LXR linux/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
  38static 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};
  51MODULE_DEVICE_TABLE(of, gef_gpio_ids);
  52
  53static 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;
  93err0:
  94        iounmap(regs);
  95        pr_err("%pOF: GPIO chip registration failed\n", pdev->dev.of_node);
  96        return ret;
  97};
  98
  99static struct platform_driver gef_gpio_driver = {
 100        .driver = {
 101                .name           = "gef-gpio",
 102                .of_match_table = gef_gpio_ids,
 103        },
 104};
 105module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);
 106
 107MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
 108MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
 109MODULE_LICENSE("GPL");
 110