--- /dev/null
+/*
+ * 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/module.h>
+#include <linux/init.h>
+#include <linux/gpio.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 __devinit 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);
+ gc->dev = nxp->parent;
+ 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) {
+ int err;
+
+ err = gpiochip_remove(&nxp->gpio_chip);
+ if (err) {
+ dev_err(&pdev->dev,
+ "unable to remove gpio chip, err=%d\n",
+ err);
+ return err;
+ }
+
+ 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 = __devexit_p(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);
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