linux/drivers/gpio/gpio-xgene-sb.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * AppliedMicro X-Gene SoC GPIO-Standby Driver
   4 *
   5 * Copyright (c) 2014, Applied Micro Circuits Corporation
   6 * Author:      Tin Huynh <tnhuynh@apm.com>.
   7 *              Y Vo <yvo@apm.com>.
   8 *              Quan Nguyen <qnguyen@apm.com>.
   9 */
  10
  11#include <linux/module.h>
  12#include <linux/io.h>
  13#include <linux/of.h>
  14#include <linux/platform_device.h>
  15#include <linux/gpio/driver.h>
  16#include <linux/acpi.h>
  17
  18#include "gpiolib.h"
  19#include "gpiolib-acpi.h"
  20
  21/* Common property names */
  22#define XGENE_NIRQ_PROPERTY             "apm,nr-irqs"
  23#define XGENE_NGPIO_PROPERTY            "apm,nr-gpios"
  24#define XGENE_IRQ_START_PROPERTY        "apm,irq-start"
  25
  26#define XGENE_DFLT_MAX_NGPIO            22
  27#define XGENE_DFLT_MAX_NIRQ             6
  28#define XGENE_DFLT_IRQ_START_PIN        8
  29#define GPIO_MASK(x)                    (1U << ((x) % 32))
  30
  31#define MPA_GPIO_INT_LVL                0x0290
  32#define MPA_GPIO_OE_ADDR                0x029c
  33#define MPA_GPIO_OUT_ADDR               0x02a0
  34#define MPA_GPIO_IN_ADDR                0x02a4
  35#define MPA_GPIO_SEL_LO                 0x0294
  36
  37#define GPIO_INT_LEVEL_H        0x000001
  38#define GPIO_INT_LEVEL_L        0x000000
  39
  40/**
  41 * struct xgene_gpio_sb - GPIO-Standby private data structure.
  42 * @gc:                         memory-mapped GPIO controllers.
  43 * @regs:                       GPIO register base offset
  44 * @irq_domain:                 GPIO interrupt domain
  45 * @irq_start:                  GPIO pin that start support interrupt
  46 * @nirq:                       Number of GPIO pins that supports interrupt
  47 * @parent_irq_base:            Start parent HWIRQ
  48 */
  49struct xgene_gpio_sb {
  50        struct gpio_chip        gc;
  51        void __iomem            *regs;
  52        struct irq_domain       *irq_domain;
  53        u16                     irq_start;
  54        u16                     nirq;
  55        u16                     parent_irq_base;
  56};
  57
  58#define HWIRQ_TO_GPIO(priv, hwirq) ((hwirq) + (priv)->irq_start)
  59#define GPIO_TO_HWIRQ(priv, gpio) ((gpio) - (priv)->irq_start)
  60
  61static void xgene_gpio_set_bit(struct gpio_chip *gc,
  62                                void __iomem *reg, u32 gpio, int val)
  63{
  64        u32 data;
  65
  66        data = gc->read_reg(reg);
  67        if (val)
  68                data |= GPIO_MASK(gpio);
  69        else
  70                data &= ~GPIO_MASK(gpio);
  71        gc->write_reg(reg, data);
  72}
  73
  74static int xgene_gpio_sb_irq_set_type(struct irq_data *d, unsigned int type)
  75{
  76        struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
  77        int gpio = HWIRQ_TO_GPIO(priv, d->hwirq);
  78        int lvl_type = GPIO_INT_LEVEL_H;
  79
  80        switch (type & IRQ_TYPE_SENSE_MASK) {
  81        case IRQ_TYPE_EDGE_RISING:
  82        case IRQ_TYPE_LEVEL_HIGH:
  83                lvl_type = GPIO_INT_LEVEL_H;
  84                break;
  85        case IRQ_TYPE_EDGE_FALLING:
  86        case IRQ_TYPE_LEVEL_LOW:
  87                lvl_type = GPIO_INT_LEVEL_L;
  88                break;
  89        default:
  90                break;
  91        }
  92
  93        xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
  94                        gpio * 2, 1);
  95        xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_INT_LVL,
  96                        d->hwirq, lvl_type);
  97
  98        /* Propagate IRQ type setting to parent */
  99        if (type & IRQ_TYPE_EDGE_BOTH)
 100                return irq_chip_set_type_parent(d, IRQ_TYPE_EDGE_RISING);
 101        else
 102                return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
 103}
 104
 105static struct irq_chip xgene_gpio_sb_irq_chip = {
 106        .name           = "sbgpio",
 107        .irq_eoi        = irq_chip_eoi_parent,
 108        .irq_mask       = irq_chip_mask_parent,
 109        .irq_unmask     = irq_chip_unmask_parent,
 110        .irq_set_type   = xgene_gpio_sb_irq_set_type,
 111};
 112
 113static int xgene_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
 114{
 115        struct xgene_gpio_sb *priv = gpiochip_get_data(gc);
 116        struct irq_fwspec fwspec;
 117
 118        if ((gpio < priv->irq_start) ||
 119                        (gpio > HWIRQ_TO_GPIO(priv, priv->nirq)))
 120                return -ENXIO;
 121
 122        fwspec.fwnode = gc->parent->fwnode;
 123        fwspec.param_count = 2;
 124        fwspec.param[0] = GPIO_TO_HWIRQ(priv, gpio);
 125        fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
 126        return irq_create_fwspec_mapping(&fwspec);
 127}
 128
 129static int xgene_gpio_sb_domain_activate(struct irq_domain *d,
 130                                         struct irq_data *irq_data,
 131                                         bool reserve)
 132{
 133        struct xgene_gpio_sb *priv = d->host_data;
 134        u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
 135        int ret;
 136
 137        ret = gpiochip_lock_as_irq(&priv->gc, gpio);
 138        if (ret) {
 139                dev_err(priv->gc.parent,
 140                "Unable to configure XGene GPIO standby pin %d as IRQ\n",
 141                                gpio);
 142                return ret;
 143        }
 144
 145        xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
 146                        gpio * 2, 1);
 147        return 0;
 148}
 149
 150static void xgene_gpio_sb_domain_deactivate(struct irq_domain *d,
 151                struct irq_data *irq_data)
 152{
 153        struct xgene_gpio_sb *priv = d->host_data;
 154        u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
 155
 156        gpiochip_unlock_as_irq(&priv->gc, gpio);
 157        xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
 158                        gpio * 2, 0);
 159}
 160
 161static int xgene_gpio_sb_domain_translate(struct irq_domain *d,
 162                struct irq_fwspec *fwspec,
 163                unsigned long *hwirq,
 164                unsigned int *type)
 165{
 166        struct xgene_gpio_sb *priv = d->host_data;
 167
 168        if ((fwspec->param_count != 2) ||
 169                (fwspec->param[0] >= priv->nirq))
 170                return -EINVAL;
 171        *hwirq = fwspec->param[0];
 172        *type = fwspec->param[1];
 173        return 0;
 174}
 175
 176static int xgene_gpio_sb_domain_alloc(struct irq_domain *domain,
 177                                        unsigned int virq,
 178                                        unsigned int nr_irqs, void *data)
 179{
 180        struct irq_fwspec *fwspec = data;
 181        struct irq_fwspec parent_fwspec;
 182        struct xgene_gpio_sb *priv = domain->host_data;
 183        irq_hw_number_t hwirq;
 184        unsigned int i;
 185
 186        hwirq = fwspec->param[0];
 187        for (i = 0; i < nr_irqs; i++)
 188                irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
 189                                &xgene_gpio_sb_irq_chip, priv);
 190
 191        parent_fwspec.fwnode = domain->parent->fwnode;
 192        if (is_of_node(parent_fwspec.fwnode)) {
 193                parent_fwspec.param_count = 3;
 194                parent_fwspec.param[0] = 0;/* SPI */
 195                /* Skip SGIs and PPIs*/
 196                parent_fwspec.param[1] = hwirq + priv->parent_irq_base - 32;
 197                parent_fwspec.param[2] = fwspec->param[1];
 198        } else if (is_fwnode_irqchip(parent_fwspec.fwnode)) {
 199                parent_fwspec.param_count = 2;
 200                parent_fwspec.param[0] = hwirq + priv->parent_irq_base;
 201                parent_fwspec.param[1] = fwspec->param[1];
 202        } else
 203                return -EINVAL;
 204
 205        return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
 206                        &parent_fwspec);
 207}
 208
 209static const struct irq_domain_ops xgene_gpio_sb_domain_ops = {
 210        .translate      = xgene_gpio_sb_domain_translate,
 211        .alloc          = xgene_gpio_sb_domain_alloc,
 212        .free           = irq_domain_free_irqs_common,
 213        .activate       = xgene_gpio_sb_domain_activate,
 214        .deactivate     = xgene_gpio_sb_domain_deactivate,
 215};
 216
 217static int xgene_gpio_sb_probe(struct platform_device *pdev)
 218{
 219        struct xgene_gpio_sb *priv;
 220        int ret;
 221        void __iomem *regs;
 222        struct irq_domain *parent_domain = NULL;
 223        u32 val32;
 224
 225        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 226        if (!priv)
 227                return -ENOMEM;
 228
 229        regs = devm_platform_ioremap_resource(pdev, 0);
 230        if (IS_ERR(regs))
 231                return PTR_ERR(regs);
 232
 233        priv->regs = regs;
 234
 235        ret = platform_get_irq(pdev, 0);
 236        if (ret > 0) {
 237                priv->parent_irq_base = irq_get_irq_data(ret)->hwirq;
 238                parent_domain = irq_get_irq_data(ret)->domain;
 239        }
 240        if (!parent_domain) {
 241                dev_err(&pdev->dev, "unable to obtain parent domain\n");
 242                return -ENODEV;
 243        }
 244
 245        ret = bgpio_init(&priv->gc, &pdev->dev, 4,
 246                        regs + MPA_GPIO_IN_ADDR,
 247                        regs + MPA_GPIO_OUT_ADDR, NULL,
 248                        regs + MPA_GPIO_OE_ADDR, NULL, 0);
 249        if (ret)
 250                return ret;
 251
 252        priv->gc.to_irq = xgene_gpio_sb_to_irq;
 253
 254        /* Retrieve start irq pin, use default if property not found */
 255        priv->irq_start = XGENE_DFLT_IRQ_START_PIN;
 256        if (!device_property_read_u32(&pdev->dev,
 257                                        XGENE_IRQ_START_PROPERTY, &val32))
 258                priv->irq_start = val32;
 259
 260        /* Retrieve number irqs, use default if property not found */
 261        priv->nirq = XGENE_DFLT_MAX_NIRQ;
 262        if (!device_property_read_u32(&pdev->dev, XGENE_NIRQ_PROPERTY, &val32))
 263                priv->nirq = val32;
 264
 265        /* Retrieve number gpio, use default if property not found */
 266        priv->gc.ngpio = XGENE_DFLT_MAX_NGPIO;
 267        if (!device_property_read_u32(&pdev->dev, XGENE_NGPIO_PROPERTY, &val32))
 268                priv->gc.ngpio = val32;
 269
 270        dev_info(&pdev->dev, "Support %d gpios, %d irqs start from pin %d\n",
 271                        priv->gc.ngpio, priv->nirq, priv->irq_start);
 272
 273        platform_set_drvdata(pdev, priv);
 274
 275        priv->irq_domain = irq_domain_create_hierarchy(parent_domain,
 276                                        0, priv->nirq, pdev->dev.fwnode,
 277                                        &xgene_gpio_sb_domain_ops, priv);
 278        if (!priv->irq_domain)
 279                return -ENODEV;
 280
 281        priv->gc.irq.domain = priv->irq_domain;
 282
 283        ret = devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
 284        if (ret) {
 285                dev_err(&pdev->dev,
 286                        "failed to register X-Gene GPIO Standby driver\n");
 287                irq_domain_remove(priv->irq_domain);
 288                return ret;
 289        }
 290
 291        dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");
 292
 293        /* Register interrupt handlers for GPIO signaled ACPI Events */
 294        acpi_gpiochip_request_interrupts(&priv->gc);
 295
 296        return ret;
 297}
 298
 299static int xgene_gpio_sb_remove(struct platform_device *pdev)
 300{
 301        struct xgene_gpio_sb *priv = platform_get_drvdata(pdev);
 302
 303        acpi_gpiochip_free_interrupts(&priv->gc);
 304
 305        irq_domain_remove(priv->irq_domain);
 306
 307        return 0;
 308}
 309
 310static const struct of_device_id xgene_gpio_sb_of_match[] = {
 311        {.compatible = "apm,xgene-gpio-sb", },
 312        {},
 313};
 314MODULE_DEVICE_TABLE(of, xgene_gpio_sb_of_match);
 315
 316#ifdef CONFIG_ACPI
 317static const struct acpi_device_id xgene_gpio_sb_acpi_match[] = {
 318        {"APMC0D15", 0},
 319        {},
 320};
 321MODULE_DEVICE_TABLE(acpi, xgene_gpio_sb_acpi_match);
 322#endif
 323
 324static struct platform_driver xgene_gpio_sb_driver = {
 325        .driver = {
 326                   .name = "xgene-gpio-sb",
 327                   .of_match_table = xgene_gpio_sb_of_match,
 328                   .acpi_match_table = ACPI_PTR(xgene_gpio_sb_acpi_match),
 329                   },
 330        .probe = xgene_gpio_sb_probe,
 331        .remove = xgene_gpio_sb_remove,
 332};
 333module_platform_driver(xgene_gpio_sb_driver);
 334
 335MODULE_AUTHOR("AppliedMicro");
 336MODULE_DESCRIPTION("APM X-Gene GPIO Standby driver");
 337MODULE_LICENSE("GPL");
 338