OpenWrt – Rev 1
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/*
* NXP 74HC153 - Dual 4-input multiplexer GPIO driver
*
* Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/version.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/nxp_74hc153.h>
#define NXP_74HC153_NUM_GPIOS 8
#define NXP_74HC153_S0_MASK 0x1
#define NXP_74HC153_S1_MASK 0x2
#define NXP_74HC153_BANK_MASK 0x4
struct nxp_74hc153_chip {
struct device *parent;
struct gpio_chip gpio_chip;
struct mutex lock;
};
static struct nxp_74hc153_chip *gpio_to_nxp(struct gpio_chip *gc)
{
return container_of(gc, struct nxp_74hc153_chip, gpio_chip);
}
static int nxp_74hc153_direction_input(struct gpio_chip *gc, unsigned offset)
{
return 0;
}
static int nxp_74hc153_direction_output(struct gpio_chip *gc,
unsigned offset, int val)
{
return -EINVAL;
}
static int nxp_74hc153_get_value(struct gpio_chip *gc, unsigned offset)
{
struct nxp_74hc153_chip *nxp;
struct nxp_74hc153_platform_data *pdata;
unsigned s0;
unsigned s1;
unsigned pin;
int ret;
nxp = gpio_to_nxp(gc);
pdata = nxp->parent->platform_data;
s0 = !!(offset & NXP_74HC153_S0_MASK);
s1 = !!(offset & NXP_74HC153_S1_MASK);
pin = (offset & NXP_74HC153_BANK_MASK) ? pdata->gpio_pin_2y
: pdata->gpio_pin_1y;
mutex_lock(&nxp->lock);
gpio_set_value(pdata->gpio_pin_s0, s0);
gpio_set_value(pdata->gpio_pin_s1, s1);
ret = gpio_get_value(pin);
mutex_unlock(&nxp->lock);
return ret;
}
static void nxp_74hc153_set_value(struct gpio_chip *gc,
unsigned offset, int val)
{
/* not supported */
}
static int nxp_74hc153_probe(struct platform_device *pdev)
{
struct nxp_74hc153_platform_data *pdata;
struct nxp_74hc153_chip *nxp;
struct gpio_chip *gc;
int err;
pdata = pdev->dev.platform_data;
if (pdata == NULL) {
dev_dbg(&pdev->dev, "no platform data specified\n");
return -EINVAL;
}
nxp = kzalloc(sizeof(struct nxp_74hc153_chip), GFP_KERNEL);
if (nxp == NULL) {
dev_err(&pdev->dev, "no memory for private data\n");
return -ENOMEM;
}
err = gpio_request(pdata->gpio_pin_s0, dev_name(&pdev->dev));
if (err) {
dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
pdata->gpio_pin_s0, err);
goto err_free_nxp;
}
err = gpio_request(pdata->gpio_pin_s1, dev_name(&pdev->dev));
if (err) {
dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
pdata->gpio_pin_s1, err);
goto err_free_s0;
}
err = gpio_request(pdata->gpio_pin_1y, dev_name(&pdev->dev));
if (err) {
dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
pdata->gpio_pin_1y, err);
goto err_free_s1;
}
err = gpio_request(pdata->gpio_pin_2y, dev_name(&pdev->dev));
if (err) {
dev_err(&pdev->dev, "unable to claim gpio %u, err=%d\n",
pdata->gpio_pin_2y, err);
goto err_free_1y;
}
err = gpio_direction_output(pdata->gpio_pin_s0, 0);
if (err) {
dev_err(&pdev->dev,
"unable to set direction of gpio %u, err=%d\n",
pdata->gpio_pin_s0, err);
goto err_free_2y;
}
err = gpio_direction_output(pdata->gpio_pin_s1, 0);
if (err) {
dev_err(&pdev->dev,
"unable to set direction of gpio %u, err=%d\n",
pdata->gpio_pin_s1, err);
goto err_free_2y;
}
err = gpio_direction_input(pdata->gpio_pin_1y);
if (err) {
dev_err(&pdev->dev,
"unable to set direction of gpio %u, err=%d\n",
pdata->gpio_pin_1y, err);
goto err_free_2y;
}
err = gpio_direction_input(pdata->gpio_pin_2y);
if (err) {
dev_err(&pdev->dev,
"unable to set direction of gpio %u, err=%d\n",
pdata->gpio_pin_2y, err);
goto err_free_2y;
}
nxp->parent = &pdev->dev;
mutex_init(&nxp->lock);
gc = &nxp->gpio_chip;
gc->direction_input = nxp_74hc153_direction_input;
gc->direction_output = nxp_74hc153_direction_output;
gc->get = nxp_74hc153_get_value;
gc->set = nxp_74hc153_set_value;
gc->can_sleep = 1;
gc->base = pdata->gpio_base;
gc->ngpio = NXP_74HC153_NUM_GPIOS;
gc->label = dev_name(nxp->parent);
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
gc->dev = nxp->parent;
#else
gc->parent = nxp->parent;
#endif
gc->owner = THIS_MODULE;
err = gpiochip_add(&nxp->gpio_chip);
if (err) {
dev_err(&pdev->dev, "unable to add gpio chip, err=%d\n", err);
goto err_free_2y;
}
platform_set_drvdata(pdev, nxp);
return 0;
err_free_2y:
gpio_free(pdata->gpio_pin_2y);
err_free_1y:
gpio_free(pdata->gpio_pin_1y);
err_free_s1:
gpio_free(pdata->gpio_pin_s1);
err_free_s0:
gpio_free(pdata->gpio_pin_s0);
err_free_nxp:
kfree(nxp);
return err;
}
static int nxp_74hc153_remove(struct platform_device *pdev)
{
struct nxp_74hc153_chip *nxp = platform_get_drvdata(pdev);
struct nxp_74hc153_platform_data *pdata = pdev->dev.platform_data;
if (nxp) {
gpiochip_remove(&nxp->gpio_chip);
gpio_free(pdata->gpio_pin_2y);
gpio_free(pdata->gpio_pin_1y);
gpio_free(pdata->gpio_pin_s1);
gpio_free(pdata->gpio_pin_s0);
kfree(nxp);
platform_set_drvdata(pdev, NULL);
}
return 0;
}
static struct platform_driver nxp_74hc153_driver = {
.probe = nxp_74hc153_probe,
.remove = nxp_74hc153_remove,
.driver = {
.name = NXP_74HC153_DRIVER_NAME,
.owner = THIS_MODULE,
},
};
static int __init nxp_74hc153_init(void)
{
return platform_driver_register(&nxp_74hc153_driver);
}
subsys_initcall(nxp_74hc153_init);
static void __exit nxp_74hc153_exit(void)
{
platform_driver_unregister(&nxp_74hc153_driver);
}
module_exit(nxp_74hc153_exit);
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
MODULE_DESCRIPTION("GPIO expander driver for NXP 74HC153");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" NXP_74HC153_DRIVER_NAME);