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");