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
gef_gpio_probe(struct platform_device * pdev)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");
110