drivers/irqchip/irq-imx-irqsteer.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2017 NXP
   4  * Copyright (C) 2018 Pengutronix, Lucas Stach <[email protected]>
   5  */
   6
   7 #include <linux/clk.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/irq.h>
  10 #include <linux/irqchip/chained_irq.h>
  11 #include <linux/irqdomain.h>
  12 #include <linux/kernel.h>
  13 #include <linux/of.h>
  14 #include <linux/of_irq.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/pm_runtime.h>
  17 #include <linux/spinlock.h>
  18
  19 #define CTRL_STRIDE_OFF(_t, _r) (_t * 4 * _r)
  20 #define CHANCTRL                0x0
  21 #define CHANMASK(n, t)          (CTRL_STRIDE_OFF(t, 0) + 0x4 * (n) + 0x4)
  22 #define CHANSET(n, t)           (CTRL_STRIDE_OFF(t, 1) + 0x4 * (n) + 0x4)
  23 #define CHANSTATUS(n, t)        (CTRL_STRIDE_OFF(t, 2) + 0x4 * (n) + 0x4)
  24 #define CHAN_MINTDIS(t)         (CTRL_STRIDE_OFF(t, 3) + 0x4)
  25 #define CHAN_MASTRSTAT(t)       (CTRL_STRIDE_OFF(t, 3) + 0x8)
  26
  27 #define CHAN_MAX_OUTPUT_INT     0x8
  28
  29 struct irqsteer_data {
  30         void __iomem            *regs;
  31         struct clk              *ipg_clk;
  32         int                     irq[CHAN_MAX_OUTPUT_INT];
  33         int                     irq_count;
  34         raw_spinlock_t          lock;
  35         int                     reg_num;
  36         int                     channel;
  37         struct irq_domain       *domain;
  38         u32                     *saved_reg;
  39         struct device           *dev;
  40 };
  41
  42 static int imx_irqsteer_get_reg_index(struct irqsteer_data *data,
  43                                       unsigned long irqnum)
  44 {
  45         return (data->reg_num - irqnum / 32 - 1);
  46 }
  47
  48 static void imx_irqsteer_irq_unmask(struct irq_data *d)
  49 {
  50         struct irqsteer_data *data = d->chip_data;
  51         int idx = imx_irqsteer_get_reg_index(data, d->hwirq);
  52         unsigned long flags;
  53         u32 val;
  54
  55         raw_spin_lock_irqsave(&data->lock, flags);
  56         val = readl_relaxed(data->regs + CHANMASK(idx, data->reg_num));
  57         val |= BIT(d->hwirq % 32);
  58         writel_relaxed(val, data->regs + CHANMASK(idx, data->reg_num));
  59         raw_spin_unlock_irqrestore(&data->lock, flags);
  60 }
  61
  62 static void imx_irqsteer_irq_mask(struct irq_data *d)
  63 {
  64         struct irqsteer_data *data = d->chip_data;
  65         int idx = imx_irqsteer_get_reg_index(data, d->hwirq);
  66         unsigned long flags;
  67         u32 val;
  68
  69         raw_spin_lock_irqsave(&data->lock, flags);
  70         val = readl_relaxed(data->regs + CHANMASK(idx, data->reg_num));
  71         val &= ~BIT(d->hwirq % 32);
  72         writel_relaxed(val, data->regs + CHANMASK(idx, data->reg_num));
  73         raw_spin_unlock_irqrestore(&data->lock, flags);
  74 }
  75
  76 static void imx_irqsteer_irq_bus_lock(struct irq_data *d)
  77 {
  78         struct irqsteer_data *data = d->chip_data;
  79
  80         pm_runtime_get_sync(data->dev);
  81 }
  82
  83 static void imx_irqsteer_irq_bus_sync_unlock(struct irq_data *d)
  84 {
  85         struct irqsteer_data *data = d->chip_data;
  86
  87         pm_runtime_put_autosuspend(data->dev);
  88 }
  89
  90 static const struct irq_chip imx_irqsteer_irq_chip = {
  91         .name                   = "irqsteer",
  92         .irq_mask               = imx_irqsteer_irq_mask,
  93         .irq_unmask             = imx_irqsteer_irq_unmask,
  94         .irq_bus_lock           = imx_irqsteer_irq_bus_lock,
  95         .irq_bus_sync_unlock    = imx_irqsteer_irq_bus_sync_unlock,
  96 };
  97
  98 static int imx_irqsteer_irq_map(struct irq_domain *h, unsigned int irq,
  99                                 irq_hw_number_t hwirq)
 100 {
 101         irq_set_status_flags(irq, IRQ_LEVEL);
 102         irq_set_chip_data(irq, h->host_data);
 103         irq_set_chip_and_handler(irq, &imx_irqsteer_irq_chip, handle_level_irq);
 104
 105         return 0;
 106 }
 107
 108 static const struct irq_domain_ops imx_irqsteer_domain_ops = {
 109         .map            = imx_irqsteer_irq_map,
 110         .xlate          = irq_domain_xlate_onecell,
 111 };
 112
 113 static int imx_irqsteer_get_hwirq_base(struct irqsteer_data *data, u32 irq)
 114 {
 115         int i;
 116
 117         for (i = 0; i < data->irq_count; i++) {
 118                 if (data->irq[i] == irq)
 119                         return i * 64;
 120         }
 121
 122         return -EINVAL;
 123 }
 124
 125 static void imx_irqsteer_irq_handler(struct irq_desc *desc)
 126 {
 127         struct irqsteer_data *data = irq_desc_get_handler_data(desc);
 128         int hwirq;
 129         int irq, i;
 130
 131         chained_irq_enter(irq_desc_get_chip(desc), desc);
 132
 133         irq = irq_desc_get_irq(desc);
 134         hwirq = imx_irqsteer_get_hwirq_base(data, irq);
 135         if (hwirq < 0) {
 136                 pr_warn("%s: unable to get hwirq base for irq %d\n",
 137                         __func__, irq);
 138                 return;
 139         }
 140
 141         for (i = 0; i < 2; i++, hwirq += 32) {
 142                 int idx = imx_irqsteer_get_reg_index(data, hwirq);
 143                 unsigned long irqmap;
 144                 int pos;
 145
 146                 if (hwirq >= data->reg_num * 32)
 147                         break;
 148
 149                 irqmap = readl_relaxed(data->regs +
 150                                        CHANSTATUS(idx, data->reg_num));
 151
 152                 for_each_set_bit(pos, &irqmap, 32)
 153                         generic_handle_domain_irq(data->domain, pos + hwirq);
 154         }
 155
 156         chained_irq_exit(irq_desc_get_chip(desc), desc);
 157 }
 158
 159 static int imx_irqsteer_probe(struct platform_device *pdev)
 160 {
 161         struct device_node *np = pdev->dev.of_node;
 162         struct irqsteer_data *data;
 163         u32 irqs_num;
 164         int i, ret;
 165
 166         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 167         if (!data)
 168                 return -ENOMEM;
 169
 170         data->dev = &pdev->dev;
 171         data->regs = devm_platform_ioremap_resource(pdev, 0);
 172         if (IS_ERR(data->regs)) {
 173                 dev_err(&pdev->dev, "failed to initialize reg\n");
 174                 return PTR_ERR(data->regs);
 175         }
 176
 177         data->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
 178         if (IS_ERR(data->ipg_clk))
 179                 return dev_err_probe(&pdev->dev, PTR_ERR(data->ipg_clk),
 180                                      "failed to get ipg clk\n");
 181
 182         raw_spin_lock_init(&data->lock);
 183
 184         ret = of_property_read_u32(np, "fsl,num-irqs", &irqs_num);
 185         if (ret)
 186                 return ret;
 187         ret = of_property_read_u32(np, "fsl,channel", &data->channel);
 188         if (ret)
 189                 return ret;
 190
 191         /*
 192          * There is one output irq for each group of 64 inputs.
 193          * One register bit map can represent 32 input interrupts.
 194          */
 195         data->irq_count = DIV_ROUND_UP(irqs_num, 64);
 196         data->reg_num = irqs_num / 32;
 197
 198         if (IS_ENABLED(CONFIG_PM)) {
 199                 data->saved_reg = devm_kzalloc(&pdev->dev,
 200                                         sizeof(u32) * data->reg_num,
 201                                         GFP_KERNEL);
 202                 if (!data->saved_reg)
 203                         return -ENOMEM;
 204         }
 205
 206         ret = clk_prepare_enable(data->ipg_clk);
 207         if (ret) {
 208                 dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
 209                 return ret;
 210         }
 211
 212         /* steer all IRQs into configured channel */
 213         writel_relaxed(BIT(data->channel), data->regs + CHANCTRL);
 214
 215         data->domain = irq_domain_add_linear(np, data->reg_num * 32,
 216                                              &imx_irqsteer_domain_ops, data);
 217         if (!data->domain) {
 218                 dev_err(&pdev->dev, "failed to create IRQ domain\n");
 219                 ret = -ENOMEM;
 220                 goto out;
 221         }
 222         irq_domain_set_pm_device(data->domain, &pdev->dev);
 223
 224         if (!data->irq_count || data->irq_count > CHAN_MAX_OUTPUT_INT) {
 225                 ret = -EINVAL;
 226                 goto out;
 227         }
 228
 229         for (i = 0; i < data->irq_count; i++) {
 230                 data->irq[i] = irq_of_parse_and_map(np, i);
 231                 if (!data->irq[i]) {
 232                         ret = -EINVAL;
 233                         goto out;
 234                 }
 235
 236                 irq_set_chained_handler_and_data(data->irq[i],
 237                                                  imx_irqsteer_irq_handler,
 238                                                  data);
 239         }
 240
 241         platform_set_drvdata(pdev, data);
 242
 243         pm_runtime_set_active(&pdev->dev);
 244         pm_runtime_enable(&pdev->dev);
 245
 246         return 0;
 247 out:
 248         clk_disable_unprepare(data->ipg_clk);
 249         return ret;
 250 }
 251
 252 static void imx_irqsteer_remove(struct platform_device *pdev)
 253 {
 254         struct irqsteer_data *irqsteer_data = platform_get_drvdata(pdev);
 255         int i;
 256
 257         for (i = 0; i < irqsteer_data->irq_count; i++)
 258                 irq_set_chained_handler_and_data(irqsteer_data->irq[i],
 259                                                  NULL, NULL);
 260
 261         irq_domain_remove(irqsteer_data->domain);
 262
 263         clk_disable_unprepare(irqsteer_data->ipg_clk);
 264 }
 265
 266 #ifdef CONFIG_PM
 267 static void imx_irqsteer_save_regs(struct irqsteer_data *data)
 268 {
 269         int i;
 270
 271         for (i = 0; i < data->reg_num; i++)
 272                 data->saved_reg[i] = readl_relaxed(data->regs +
 273                                                 CHANMASK(i, data->reg_num));
 274 }
 275
 276 static void imx_irqsteer_restore_regs(struct irqsteer_data *data)
 277 {
 278         int i;
 279
 280         writel_relaxed(BIT(data->channel), data->regs + CHANCTRL);
 281         for (i = 0; i < data->reg_num; i++)
 282                 writel_relaxed(data->saved_reg[i],
 283                                data->regs + CHANMASK(i, data->reg_num));
 284 }
 285
 286 static int imx_irqsteer_suspend(struct device *dev)
 287 {
 288         struct irqsteer_data *irqsteer_data = dev_get_drvdata(dev);
 289
 290         imx_irqsteer_save_regs(irqsteer_data);
 291         clk_disable_unprepare(irqsteer_data->ipg_clk);
 292
 293         return 0;
 294 }
 295
 296 static int imx_irqsteer_resume(struct device *dev)
 297 {
 298         struct irqsteer_data *irqsteer_data = dev_get_drvdata(dev);
 299         int ret;
 300
 301         ret = clk_prepare_enable(irqsteer_data->ipg_clk);
 302         if (ret) {
 303                 dev_err(dev, "failed to enable ipg clk: %d\n", ret);
 304                 return ret;
 305         }
 306         imx_irqsteer_restore_regs(irqsteer_data);
 307
 308         return 0;
 309 }
 310 #endif
 311
 312 static const struct dev_pm_ops imx_irqsteer_pm_ops = {
 313         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 314                                       pm_runtime_force_resume)
 315         SET_RUNTIME_PM_OPS(imx_irqsteer_suspend,
 316                            imx_irqsteer_resume, NULL)
 317 };
 318
 319 static const struct of_device_id imx_irqsteer_dt_ids[] = {
 320         { .compatible = "fsl,imx-irqsteer", },
 321         {},
 322 };
 323
 324 static struct platform_driver imx_irqsteer_driver = {
 325         .driver = {
 326                 .name           = "imx-irqsteer",
 327                 .of_match_table = imx_irqsteer_dt_ids,
 328                 .pm             = &imx_irqsteer_pm_ops,
 329         },
 330         .probe          = imx_irqsteer_probe,
 331         .remove         = imx_irqsteer_remove,
 332 };
 333 builtin_platform_driver(imx_irqsteer_driver);