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path: root/drivers/parrot/gpio/p7mu-gpio.c
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Diffstat (limited to 'drivers/parrot/gpio/p7mu-gpio.c')
-rw-r--r--drivers/parrot/gpio/p7mu-gpio.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/drivers/parrot/gpio/p7mu-gpio.c b/drivers/parrot/gpio/p7mu-gpio.c
new file mode 100644
index 00000000000000..fa55dc92b939df
--- /dev/null
+++ b/drivers/parrot/gpio/p7mu-gpio.c
@@ -0,0 +1,301 @@
+/**
+ * linux/drivers/parrot/gpio/p7mu-gpio.c - Parrot7 power management unit GPIOs
+ * implementation
+ *
+ * Copyright (C) 2012 Parrot S.A.
+ *
+ *
+ * This file is released under the GPL
+ *
+ */
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/gpio.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <mfd/p7mu-pin.h>
+
+DEFINE_MUTEX( p7mu_gpio_lck);
+static struct resource const* p7mu_gpio_res;
+
+struct p7mu_gpio_chip {
+ struct gpio_chip gpio_chip;
+};
+
+
+#ifdef DEBUG
+#define P7MU_ASSERT_GPIO(_chip, _gpio) \
+ BUG_ON(! p7mu_gpio_res); \
+ BUG_ON(_gpio >= _chip->ngpio)
+#else
+#define P7MU_ASSERT_GPIO(_chip, _gpio)
+#endif
+
+/*
+ * Reserve GPIO line for future usage.
+ */
+static int p7mu_request_gpio(struct gpio_chip* chip, unsigned int gpio)
+{
+ P7MU_ASSERT_GPIO(chip, gpio);
+
+ /* Forward call to P7MU pin management layer. */
+ return p7mu_request_pin(gpio, P7MU_INGPIO_MUX);
+}
+
+/*
+ * Release GPIO line previously reserved with p7mu_request_gpio.
+ */
+static void p7mu_free_gpio(struct gpio_chip* chip, unsigned int gpio)
+{
+ P7MU_ASSERT_GPIO(chip, gpio);
+
+ /* Forward call to P7MU pin management layer. */
+ p7mu_free_pin(gpio);
+}
+
+/*
+ * Switch GPIO line to input mode.
+ */
+static int p7mu_gpio_input(struct gpio_chip* chip, unsigned int gpio)
+{
+ P7MU_ASSERT_GPIO(chip, gpio);
+
+ /* Forward call to P7MU pin management layer. */
+ return p7mu_setup_pin(gpio, P7MU_INGPIO_MUX);
+}
+
+/*
+ * Retrieve current value of GPIO line passed in argument.
+ */
+static int p7mu_get_gpio(struct gpio_chip* chip, unsigned int gpio)
+{
+ int val;
+ int err;
+ u16 p7mu_gpio_val;
+
+ P7MU_ASSERT_GPIO(chip, gpio);
+
+ err = p7mu_read16(p7mu_gpio_res->start, &p7mu_gpio_val);
+
+ if (err)
+ return err;
+
+ val = !! (p7mu_gpio_val & (u16) (1U << gpio));
+
+ return val;
+}
+
+/*
+ * Set current value of GPIO line passed in argument.
+ */
+static void p7mu_set_gpio(struct gpio_chip* chip,
+ unsigned int gpio,
+ int value)
+{
+ int err;
+ u16 p7mu_gpio_val;
+
+ P7MU_ASSERT_GPIO(chip, gpio);
+
+ mutex_lock(&p7mu_gpio_lck);
+
+ /* Fetch all GPIO lines values. */
+ err = p7mu_read16(p7mu_gpio_res->start, &p7mu_gpio_val);
+ if (err) {
+ goto err;
+ }
+
+ /* Update GPIO line value. */
+ if (value)
+ p7mu_gpio_val |= 1U << gpio;
+ else
+ p7mu_gpio_val &= ~(1U << gpio);
+
+ err = p7mu_write16(p7mu_gpio_res->start, p7mu_gpio_val);
+ if (! err)
+ /* Success */
+ goto unlock;
+
+err:
+ dev_warn(chip->dev,
+ "failed to set GPIO %d value (%d)\n",
+ gpio,
+ err);
+unlock:
+ mutex_unlock(&p7mu_gpio_lck);
+}
+
+/*
+ * Switch GPIO line to output mode.
+ */
+static int p7mu_gpio_output(struct gpio_chip* chip, unsigned int gpio, int value)
+{
+ int err;
+
+ P7MU_ASSERT_GPIO(chip, gpio);
+
+ err = p7mu_setup_pin(gpio, P7MU_OUTGPIO_MUX);
+ if (err)
+ return err;
+
+ p7mu_set_gpio(chip, gpio, value);
+ return 0;
+}
+
+static int p7mu_gpio2irq(struct gpio_chip* chip, unsigned int gpio)
+{
+ return p7mu_gpio_to_irq(gpio);
+}
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/seq_file.h>
+
+/*
+ * Show requested GPIO lines current state.
+ */
+static void p7mu_show_gpio(struct seq_file* seq, struct gpio_chip* chip)
+{
+ unsigned int gpio;
+
+ for (gpio = 0; gpio < chip->ngpio; gpio++) {
+ char const* const label = gpiochip_is_requested(chip, gpio);
+
+ P7MU_ASSERT_GPIO(chip, gpio);
+
+ if (label) {
+ char const* dir = dir;
+ int irq;
+
+ switch (p7mu_pin_mux(gpio)) {
+ case P7MU_INGPIO_MUX:
+ dir = "in ";
+ break;
+
+ case P7MU_OUTGPIO_MUX:
+ dir = "out";
+ break;
+#ifdef DEBUG
+ default:
+ BUG();
+#endif
+ }
+
+ seq_printf(seq,
+ " gpio-%-3d (%-20.20s) %s %s",
+ chip->base + gpio,
+ label,
+ dir,
+ p7mu_get_gpio(chip, gpio) ? "hi" : "lo");
+
+ irq = gpio_to_irq(chip->base + gpio);
+ if (irq >= 0)
+ seq_printf(seq, " [IRQ %d]", irq);
+
+ seq_printf(seq, "\n");
+ }
+ }
+}
+
+#define P7MU_SHOW_GPIO p7mu_show_gpio
+
+#else /* CONFIG_DEBUG_FS */
+
+#define P7MU_SHOW_GPIO NULL
+
+#endif /* CONFIG_DEBUG_FS */
+
+#define P7MU_GPIO_DRV_NAME "p7mu-gpio"
+
+static struct p7mu_gpio_chip p7mu_gpio_chip
+= {
+ .gpio_chip = {
+ .label = P7MU_GPIO_DRV_NAME,
+ .request = p7mu_request_gpio,
+ .free = p7mu_free_gpio,
+ .direction_input = p7mu_gpio_input,
+ .get = p7mu_get_gpio,
+ .direction_output = p7mu_gpio_output,
+ .set = p7mu_set_gpio,
+ .base = P7MU_FIRST_GPIO,
+ .to_irq = p7mu_gpio2irq,
+ .ngpio = P7MU_GPIOS_MAX,
+ .dbg_show = P7MU_SHOW_GPIO,
+ .can_sleep = 1,
+ },
+};
+
+static int __devinit p7mu_probe_gpio(struct platform_device* pdev)
+{
+ int err;
+
+ p7mu_gpio_res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (! p7mu_gpio_res) {
+ dev_err(&pdev->dev, "failed to find I/O region address\n");
+ err = -ENXIO;
+ goto err;
+ }
+
+ p7mu_gpio_res = p7mu_request_region(pdev, p7mu_gpio_res);
+ if (IS_ERR(p7mu_gpio_res)) {
+ err = PTR_ERR(p7mu_gpio_res);
+ goto err;
+ }
+
+ p7mu_gpio_chip.gpio_chip.dev = &pdev->dev;
+ err = gpiochip_add(&p7mu_gpio_chip.gpio_chip);
+ if (! err)
+ return 0;
+
+ p7mu_release_region(p7mu_gpio_res);
+
+err:
+ dev_err(&pdev->dev,
+ "failed to register gpio chip (%d)\n",
+ err);
+ return err;
+}
+
+static int __devexit p7mu_remove_gpio(struct platform_device* pdev)
+{
+ int const err = gpiochip_remove(&p7mu_gpio_chip.gpio_chip);
+ if (err) {
+ dev_err(&pdev->dev,
+ "failed to unregister gpio chip (%d)\n",
+ err);
+ return err;
+ }
+
+#ifdef DEBUG
+ BUG_ON(! p7mu_gpio_res);
+ BUG_ON(IS_ERR(p7mu_gpio_res));
+#endif
+ p7mu_release_region(p7mu_gpio_res);
+
+ return 0;
+}
+
+static struct platform_driver p7mu_gpio_driver = {
+ .driver = {
+ .name = P7MU_GPIO_DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = p7mu_probe_gpio,
+ .remove = __devexit_p(&p7mu_remove_gpio),
+};
+
+static int __init p7mu_init_gpio(void)
+{
+ return platform_driver_register(&p7mu_gpio_driver);
+}
+postcore_initcall(p7mu_init_gpio);
+
+static void __exit p7mu_exit_gpio(void)
+{
+ platform_driver_unregister(&p7mu_gpio_driver);
+}
+module_exit(p7mu_exit_gpio);
+
+MODULE_DESCRIPTION("Parrot Power Management Unit GPIO driver");
+MODULE_AUTHOR("Grégor Boirie <gregor.boirie@parrot.com>");
+MODULE_LICENSE("GPL");
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-29 08:11:23 +0000