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 #define SPURIOUS_IRQ    (-1U)
  36
  37 static DEFINE_STATIC_KEY_FALSE(xintc_is_be);
  38
  39 struct xintc_irq_chip {
  40         void            __iomem *base;
  41         struct          irq_domain *root_domain;
  42         u32             intr_mask;
  43         u32             nr_irq;
  44 };
  45
  46 static struct xintc_irq_chip *primary_intc;
  47
  48 static void xintc_write(struct xintc_irq_chip *irqc, int reg, u32 data)
  49 {
  50         if (static_branch_unlikely(&xintc_is_be))
  51                 iowrite32be(data, irqc->base + reg);
  52         else
  53                 iowrite32(data, irqc->base + reg);
  54 }
  55
  56 static u32 xintc_read(struct xintc_irq_chip *irqc, int reg)
  57 {
  58         if (static_branch_unlikely(&xintc_is_be))
  59                 return ioread32be(irqc->base + reg);
  60         else
  61                 return ioread32(irqc->base + reg);
  62 }
  63
  64 static void intc_enable_or_unmask(struct irq_data *d)
  65 {
  66         struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
  67         unsigned long mask = BIT(d->hwirq);
  68
  69         pr_debug("irq-xilinx: enable_or_unmask: %ld\n", d->hwirq);
  70
  71         /* ack level irqs because they can't be acked during
  72          * ack function since the handle_level_irq function
  73          * acks the irq before calling the interrupt handler
  74          */
  75         if (irqd_is_level_type(d))
  76                 xintc_write(irqc, IAR, mask);
  77
  78         xintc_write(irqc, SIE, mask);
  79 }
  80
  81 static void intc_disable_or_mask(struct irq_data *d)
  82 {
  83         struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
  84
  85         pr_debug("irq-xilinx: disable: %ld\n", d->hwirq);
  86         xintc_write(irqc, CIE, BIT(d->hwirq));
  87 }
  88
  89 static void intc_ack(struct irq_data *d)
  90 {
  91         struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
  92
  93         pr_debug("irq-xilinx: ack: %ld\n", d->hwirq);
  94         xintc_write(irqc, IAR, BIT(d->hwirq));
  95 }
  96
  97 static void intc_mask_ack(struct irq_data *d)
  98 {
  99         struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
 100         unsigned long mask = BIT(d->hwirq);
 101
 102         pr_debug("irq-xilinx: disable_and_ack: %ld\n", d->hwirq);
 103         xintc_write(irqc, CIE, mask);
 104         xintc_write(irqc, IAR, mask);
 105 }
 106
 107 static struct irq_chip intc_dev = {
 108         .name = "Xilinx INTC",
 109         .irq_unmask = intc_enable_or_unmask,
 110         .irq_mask = intc_disable_or_mask,
 111         .irq_ack = intc_ack,
 112         .irq_mask_ack = intc_mask_ack,
 113 };
 114
 115 static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
 116 {
 117         struct xintc_irq_chip *irqc = d->host_data;
 118
 119         if (irqc->intr_mask & BIT(hw)) {
 120                 irq_set_chip_and_handler_name(irq, &intc_dev,
 121                                               handle_edge_irq, "edge");
 122                 irq_clear_status_flags(irq, IRQ_LEVEL);
 123         } else {
 124                 irq_set_chip_and_handler_name(irq, &intc_dev,
 125                                               handle_level_irq, "level");
 126                 irq_set_status_flags(irq, IRQ_LEVEL);
 127         }
 128         irq_set_chip_data(irq, irqc);
 129         return 0;
 130 }
 131
 132 static const struct irq_domain_ops xintc_irq_domain_ops = {
 133         .xlate = irq_domain_xlate_onetwocell,
 134         .map = xintc_map,
 135 };
 136
 137 static void xil_intc_irq_handler(struct irq_desc *desc)
 138 {
 139         struct irq_chip *chip = irq_desc_get_chip(desc);
 140         struct xintc_irq_chip *irqc;
 141
 142         irqc = irq_data_get_irq_handler_data(&desc->irq_data);
 143         chained_irq_enter(chip, desc);
 144         do {
 145                 u32 hwirq = xintc_read(irqc, IVR);
 146
 147                 if (hwirq == -1U)
 148                         break;
 149
 150                 generic_handle_domain_irq(irqc->root_domain, hwirq);
 151         } while (true);
 152         chained_irq_exit(chip, desc);
 153 }
 154
 155 static void xil_intc_handle_irq(struct pt_regs *regs)
 156 {
 157         u32 hwirq;
 158
 159         do {
 160                 hwirq = xintc_read(primary_intc, IVR);
 161                 if (unlikely(hwirq == SPURIOUS_IRQ))
 162                         break;
 163
 164                 generic_handle_domain_irq(primary_intc->root_domain, hwirq);
 165         } while (true);
 166 }
 167
 168 static int __init xilinx_intc_of_init(struct device_node *intc,
 169                                              struct device_node *parent)
 170 {
 171         struct xintc_irq_chip *irqc;
 172         int ret, irq;
 173
 174         irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
 175         if (!irqc)
 176                 return -ENOMEM;
 177         irqc->base = of_iomap(intc, 0);
 178         BUG_ON(!irqc->base);
 179
 180         ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &irqc->nr_irq);
 181         if (ret < 0) {
 182                 pr_err("irq-xilinx: unable to read xlnx,num-intr-inputs\n");
 183                 goto error;
 184         }
 185
 186         ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &irqc->intr_mask);
 187         if (ret < 0) {
 188                 pr_warn("irq-xilinx: unable to read xlnx,kind-of-intr\n");
 189                 irqc->intr_mask = 0;
 190         }
 191
 192         if (irqc->intr_mask >> irqc->nr_irq)
 193                 pr_warn("irq-xilinx: mismatch in kind-of-intr param\n");
 194
 195         pr_info("irq-xilinx: %pOF: num_irq=%d, edge=0x%x\n",
 196                 intc, irqc->nr_irq, irqc->intr_mask);
 197
 198
 199         /*
 200          * Disable all external interrupts until they are
 201          * explicitly requested.
 202          */
 203         xintc_write(irqc, IER, 0);
 204
 205         /* Acknowledge any pending interrupts just in case. */
 206         xintc_write(irqc, IAR, 0xffffffff);
 207
 208         /* Turn on the Master Enable. */
 209         xintc_write(irqc, MER, MER_HIE | MER_ME);
 210         if (xintc_read(irqc, MER) != (MER_HIE | MER_ME)) {
 211                 static_branch_enable(&xintc_is_be);
 212                 xintc_write(irqc, MER, MER_HIE | MER_ME);
 213         }
 214
 215         irqc->root_domain = irq_domain_add_linear(intc, irqc->nr_irq,
 216                                                   &xintc_irq_domain_ops, irqc);
 217         if (!irqc->root_domain) {
 218                 pr_err("irq-xilinx: Unable to create IRQ domain\n");
 219                 ret = -EINVAL;
 220                 goto error;
 221         }
 222
 223         if (parent) {
 224                 irq = irq_of_parse_and_map(intc, 0);
 225                 if (irq) {
 226                         irq_set_chained_handler_and_data(irq,
 227                                                          xil_intc_irq_handler,
 228                                                          irqc);
 229                 } else {
 230                         pr_err("irq-xilinx: interrupts property not in DT\n");
 231                         ret = -EINVAL;
 232                         goto error;
 233                 }
 234         } else {
 235                 primary_intc = irqc;
 236                 irq_set_default_host(primary_intc->root_domain);
 237                 set_handle_irq(xil_intc_handle_irq);
 238         }
 239
 240         return 0;
 241
 242 error:
 243         iounmap(irqc->base);
 244         kfree(irqc);
 245         return ret;
 246
 247 }
 248
 249 IRQCHIP_DECLARE(xilinx_intc_xps, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);
 250 IRQCHIP_DECLARE(xilinx_intc_opb, "xlnx,opb-intc-1.00.c", xilinx_intc_of_init);