linux/arch/mips/ath25/ar2315.c
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   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/memblock.h>
  23#include <linux/platform_device.h>
  24#include <linux/reboot.h>
  25#include <asm/bootinfo.h>
  26#include <asm/reboot.h>
  27#include <asm/time.h>
  28
  29#include <ath25_platform.h>
  30
  31#include "devices.h"
  32#include "ar2315.h"
  33#include "ar2315_regs.h"
  34
  35static void __iomem *ar2315_rst_base;
  36static struct irq_domain *ar2315_misc_irq_domain;
  37
  38static inline u32 ar2315_rst_reg_read(u32 reg)
  39{
  40        return __raw_readl(ar2315_rst_base + reg);
  41}
  42
  43static inline void ar2315_rst_reg_write(u32 reg, u32 val)
  44{
  45        __raw_writel(val, ar2315_rst_base + reg);
  46}
  47
  48static inline void ar2315_rst_reg_mask(u32 reg, u32 mask, u32 val)
  49{
  50        u32 ret = ar2315_rst_reg_read(reg);
  51
  52        ret &= ~mask;
  53        ret |= val;
  54        ar2315_rst_reg_write(reg, ret);
  55}
  56
  57static irqreturn_t ar2315_ahb_err_handler(int cpl, void *dev_id)
  58{
  59        ar2315_rst_reg_write(AR2315_AHB_ERR0, AR2315_AHB_ERROR_DET);
  60        ar2315_rst_reg_read(AR2315_AHB_ERR1);
  61
  62        pr_emerg("AHB fatal error\n");
  63        machine_restart("AHB error"); /* Catastrophic failure */
  64
  65        return IRQ_HANDLED;
  66}
  67
  68static void ar2315_misc_irq_handler(struct irq_desc *desc)
  69{
  70        u32 pending = ar2315_rst_reg_read(AR2315_ISR) &
  71                      ar2315_rst_reg_read(AR2315_IMR);
  72        unsigned nr;
  73        int ret = 0;
  74
  75        if (pending) {
  76                struct irq_domain *domain = irq_desc_get_handler_data(desc);
  77
  78                nr = __ffs(pending);
  79
  80                if (nr == AR2315_MISC_IRQ_GPIO)
  81                        ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_GPIO);
  82                else if (nr == AR2315_MISC_IRQ_WATCHDOG)
  83                        ar2315_rst_reg_write(AR2315_ISR, AR2315_ISR_WD);
  84
  85                ret = generic_handle_domain_irq(domain, nr);
  86        }
  87
  88        if (!pending || ret)
  89                spurious_interrupt();
  90}
  91
  92static void ar2315_misc_irq_unmask(struct irq_data *d)
  93{
  94        ar2315_rst_reg_mask(AR2315_IMR, 0, BIT(d->hwirq));
  95}
  96
  97static void ar2315_misc_irq_mask(struct irq_data *d)
  98{
  99        ar2315_rst_reg_mask(AR2315_IMR, BIT(d->hwirq), 0);
 100}
 101
 102static struct irq_chip ar2315_misc_irq_chip = {
 103        .name           = "ar2315-misc",
 104        .irq_unmask     = ar2315_misc_irq_unmask,
 105        .irq_mask       = ar2315_misc_irq_mask,
 106};
 107
 108static int ar2315_misc_irq_map(struct irq_domain *d, unsigned irq,
 109                               irq_hw_number_t hw)
 110{
 111        irq_set_chip_and_handler(irq, &ar2315_misc_irq_chip, handle_level_irq);
 112        return 0;
 113}
 114
 115static struct irq_domain_ops ar2315_misc_irq_domain_ops = {
 116        .map = ar2315_misc_irq_map,
 117};
 118
 119/*
 120 * Called when an interrupt is received, this function
 121 * determines exactly which interrupt it was, and it
 122 * invokes the appropriate handler.
 123 *
 124 * Implicitly, we also define interrupt priority by
 125 * choosing which to dispatch first.
 126 */
 127static void ar2315_irq_dispatch(void)
 128{
 129        u32 pending = read_c0_status() & read_c0_cause();
 130
 131        if (pending & CAUSEF_IP3)
 132                do_IRQ(AR2315_IRQ_WLAN0);
 133#ifdef CONFIG_PCI_AR2315
 134        else if (pending & CAUSEF_IP5)
 135                do_IRQ(AR2315_IRQ_LCBUS_PCI);
 136#endif
 137        else if (pending & CAUSEF_IP2)
 138                do_IRQ(AR2315_IRQ_MISC);
 139        else if (pending & CAUSEF_IP7)
 140                do_IRQ(ATH25_IRQ_CPU_CLOCK);
 141        else
 142                spurious_interrupt();
 143}
 144
 145void __init ar2315_arch_init_irq(void)
 146{
 147        struct irq_domain *domain;
 148        unsigned irq;
 149
 150        ath25_irq_dispatch = ar2315_irq_dispatch;
 151
 152        domain = irq_domain_add_linear(NULL, AR2315_MISC_IRQ_COUNT,
 153                                       &ar2315_misc_irq_domain_ops, NULL);
 154        if (!domain)
 155                panic("Failed to add IRQ domain");
 156
 157        irq = irq_create_mapping(domain, AR2315_MISC_IRQ_AHB);
 158        if (request_irq(irq, ar2315_ahb_err_handler, 0, "ar2315-ahb-error",
 159                        NULL))
 160                pr_err("Failed to register ar2315-ahb-error interrupt\n");
 161
 162        irq_set_chained_handler_and_data(AR2315_IRQ_MISC,
 163                                         ar2315_misc_irq_handler, domain);
 164
 165        ar2315_misc_irq_domain = domain;
 166}
 167
 168void __init ar2315_init_devices(void)
 169{
 170        /* Find board configuration */
 171        ath25_find_config(AR2315_SPI_READ_BASE, AR2315_SPI_READ_SIZE);
 172
 173        ath25_add_wmac(0, AR2315_WLAN0_BASE, AR2315_IRQ_WLAN0);
 174}
 175
 176static void ar2315_restart(char *command)
 177{
 178        void (*mips_reset_vec)(void) = (void *)0xbfc00000;
 179
 180        local_irq_disable();
 181
 182        /* try reset the system via reset control */
 183        ar2315_rst_reg_write(AR2315_COLD_RESET, AR2317_RESET_SYSTEM);
 184
 185        /* Cold reset does not work on the AR2315/6, use the GPIO reset bits
 186         * a workaround. Give it some time to attempt a gpio based hardware
 187         * reset (atheros reference design workaround) */
 188
 189        /* TODO: implement the GPIO reset workaround */
 190
 191        /* Some boards (e.g. Senao EOC-2610) don't implement the reset logic
 192         * workaround. Attempt to jump to the mips reset location -
 193         * the boot loader itself might be able to recover the system */
 194        mips_reset_vec();
 195}
 196
 197/*
 198 * This table is indexed by bits 5..4 of the CLOCKCTL1 register
 199 * to determine the predevisor value.
 200 */
 201static int clockctl1_predivide_table[4] __initdata = { 1, 2, 4, 5 };
 202static int pllc_divide_table[5] __initdata = { 2, 3, 4, 6, 3 };
 203
 204static unsigned __init ar2315_sys_clk(u32 clock_ctl)
 205{
 206        unsigned int pllc_ctrl, cpu_div;
 207        unsigned int pllc_out, refdiv, fdiv, divby2;
 208        unsigned int clk_div;
 209
 210        pllc_ctrl = ar2315_rst_reg_read(AR2315_PLLC_CTL);
 211        refdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_REF_DIV);
 212        refdiv = clockctl1_predivide_table[refdiv];
 213        fdiv = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_FDBACK_DIV);
 214        divby2 = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_ADD_FDBACK_DIV) + 1;
 215        pllc_out = (40000000 / refdiv) * (2 * divby2) * fdiv;
 216
 217        /* clkm input selected */
 218        switch (clock_ctl & AR2315_CPUCLK_CLK_SEL_M) {
 219        case 0:
 220        case 1:
 221                clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKM_DIV);
 222                clk_div = pllc_divide_table[clk_div];
 223                break;
 224        case 2:
 225                clk_div = ATH25_REG_MS(pllc_ctrl, AR2315_PLLC_CLKC_DIV);
 226                clk_div = pllc_divide_table[clk_div];
 227                break;
 228        default:
 229                pllc_out = 40000000;
 230                clk_div = 1;
 231                break;
 232        }
 233
 234        cpu_div = ATH25_REG_MS(clock_ctl, AR2315_CPUCLK_CLK_DIV);
 235        cpu_div = cpu_div * 2 ?: 1;
 236
 237        return pllc_out / (clk_div * cpu_div);
 238}
 239
 240static inline unsigned ar2315_cpu_frequency(void)
 241{
 242        return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_CPUCLK));
 243}
 244
 245static inline unsigned ar2315_apb_frequency(void)
 246{
 247        return ar2315_sys_clk(ar2315_rst_reg_read(AR2315_AMBACLK));
 248}
 249
 250void __init ar2315_plat_time_init(void)
 251{
 252        mips_hpt_frequency = ar2315_cpu_frequency() / 2;
 253}
 254
 255void __init ar2315_plat_mem_setup(void)
 256{
 257        void __iomem *sdram_base;
 258        u32 memsize, memcfg;
 259        u32 devid;
 260        u32 config;
 261
 262        /* Detect memory size */
 263        sdram_base = ioremap(AR2315_SDRAMCTL_BASE,
 264                                     AR2315_SDRAMCTL_SIZE);
 265        memcfg = __raw_readl(sdram_base + AR2315_MEM_CFG);
 266        memsize   = 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_DATA_WIDTH);
 267        memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_COL_WIDTH);
 268        memsize <<= 1 + ATH25_REG_MS(memcfg, AR2315_MEM_CFG_ROW_WIDTH);
 269        memsize <<= 3;
 270        memblock_add(0, memsize);
 271        iounmap(sdram_base);
 272
 273        ar2315_rst_base = ioremap(AR2315_RST_BASE, AR2315_RST_SIZE);
 274
 275        /* Detect the hardware based on the device ID */
 276        devid = ar2315_rst_reg_read(AR2315_SREV) & AR2315_REV_CHIP;
 277        switch (devid) {
 278        case 0x91:      /* Need to check */
 279                ath25_soc = ATH25_SOC_AR2318;
 280                break;
 281        case 0x90:
 282                ath25_soc = ATH25_SOC_AR2317;
 283                break;
 284        case 0x87:
 285                ath25_soc = ATH25_SOC_AR2316;
 286                break;
 287        case 0x86:
 288        default:
 289                ath25_soc = ATH25_SOC_AR2315;
 290                break;
 291        }
 292        ath25_board.devid = devid;
 293
 294        /* Clear any lingering AHB errors */
 295        config = read_c0_config();
 296        write_c0_config(config & ~0x3);
 297        ar2315_rst_reg_write(AR2315_AHB_ERR0, AR2315_AHB_ERROR_DET);
 298        ar2315_rst_reg_read(AR2315_AHB_ERR1);
 299        ar2315_rst_reg_write(AR2315_WDT_CTRL, AR2315_WDT_CTRL_IGNORE);
 300
 301        _machine_restart = ar2315_restart;
 302}
 303
 304#ifdef CONFIG_PCI_AR2315
 305static struct resource ar2315_pci_res[] = {
 306        {
 307                .name = "ar2315-pci-ctrl",
 308                .flags = IORESOURCE_MEM,
 309                .start = AR2315_PCI_BASE,
 310                .end = AR2315_PCI_BASE + AR2315_PCI_SIZE - 1,
 311        },
 312        {
 313                .name = "ar2315-pci-ext",
 314                .flags = IORESOURCE_MEM,
 315                .start = AR2315_PCI_EXT_BASE,
 316                .end = AR2315_PCI_EXT_BASE + AR2315_PCI_EXT_SIZE - 1,
 317        },
 318        {
 319                .name = "ar2315-pci",
 320                .flags = IORESOURCE_IRQ,
 321                .start = AR2315_IRQ_LCBUS_PCI,
 322                .end = AR2315_IRQ_LCBUS_PCI,
 323        },
 324};
 325#endif
 326
 327void __init ar2315_arch_init(void)
 328{
 329        unsigned irq = irq_create_mapping(ar2315_misc_irq_domain,
 330                                          AR2315_MISC_IRQ_UART0);
 331
 332        ath25_serial_setup(AR2315_UART0_BASE, irq, ar2315_apb_frequency());
 333
 334#ifdef CONFIG_PCI_AR2315
 335        if (ath25_soc == ATH25_SOC_AR2315) {
 336                /* Reset PCI DMA logic */
 337                ar2315_rst_reg_mask(AR2315_RESET, 0, AR2315_RESET_PCIDMA);
 338                msleep(20);
 339                ar2315_rst_reg_mask(AR2315_RESET, AR2315_RESET_PCIDMA, 0);
 340                msleep(20);
 341
 342                /* Configure endians */
 343                ar2315_rst_reg_mask(AR2315_ENDIAN_CTL, 0, AR2315_CONFIG_PCIAHB |
 344                                    AR2315_CONFIG_PCIAHB_BRIDGE);
 345
 346                /* Configure as PCI host with DMA */
 347                ar2315_rst_reg_write(AR2315_PCICLK, AR2315_PCICLK_PLLC_CLKM |
 348                                  (AR2315_PCICLK_IN_FREQ_DIV_6 <<
 349                                   AR2315_PCICLK_DIV_S));
 350                ar2315_rst_reg_mask(AR2315_AHB_ARB_CTL, 0, AR2315_ARB_PCI);
 351                ar2315_rst_reg_mask(AR2315_IF_CTL, AR2315_IF_PCI_CLK_MASK |
 352                                    AR2315_IF_MASK, AR2315_IF_PCI |
 353                                    AR2315_IF_PCI_HOST | AR2315_IF_PCI_INTR |
 354                                    (AR2315_IF_PCI_CLK_OUTPUT_CLK <<
 355                                     AR2315_IF_PCI_CLK_SHIFT));
 356
 357                platform_device_register_simple("ar2315-pci", -1,
 358                                                ar2315_pci_res,
 359                                                ARRAY_SIZE(ar2315_pci_res));
 360        }
 361#endif
 362}
 363