drivers/gpio/gpio-sl28cpld.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * sl28cpld GPIO driver
   4  *
   5  * Copyright 2020 Michael Walle <michael@walle.cc>
   6  */
   7
   8 #include <linux/device.h>
   9 #include <linux/gpio/driver.h>
  10 #include <linux/gpio/regmap.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/kernel.h>
  13 #include <linux/mod_devicetable.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regmap.h>
  17
  18 /* GPIO flavor */
  19 #define GPIO_REG_DIR    0x00
  20 #define GPIO_REG_OUT    0x01
  21 #define GPIO_REG_IN     0x02
  22 #define GPIO_REG_IE     0x03
  23 #define GPIO_REG_IP     0x04
  24
  25 /* input-only flavor */
  26 #define GPI_REG_IN      0x00
  27
  28 /* output-only flavor */
  29 #define GPO_REG_OUT     0x00
  30
  31 enum sl28cpld_gpio_type {
  32         SL28CPLD_GPIO = 1,
  33         SL28CPLD_GPI,
  34         SL28CPLD_GPO,
  35 };
  36
  37 static const struct regmap_irq sl28cpld_gpio_irqs[] = {
  38         REGMAP_IRQ_REG_LINE(0, 8),
  39         REGMAP_IRQ_REG_LINE(1, 8),
  40         REGMAP_IRQ_REG_LINE(2, 8),
  41         REGMAP_IRQ_REG_LINE(3, 8),
  42         REGMAP_IRQ_REG_LINE(4, 8),
  43         REGMAP_IRQ_REG_LINE(5, 8),
  44         REGMAP_IRQ_REG_LINE(6, 8),
  45         REGMAP_IRQ_REG_LINE(7, 8),
  46 };
  47
  48 static int sl28cpld_gpio_irq_init(struct platform_device *pdev,
  49                                   unsigned int base,
  50                                   struct gpio_regmap_config *config)
  51 {
  52         struct regmap_irq_chip_data *irq_data;
  53         struct regmap_irq_chip *irq_chip;
  54         struct device *dev = &pdev->dev;
  55         int irq, ret;
  56
  57         if (!device_property_read_bool(dev, "interrupt-controller"))
  58                 return 0;
  59
  60         irq = platform_get_irq(pdev, 0);
  61         if (irq < 0)
  62                 return irq;
  63
  64         irq_chip = devm_kzalloc(dev, sizeof(*irq_chip), GFP_KERNEL);
  65         if (!irq_chip)
  66                 return -ENOMEM;
  67
  68         irq_chip->name = "sl28cpld-gpio-irq",
  69         irq_chip->irqs = sl28cpld_gpio_irqs;
  70         irq_chip->num_irqs = ARRAY_SIZE(sl28cpld_gpio_irqs);
  71         irq_chip->num_regs = 1;
  72         irq_chip->status_base = base + GPIO_REG_IP;
  73         irq_chip->mask_base = base + GPIO_REG_IE;
  74         irq_chip->mask_invert = true,
  75         irq_chip->ack_base = base + GPIO_REG_IP;
  76
  77         ret = devm_regmap_add_irq_chip_fwnode(dev, dev_fwnode(dev),
  78                                               config->regmap, irq,
  79                                               IRQF_SHARED | IRQF_ONESHOT,
  80                                               0, irq_chip, &irq_data);
  81         if (ret)
  82                 return ret;
  83
  84         config->irq_domain = regmap_irq_get_domain(irq_data);
  85
  86         return 0;
  87 }
  88
  89 static int sl28cpld_gpio_probe(struct platform_device *pdev)
  90 {
  91         struct gpio_regmap_config config = {0};
  92         enum sl28cpld_gpio_type type;
  93         struct regmap *regmap;
  94         u32 base;
  95         int ret;
  96
  97         if (!pdev->dev.parent)
  98                 return -ENODEV;
  99
 100         type = (uintptr_t)device_get_match_data(&pdev->dev);
 101         if (!type)
 102                 return -ENODEV;
 103
 104         ret = device_property_read_u32(&pdev->dev, "reg", &base);
 105         if (ret)
 106                 return -EINVAL;
 107
 108         regmap = dev_get_regmap(pdev->dev.parent, NULL);
 109         if (!regmap)
 110                 return -ENODEV;
 111
 112         config.regmap = regmap;
 113         config.parent = &pdev->dev;
 114         config.ngpio = 8;
 115
 116         switch (type) {
 117         case SL28CPLD_GPIO:
 118                 config.reg_dat_base = base + GPIO_REG_IN;
 119                 config.reg_set_base = base + GPIO_REG_OUT;
 120                 /* reg_dir_out_base might be zero */
 121                 config.reg_dir_out_base = GPIO_REGMAP_ADDR(base + GPIO_REG_DIR);
 122
 123                 /* This type supports interrupts */
 124                 ret = sl28cpld_gpio_irq_init(pdev, base, &config);
 125                 if (ret)
 126                         return ret;
 127                 break;
 128         case SL28CPLD_GPO:
 129                 config.reg_set_base = base + GPO_REG_OUT;
 130                 break;
 131         case SL28CPLD_GPI:
 132                 config.reg_dat_base = base + GPI_REG_IN;
 133                 break;
 134         default:
 135                 dev_err(&pdev->dev, "unknown type %d\n", type);
 136                 return -ENODEV;
 137         }
 138
 139         return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
 140 }
 141
 142 static const struct of_device_id sl28cpld_gpio_of_match[] = {
 143         { .compatible = "kontron,sl28cpld-gpio", .data = (void *)SL28CPLD_GPIO },
 144         { .compatible = "kontron,sl28cpld-gpi", .data = (void *)SL28CPLD_GPI },
 145         { .compatible = "kontron,sl28cpld-gpo", .data = (void *)SL28CPLD_GPO },
 146         {}
 147 };
 148 MODULE_DEVICE_TABLE(of, sl28cpld_gpio_of_match);
 149
 150 static struct platform_driver sl28cpld_gpio_driver = {
 151         .probe = sl28cpld_gpio_probe,
 152         .driver = {
 153                 .name = "sl28cpld-gpio",
 154                 .of_match_table = sl28cpld_gpio_of_match,
 155         },
 156 };
 157 module_platform_driver(sl28cpld_gpio_driver);
 158
 159 MODULE_DESCRIPTION("sl28cpld GPIO Driver");
 160 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
 161 MODULE_LICENSE("GPL");