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_gpio.h>
  25 #include <linux/of_address.h>
  26 #include <linux/module.h>
  27 #include <linux/gpio/driver.h>
  28
  29 #define GEF_GPIO_DIRECT         0x00
  30 #define GEF_GPIO_IN             0x04
  31 #define GEF_GPIO_OUT            0x08
  32 #define GEF_GPIO_TRIG           0x0C
  33 #define GEF_GPIO_POLAR_A        0x10
  34 #define GEF_GPIO_POLAR_B        0x14
  35 #define GEF_GPIO_INT_STAT       0x18
  36 #define GEF_GPIO_OVERRUN        0x1C
  37 #define GEF_GPIO_MODE           0x20
  38
  39 static const struct of_device_id gef_gpio_ids[] = {
  40         {
  41                 .compatible     = "gef,sbc610-gpio",
  42                 .data           = (void *)19,
  43         }, {
  44                 .compatible     = "gef,sbc310-gpio",
  45                 .data           = (void *)6,
  46         }, {
  47                 .compatible     = "ge,imp3a-gpio",
  48                 .data           = (void *)16,
  49         },
  50         { }
  51 };
  52 MODULE_DEVICE_TABLE(of, gef_gpio_ids);
  53
  54 static int __init gef_gpio_probe(struct platform_device *pdev)
  55 {
  56         const struct of_device_id *of_id =
  57                 of_match_device(gef_gpio_ids, &pdev->dev);
  58         struct gpio_chip *gc;
  59         void __iomem *regs;
  60         int ret;
  61
  62         gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
  63         if (!gc)
  64                 return -ENOMEM;
  65
  66         regs = of_iomap(pdev->dev.of_node, 0);
  67         if (!regs)
  68                 return -ENOMEM;
  69
  70         ret = bgpio_init(gc, &pdev->dev, 4, regs + GEF_GPIO_IN,
  71                          regs + GEF_GPIO_OUT, NULL, NULL,
  72                          regs + GEF_GPIO_DIRECT, BGPIOF_BIG_ENDIAN_BYTE_ORDER);
  73         if (ret) {
  74                 dev_err(&pdev->dev, "bgpio_init failed\n");
  75                 goto err0;
  76         }
  77
  78         /* Setup pointers to chip functions */
  79         gc->label = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOF", pdev->dev.of_node);
  80         if (!gc->label) {
  81                 ret = -ENOMEM;
  82                 goto err0;
  83         }
  84
  85         gc->base = -1;
  86         gc->ngpio = (u16)(uintptr_t)of_id->data;
  87         gc->of_gpio_n_cells = 2;
  88         gc->of_node = pdev->dev.of_node;
  89
  90         /* This function adds a memory mapped GPIO chip */
  91         ret = devm_gpiochip_add_data(&pdev->dev, gc, NULL);
  92         if (ret)
  93                 goto err0;
  94
  95         return 0;
  96 err0:
  97         iounmap(regs);
  98         pr_err("%pOF: GPIO chip registration failed\n", pdev->dev.of_node);
  99         return ret;
 100 };
 101
 102 static struct platform_driver gef_gpio_driver = {
 103         .driver = {
 104                 .name           = "gef-gpio",
 105                 .of_match_table = gef_gpio_ids,
 106         },
 107 };
 108 module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);
 109
 110 MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
 111 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
 112 MODULE_LICENSE("GPL");