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_gpio.h>
  25#include <linux/of_address.h>
  26#include <linux/module.h>
  27#include <linux/basic_mmio_gpio.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
  39static 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};
  52MODULE_DEVICE_TABLE(of, gef_gpio_ids);
  53
  54static 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 bgpio_chip *bgc;
  59        void __iomem *regs;
  60        int ret;
  61
  62        bgc = devm_kzalloc(&pdev->dev, sizeof(*bgc), GFP_KERNEL);
  63        if (!bgc)
  64                return -ENOMEM;
  65
  66        regs = of_iomap(pdev->dev.of_node, 0);
  67        if (!regs)
  68                return -ENOMEM;
  69
  70        ret = bgpio_init(bgc, &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        bgc->gc.label = devm_kstrdup(&pdev->dev, pdev->dev.of_node->full_name,
  80                                     GFP_KERNEL);
  81        if (!bgc->gc.label) {
  82                ret = -ENOMEM;
  83                goto err0;
  84        }
  85
  86        bgc->gc.base = -1;
  87        bgc->gc.ngpio = (u16)(uintptr_t)of_id->data;
  88        bgc->gc.of_gpio_n_cells = 2;
  89        bgc->gc.of_node = pdev->dev.of_node;
  90
  91        /* This function adds a memory mapped GPIO chip */
  92        ret = gpiochip_add(&bgc->gc);
  93        if (ret)
  94                goto err0;
  95
  96        return 0;
  97err0:
  98        iounmap(regs);
  99        pr_err("%s: GPIO chip registration failed\n",
 100                        pdev->dev.of_node->full_name);
 101        return ret;
 102};
 103
 104static struct platform_driver gef_gpio_driver = {
 105        .driver = {
 106                .name           = "gef-gpio",
 107                .of_match_table = gef_gpio_ids,
 108        },
 109};
 110module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);
 111
 112MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
 113MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
 114MODULE_LICENSE("GPL");
 115