drivers/irqchip/irq-xilinx-intc.c

   1 /*
   2  * Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2012-2013 Xilinx, Inc.
   4  * Copyright (C) 2007-2009 PetaLogix
   5  * Copyright (C) 2006 Atmark Techno, Inc.
   6  *
   7  * This file is subject to the terms and conditions of the GNU General Public
   8  * License. See the file "COPYING" in the main directory of this archive
   9  * for more details.
  10  */
  11
  12 #include <linux/irqdomain.h>
  13 #include <linux/irq.h>
  14 #include <linux/irqchip.h>
  15 #include <linux/irqchip/chained_irq.h>
  16 #include <linux/of_address.h>
  17 #include <linux/io.h>
  18 #include <linux/jump_label.h>
  19 #include <linux/bug.h>
  20 #include <linux/of_irq.h>
  21
  22 /* No one else should require these constants, so define them locally here. */
  23 #define ISR 0x00                        /* Interrupt Status Register */
  24 #define IPR 0x04                        /* Interrupt Pending Register */
  25 #define IER 0x08                        /* Interrupt Enable Register */
  26 #define IAR 0x0c                        /* Interrupt Acknowledge Register */
  27 #define SIE 0x10                        /* Set Interrupt Enable bits */
  28 #define CIE 0x14                        /* Clear Interrupt Enable bits */
  29 #define IVR 0x18                        /* Interrupt Vector Register */
  30 #define MER 0x1c                        /* Master Enable Register */
  31
  32 #define MER_ME (1<<0)
  33 #define MER_HIE (1<<1)
  34
  35 static DEFINE_STATIC_KEY_FALSE(xintc_is_be);
  36
  37 struct xintc_irq_chip {
  38         void            __iomem *base;
  39         struct          irq_domain *root_domain;
  40         u32             intr_mask;
  41         u32             nr_irq;
  42 };
  43
  44 static struct xintc_irq_chip *primary_intc;
  45
  46 static void xintc_write(struct xintc_irq_chip *irqc, int reg, u32 data)
  47 {
  48         if (static_branch_unlikely(&xintc_is_be))
  49                 iowrite32be(data, irqc->base + reg);
  50         else
  51                 iowrite32(data, irqc->base + reg);
  52 }
  53
  54 static u32 xintc_read(struct xintc_irq_chip *irqc, int reg)
  55 {
  56         if (static_branch_unlikely(&xintc_is_be))
  57                 return ioread32be(irqc->base + reg);
  58         else
  59                 return ioread32(irqc->base + reg);
  60 }
  61
  62 static void intc_enable_or_unmask(struct irq_data *d)
  63 {
  64         struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
  65         unsigned long mask = BIT(d->hwirq);
  66
  67         pr_debug("irq-xilinx: enable_or_unmask: %ld\n", d->hwirq);
  68
  69         /* ack level irqs because they can't be acked during
  70          * ack function since the handle_level_irq function
  71          * acks the irq before calling the interrupt handler
  72          */
  73         if (irqd_is_level_type(d))
  74                 xintc_write(irqc, IAR, mask);
  75
  76         xintc_write(irqc, SIE, mask);
  77 }
  78
  79 static void intc_disable_or_mask(struct irq_data *d)
  80 {
  81         struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
  82
  83         pr_debug("irq-xilinx: disable: %ld\n", d->hwirq);
  84         xintc_write(irqc, CIE, BIT(d->hwirq));
  85 }
  86
  87 static void intc_ack(struct irq_data *d)
  88 {
  89         struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
  90
  91         pr_debug("irq-xilinx: ack: %ld\n", d->hwirq);
  92         xintc_write(irqc, IAR, BIT(d->hwirq));
  93 }
  94
  95 static void intc_mask_ack(struct irq_data *d)
  96 {
  97         struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
  98         unsigned long mask = BIT(d->hwirq);
  99
 100         pr_debug("irq-xilinx: disable_and_ack: %ld\n", d->hwirq);
 101         xintc_write(irqc, CIE, mask);
 102         xintc_write(irqc, IAR, mask);
 103 }
 104
 105 static struct irq_chip intc_dev = {
 106         .name = "Xilinx INTC",
 107         .irq_unmask = intc_enable_or_unmask,
 108         .irq_mask = intc_disable_or_mask,
 109         .irq_ack = intc_ack,
 110         .irq_mask_ack = intc_mask_ack,
 111 };
 112
 113 static unsigned int xintc_get_irq_local(struct xintc_irq_chip *irqc)
 114 {
 115         unsigned int irq = 0;
 116         u32 hwirq;
 117
 118         hwirq = xintc_read(irqc, IVR);
 119         if (hwirq != -1U)
 120                 irq = irq_find_mapping(irqc->root_domain, hwirq);
 121
 122         pr_debug("irq-xilinx: hwirq=%d, irq=%d\n", hwirq, irq);
 123
 124         return irq;
 125 }
 126
 127 static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
 128 {
 129         struct xintc_irq_chip *irqc = d->host_data;
 130
 131         if (irqc->intr_mask & BIT(hw)) {
 132                 irq_set_chip_and_handler_name(irq, &intc_dev,
 133                                               handle_edge_irq, "edge");
 134                 irq_clear_status_flags(irq, IRQ_LEVEL);
 135         } else {
 136                 irq_set_chip_and_handler_name(irq, &intc_dev,
 137                                               handle_level_irq, "level");
 138                 irq_set_status_flags(irq, IRQ_LEVEL);
 139         }
 140         irq_set_chip_data(irq, irqc);
 141         return 0;
 142 }
 143
 144 static const struct irq_domain_ops xintc_irq_domain_ops = {
 145         .xlate = irq_domain_xlate_onetwocell,
 146         .map = xintc_map,
 147 };
 148
 149 static void xil_intc_irq_handler(struct irq_desc *desc)
 150 {
 151         struct irq_chip *chip = irq_desc_get_chip(desc);
 152         struct xintc_irq_chip *irqc;
 153         u32 pending;
 154
 155         irqc = irq_data_get_irq_handler_data(&desc->irq_data);
 156         chained_irq_enter(chip, desc);
 157         do {
 158                 pending = xintc_get_irq_local(irqc);
 159                 if (pending == 0)
 160                         break;
 161                 generic_handle_irq(pending);
 162         } while (true);
 163         chained_irq_exit(chip, desc);
 164 }
 165
 166 static void xil_intc_handle_irq(struct pt_regs *regs)
 167 {
 168         u32 hwirq;
 169         struct xintc_irq_chip *irqc = primary_intc;
 170
 171         do {
 172                 hwirq = xintc_read(irqc, IVR);
 173                 if (likely(hwirq != -1U)) {
 174                         int ret;
 175
 176                         ret = handle_domain_irq(irqc->root_domain, hwirq, regs);
 177                         WARN_ONCE(ret, "Unhandled HWIRQ %d\n", hwirq);
 178                         continue;
 179                 }
 180
 181                 break;
 182         } while (1);
 183 }
 184
 185 static int __init xilinx_intc_of_init(struct device_node *intc,
 186                                              struct device_node *parent)
 187 {
 188         struct xintc_irq_chip *irqc;
 189         int ret, irq;
 190
 191         irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
 192         if (!irqc)
 193                 return -ENOMEM;
 194         irqc->base = of_iomap(intc, 0);
 195         BUG_ON(!irqc->base);
 196
 197         ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &irqc->nr_irq);
 198         if (ret < 0) {
 199                 pr_err("irq-xilinx: unable to read xlnx,num-intr-inputs\n");
 200                 goto error;
 201         }
 202
 203         ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &irqc->intr_mask);
 204         if (ret < 0) {
 205                 pr_warn("irq-xilinx: unable to read xlnx,kind-of-intr\n");
 206                 irqc->intr_mask = 0;
 207         }
 208
 209         if (irqc->intr_mask >> irqc->nr_irq)
 210                 pr_warn("irq-xilinx: mismatch in kind-of-intr param\n");
 211
 212         pr_info("irq-xilinx: %pOF: num_irq=%d, edge=0x%x\n",
 213                 intc, irqc->nr_irq, irqc->intr_mask);
 214
 215
 216         /*
 217          * Disable all external interrupts until they are
 218          * explicity requested.
 219          */
 220         xintc_write(irqc, IER, 0);
 221
 222         /* Acknowledge any pending interrupts just in case. */
 223         xintc_write(irqc, IAR, 0xffffffff);
 224
 225         /* Turn on the Master Enable. */
 226         xintc_write(irqc, MER, MER_HIE | MER_ME);
 227         if (xintc_read(irqc, MER) != (MER_HIE | MER_ME)) {
 228                 static_branch_enable(&xintc_is_be);
 229                 xintc_write(irqc, MER, MER_HIE | MER_ME);
 230         }
 231
 232         irqc->root_domain = irq_domain_add_linear(intc, irqc->nr_irq,
 233                                                   &xintc_irq_domain_ops, irqc);
 234         if (!irqc->root_domain) {
 235                 pr_err("irq-xilinx: Unable to create IRQ domain\n");
 236                 ret = -EINVAL;
 237                 goto error;
 238         }
 239
 240         if (parent) {
 241                 irq = irq_of_parse_and_map(intc, 0);
 242                 if (irq) {
 243                         irq_set_chained_handler_and_data(irq,
 244                                                          xil_intc_irq_handler,
 245                                                          irqc);
 246                 } else {
 247                         pr_err("irq-xilinx: interrupts property not in DT\n");
 248                         ret = -EINVAL;
 249                         goto error;
 250                 }
 251         } else {
 252                 primary_intc = irqc;
 253                 irq_set_default_host(primary_intc->root_domain);
 254                 set_handle_irq(xil_intc_handle_irq);
 255         }
 256
 257         return 0;
 258
 259 error:
 260         iounmap(irqc->base);
 261         kfree(irqc);
 262         return ret;
 263
 264 }
 265
 266 IRQCHIP_DECLARE(xilinx_intc_xps, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);
 267 IRQCHIP_DECLARE(xilinx_intc_opb, "xlnx,opb-intc-1.00.c", xilinx_intc_of_init);