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authorJoachim Eastwood <manabian@gmail.com>2015-05-02 23:11:34 +0200
committerLinus Walleij <linus.walleij@linaro.org>2015-05-05 17:50:07 +0200
commit13a43fd9e90552c8258981d0a0eb82d73406c24d (patch)
tree0656b930ebdb98fc6d6c9232efd3762f5752bb81 /drivers/gpio/gpio-lpc18xx.c
parent67ddd32bfc9f5746e6c293154f8287278e6744ba (diff)
gpio: add lpc18xx gpio driver
Driver for the GPIO block found on NXP LPC18xx/43xx devices. Signed-off-by: Joachim Eastwood <manabian@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpio-lpc18xx.c')
-rw-r--r--drivers/gpio/gpio-lpc18xx.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-lpc18xx.c b/drivers/gpio/gpio-lpc18xx.c
new file mode 100644
index 000000000000..eb68603136b0
--- /dev/null
+++ b/drivers/gpio/gpio-lpc18xx.c
@@ -0,0 +1,180 @@
+/*
+ * GPIO driver for NXP LPC18xx/43xx.
+ *
+ * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
+ *
+ * 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/clk.h>
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+
+/* LPC18xx GPIO register offsets */
+#define LPC18XX_REG_DIR(n) (0x2000 + n * sizeof(u32))
+
+#define LPC18XX_MAX_PORTS 8
+#define LPC18XX_PINS_PER_PORT 32
+
+struct lpc18xx_gpio_chip {
+ struct gpio_chip gpio;
+ void __iomem *base;
+ struct clk *clk;
+ spinlock_t lock;
+};
+
+static inline struct lpc18xx_gpio_chip *to_lpc18xx_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct lpc18xx_gpio_chip, gpio);
+}
+
+static int lpc18xx_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+ return pinctrl_request_gpio(offset);
+}
+
+static void lpc18xx_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+ pinctrl_free_gpio(offset);
+}
+
+static void lpc18xx_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip);
+ writeb(value ? 1 : 0, gc->base + offset);
+}
+
+static int lpc18xx_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip);
+ return !!readb(gc->base + offset);
+}
+
+static int lpc18xx_gpio_direction(struct gpio_chip *chip, unsigned offset,
+ bool out)
+{
+ struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip);
+ unsigned long flags;
+ u32 port, pin, dir;
+
+ port = offset / LPC18XX_PINS_PER_PORT;
+ pin = offset % LPC18XX_PINS_PER_PORT;
+
+ spin_lock_irqsave(&gc->lock, flags);
+ dir = readl(gc->base + LPC18XX_REG_DIR(port));
+ if (out)
+ dir |= BIT(pin);
+ else
+ dir &= ~BIT(pin);
+ writel(dir, gc->base + LPC18XX_REG_DIR(port));
+ spin_unlock_irqrestore(&gc->lock, flags);
+
+ return 0;
+}
+
+static int lpc18xx_gpio_direction_input(struct gpio_chip *chip,
+ unsigned offset)
+{
+ return lpc18xx_gpio_direction(chip, offset, false);
+}
+
+static int lpc18xx_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ lpc18xx_gpio_set(chip, offset, value);
+ return lpc18xx_gpio_direction(chip, offset, true);
+}
+
+static struct gpio_chip lpc18xx_chip = {
+ .label = "lpc18xx/43xx-gpio",
+ .request = lpc18xx_gpio_request,
+ .free = lpc18xx_gpio_free,
+ .direction_input = lpc18xx_gpio_direction_input,
+ .direction_output = lpc18xx_gpio_direction_output,
+ .set = lpc18xx_gpio_set,
+ .get = lpc18xx_gpio_get,
+ .ngpio = LPC18XX_MAX_PORTS * LPC18XX_PINS_PER_PORT,
+ .owner = THIS_MODULE,
+};
+
+static int lpc18xx_gpio_probe(struct platform_device *pdev)
+{
+ struct lpc18xx_gpio_chip *gc;
+ struct resource *res;
+ int ret;
+
+ gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
+ if (!gc)
+ return -ENOMEM;
+
+ gc->gpio = lpc18xx_chip;
+ platform_set_drvdata(pdev, gc);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ gc->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(gc->base))
+ return PTR_ERR(gc->base);
+
+ gc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(gc->clk)) {
+ dev_err(&pdev->dev, "input clock not found\n");
+ return PTR_ERR(gc->clk);
+ }
+
+ ret = clk_prepare_enable(gc->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to enable clock\n");
+ return ret;
+ }
+
+ spin_lock_init(&gc->lock);
+
+ gc->gpio.dev = &pdev->dev;
+
+ ret = gpiochip_add(&gc->gpio);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to add gpio chip\n");
+ clk_disable_unprepare(gc->clk);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int lpc18xx_gpio_remove(struct platform_device *pdev)
+{
+ struct lpc18xx_gpio_chip *gc = platform_get_drvdata(pdev);
+
+ gpiochip_remove(&gc->gpio);
+ clk_disable_unprepare(gc->clk);
+
+ return 0;
+}
+
+static const struct of_device_id lpc18xx_gpio_match[] = {
+ { .compatible = "nxp,lpc1850-gpio" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, lpc18xx_gpio_match);
+
+static struct platform_driver lpc18xx_gpio_driver = {
+ .probe = lpc18xx_gpio_probe,
+ .remove = lpc18xx_gpio_remove,
+ .driver = {
+ .name = "lpc18xx-gpio",
+ .of_match_table = lpc18xx_gpio_match,
+ },
+};
+module_platform_driver(lpc18xx_gpio_driver);
+
+MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
+MODULE_DESCRIPTION("GPIO driver for LPC18xx/43xx");
+MODULE_LICENSE("GPL v2");