Santosh Shilimkar | fcf6efa | 2010-06-16 22:19:47 +0530 | [diff] [blame] | 1 | /* |
| 2 | * OMAP WakeupGen Source file |
| 3 | * |
| 4 | * OMAP WakeupGen is the interrupt controller extension used along |
| 5 | * with ARM GIC to wake the CPU out from low power states on |
| 6 | * external interrupts. It is responsible for generating wakeup |
| 7 | * event from the incoming interrupts and enable bits. It is |
| 8 | * implemented in MPU always ON power domain. During normal operation, |
| 9 | * WakeupGen delivers external interrupts directly to the GIC. |
| 10 | * |
| 11 | * Copyright (C) 2011 Texas Instruments, Inc. |
| 12 | * Santosh Shilimkar <santosh.shilimkar@ti.com> |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License version 2 as |
| 16 | * published by the Free Software Foundation. |
| 17 | */ |
| 18 | |
| 19 | #include <linux/kernel.h> |
| 20 | #include <linux/init.h> |
| 21 | #include <linux/io.h> |
| 22 | #include <linux/irq.h> |
| 23 | #include <linux/platform_device.h> |
| 24 | #include <linux/cpu.h> |
| 25 | |
| 26 | #include <asm/hardware/gic.h> |
| 27 | |
| 28 | #include <mach/omap-wakeupgen.h> |
| 29 | |
| 30 | #define NR_REG_BANKS 4 |
| 31 | #define MAX_IRQS 128 |
| 32 | #define WKG_MASK_ALL 0x00000000 |
| 33 | #define WKG_UNMASK_ALL 0xffffffff |
| 34 | #define CPU_ENA_OFFSET 0x400 |
| 35 | #define CPU0_ID 0x0 |
| 36 | #define CPU1_ID 0x1 |
| 37 | |
| 38 | static void __iomem *wakeupgen_base; |
| 39 | static DEFINE_PER_CPU(u32 [NR_REG_BANKS], irqmasks); |
| 40 | static DEFINE_SPINLOCK(wakeupgen_lock); |
| 41 | static unsigned int irq_target_cpu[NR_IRQS]; |
| 42 | |
| 43 | /* |
| 44 | * Static helper functions. |
| 45 | */ |
| 46 | static inline u32 wakeupgen_readl(u8 idx, u32 cpu) |
| 47 | { |
| 48 | return __raw_readl(wakeupgen_base + OMAP_WKG_ENB_A_0 + |
| 49 | (cpu * CPU_ENA_OFFSET) + (idx * 4)); |
| 50 | } |
| 51 | |
| 52 | static inline void wakeupgen_writel(u32 val, u8 idx, u32 cpu) |
| 53 | { |
| 54 | __raw_writel(val, wakeupgen_base + OMAP_WKG_ENB_A_0 + |
| 55 | (cpu * CPU_ENA_OFFSET) + (idx * 4)); |
| 56 | } |
| 57 | |
| 58 | static void _wakeupgen_set_all(unsigned int cpu, unsigned int reg) |
| 59 | { |
| 60 | u8 i; |
| 61 | |
| 62 | for (i = 0; i < NR_REG_BANKS; i++) |
| 63 | wakeupgen_writel(reg, i, cpu); |
| 64 | } |
| 65 | |
| 66 | static inline int _wakeupgen_get_irq_info(u32 irq, u32 *bit_posn, u8 *reg_index) |
| 67 | { |
| 68 | unsigned int spi_irq; |
| 69 | |
| 70 | /* |
| 71 | * PPIs and SGIs are not supported. |
| 72 | */ |
| 73 | if (irq < OMAP44XX_IRQ_GIC_START) |
| 74 | return -EINVAL; |
| 75 | |
| 76 | /* |
| 77 | * Subtract the GIC offset. |
| 78 | */ |
| 79 | spi_irq = irq - OMAP44XX_IRQ_GIC_START; |
| 80 | if (spi_irq > MAX_IRQS) { |
| 81 | pr_err("omap wakeupGen: Invalid IRQ%d\n", irq); |
| 82 | return -EINVAL; |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * Each WakeupGen register controls 32 interrupt. |
| 87 | * i.e. 1 bit per SPI IRQ |
| 88 | */ |
| 89 | *reg_index = spi_irq >> 5; |
| 90 | *bit_posn = spi_irq %= 32; |
| 91 | |
| 92 | return 0; |
| 93 | } |
| 94 | |
| 95 | static void _wakeupgen_clear(unsigned int irq, unsigned int cpu) |
| 96 | { |
| 97 | u32 val, bit_number; |
| 98 | u8 i; |
| 99 | |
| 100 | if (_wakeupgen_get_irq_info(irq, &bit_number, &i)) |
| 101 | return; |
| 102 | |
| 103 | val = wakeupgen_readl(i, cpu); |
| 104 | val &= ~BIT(bit_number); |
| 105 | wakeupgen_writel(val, i, cpu); |
| 106 | } |
| 107 | |
| 108 | static void _wakeupgen_set(unsigned int irq, unsigned int cpu) |
| 109 | { |
| 110 | u32 val, bit_number; |
| 111 | u8 i; |
| 112 | |
| 113 | if (_wakeupgen_get_irq_info(irq, &bit_number, &i)) |
| 114 | return; |
| 115 | |
| 116 | val = wakeupgen_readl(i, cpu); |
| 117 | val |= BIT(bit_number); |
| 118 | wakeupgen_writel(val, i, cpu); |
| 119 | } |
| 120 | |
| 121 | static void _wakeupgen_save_masks(unsigned int cpu) |
| 122 | { |
| 123 | u8 i; |
| 124 | |
| 125 | for (i = 0; i < NR_REG_BANKS; i++) |
| 126 | per_cpu(irqmasks, cpu)[i] = wakeupgen_readl(i, cpu); |
| 127 | } |
| 128 | |
| 129 | static void _wakeupgen_restore_masks(unsigned int cpu) |
| 130 | { |
| 131 | u8 i; |
| 132 | |
| 133 | for (i = 0; i < NR_REG_BANKS; i++) |
| 134 | wakeupgen_writel(per_cpu(irqmasks, cpu)[i], i, cpu); |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * Architecture specific Mask extension |
| 139 | */ |
| 140 | static void wakeupgen_mask(struct irq_data *d) |
| 141 | { |
| 142 | unsigned long flags; |
| 143 | |
| 144 | spin_lock_irqsave(&wakeupgen_lock, flags); |
| 145 | _wakeupgen_clear(d->irq, irq_target_cpu[d->irq]); |
| 146 | spin_unlock_irqrestore(&wakeupgen_lock, flags); |
| 147 | } |
| 148 | |
| 149 | /* |
| 150 | * Architecture specific Unmask extension |
| 151 | */ |
| 152 | static void wakeupgen_unmask(struct irq_data *d) |
| 153 | { |
| 154 | unsigned long flags; |
| 155 | |
| 156 | spin_lock_irqsave(&wakeupgen_lock, flags); |
| 157 | _wakeupgen_set(d->irq, irq_target_cpu[d->irq]); |
| 158 | spin_unlock_irqrestore(&wakeupgen_lock, flags); |
| 159 | } |
| 160 | |
| 161 | /* |
| 162 | * Mask or unmask all interrupts on given CPU. |
| 163 | * 0 = Mask all interrupts on the 'cpu' |
| 164 | * 1 = Unmask all interrupts on the 'cpu' |
| 165 | * Ensure that the initial mask is maintained. This is faster than |
| 166 | * iterating through GIC registers to arrive at the correct masks. |
| 167 | */ |
| 168 | static void wakeupgen_irqmask_all(unsigned int cpu, unsigned int set) |
| 169 | { |
| 170 | unsigned long flags; |
| 171 | |
| 172 | spin_lock_irqsave(&wakeupgen_lock, flags); |
| 173 | if (set) { |
| 174 | _wakeupgen_save_masks(cpu); |
| 175 | _wakeupgen_set_all(cpu, WKG_MASK_ALL); |
| 176 | } else { |
| 177 | _wakeupgen_set_all(cpu, WKG_UNMASK_ALL); |
| 178 | _wakeupgen_restore_masks(cpu); |
| 179 | } |
| 180 | spin_unlock_irqrestore(&wakeupgen_lock, flags); |
| 181 | } |
| 182 | |
Santosh Shilimkar | b5b4f28 | 2010-06-16 22:19:48 +0530 | [diff] [blame^] | 183 | #ifdef CONFIG_HOTPLUG_CPU |
| 184 | static int __cpuinit irq_cpu_hotplug_notify(struct notifier_block *self, |
| 185 | unsigned long action, void *hcpu) |
| 186 | { |
| 187 | unsigned int cpu = (unsigned int)hcpu; |
| 188 | |
| 189 | switch (action) { |
| 190 | case CPU_ONLINE: |
| 191 | wakeupgen_irqmask_all(cpu, 0); |
| 192 | break; |
| 193 | case CPU_DEAD: |
| 194 | wakeupgen_irqmask_all(cpu, 1); |
| 195 | break; |
| 196 | } |
| 197 | return NOTIFY_OK; |
| 198 | } |
| 199 | |
| 200 | static struct notifier_block __refdata irq_hotplug_notifier = { |
| 201 | .notifier_call = irq_cpu_hotplug_notify, |
| 202 | }; |
| 203 | |
| 204 | static void __init irq_hotplug_init(void) |
| 205 | { |
| 206 | register_hotcpu_notifier(&irq_hotplug_notifier); |
| 207 | } |
| 208 | #else |
| 209 | static void __init irq_hotplug_init(void) |
| 210 | {} |
| 211 | #endif |
| 212 | |
Santosh Shilimkar | fcf6efa | 2010-06-16 22:19:47 +0530 | [diff] [blame] | 213 | /* |
| 214 | * Initialise the wakeupgen module. |
| 215 | */ |
| 216 | int __init omap_wakeupgen_init(void) |
| 217 | { |
| 218 | int i; |
| 219 | unsigned int boot_cpu = smp_processor_id(); |
| 220 | |
| 221 | /* Not supported on OMAP4 ES1.0 silicon */ |
| 222 | if (omap_rev() == OMAP4430_REV_ES1_0) { |
| 223 | WARN(1, "WakeupGen: Not supported on OMAP4430 ES1.0\n"); |
| 224 | return -EPERM; |
| 225 | } |
| 226 | |
| 227 | /* Static mapping, never released */ |
| 228 | wakeupgen_base = ioremap(OMAP44XX_WKUPGEN_BASE, SZ_4K); |
| 229 | if (WARN_ON(!wakeupgen_base)) |
| 230 | return -ENOMEM; |
| 231 | |
| 232 | /* Clear all IRQ bitmasks at wakeupGen level */ |
| 233 | for (i = 0; i < NR_REG_BANKS; i++) { |
| 234 | wakeupgen_writel(0, i, CPU0_ID); |
| 235 | wakeupgen_writel(0, i, CPU1_ID); |
| 236 | } |
| 237 | |
| 238 | /* |
| 239 | * Override GIC architecture specific functions to add |
| 240 | * OMAP WakeupGen interrupt controller along with GIC |
| 241 | */ |
| 242 | gic_arch_extn.irq_mask = wakeupgen_mask; |
| 243 | gic_arch_extn.irq_unmask = wakeupgen_unmask; |
| 244 | gic_arch_extn.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE; |
| 245 | |
| 246 | /* |
| 247 | * FIXME: Add support to set_smp_affinity() once the core |
| 248 | * GIC code has necessary hooks in place. |
| 249 | */ |
| 250 | |
| 251 | /* Associate all the IRQs to boot CPU like GIC init does. */ |
| 252 | for (i = 0; i < NR_IRQS; i++) |
| 253 | irq_target_cpu[i] = boot_cpu; |
| 254 | |
Santosh Shilimkar | b5b4f28 | 2010-06-16 22:19:48 +0530 | [diff] [blame^] | 255 | irq_hotplug_init(); |
| 256 | |
Santosh Shilimkar | fcf6efa | 2010-06-16 22:19:47 +0530 | [diff] [blame] | 257 | return 0; |
| 258 | } |