| David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 2 | /* |
| 3 | * arch/sh/mach-cayman/irq.c - SH-5 Cayman Interrupt Support |
| 4 | * |
| 5 | * This file handles the board specific parts of the Cayman interrupt system |
| 6 | * |
| 7 | * Copyright (C) 2002 Stuart Menefy |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 8 | */ |
| 9 | #include <linux/io.h> |
| 10 | #include <linux/irq.h> |
| 11 | #include <linux/interrupt.h> |
| 12 | #include <linux/signal.h> |
| 13 | #include <cpu/irq.h> |
| 14 | #include <asm/page.h> |
| 15 | |
| 16 | /* Setup for the SMSC FDC37C935 / LAN91C100FD */ |
| 17 | #define SMSC_IRQ IRQ_IRL1 |
| 18 | |
| 19 | /* Setup for PCI Bus 2, which transmits interrupts via the EPLD */ |
| 20 | #define PCI2_IRQ IRQ_IRL3 |
| 21 | |
| 22 | unsigned long epld_virt; |
| 23 | |
| 24 | #define EPLD_BASE 0x04002000 |
| 25 | #define EPLD_STATUS_BASE (epld_virt + 0x10) |
| 26 | #define EPLD_MASK_BASE (epld_virt + 0x20) |
| 27 | |
| 28 | /* Note the SMSC SuperIO chip and SMSC LAN chip interrupts are all muxed onto |
| 29 | the same SH-5 interrupt */ |
| 30 | |
| 31 | static irqreturn_t cayman_interrupt_smsc(int irq, void *dev_id) |
| 32 | { |
| 33 | printk(KERN_INFO "CAYMAN: spurious SMSC interrupt\n"); |
| 34 | return IRQ_NONE; |
| 35 | } |
| 36 | |
| 37 | static irqreturn_t cayman_interrupt_pci2(int irq, void *dev_id) |
| 38 | { |
| 39 | printk(KERN_INFO "CAYMAN: spurious PCI interrupt, IRQ %d\n", irq); |
| 40 | return IRQ_NONE; |
| 41 | } |
| 42 | |
| 43 | static struct irqaction cayman_action_smsc = { |
| 44 | .name = "Cayman SMSC Mux", |
| 45 | .handler = cayman_interrupt_smsc, |
| 46 | }; |
| 47 | |
| 48 | static struct irqaction cayman_action_pci2 = { |
| 49 | .name = "Cayman PCI2 Mux", |
| 50 | .handler = cayman_interrupt_pci2, |
| 51 | }; |
| 52 | |
| 53 | static void enable_cayman_irq(struct irq_data *data) |
| 54 | { |
| 55 | unsigned int irq = data->irq; |
| 56 | unsigned long flags; |
| 57 | unsigned long mask; |
| 58 | unsigned int reg; |
| 59 | unsigned char bit; |
| 60 | |
| 61 | irq -= START_EXT_IRQS; |
| 62 | reg = EPLD_MASK_BASE + ((irq / 8) << 2); |
| 63 | bit = 1<<(irq % 8); |
| 64 | local_irq_save(flags); |
| 65 | mask = __raw_readl(reg); |
| 66 | mask |= bit; |
| 67 | __raw_writel(mask, reg); |
| 68 | local_irq_restore(flags); |
| 69 | } |
| 70 | |
| 71 | static void disable_cayman_irq(struct irq_data *data) |
| 72 | { |
| 73 | unsigned int irq = data->irq; |
| 74 | unsigned long flags; |
| 75 | unsigned long mask; |
| 76 | unsigned int reg; |
| 77 | unsigned char bit; |
| 78 | |
| 79 | irq -= START_EXT_IRQS; |
| 80 | reg = EPLD_MASK_BASE + ((irq / 8) << 2); |
| 81 | bit = 1<<(irq % 8); |
| 82 | local_irq_save(flags); |
| 83 | mask = __raw_readl(reg); |
| 84 | mask &= ~bit; |
| 85 | __raw_writel(mask, reg); |
| 86 | local_irq_restore(flags); |
| 87 | } |
| 88 | |
| 89 | struct irq_chip cayman_irq_type = { |
| 90 | .name = "Cayman-IRQ", |
| 91 | .irq_unmask = enable_cayman_irq, |
| 92 | .irq_mask = disable_cayman_irq, |
| 93 | }; |
| 94 | |
| 95 | int cayman_irq_demux(int evt) |
| 96 | { |
| 97 | int irq = intc_evt_to_irq[evt]; |
| 98 | |
| 99 | if (irq == SMSC_IRQ) { |
| 100 | unsigned long status; |
| 101 | int i; |
| 102 | |
| 103 | status = __raw_readl(EPLD_STATUS_BASE) & |
| 104 | __raw_readl(EPLD_MASK_BASE) & 0xff; |
| 105 | if (status == 0) { |
| 106 | irq = -1; |
| 107 | } else { |
| 108 | for (i=0; i<8; i++) { |
| 109 | if (status & (1<<i)) |
| 110 | break; |
| 111 | } |
| 112 | irq = START_EXT_IRQS + i; |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | if (irq == PCI2_IRQ) { |
| 117 | unsigned long status; |
| 118 | int i; |
| 119 | |
| 120 | status = __raw_readl(EPLD_STATUS_BASE + 3 * sizeof(u32)) & |
| 121 | __raw_readl(EPLD_MASK_BASE + 3 * sizeof(u32)) & 0xff; |
| 122 | if (status == 0) { |
| 123 | irq = -1; |
| 124 | } else { |
| 125 | for (i=0; i<8; i++) { |
| 126 | if (status & (1<<i)) |
| 127 | break; |
| 128 | } |
| 129 | irq = START_EXT_IRQS + (3 * 8) + i; |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | return irq; |
| 134 | } |
| 135 | |
| 136 | void init_cayman_irq(void) |
| 137 | { |
| 138 | int i; |
| 139 | |
| 140 | epld_virt = (unsigned long)ioremap_nocache(EPLD_BASE, 1024); |
| 141 | if (!epld_virt) { |
| 142 | printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n"); |
| 143 | return; |
| 144 | } |
| 145 | |
| 146 | for (i = 0; i < NR_EXT_IRQS; i++) { |
| 147 | irq_set_chip_and_handler(START_EXT_IRQS + i, |
| 148 | &cayman_irq_type, handle_level_irq); |
| 149 | } |
| 150 | |
| 151 | /* Setup the SMSC interrupt */ |
| 152 | setup_irq(SMSC_IRQ, &cayman_action_smsc); |
| 153 | setup_irq(PCI2_IRQ, &cayman_action_pci2); |
| 154 | } |