nfsd4: typo logical vs bitwise negate for want_mask
[linux-btrfs-devel.git] / arch / mips / lantiq / xway / gpio_ebu.c
bloba479355abdb92755759366fa1b50325474d93810
1 /*
2 * This program is free software; you can redistribute it and/or modify it
3 * under the terms of the GNU General Public License version 2 as published
4 * by the Free Software Foundation.
6 * Copyright (C) 2010 John Crispin <blogic@openwrt.org>
7 */
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/platform_device.h>
13 #include <linux/mutex.h>
14 #include <linux/gpio.h>
15 #include <linux/io.h>
17 #include <lantiq_soc.h>
20 * By attaching hardware latches to the EBU it is possible to create output
21 * only gpios. This driver configures a special memory address, which when
22 * written to outputs 16 bit to the latches.
25 #define LTQ_EBU_BUSCON 0x1e7ff /* 16 bit access, slowest timing */
26 #define LTQ_EBU_WP 0x80000000 /* write protect bit */
28 /* we keep a shadow value of the last value written to the ebu */
29 static int ltq_ebu_gpio_shadow = 0x0;
30 static void __iomem *ltq_ebu_gpio_membase;
32 static void ltq_ebu_apply(void)
34 unsigned long flags;
36 spin_lock_irqsave(&ebu_lock, flags);
37 ltq_ebu_w32(LTQ_EBU_BUSCON, LTQ_EBU_BUSCON1);
38 *((__u16 *)ltq_ebu_gpio_membase) = ltq_ebu_gpio_shadow;
39 ltq_ebu_w32(LTQ_EBU_BUSCON | LTQ_EBU_WP, LTQ_EBU_BUSCON1);
40 spin_unlock_irqrestore(&ebu_lock, flags);
43 static void ltq_ebu_set(struct gpio_chip *chip, unsigned offset, int value)
45 if (value)
46 ltq_ebu_gpio_shadow |= (1 << offset);
47 else
48 ltq_ebu_gpio_shadow &= ~(1 << offset);
49 ltq_ebu_apply();
52 static int ltq_ebu_direction_output(struct gpio_chip *chip, unsigned offset,
53 int value)
55 ltq_ebu_set(chip, offset, value);
57 return 0;
60 static struct gpio_chip ltq_ebu_chip = {
61 .label = "ltq_ebu",
62 .direction_output = ltq_ebu_direction_output,
63 .set = ltq_ebu_set,
64 .base = 72,
65 .ngpio = 16,
66 .can_sleep = 1,
67 .owner = THIS_MODULE,
70 static int ltq_ebu_probe(struct platform_device *pdev)
72 int ret = 0;
73 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
75 if (!res) {
76 dev_err(&pdev->dev, "failed to get memory resource\n");
77 return -ENOENT;
80 res = devm_request_mem_region(&pdev->dev, res->start,
81 resource_size(res), dev_name(&pdev->dev));
82 if (!res) {
83 dev_err(&pdev->dev, "failed to request memory resource\n");
84 return -EBUSY;
87 ltq_ebu_gpio_membase = devm_ioremap_nocache(&pdev->dev, res->start,
88 resource_size(res));
89 if (!ltq_ebu_gpio_membase) {
90 dev_err(&pdev->dev, "Failed to ioremap mem region\n");
91 return -ENOMEM;
94 /* grab the default shadow value passed form the platform code */
95 ltq_ebu_gpio_shadow = (unsigned int) pdev->dev.platform_data;
97 /* tell the ebu controller which memory address we will be using */
98 ltq_ebu_w32(pdev->resource->start | 0x1, LTQ_EBU_ADDRSEL1);
100 /* write protect the region */
101 ltq_ebu_w32(LTQ_EBU_BUSCON | LTQ_EBU_WP, LTQ_EBU_BUSCON1);
103 ret = gpiochip_add(&ltq_ebu_chip);
104 if (!ret)
105 ltq_ebu_apply();
106 return ret;
109 static struct platform_driver ltq_ebu_driver = {
110 .probe = ltq_ebu_probe,
111 .driver = {
112 .name = "ltq_ebu",
113 .owner = THIS_MODULE,
117 static int __init ltq_ebu_init(void)
119 int ret = platform_driver_register(&ltq_ebu_driver);
121 if (ret)
122 pr_info("ltq_ebu : Error registering platfom driver!");
123 return ret;
126 postcore_initcall(ltq_ebu_init);