linux/drivers/irqchip/irq-imx-intmux.c
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   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright 2017 NXP
   3
   4/*                     INTMUX Block Diagram
   5 *
   6 *                               ________________
   7 * interrupt source #  0  +---->|                |
   8 *                        |     |                |
   9 * interrupt source #  1  +++-->|                |
  10 *            ...         | |   |   channel # 0  |--------->interrupt out # 0
  11 *            ...         | |   |                |
  12 *            ...         | |   |                |
  13 * interrupt source # X-1 +++-->|________________|
  14 *                        | | |
  15 *                        | | |
  16 *                        | | |  ________________
  17 *                        +---->|                |
  18 *                        | | | |                |
  19 *                        | +-->|                |
  20 *                        | | | |   channel # 1  |--------->interrupt out # 1
  21 *                        | | +>|                |
  22 *                        | | | |                |
  23 *                        | | | |________________|
  24 *                        | | |
  25 *                        | | |
  26 *                        | | |       ...
  27 *                        | | |       ...
  28 *                        | | |
  29 *                        | | |  ________________
  30 *                        +---->|                |
  31 *                          | | |                |
  32 *                          +-->|                |
  33 *                            | |   channel # N  |--------->interrupt out # N
  34 *                            +>|                |
  35 *                              |                |
  36 *                              |________________|
  37 *
  38 *
  39 * N: Interrupt Channel Instance Number (N=7)
  40 * X: Interrupt Source Number for each channel (X=32)
  41 *
  42 * The INTMUX interrupt multiplexer has 8 channels, each channel receives 32
  43 * interrupt sources and generates 1 interrupt output.
  44 *
  45 */
  46
  47#include <linux/clk.h>
  48#include <linux/interrupt.h>
  49#include <linux/irq.h>
  50#include <linux/irqchip/chained_irq.h>
  51#include <linux/irqdomain.h>
  52#include <linux/kernel.h>
  53#include <linux/of_irq.h>
  54#include <linux/of_platform.h>
  55#include <linux/spinlock.h>
  56
  57#define CHANIER(n)      (0x10 + (0x40 * n))
  58#define CHANIPR(n)      (0x20 + (0x40 * n))
  59
  60#define CHAN_MAX_NUM            0x8
  61
  62struct intmux_irqchip_data {
  63        int                     chanidx;
  64        int                     irq;
  65        struct irq_domain       *domain;
  66};
  67
  68struct intmux_data {
  69        raw_spinlock_t                  lock;
  70        void __iomem                    *regs;
  71        struct clk                      *ipg_clk;
  72        int                             channum;
  73        struct intmux_irqchip_data      irqchip_data[];
  74};
  75
  76static void imx_intmux_irq_mask(struct irq_data *d)
  77{
  78        struct intmux_irqchip_data *irqchip_data = d->chip_data;
  79        int idx = irqchip_data->chanidx;
  80        struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
  81                                                irqchip_data[idx]);
  82        unsigned long flags;
  83        void __iomem *reg;
  84        u32 val;
  85
  86        raw_spin_lock_irqsave(&data->lock, flags);
  87        reg = data->regs + CHANIER(idx);
  88        val = readl_relaxed(reg);
  89        /* disable the interrupt source of this channel */
  90        val &= ~BIT(d->hwirq);
  91        writel_relaxed(val, reg);
  92        raw_spin_unlock_irqrestore(&data->lock, flags);
  93}
  94
  95static void imx_intmux_irq_unmask(struct irq_data *d)
  96{
  97        struct intmux_irqchip_data *irqchip_data = d->chip_data;
  98        int idx = irqchip_data->chanidx;
  99        struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
 100                                                irqchip_data[idx]);
 101        unsigned long flags;
 102        void __iomem *reg;
 103        u32 val;
 104
 105        raw_spin_lock_irqsave(&data->lock, flags);
 106        reg = data->regs + CHANIER(idx);
 107        val = readl_relaxed(reg);
 108        /* enable the interrupt source of this channel */
 109        val |= BIT(d->hwirq);
 110        writel_relaxed(val, reg);
 111        raw_spin_unlock_irqrestore(&data->lock, flags);
 112}
 113
 114static struct irq_chip imx_intmux_irq_chip = {
 115        .name           = "intmux",
 116        .irq_mask       = imx_intmux_irq_mask,
 117        .irq_unmask     = imx_intmux_irq_unmask,
 118};
 119
 120static int imx_intmux_irq_map(struct irq_domain *h, unsigned int irq,
 121                              irq_hw_number_t hwirq)
 122{
 123        irq_set_chip_data(irq, h->host_data);
 124        irq_set_chip_and_handler(irq, &imx_intmux_irq_chip, handle_level_irq);
 125
 126        return 0;
 127}
 128
 129static int imx_intmux_irq_xlate(struct irq_domain *d, struct device_node *node,
 130                                const u32 *intspec, unsigned int intsize,
 131                                unsigned long *out_hwirq, unsigned int *out_type)
 132{
 133        struct intmux_irqchip_data *irqchip_data = d->host_data;
 134        int idx = irqchip_data->chanidx;
 135        struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
 136                                                irqchip_data[idx]);
 137
 138        /*
 139         * two cells needed in interrupt specifier:
 140         * the 1st cell: hw interrupt number
 141         * the 2nd cell: channel index
 142         */
 143        if (WARN_ON(intsize != 2))
 144                return -EINVAL;
 145
 146        if (WARN_ON(intspec[1] >= data->channum))
 147                return -EINVAL;
 148
 149        *out_hwirq = intspec[0];
 150        *out_type = IRQ_TYPE_LEVEL_HIGH;
 151
 152        return 0;
 153}
 154
 155static int imx_intmux_irq_select(struct irq_domain *d, struct irq_fwspec *fwspec,
 156                                 enum irq_domain_bus_token bus_token)
 157{
 158        struct intmux_irqchip_data *irqchip_data = d->host_data;
 159
 160        /* Not for us */
 161        if (fwspec->fwnode != d->fwnode)
 162                return false;
 163
 164        return irqchip_data->chanidx == fwspec->param[1];
 165}
 166
 167static const struct irq_domain_ops imx_intmux_domain_ops = {
 168        .map            = imx_intmux_irq_map,
 169        .xlate          = imx_intmux_irq_xlate,
 170        .select         = imx_intmux_irq_select,
 171};
 172
 173static void imx_intmux_irq_handler(struct irq_desc *desc)
 174{
 175        struct intmux_irqchip_data *irqchip_data = irq_desc_get_handler_data(desc);
 176        int idx = irqchip_data->chanidx;
 177        struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
 178                                                irqchip_data[idx]);
 179        unsigned long irqstat;
 180        int pos, virq;
 181
 182        chained_irq_enter(irq_desc_get_chip(desc), desc);
 183
 184        /* read the interrupt source pending status of this channel */
 185        irqstat = readl_relaxed(data->regs + CHANIPR(idx));
 186
 187        for_each_set_bit(pos, &irqstat, 32) {
 188                virq = irq_find_mapping(irqchip_data->domain, pos);
 189                if (virq)
 190                        generic_handle_irq(virq);
 191        }
 192
 193        chained_irq_exit(irq_desc_get_chip(desc), desc);
 194}
 195
 196static int imx_intmux_probe(struct platform_device *pdev)
 197{
 198        struct device_node *np = pdev->dev.of_node;
 199        struct irq_domain *domain;
 200        struct intmux_data *data;
 201        int channum;
 202        int i, ret;
 203
 204        channum = platform_irq_count(pdev);
 205        if (channum == -EPROBE_DEFER) {
 206                return -EPROBE_DEFER;
 207        } else if (channum > CHAN_MAX_NUM) {
 208                dev_err(&pdev->dev, "supports up to %d multiplex channels\n",
 209                        CHAN_MAX_NUM);
 210                return -EINVAL;
 211        }
 212
 213        data = devm_kzalloc(&pdev->dev, sizeof(*data) +
 214                            channum * sizeof(data->irqchip_data[0]), GFP_KERNEL);
 215        if (!data)
 216                return -ENOMEM;
 217
 218        data->regs = devm_platform_ioremap_resource(pdev, 0);
 219        if (IS_ERR(data->regs)) {
 220                dev_err(&pdev->dev, "failed to initialize reg\n");
 221                return PTR_ERR(data->regs);
 222        }
 223
 224        data->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
 225        if (IS_ERR(data->ipg_clk)) {
 226                ret = PTR_ERR(data->ipg_clk);
 227                if (ret != -EPROBE_DEFER)
 228                        dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
 229                return ret;
 230        }
 231
 232        data->channum = channum;
 233        raw_spin_lock_init(&data->lock);
 234
 235        ret = clk_prepare_enable(data->ipg_clk);
 236        if (ret) {
 237                dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
 238                return ret;
 239        }
 240
 241        for (i = 0; i < channum; i++) {
 242                data->irqchip_data[i].chanidx = i;
 243
 244                data->irqchip_data[i].irq = irq_of_parse_and_map(np, i);
 245                if (data->irqchip_data[i].irq <= 0) {
 246                        ret = -EINVAL;
 247                        dev_err(&pdev->dev, "failed to get irq\n");
 248                        goto out;
 249                }
 250
 251                domain = irq_domain_add_linear(np, 32, &imx_intmux_domain_ops,
 252                                               &data->irqchip_data[i]);
 253                if (!domain) {
 254                        ret = -ENOMEM;
 255                        dev_err(&pdev->dev, "failed to create IRQ domain\n");
 256                        goto out;
 257                }
 258                data->irqchip_data[i].domain = domain;
 259
 260                /* disable all interrupt sources of this channel firstly */
 261                writel_relaxed(0, data->regs + CHANIER(i));
 262
 263                irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
 264                                                 imx_intmux_irq_handler,
 265                                                 &data->irqchip_data[i]);
 266        }
 267
 268        platform_set_drvdata(pdev, data);
 269
 270        return 0;
 271out:
 272        clk_disable_unprepare(data->ipg_clk);
 273        return ret;
 274}
 275
 276static int imx_intmux_remove(struct platform_device *pdev)
 277{
 278        struct intmux_data *data = platform_get_drvdata(pdev);
 279        int i;
 280
 281        for (i = 0; i < data->channum; i++) {
 282                /* disable all interrupt sources of this channel */
 283                writel_relaxed(0, data->regs + CHANIER(i));
 284
 285                irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
 286                                                 NULL, NULL);
 287
 288                irq_domain_remove(data->irqchip_data[i].domain);
 289        }
 290
 291        clk_disable_unprepare(data->ipg_clk);
 292
 293        return 0;
 294}
 295
 296static const struct of_device_id imx_intmux_id[] = {
 297        { .compatible = "fsl,imx-intmux", },
 298        { /* sentinel */ },
 299};
 300
 301static struct platform_driver imx_intmux_driver = {
 302        .driver = {
 303                .name = "imx-intmux",
 304                .of_match_table = imx_intmux_id,
 305        },
 306        .probe = imx_intmux_probe,
 307        .remove = imx_intmux_remove,
 308};
 309builtin_platform_driver(imx_intmux_driver);
 310