diff options
Diffstat (limited to 'drivers/misc/c55_ctrl.c')
| -rw-r--r-- | drivers/misc/c55_ctrl.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/drivers/misc/c55_ctrl.c b/drivers/misc/c55_ctrl.c new file mode 100644 index 00000000000..04f29d3ff9a --- /dev/null +++ b/drivers/misc/c55_ctrl.c @@ -0,0 +1,191 @@ +/* + * Copyright (C) 2013 Motorola Mobility LLC + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/err.h> +#include <linux/gpio.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/wakelock.h> +#include <linux/of.h> +#include <linux/of_gpio.h> +#include <linux/clk.h> + +struct c55_ctrl_data { + int int_gpio; + struct wake_lock wake_lock; +}; + +#define NUM_GPIOS 3 + +const char *gpio_labels[NUM_GPIOS] = { + "gpio_ap_int", + "gpio_reset", + "gpio_c55_int" +}; + +static irqreturn_t c55_ctrl_isr(int irq, void *data) +{ + struct c55_ctrl_data *cdata = data; + + pr_debug("%s: value=%d\n", __func__, gpio_get_value(cdata->int_gpio)); + + /* Interrupt is active low */ + if (gpio_get_value(cdata->int_gpio) == 0) + wake_lock(&cdata->wake_lock); + else + wake_unlock(&cdata->wake_lock); + + return IRQ_HANDLED; +} + +static void c55_ctrl_int_setup(struct c55_ctrl_data *cdata, int gpio) +{ + int ret; + int irq = __gpio_to_irq(gpio); + unsigned int flags = 0; + + if (cdata->int_gpio >= 0) { + /* Interrupt already registered */ + return; + } + + /* Interrupt is shared with user space */ + flags |= IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING; + flags |= IRQF_SHARED|IRQF_ONESHOT; + + ret = request_threaded_irq(irq, NULL, c55_ctrl_isr, + flags, "c55_ctrl", cdata); + if (ret) { + pr_err("%s: IRQ request failed: %d\n", __func__, ret); + return; + } + + enable_irq_wake(irq); + cdata->int_gpio = gpio; +} + +static int c55_ctrl_gpio_setup(struct c55_ctrl_data *cdata, struct device *dev) +{ + int i; + + if (of_gpio_count(dev->of_node) != NUM_GPIOS) { + dev_err(dev, "%s: gpio count is not %d.\n", __func__, NUM_GPIOS); + return -EINVAL; + } + + for (i = 0; i < NUM_GPIOS; i++) { + enum of_gpio_flags flags; + int gpio; + + gpio = of_get_gpio_flags(dev->of_node, i, &flags); + if (gpio < 0) { + pr_err("%s: of_get_gpio failed: %d\n", __func__, gpio); + return gpio; + } + + gpio_request(gpio, gpio_labels[i]); + + gpio_export(gpio, false); + gpio_export_link(dev, gpio_labels[i], gpio); + + if ((flags & GPIOF_IN) == GPIOF_IN) { + gpio_direction_input(gpio); + c55_ctrl_int_setup(cdata, gpio); + } else { + if ((flags & GPIOF_OUT_INIT_HIGH) == GPIOF_OUT_INIT_HIGH) + gpio_direction_output(gpio, 1); + else + gpio_direction_output(gpio, 0); + } + } + + return 0; +} + +static int c55_ctrl_probe(struct platform_device *pdev) +{ + struct c55_ctrl_data *cdata; + int ret; + if (!pdev->dev.of_node) { + /* Platform data not currently supported */ + dev_err(&pdev->dev, "%s: of devtree data not found\n", __func__); + return -EINVAL; + } + + cdata = devm_kzalloc(&pdev->dev, sizeof(*cdata), GFP_KERNEL); + if (cdata == NULL) { + dev_err(&pdev->dev, "%s: devm_kzalloc failed.\n", __func__); + return -ENOMEM; + } + cdata->int_gpio = -1; + ret = c55_ctrl_gpio_setup(cdata, &pdev->dev); + + if (ret) { + dev_err(&pdev->dev, "%s: c55_ctrl_gpio_setup failed.\n", __func__); + return ret; + } + + wake_lock_init(&cdata->wake_lock, WAKE_LOCK_SUSPEND, "c55_ctrl"); + + platform_set_drvdata(pdev, cdata); + return 0; +} + +static int c55_ctrl_remove(struct platform_device *pdev) +{ + return 0; +} + +static struct of_device_id c55_ctrl_match[] = { + {.compatible = "ti,c55-ctrl",}, + {}, +}; +MODULE_DEVICE_TABLE(of, c55_ctrl_match); + +static const struct platform_device_id c55_ctrl_id_table[] = { + {"c55_ctrl", 0}, + {}, +}; +MODULE_DEVICE_TABLE(of, c55_ctrl_id_table); + +static struct platform_driver c55_ctrl_driver = { + .driver = { + .name = "c55_ctrl", + .owner = THIS_MODULE, + .of_match_table = c55_ctrl_match, + }, + .probe = c55_ctrl_probe, + .remove = c55_ctrl_remove, + .id_table = c55_ctrl_id_table, +}; + +static int __init c55_ctrl_init(void) +{ + return platform_driver_register(&c55_ctrl_driver); +} + +static void __exit c55_ctrl_exit(void) +{ + platform_driver_unregister(&c55_ctrl_driver); +} + +module_init(c55_ctrl_init); +module_exit(c55_ctrl_exit); + +MODULE_ALIAS("platform:c55_ctrl"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Motorola"); +MODULE_DESCRIPTION("TI C55 control driver"); |