drivers/irqchip/irq-lpc32xx.c

   1 /*
   2  * Copyright 2015-2016 Vladimir Zapolskiy <vz@mleia.com>
   3  *
   4  * The code contained herein is licensed under the GNU General Public
   5  * License. You may obtain a copy of the GNU General Public License
   6  * Version 2 or later at the following locations:
   7  *
   8  * http://www.opensource.org/licenses/gpl-license.html
   9  * http://www.gnu.org/copyleft/gpl.html
  10  */
  11
  12 #define pr_fmt(fmt) "%s: " fmt, __func__
  13
  14 #include <linux/io.h>
  15 #include <linux/irqchip.h>
  16 #include <linux/irqchip/chained_irq.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_irq.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/slab.h>
  21 #include <asm/exception.h>
  22
  23 #define LPC32XX_INTC_MASK               0x00
  24 #define LPC32XX_INTC_RAW                0x04
  25 #define LPC32XX_INTC_STAT               0x08
  26 #define LPC32XX_INTC_POL                0x0C
  27 #define LPC32XX_INTC_TYPE               0x10
  28 #define LPC32XX_INTC_FIQ                0x14
  29
  30 #define NR_LPC32XX_IC_IRQS              32
  31
  32 struct lpc32xx_irq_chip {
  33         void __iomem *base;
  34         struct irq_domain *domain;
  35         struct irq_chip chip;
  36 };
  37
  38 static struct lpc32xx_irq_chip *lpc32xx_mic_irqc;
  39
  40 static inline u32 lpc32xx_ic_read(struct lpc32xx_irq_chip *ic, u32 reg)
  41 {
  42         return readl_relaxed(ic->base + reg);
  43 }
  44
  45 static inline void lpc32xx_ic_write(struct lpc32xx_irq_chip *ic,
  46                                     u32 reg, u32 val)
  47 {
  48         writel_relaxed(val, ic->base + reg);
  49 }
  50
  51 static void lpc32xx_irq_mask(struct irq_data *d)
  52 {
  53         struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
  54         u32 val, mask = BIT(d->hwirq);
  55
  56         val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) & ~mask;
  57         lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);
  58 }
  59
  60 static void lpc32xx_irq_unmask(struct irq_data *d)
  61 {
  62         struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
  63         u32 val, mask = BIT(d->hwirq);
  64
  65         val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) | mask;
  66         lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);
  67 }
  68
  69 static void lpc32xx_irq_ack(struct irq_data *d)
  70 {
  71         struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
  72         u32 mask = BIT(d->hwirq);
  73
  74         lpc32xx_ic_write(ic, LPC32XX_INTC_RAW, mask);
  75 }
  76
  77 static int lpc32xx_irq_set_type(struct irq_data *d, unsigned int type)
  78 {
  79         struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
  80         u32 val, mask = BIT(d->hwirq);
  81         bool high, edge;
  82
  83         switch (type) {
  84         case IRQ_TYPE_EDGE_RISING:
  85                 edge = true;
  86                 high = true;
  87                 break;
  88         case IRQ_TYPE_EDGE_FALLING:
  89                 edge = true;
  90                 high = false;
  91                 break;
  92         case IRQ_TYPE_LEVEL_HIGH:
  93                 edge = false;
  94                 high = true;
  95                 break;
  96         case IRQ_TYPE_LEVEL_LOW:
  97                 edge = false;
  98                 high = false;
  99                 break;
 100         default:
 101                 pr_info("unsupported irq type %d\n", type);
 102                 return -EINVAL;
 103         }
 104
 105         irqd_set_trigger_type(d, type);
 106
 107         val = lpc32xx_ic_read(ic, LPC32XX_INTC_POL);
 108         if (high)
 109                 val |= mask;
 110         else
 111                 val &= ~mask;
 112         lpc32xx_ic_write(ic, LPC32XX_INTC_POL, val);
 113
 114         val = lpc32xx_ic_read(ic, LPC32XX_INTC_TYPE);
 115         if (edge) {
 116                 val |= mask;
 117                 irq_set_handler_locked(d, handle_edge_irq);
 118         } else {
 119                 val &= ~mask;
 120                 irq_set_handler_locked(d, handle_level_irq);
 121         }
 122         lpc32xx_ic_write(ic, LPC32XX_INTC_TYPE, val);
 123
 124         return 0;
 125 }
 126
 127 static void __exception_irq_entry lpc32xx_handle_irq(struct pt_regs *regs)
 128 {
 129         struct lpc32xx_irq_chip *ic = lpc32xx_mic_irqc;
 130         u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;
 131
 132         while (hwirq) {
 133                 irq = __ffs(hwirq);
 134                 hwirq &= ~BIT(irq);
 135                 handle_domain_irq(lpc32xx_mic_irqc->domain, irq, regs);
 136         }
 137 }
 138
 139 static void lpc32xx_sic_handler(struct irq_desc *desc)
 140 {
 141         struct lpc32xx_irq_chip *ic = irq_desc_get_handler_data(desc);
 142         struct irq_chip *chip = irq_desc_get_chip(desc);
 143         u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;
 144
 145         chained_irq_enter(chip, desc);
 146
 147         while (hwirq) {
 148                 irq = __ffs(hwirq);
 149                 hwirq &= ~BIT(irq);
 150                 generic_handle_irq(irq_find_mapping(ic->domain, irq));
 151         }
 152
 153         chained_irq_exit(chip, desc);
 154 }
 155
 156 static int lpc32xx_irq_domain_map(struct irq_domain *id, unsigned int virq,
 157                                   irq_hw_number_t hw)
 158 {
 159         struct lpc32xx_irq_chip *ic = id->host_data;
 160
 161         irq_set_chip_data(virq, ic);
 162         irq_set_chip_and_handler(virq, &ic->chip, handle_level_irq);
 163         irq_set_status_flags(virq, IRQ_LEVEL);
 164         irq_set_noprobe(virq);
 165
 166         return 0;
 167 }
 168
 169 static void lpc32xx_irq_domain_unmap(struct irq_domain *id, unsigned int virq)
 170 {
 171         irq_set_chip_and_handler(virq, NULL, NULL);
 172 }
 173
 174 static const struct irq_domain_ops lpc32xx_irq_domain_ops = {
 175         .map    = lpc32xx_irq_domain_map,
 176         .unmap  = lpc32xx_irq_domain_unmap,
 177         .xlate  = irq_domain_xlate_twocell,
 178 };
 179
 180 static int __init lpc32xx_of_ic_init(struct device_node *node,
 181                                      struct device_node *parent)
 182 {
 183         struct lpc32xx_irq_chip *irqc;
 184         bool is_mic = of_device_is_compatible(node, "nxp,lpc3220-mic");
 185         const __be32 *reg = of_get_property(node, "reg", NULL);
 186         u32 parent_irq, i, addr = reg ? be32_to_cpu(*reg) : 0;
 187
 188         irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
 189         if (!irqc)
 190                 return -ENOMEM;
 191
 192         irqc->base = of_iomap(node, 0);
 193         if (!irqc->base) {
 194                 pr_err("%s: unable to map registers\n", node->full_name);
 195                 kfree(irqc);
 196                 return -EINVAL;
 197         }
 198
 199         irqc->chip.irq_ack = lpc32xx_irq_ack;
 200         irqc->chip.irq_mask = lpc32xx_irq_mask;
 201         irqc->chip.irq_unmask = lpc32xx_irq_unmask;
 202         irqc->chip.irq_set_type = lpc32xx_irq_set_type;
 203         if (is_mic)
 204                 irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.mic", addr);
 205         else
 206                 irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.sic", addr);
 207
 208         irqc->domain = irq_domain_add_linear(node, NR_LPC32XX_IC_IRQS,
 209                                              &lpc32xx_irq_domain_ops, irqc);
 210         if (!irqc->domain) {
 211                 pr_err("unable to add irq domain\n");
 212                 iounmap(irqc->base);
 213                 kfree(irqc->chip.name);
 214                 kfree(irqc);
 215                 return -ENODEV;
 216         }
 217
 218         if (is_mic) {
 219                 lpc32xx_mic_irqc = irqc;
 220                 set_handle_irq(lpc32xx_handle_irq);
 221         } else {
 222                 for (i = 0; i < of_irq_count(node); i++) {
 223                         parent_irq = irq_of_parse_and_map(node, i);
 224                         if (parent_irq)
 225                                 irq_set_chained_handler_and_data(parent_irq,
 226                                                  lpc32xx_sic_handler, irqc);
 227                 }
 228         }
 229
 230         lpc32xx_ic_write(irqc, LPC32XX_INTC_MASK, 0x00);
 231         lpc32xx_ic_write(irqc, LPC32XX_INTC_POL,  0x00);
 232         lpc32xx_ic_write(irqc, LPC32XX_INTC_TYPE, 0x00);
 233
 234         return 0;
 235 }
 236
 237 IRQCHIP_DECLARE(nxp_lpc32xx_mic, "nxp,lpc3220-mic", lpc32xx_of_ic_init);
 238 IRQCHIP_DECLARE(nxp_lpc32xx_sic, "nxp,lpc3220-sic", lpc32xx_of_ic_init);