drivers/gpio/gpio-ge.c

   1 /*
   2  * Driver for GE FPGA based GPIO
   3  *
   4  * Author: Martyn Welch <martyn.welch@ge.com>
   5  *
   6  * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.
   7  *
   8  * This file is licensed under the terms of the GNU General Public License
   9  * version 2.  This program is licensed "as is" without any warranty of any
  10  * kind, whether express or implied.
  11  */
  12
  13 /* TODO
  14  *
  15  * Configuration of output modes (totem-pole/open-drain)
  16  * Interrupt configuration - interrupts are always generated the FPGA relies on
  17  * the I/O interrupt controllers mask to stop them propergating
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/io.h>
  22 #include <linux/slab.h>
  23 #include <linux/of_device.h>
  24 #include <linux/of_address.h>
  25 #include <linux/module.h>
  26 #include <linux/gpio/driver.h>
  27
  28 #define GEF_GPIO_DIRECT         0x00
  29 #define GEF_GPIO_IN             0x04
  30 #define GEF_GPIO_OUT            0x08
  31 #define GEF_GPIO_TRIG           0x0C
  32 #define GEF_GPIO_POLAR_A        0x10
  33 #define GEF_GPIO_POLAR_B        0x14
  34 #define GEF_GPIO_INT_STAT       0x18
  35 #define GEF_GPIO_OVERRUN        0x1C
  36 #define GEF_GPIO_MODE           0x20
  37
  38 static const struct of_device_id gef_gpio_ids[] = {
  39         {
  40                 .compatible     = "gef,sbc610-gpio",
  41                 .data           = (void *)19,
  42         }, {
  43                 .compatible     = "gef,sbc310-gpio",
  44                 .data           = (void *)6,
  45         }, {
  46                 .compatible     = "ge,imp3a-gpio",
  47                 .data           = (void *)16,
  48         },
  49         { }
  50 };
  51 MODULE_DEVICE_TABLE(of, gef_gpio_ids);
  52
  53 static int __init gef_gpio_probe(struct platform_device *pdev)
  54 {
  55         struct gpio_chip *gc;
  56         void __iomem *regs;
  57         int ret;
  58
  59         gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
  60         if (!gc)
  61                 return -ENOMEM;
  62
  63         regs = of_iomap(pdev->dev.of_node, 0);
  64         if (!regs)
  65                 return -ENOMEM;
  66
  67         ret = bgpio_init(gc, &pdev->dev, 4, regs + GEF_GPIO_IN,
  68                          regs + GEF_GPIO_OUT, NULL, NULL,
  69                          regs + GEF_GPIO_DIRECT, BGPIOF_BIG_ENDIAN_BYTE_ORDER);
  70         if (ret) {
  71                 dev_err(&pdev->dev, "bgpio_init failed\n");
  72                 goto err0;
  73         }
  74
  75         /* Setup pointers to chip functions */
  76         gc->label = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOF", pdev->dev.of_node);
  77         if (!gc->label) {
  78                 ret = -ENOMEM;
  79                 goto err0;
  80         }
  81
  82         gc->base = -1;
  83         gc->ngpio = (u16)(uintptr_t)of_device_get_match_data(&pdev->dev);
  84         gc->of_gpio_n_cells = 2;
  85         gc->of_node = pdev->dev.of_node;
  86
  87         /* This function adds a memory mapped GPIO chip */
  88         ret = devm_gpiochip_add_data(&pdev->dev, gc, NULL);
  89         if (ret)
  90                 goto err0;
  91
  92         return 0;
  93 err0:
  94         iounmap(regs);
  95         pr_err("%pOF: GPIO chip registration failed\n", pdev->dev.of_node);
  96         return ret;
  97 };
  98
  99 static struct platform_driver gef_gpio_driver = {
 100         .driver = {
 101                 .name           = "gef-gpio",
 102                 .of_match_table = gef_gpio_ids,
 103         },
 104 };
 105 module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);
 106
 107 MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
 108 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
 109 MODULE_LICENSE("GPL");