drivers/irqchip/qcom-pdc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
   4  */
   5
   6 #include <linux/err.h>
   7 #include <linux/init.h>
   8 #include <linux/irq.h>
   9 #include <linux/irqchip.h>
  10 #include <linux/irqdomain.h>
  11 #include <linux/io.h>
  12 #include <linux/kernel.h>
  13 #include <linux/of.h>
  14 #include <linux/of_address.h>
  15 #include <linux/of_device.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19 #include <linux/types.h>
  20
  21 #define PDC_MAX_IRQS            126
  22
  23 #define CLEAR_INTR(reg, intr)   (reg & ~(1 << intr))
  24 #define ENABLE_INTR(reg, intr)  (reg | (1 << intr))
  25
  26 #define IRQ_ENABLE_BANK         0x10
  27 #define IRQ_i_CFG               0x110
  28
  29 struct pdc_pin_region {
  30         u32 pin_base;
  31         u32 parent_base;
  32         u32 cnt;
  33 };
  34
  35 static DEFINE_RAW_SPINLOCK(pdc_lock);
  36 static void __iomem *pdc_base;
  37 static struct pdc_pin_region *pdc_region;
  38 static int pdc_region_cnt;
  39
  40 static void pdc_reg_write(int reg, u32 i, u32 val)
  41 {
  42         writel_relaxed(val, pdc_base + reg + i * sizeof(u32));
  43 }
  44
  45 static u32 pdc_reg_read(int reg, u32 i)
  46 {
  47         return readl_relaxed(pdc_base + reg + i * sizeof(u32));
  48 }
  49
  50 static void pdc_enable_intr(struct irq_data *d, bool on)
  51 {
  52         int pin_out = d->hwirq;
  53         u32 index, mask;
  54         u32 enable;
  55
  56         index = pin_out / 32;
  57         mask = pin_out % 32;
  58
  59         raw_spin_lock(&pdc_lock);
  60         enable = pdc_reg_read(IRQ_ENABLE_BANK, index);
  61         enable = on ? ENABLE_INTR(enable, mask) : CLEAR_INTR(enable, mask);
  62         pdc_reg_write(IRQ_ENABLE_BANK, index, enable);
  63         raw_spin_unlock(&pdc_lock);
  64 }
  65
  66 static void qcom_pdc_gic_mask(struct irq_data *d)
  67 {
  68         pdc_enable_intr(d, false);
  69         irq_chip_mask_parent(d);
  70 }
  71
  72 static void qcom_pdc_gic_unmask(struct irq_data *d)
  73 {
  74         pdc_enable_intr(d, true);
  75         irq_chip_unmask_parent(d);
  76 }
  77
  78 /*
  79  * GIC does not handle falling edge or active low. To allow falling edge and
  80  * active low interrupts to be handled at GIC, PDC has an inverter that inverts
  81  * falling edge into a rising edge and active low into an active high.
  82  * For the inverter to work, the polarity bit in the IRQ_CONFIG register has to
  83  * set as per the table below.
  84  * Level sensitive active low    LOW
  85  * Rising edge sensitive         NOT USED
  86  * Falling edge sensitive        LOW
  87  * Dual Edge sensitive           NOT USED
  88  * Level sensitive active High   HIGH
  89  * Falling Edge sensitive        NOT USED
  90  * Rising edge sensitive         HIGH
  91  * Dual Edge sensitive           HIGH
  92  */
  93 enum pdc_irq_config_bits {
  94         PDC_LEVEL_LOW           = 0b000,
  95         PDC_EDGE_FALLING        = 0b010,
  96         PDC_LEVEL_HIGH          = 0b100,
  97         PDC_EDGE_RISING         = 0b110,
  98         PDC_EDGE_DUAL           = 0b111,
  99 };
 100
 101 /**
 102  * qcom_pdc_gic_set_type: Configure PDC for the interrupt
 103  *
 104  * @d: the interrupt data
 105  * @type: the interrupt type
 106  *
 107  * If @type is edge triggered, forward that as Rising edge as PDC
 108  * takes care of converting falling edge to rising edge signal
 109  * If @type is level, then forward that as level high as PDC
 110  * takes care of converting falling edge to rising edge signal
 111  */
 112 static int qcom_pdc_gic_set_type(struct irq_data *d, unsigned int type)
 113 {
 114         int pin_out = d->hwirq;
 115         enum pdc_irq_config_bits pdc_type;
 116
 117         switch (type) {
 118         case IRQ_TYPE_EDGE_RISING:
 119                 pdc_type = PDC_EDGE_RISING;
 120                 break;
 121         case IRQ_TYPE_EDGE_FALLING:
 122                 pdc_type = PDC_EDGE_FALLING;
 123                 type = IRQ_TYPE_EDGE_RISING;
 124                 break;
 125         case IRQ_TYPE_EDGE_BOTH:
 126                 pdc_type = PDC_EDGE_DUAL;
 127                 break;
 128         case IRQ_TYPE_LEVEL_HIGH:
 129                 pdc_type = PDC_LEVEL_HIGH;
 130                 break;
 131         case IRQ_TYPE_LEVEL_LOW:
 132                 pdc_type = PDC_LEVEL_LOW;
 133                 type = IRQ_TYPE_LEVEL_HIGH;
 134                 break;
 135         default:
 136                 WARN_ON(1);
 137                 return -EINVAL;
 138         }
 139
 140         pdc_reg_write(IRQ_i_CFG, pin_out, pdc_type);
 141
 142         return irq_chip_set_type_parent(d, type);
 143 }
 144
 145 static struct irq_chip qcom_pdc_gic_chip = {
 146         .name                   = "PDC",
 147         .irq_eoi                = irq_chip_eoi_parent,
 148         .irq_mask               = qcom_pdc_gic_mask,
 149         .irq_unmask             = qcom_pdc_gic_unmask,
 150         .irq_retrigger          = irq_chip_retrigger_hierarchy,
 151         .irq_set_type           = qcom_pdc_gic_set_type,
 152         .flags                  = IRQCHIP_MASK_ON_SUSPEND |
 153                                   IRQCHIP_SET_TYPE_MASKED |
 154                                   IRQCHIP_SKIP_SET_WAKE,
 155         .irq_set_vcpu_affinity  = irq_chip_set_vcpu_affinity_parent,
 156         .irq_set_affinity       = irq_chip_set_affinity_parent,
 157 };
 158
 159 static irq_hw_number_t get_parent_hwirq(int pin)
 160 {
 161         int i;
 162         struct pdc_pin_region *region;
 163
 164         for (i = 0; i < pdc_region_cnt; i++) {
 165                 region = &pdc_region[i];
 166                 if (pin >= region->pin_base &&
 167                     pin < region->pin_base + region->cnt)
 168                         return (region->parent_base + pin - region->pin_base);
 169         }
 170
 171         WARN_ON(1);
 172         return ~0UL;
 173 }
 174
 175 static int qcom_pdc_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
 176                               unsigned long *hwirq, unsigned int *type)
 177 {
 178         if (is_of_node(fwspec->fwnode)) {
 179                 if (fwspec->param_count != 2)
 180                         return -EINVAL;
 181
 182                 *hwirq = fwspec->param[0];
 183                 *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
 184                 return 0;
 185         }
 186
 187         return -EINVAL;
 188 }
 189
 190 static int qcom_pdc_alloc(struct irq_domain *domain, unsigned int virq,
 191                           unsigned int nr_irqs, void *data)
 192 {
 193         struct irq_fwspec *fwspec = data;
 194         struct irq_fwspec parent_fwspec;
 195         irq_hw_number_t hwirq, parent_hwirq;
 196         unsigned int type;
 197         int ret;
 198
 199         ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
 200         if (ret)
 201                 return -EINVAL;
 202
 203         parent_hwirq = get_parent_hwirq(hwirq);
 204         if (parent_hwirq == ~0UL)
 205                 return -EINVAL;
 206
 207         ret  = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
 208                                              &qcom_pdc_gic_chip, NULL);
 209         if (ret)
 210                 return ret;
 211
 212         if (type & IRQ_TYPE_EDGE_BOTH)
 213                 type = IRQ_TYPE_EDGE_RISING;
 214
 215         if (type & IRQ_TYPE_LEVEL_MASK)
 216                 type = IRQ_TYPE_LEVEL_HIGH;
 217
 218         parent_fwspec.fwnode      = domain->parent->fwnode;
 219         parent_fwspec.param_count = 3;
 220         parent_fwspec.param[0]    = 0;
 221         parent_fwspec.param[1]    = parent_hwirq;
 222         parent_fwspec.param[2]    = type;
 223
 224         return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
 225                                             &parent_fwspec);
 226 }
 227
 228 static const struct irq_domain_ops qcom_pdc_ops = {
 229         .translate      = qcom_pdc_translate,
 230         .alloc          = qcom_pdc_alloc,
 231         .free           = irq_domain_free_irqs_common,
 232 };
 233
 234 static int pdc_setup_pin_mapping(struct device_node *np)
 235 {
 236         int ret, n;
 237
 238         n = of_property_count_elems_of_size(np, "qcom,pdc-ranges", sizeof(u32));
 239         if (n <= 0 || n % 3)
 240                 return -EINVAL;
 241
 242         pdc_region_cnt = n / 3;
 243         pdc_region = kcalloc(pdc_region_cnt, sizeof(*pdc_region), GFP_KERNEL);
 244         if (!pdc_region) {
 245                 pdc_region_cnt = 0;
 246                 return -ENOMEM;
 247         }
 248
 249         for (n = 0; n < pdc_region_cnt; n++) {
 250                 ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
 251                                                  n * 3 + 0,
 252                                                  &pdc_region[n].pin_base);
 253                 if (ret)
 254                         return ret;
 255                 ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
 256                                                  n * 3 + 1,
 257                                                  &pdc_region[n].parent_base);
 258                 if (ret)
 259                         return ret;
 260                 ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
 261                                                  n * 3 + 2,
 262                                                  &pdc_region[n].cnt);
 263                 if (ret)
 264                         return ret;
 265         }
 266
 267         return 0;
 268 }
 269
 270 static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
 271 {
 272         struct irq_domain *parent_domain, *pdc_domain;
 273         int ret;
 274
 275         pdc_base = of_iomap(node, 0);
 276         if (!pdc_base) {
 277                 pr_err("%pOF: unable to map PDC registers\n", node);
 278                 return -ENXIO;
 279         }
 280
 281         parent_domain = irq_find_host(parent);
 282         if (!parent_domain) {
 283                 pr_err("%pOF: unable to find PDC's parent domain\n", node);
 284                 ret = -ENXIO;
 285                 goto fail;
 286         }
 287
 288         ret = pdc_setup_pin_mapping(node);
 289         if (ret) {
 290                 pr_err("%pOF: failed to init PDC pin-hwirq mapping\n", node);
 291                 goto fail;
 292         }
 293
 294         pdc_domain = irq_domain_create_hierarchy(parent_domain, 0, PDC_MAX_IRQS,
 295                                                  of_fwnode_handle(node),
 296                                                  &qcom_pdc_ops, NULL);
 297         if (!pdc_domain) {
 298                 pr_err("%pOF: GIC domain add failed\n", node);
 299                 ret = -ENOMEM;
 300                 goto fail;
 301         }
 302
 303         return 0;
 304
 305 fail:
 306         kfree(pdc_region);
 307         iounmap(pdc_base);
 308         return ret;
 309 }
 310
 311 IRQCHIP_DECLARE(pdc_sdm845, "qcom,sdm845-pdc", qcom_pdc_init);