_config, mux & (~gpio)); 277 278 /* enable gpio pins for output */ 279 setbits8(&wkup_gpio->wkup_gpioe, reset); 280 setbits32(&simple_gpio->simple_gpioe, sync | out); 281 282 setbits8(&wkup_gpio->wkup_ddr, reset); 283 setbits32(&simple_gpio->simple_ddr, sync | out); 284 285 /* Assert cold reset */ 286 clrbits32(&simple_gpio->simple_dvo, sync | out); 287 clrbits8(&wkup_gpio->wkup_dvo, reset); 288 289 /* wait for 1 us */ 290 udelay(1); 291 292 /* Deassert reset */ 293 setbits8(&wkup_gpio->wkup_dvo, reset); 294 295 /* wait at least 200ns */ 296 /* 7 ~= (200ns * timebase) / ns2sec */ 297 __delay(7); 298 299 /* Restore pin-muxing */ 300 out_be32(&simple_gpio->port_config, mux); 301 302 spin_unlock_irqrestore(&gpio_lock, flags); 303 304 return 0; 305 } 306 EXPORT_SYMBOL(mpc5200_psc_ac97_gpio_reset); 307