Root/target/linux/ar71xx/files/drivers/gpio/gpio-nxp-74hc153.c

1/*
2 * NXP 74HC153 - Dual 4-input multiplexer GPIO driver
3 *
4 * Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/gpio.h>
14#include <linux/slab.h>
15#include <linux/platform_device.h>
16#include <linux/nxp_74hc153.h>
17
18#define NXP_74HC153_NUM_GPIOS 8
19#define NXP_74HC153_S0_MASK 0x1
20#define NXP_74HC153_S1_MASK 0x2
21#define NXP_74HC153_BANK_MASK 0x4
22
23struct nxp_74hc153_chip {
24    struct device *parent;
25    struct gpio_chip gpio_chip;
26    struct mutex lock;
27};
28
29static struct nxp_74hc153_chip *gpio_to_nxp(struct gpio_chip *gc)
30{
31    return container_of(gc, struct nxp_74hc153_chip, gpio_chip);
32}
33
34static int nxp_74hc153_direction_input(struct gpio_chip *gc, unsigned offset)
35{
36    return 0;
37}
38
39static int nxp_74hc153_direction_output(struct gpio_chip *gc,
40                    unsigned offset, int val)
41{
42    return -EINVAL;
43}
44
45static int nxp_74hc153_get_value(struct gpio_chip *gc, unsigned offset)
46{
47    struct nxp_74hc153_chip *nxp;
48    struct nxp_74hc153_platform_data *pdata;
49    unsigned s0;
50    unsigned s1;
51    unsigned pin;
52    int ret;
53
54    nxp = gpio_to_nxp(gc);
55    pdata = nxp->parent->platform_data;
56
57    s0 = !!(offset & NXP_74HC153_S0_MASK);
58    s1 = !!(offset & NXP_74HC153_S1_MASK);
59    pin = (offset & NXP_74HC153_BANK_MASK) ? pdata->gpio_pin_2y
60                           : pdata->gpio_pin_1y;
61
62    mutex_lock(&nxp->lock);
63    gpio_set_value(pdata->gpio_pin_s0, s0);
64    gpio_set_value(pdata->gpio_pin_s1, s1);
65    ret = gpio_get_value(pin);
66    mutex_unlock(&nxp->lock);
67
68    return ret;
69}
70
71static void nxp_74hc153_set_value(struct gpio_chip *gc,
72                  unsigned offset, int val)
73{
74    /* not supported */
75}
76
77static int __devinit nxp_74hc153_probe(struct platform_device *pdev)
78{
79    struct nxp_74hc153_platform_data *pdata;
80    struct nxp_74hc153_chip *nxp;
81    struct gpio_chip *gc;
82    int err;
83
84    pdata = pdev->dev.platform_data;
85    if (pdata == NULL) {
86        dev_dbg(&pdev->dev, "no platform data specified\n");
87        return -EINVAL;
88    }
89
90    nxp = kzalloc(sizeof(struct nxp_74hc153_chip), GFP_KERNEL);
91    if (nxp == NULL) {
92        dev_err(&pdev->dev, "no memory for private data\n");
93        return -ENOMEM;
94    }
95
96    err = gpio_request(pdata->gpio_pin_s0, dev_name(&pdev->dev));
97    if (err) {
98        dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
99            pdata->gpio_pin_s0, err);
100        goto err_free_nxp;
101    }
102
103    err = gpio_request(pdata->gpio_pin_s1, dev_name(&pdev->dev));
104    if (err) {
105        dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
106            pdata->gpio_pin_s1, err);
107        goto err_free_s0;
108    }
109
110    err = gpio_request(pdata->gpio_pin_1y, dev_name(&pdev->dev));
111    if (err) {
112        dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
113            pdata->gpio_pin_1y, err);
114        goto err_free_s1;
115    }
116
117    err = gpio_request(pdata->gpio_pin_2y, dev_name(&pdev->dev));
118    if (err) {
119        dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
120            pdata->gpio_pin_2y, err);
121        goto err_free_1y;
122    }
123
124    err = gpio_direction_output(pdata->gpio_pin_s0, 0);
125    if (err) {
126        dev_err(&pdev->dev,
127            "unable to set direction of gpio %u, err=%d\n",
128            pdata->gpio_pin_s0, err);
129        goto err_free_2y;
130    }
131
132    err = gpio_direction_output(pdata->gpio_pin_s1, 0);
133    if (err) {
134        dev_err(&pdev->dev,
135            "unable to set direction of gpio %u, err=%d\n",
136            pdata->gpio_pin_s1, err);
137        goto err_free_2y;
138    }
139
140    err = gpio_direction_input(pdata->gpio_pin_1y);
141    if (err) {
142        dev_err(&pdev->dev,
143            "unable to set direction of gpio %u, err=%d\n",
144            pdata->gpio_pin_1y, err);
145        goto err_free_2y;
146    }
147
148    err = gpio_direction_input(pdata->gpio_pin_2y);
149    if (err) {
150        dev_err(&pdev->dev,
151            "unable to set direction of gpio %u, err=%d\n",
152            pdata->gpio_pin_2y, err);
153        goto err_free_2y;
154    }
155
156    nxp->parent = &pdev->dev;
157    mutex_init(&nxp->lock);
158
159    gc = &nxp->gpio_chip;
160
161    gc->direction_input = nxp_74hc153_direction_input;
162    gc->direction_output = nxp_74hc153_direction_output;
163    gc->get = nxp_74hc153_get_value;
164    gc->set = nxp_74hc153_set_value;
165    gc->can_sleep = 1;
166
167    gc->base = pdata->gpio_base;
168    gc->ngpio = NXP_74HC153_NUM_GPIOS;
169    gc->label = dev_name(nxp->parent);
170    gc->dev = nxp->parent;
171    gc->owner = THIS_MODULE;
172
173    err = gpiochip_add(&nxp->gpio_chip);
174    if (err) {
175        dev_err(&pdev->dev, "unable to add gpio chip, err=%d\n", err);
176        goto err_free_2y;
177    }
178
179    platform_set_drvdata(pdev, nxp);
180    return 0;
181
182err_free_2y:
183    gpio_free(pdata->gpio_pin_2y);
184err_free_1y:
185    gpio_free(pdata->gpio_pin_1y);
186err_free_s1:
187    gpio_free(pdata->gpio_pin_s1);
188err_free_s0:
189    gpio_free(pdata->gpio_pin_s0);
190err_free_nxp:
191    kfree(nxp);
192    return err;
193}
194
195static int nxp_74hc153_remove(struct platform_device *pdev)
196{
197    struct nxp_74hc153_chip *nxp = platform_get_drvdata(pdev);
198    struct nxp_74hc153_platform_data *pdata = pdev->dev.platform_data;
199
200    if (nxp) {
201        int err;
202
203        err = gpiochip_remove(&nxp->gpio_chip);
204        if (err) {
205            dev_err(&pdev->dev,
206                "unable to remove gpio chip, err=%d\n",
207                err);
208            return err;
209        }
210
211        gpio_free(pdata->gpio_pin_2y);
212        gpio_free(pdata->gpio_pin_1y);
213        gpio_free(pdata->gpio_pin_s1);
214        gpio_free(pdata->gpio_pin_s0);
215
216        kfree(nxp);
217        platform_set_drvdata(pdev, NULL);
218    }
219
220    return 0;
221}
222
223static struct platform_driver nxp_74hc153_driver = {
224    .probe = nxp_74hc153_probe,
225    .remove = __devexit_p(nxp_74hc153_remove),
226    .driver = {
227        .name = NXP_74HC153_DRIVER_NAME,
228        .owner = THIS_MODULE,
229    },
230};
231
232static int __init nxp_74hc153_init(void)
233{
234    return platform_driver_register(&nxp_74hc153_driver);
235}
236subsys_initcall(nxp_74hc153_init);
237
238static void __exit nxp_74hc153_exit(void)
239{
240    platform_driver_unregister(&nxp_74hc153_driver);
241}
242module_exit(nxp_74hc153_exit);
243
244MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
245MODULE_DESCRIPTION("GPIO expander driver for NXP 74HC153");
246MODULE_LICENSE("GPL v2");
247MODULE_ALIAS("platform:" NXP_74HC153_DRIVER_NAME);
248

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