arch/mips/ath25/ar2315.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2003 Atheros Communications, Inc.,  All Rights Reserved.
   7  * Copyright (C) 2006 FON Technology, SL.
   8  * Copyright (C) 2006 Imre Kaloz <kaloz@openwrt.org>
   9  * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
  10  * Copyright (C) 2012 Alexandros C. Couloumbis <alex@ozo.com>
  11  */
  12
  13 /*
  14  * Platform devices for Atheros AR2315 SoCs
  15  */
  16
  17 #include <linux/init.h>
  18 #include <linux/kernel.h>
  19 #include <linux/bitops.h>
  20 #include <linux/irqdomain.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/reboot.h>
  24 #include <asm/bootinfo.h>
  25 #include <asm/reboot.h>
  26 #include <asm/time.h>
  27
  28 #include <ath25_platform.h>
  29
  30 #include "devices.h"
  31 #include "ar2315.h"
  32 #include "ar2315_regs.h"
  33
  34 static void __iomem *ar2315_rst_base;
  35 static struct irq_domain *ar2315_misc_irq_domain;
  36
  37 static inline u32 ar2315_rst_reg_read(u32 reg)
  38 {
  39         return __raw_readl(ar2315_rst_base + reg);
  40 }
  41
  42 static inline void ar2315_rst_reg_write(u32 reg, u32 val)
  43 {
  44         __raw_writel(val, ar2315_rst_base + reg);
  45 }
  46
  47 static inline void ar2315_rst_reg_mask(u32 reg, u32 mask, u32 val)
  48 {
  49         u32 ret = ar2315_rst_reg_read(reg);
  50
  51         ret &= ~mask;
  52         ret |= val;
  53         ar2315_rst_reg_write(reg, ret);
  54 }
  55
  56 static irqreturn_t ar2315_ahb_err_handler(int cpl, void *dev_id)
  57 {
  58         ar2315_rst_reg_write(AR2315_AHB_ERR0, AR2315_AHB_ERROR_DET);
  59         ar2315_rst_reg_read(AR2315_AHB_ERR1);
  60
  61         pr_emerg("AHB fatal error\n");
  62         machine_restart("AHB error"); /* Catastrophic failure */
  63
  64         return IRQ_HANDLED;
  65 }
  66
  67 static struct irqaction ar2315_ahb_err_interrupt  = {
  68         .handler        = ar2315_ahb_err_handler,
  69         .name           = "ar2315-ahb-error",
  70 };
  71
  72 static void ar2315_misc_irq_handler(unsigned irq, struct irq_desc *desc)
  73 {
  74         u32 pending = ar2315_rst_reg_read(AR2315_ISR) &
  75                       ar2315_rst_reg_read(AR2315_IMR);
  76         unsigned nr, misc_irq = 0;
  77
  78         if (pending) {
  79                 struct irq_domain *domain = irq_get_handler_data(irq);
  80
  81                 nr = __ffs(pending);
  82                 misc_irq = irq_find_mapping(domain, nr);
  83         }
  84
  85         if (misc_irq) {
  86                 if (nr == AR2315_MISC_IRQ_GPIO)
  87                         ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_GPIO);
  88                 else if (nr == AR2315_MISC_IRQ_WATCHDOG)
  89                         ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_WD);
  90                 generic_handle_irq(misc_irq);
  91         } else {
  92                 spurious_interrupt();
  93         }
  94 }
  95
  96 static void ar2315_misc_irq_unmask(struct irq_data *d)
  97 {
  98         ar2315_rst_reg_mask(AR2315_IMR, 0, BIT(d->hwirq));
  99 }
 100
 101 static void ar2315_misc_irq_mask(struct irq_data *d)
 102 {
 103         ar2315_rst_reg_mask(AR2315_IMR, BIT(d->hwirq), 0);
 104 }
 105
 106 static struct irq_chip ar2315_misc_irq_chip = {
 107         .name           = "ar2315-misc",
 108         .irq_unmask     = ar2315_misc_irq_unmask,
 109         .irq_mask       = ar2315_misc_irq_mask,
 110 };
 111
 112 static int ar2315_misc_irq_map(struct irq_domain *d, unsigned irq,
 113                                irq_hw_number_t hw)
 114 {
 115         irq_set_chip_and_handler(irq, &ar2315_misc_irq_chip, handle_level_irq);
 116         return 0;
 117 }
 118
 119 static struct irq_domain_ops ar2315_misc_irq_domain_ops = {
 120         .map = ar2315_misc_irq_map,
 121 };
 122
 123 /*
 124  * Called when an interrupt is received, this function
 125  * determines exactly which interrupt it was, and it
 126  * invokes the appropriate handler.
 127  *
 128  * Implicitly, we also define interrupt priority by
 129  * choosing which to dispatch first.
 130  */
 131 static void ar2315_irq_dispatch(void)
 132 {
 133         u32 pending = read_c0_status() & read_c0_cause();
 134
 135         if (pending & CAUSEF_IP3)
 136                 do_IRQ(AR2315_IRQ_WLAN0);
 137 #ifdef CONFIG_PCI_AR2315
 138         else if (pending & CAUSEF_IP5)
 139                 do_IRQ(AR2315_IRQ_LCBUS_PCI);
 140 #endif
 141         else if (pending & CAUSEF_IP2)
 142                 do_IRQ(AR2315_IRQ_MISC);
 143         else if (pending & CAUSEF_IP7)
 144                 do_IRQ(ATH25_IRQ_CPU_CLOCK);
 145         else
 146                 spurious_interrupt();
 147 }
 148
 149 void __init ar2315_arch_init_irq(void)
 150 {
 151         struct irq_domain *domain;
 152         unsigned irq;
 153
 154         ath25_irq_dispatch = ar2315_irq_dispatch;
 155
 156         domain = irq_domain_add_linear(NULL, AR2315_MISC_IRQ_COUNT,
 157                                        &ar2315_misc_irq_domain_ops, NULL);
 158         if (!domain)
 159                 panic("Failed to add IRQ domain");
 160
 161         irq = irq_create_mapping(domain, AR2315_MISC_IRQ_AHB);
 162         setup_irq(irq, &ar2315_ahb_err_interrupt);
 163
 164         irq_set_chained_handler(AR2315_IRQ_MISC, ar2315_misc_irq_handler);
 165         irq_set_handler_data(AR2315_IRQ_MISC, domain);
 166
 167         ar2315_misc_irq_domain = domain;
 168 }
 169
 170 void __init ar2315_init_devices(void)
 171 {
 172         /* Find board configuration */
 173         ath25_find_config(AR2315_SPI_READ_BASE, AR2315_SPI_READ_SIZE);
 174
 175         ath25_add_wmac(0, AR2315_WLAN0_BASE, AR2315_IRQ_WLAN0);
 176 }
 177
 178 static void ar2315_restart(char *command)
 179 {
 180         void (*mips_reset_vec)(void) = (void *)0xbfc00000;
 181
 182         local_irq_disable();
 183
 184         /* try reset the system via reset control */
 185         ar2315_rst_reg_write(AR2315_COLD_RESET, AR2317_RESET_SYSTEM);
 186
 187         /* Cold reset does not work on the AR2315/6, use the GPIO reset bits
 188          * a workaround. Give it some time to attempt a gpio based hardware
 189          * reset (atheros reference design workaround) */
 190
 191         /* TODO: implement the GPIO reset workaround */
 192
 193         /* Some boards (e.g. Senao EOC-2610) don't implement the reset logic
 194          * workaround. Attempt to jump to the mips reset location -
 195          * the boot loader itself might be able to recover the system */
 196         mips_reset_vec();
 197 }
 198
 199 /*
 200  * This table is indexed by bits 5..4 of the CLOCKCTL1 register
 201  * to determine the predevisor value.
 202  */
 203 static int clockctl1_predivide_table[4] __initdata = { 1, 2, 4, 5 };
 204 static int pllc_divide_table[5] __initdata = { 2, 3, 4, 6, 3 };
 205
 206 static unsigned __init ar2315_sys_clk(u32 clock_ctl)
 207 {
 208         unsigned int pllc_ctrl, cpu_div;
 209         unsigned int pllc_out, refdiv, fdiv, divby2;
 210         unsigned int clk_div;
 211
 212         pllc_ctrl = ar2315_rst_reg_read(AR2315_PLLC_CTL);
 213         refdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_REF_DIV);
 214         refdiv = clockctl1_predivide_table[refdiv];
 215         fdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_FDBACK_DIV);
 216         divby2 = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_ADD_FDBACK_DIV) + 1;
 217         pllc_out = (40000000 / refdiv) * (2 * divby2) * fdiv;
 218
 219         /* clkm input selected */
 220         switch (clock_ctl & AR2315_CPUCLK_CLK_SEL_M) {
 221         case 0:
 222         case 1:
 223                 clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKM_DIV);
 224                 clk_div = pllc_divide_table[clk_div];
 225                 break;
 226         case 2:
 227                 clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKC_DIV);
 228                 clk_div = pllc_divide_table[clk_div];
 229                 break;
 230         default:
 231                 pllc_out = 40000000;
 232                 clk_div = 1;
 233                 break;
 234         }
 235
 236         cpu_div = ATH25_REG_MS(clock_ctl, AR2315_CPUCLK_CLK_DIV);
 237         cpu_div = cpu_div * 2 ?: 1;
 238
 239         return pllc_out / (clk_div * cpu_div);
 240 }
 241
 242 static inline unsigned ar2315_cpu_frequency(void)
 243 {
 244         return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_CPUCLK));
 245 }
 246
 247 static inline unsigned ar2315_apb_frequency(void)
 248 {
 249         return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_AMBACLK));
 250 }
 251
 252 void __init ar2315_plat_time_init(void)
 253 {
 254         mips_hpt_frequency = ar2315_cpu_frequency() / 2;
 255 }
 256
 257 void __init ar2315_plat_mem_setup(void)
 258 {
 259         void __iomem *sdram_base;
 260         u32 memsize, memcfg;
 261         u32 devid;
 262         u32 config;
 263
 264         /* Detect memory size */
 265         sdram_base = ioremap_nocache(AR2315_SDRAMCTL_BASE,
 266                                      AR2315_SDRAMCTL_SIZE);
 267         memcfg = __raw_readl(sdram_base + AR2315_MEM_CFG);
 268         memsize   = 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_DATA_WIDTH);
 269         memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_COL_WIDTH);
 270         memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_ROW_WIDTH);
 271         memsize <<= 3;
 272         add_memory_region(0, memsize, BOOT_MEM_RAM);
 273         iounmap(sdram_base);
 274
 275         ar2315_rst_base = ioremap_nocache(AR2315_RST_BASE, AR2315_RST_SIZE);
 276
 277         /* Detect the hardware based on the device ID */
 278         devid = ar2315_rst_reg_read(AR2315_SREV) & AR2315_REV_CHIP;
 279         switch (devid) {
 280         case 0x91:      /* Need to check */
 281                 ath25_soc = ATH25_SOC_AR2318;
 282                 break;
 283         case 0x90:
 284                 ath25_soc = ATH25_SOC_AR2317;
 285                 break;
 286         case 0x87:
 287                 ath25_soc = ATH25_SOC_AR2316;
 288                 break;
 289         case 0x86:
 290         default:
 291                 ath25_soc = ATH25_SOC_AR2315;
 292                 break;
 293         }
 294         ath25_board.devid = devid;
 295
 296         /* Clear any lingering AHB errors */
 297         config = read_c0_config();
 298         write_c0_config(config & ~0x3);
 299         ar2315_rst_reg_write(AR2315_AHB_ERR0, AR2315_AHB_ERROR_DET);
 300         ar2315_rst_reg_read(AR2315_AHB_ERR1);
 301         ar2315_rst_reg_write(AR2315_WDT_CTRL, AR2315_WDT_CTRL_IGNORE);
 302
 303         _machine_restart = ar2315_restart;
 304 }
 305
 306 #ifdef CONFIG_PCI_AR2315
 307 static struct resource ar2315_pci_res[] = {
 308         {
 309                 .name = "ar2315-pci-ctrl",
 310                 .flags = IORESOURCE_MEM,
 311                 .start = AR2315_PCI_BASE,
 312                 .end = AR2315_PCI_BASE + AR2315_PCI_SIZE - 1,
 313         },
 314         {
 315                 .name = "ar2315-pci-ext",
 316                 .flags = IORESOURCE_MEM,
 317                 .start = AR2315_PCI_EXT_BASE,
 318                 .end = AR2315_PCI_EXT_BASE + AR2315_PCI_EXT_SIZE - 1,
 319         },
 320         {
 321                 .name = "ar2315-pci",
 322                 .flags = IORESOURCE_IRQ,
 323                 .start = AR2315_IRQ_LCBUS_PCI,
 324                 .end = AR2315_IRQ_LCBUS_PCI,
 325         },
 326 };
 327 #endif
 328
 329 void __init ar2315_arch_init(void)
 330 {
 331         unsigned irq = irq_create_mapping(ar2315_misc_irq_domain,
 332                                           AR2315_MISC_IRQ_UART0);
 333
 334         ath25_serial_setup(AR2315_UART0_BASE, irq, ar2315_apb_frequency());
 335
 336 #ifdef CONFIG_PCI_AR2315
 337         if (ath25_soc == ATH25_SOC_AR2315) {
 338                 /* Reset PCI DMA logic */
 339                 ar2315_rst_reg_mask(AR2315_RESET, 0, AR2315_RESET_PCIDMA);
 340                 msleep(20);
 341                 ar2315_rst_reg_mask(AR2315_RESET, AR2315_RESET_PCIDMA, 0);
 342                 msleep(20);
 343
 344                 /* Configure endians */
 345                 ar2315_rst_reg_mask(AR2315_ENDIAN_CTL, 0, AR2315_CONFIG_PCIAHB |
 346                                     AR2315_CONFIG_PCIAHB_BRIDGE);
 347
 348                 /* Configure as PCI host with DMA */
 349                 ar2315_rst_reg_write(AR2315_PCICLK, AR2315_PCICLK_PLLC_CLKM |
 350                                   (AR2315_PCICLK_IN_FREQ_DIV_6 <<
 351                                    AR2315_PCICLK_DIV_S));
 352                 ar2315_rst_reg_mask(AR2315_AHB_ARB_CTL, 0, AR2315_ARB_PCI);
 353                 ar2315_rst_reg_mask(AR2315_IF_CTL, AR2315_IF_PCI_CLK_MASK |
 354                                     AR2315_IF_MASK, AR2315_IF_PCI |
 355                                     AR2315_IF_PCI_HOST | AR2315_IF_PCI_INTR |
 356                                     (AR2315_IF_PCI_CLK_OUTPUT_CLK <<
 357                                      AR2315_IF_PCI_CLK_SHIFT));
 358
 359                 platform_device_register_simple("ar2315-pci", -1,
 360                                                 ar2315_pci_res,
 361                                                 ARRAY_SIZE(ar2315_pci_res));
 362         }
 363 #endif
 364 }