drivers/gpio/gpio-ge.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for GE FPGA based GPIO
   4  *
   5  * Author: Martyn Welch <martyn.welch@ge.com>
   6  *
   7  * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.
   8  */
   9
  10 /*
  11  * TODO:
  12  *
  13  * Configuration of output modes (totem-pole/open-drain).
  14  * Interrupt configuration - interrupts are always generated, the FPGA relies
  15  * on the I/O interrupt controllers mask to stop them from being propagated.
  16  */
  17
  18 #include <linux/gpio/driver.h>
  19 #include <linux/io.h>
  20 #include <linux/kernel.h>
  21 #include <linux/mod_devicetable.h>
  22 #include <linux/module.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/property.h>
  25 #include <linux/slab.h>
  26
  27 #define GEF_GPIO_DIRECT         0x00
  28 #define GEF_GPIO_IN             0x04
  29 #define GEF_GPIO_OUT            0x08
  30 #define GEF_GPIO_TRIG           0x0C
  31 #define GEF_GPIO_POLAR_A        0x10
  32 #define GEF_GPIO_POLAR_B        0x14
  33 #define GEF_GPIO_INT_STAT       0x18
  34 #define GEF_GPIO_OVERRUN        0x1C
  35 #define GEF_GPIO_MODE           0x20
  36
  37 static const struct of_device_id gef_gpio_ids[] = {
  38         {
  39                 .compatible     = "gef,sbc610-gpio",
  40                 .data           = (void *)19,
  41         }, {
  42                 .compatible     = "gef,sbc310-gpio",
  43                 .data           = (void *)6,
  44         }, {
  45                 .compatible     = "ge,imp3a-gpio",
  46                 .data           = (void *)16,
  47         },
  48         { }
  49 };
  50 MODULE_DEVICE_TABLE(of, gef_gpio_ids);
  51
  52 static int __init gef_gpio_probe(struct platform_device *pdev)
  53 {
  54         struct device *dev = &pdev->dev;
  55         struct gpio_chip *gc;
  56         void __iomem *regs;
  57         int ret;
  58
  59         gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
  60         if (!gc)
  61                 return -ENOMEM;
  62
  63         regs = devm_platform_ioremap_resource(pdev, 0);
  64         if (IS_ERR(regs))
  65                 return PTR_ERR(regs);
  66
  67         ret = bgpio_init(gc, dev, 4, regs + GEF_GPIO_IN, regs + GEF_GPIO_OUT,
  68                          NULL, NULL, regs + GEF_GPIO_DIRECT,
  69                          BGPIOF_BIG_ENDIAN_BYTE_ORDER);
  70         if (ret)
  71                 return dev_err_probe(dev, ret, "bgpio_init failed\n");
  72
  73         /* Setup pointers to chip functions */
  74         gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pfw", dev_fwnode(dev));
  75         if (!gc->label)
  76                 return -ENOMEM;
  77
  78         gc->base = -1;
  79         gc->ngpio = (uintptr_t)device_get_match_data(dev);
  80
  81         /* This function adds a memory mapped GPIO chip */
  82         ret = devm_gpiochip_add_data(dev, gc, NULL);
  83         if (ret)
  84                 return dev_err_probe(dev, ret, "GPIO chip registration failed\n");
  85
  86         return 0;
  87 };
  88
  89 static struct platform_driver gef_gpio_driver = {
  90         .driver = {
  91                 .name           = "gef-gpio",
  92                 .of_match_table = gef_gpio_ids,
  93         },
  94 };
  95 module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);
  96
  97 MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
  98 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
  99 MODULE_LICENSE("GPL");