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