1 files changed, 163 insertions, 0 deletions

diff --git a/kernel/drivers/gpio/gpio-mm-lantiq.c b/kernel/drivers/gpio/gpio-mm-lantiq.c
new file mode 100644
index 000000000..f67ef2283
--- /dev/null
+++ b/kernel/drivers/gpio/gpio-mm-lantiq.c
@@ -0,0 +1,163 @@
+/*
+ *  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.
+ *
+ *  Copyright (C) 2012 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include <lantiq_soc.h>
+
+/*
+ * By attaching hardware latches to the EBU it is possible to create output
+ * only gpios. This driver configures a special memory address, which when
+ * written to outputs 16 bit to the latches.
+ */
+
+#define LTQ_EBU_BUSCON	0x1e7ff		/* 16 bit access, slowest timing */
+#define LTQ_EBU_WP	0x80000000	/* write protect bit */
+
+struct ltq_mm {
+	struct of_mm_gpio_chip mmchip;
+	u16 shadow;	/* shadow the latches state */
+};
+
+/**
+ * ltq_mm_apply() - write the shadow value to the ebu address.
+ * @chip:     Pointer to our private data structure.
+ *
+ * Write the shadow value to the EBU to set the gpios. We need to set the
+ * global EBU lock to make sure that PCI/MTD dont break.
+ */
+static void ltq_mm_apply(struct ltq_mm *chip)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ebu_lock, flags);
+	ltq_ebu_w32(LTQ_EBU_BUSCON, LTQ_EBU_BUSCON1);
+	__raw_writew(chip->shadow, chip->mmchip.regs);
+	ltq_ebu_w32(LTQ_EBU_BUSCON | LTQ_EBU_WP, LTQ_EBU_BUSCON1);
+	spin_unlock_irqrestore(&ebu_lock, flags);
+}
+
+/**
+ * ltq_mm_set() - gpio_chip->set - set gpios.
+ * @gc:     Pointer to gpio_chip device structure.
+ * @gpio:   GPIO signal number.
+ * @val:    Value to be written to specified signal.
+ *
+ * Set the shadow value and call ltq_mm_apply.
+ */
+static void ltq_mm_set(struct gpio_chip *gc, unsigned offset, int value)
+{
+	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+	struct ltq_mm *chip =
+		container_of(mm_gc, struct ltq_mm, mmchip);
+
+	if (value)
+		chip->shadow |= (1 << offset);
+	else
+		chip->shadow &= ~(1 << offset);
+	ltq_mm_apply(chip);
+}
+
+/**
+ * ltq_mm_dir_out() - gpio_chip->dir_out - set gpio direction.
+ * @gc:     Pointer to gpio_chip device structure.
+ * @gpio:   GPIO signal number.
+ * @val:    Value to be written to specified signal.
+ *
+ * Same as ltq_mm_set, always returns 0.
+ */
+static int ltq_mm_dir_out(struct gpio_chip *gc, unsigned offset, int value)
+{
+	ltq_mm_set(gc, offset, value);
+
+	return 0;
+}
+
+/**
+ * ltq_mm_save_regs() - Set initial values of GPIO pins
+ * @mm_gc: pointer to memory mapped GPIO chip structure
+ */
+static void ltq_mm_save_regs(struct of_mm_gpio_chip *mm_gc)
+{
+	struct ltq_mm *chip =
+		container_of(mm_gc, struct ltq_mm, mmchip);
+
+	/* tell the ebu controller which memory address we will be using */
+	ltq_ebu_w32(CPHYSADDR(chip->mmchip.regs) | 0x1, LTQ_EBU_ADDRSEL1);
+
+	ltq_mm_apply(chip);
+}
+
+static int ltq_mm_probe(struct platform_device *pdev)
+{
+	struct ltq_mm *chip;
+	u32 shadow;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, chip);
+
+	chip->mmchip.gc.ngpio = 16;
+	chip->mmchip.gc.direction_output = ltq_mm_dir_out;
+	chip->mmchip.gc.set = ltq_mm_set;
+	chip->mmchip.save_regs = ltq_mm_save_regs;
+
+	/* store the shadow value if one was passed by the devicetree */
+	if (!of_property_read_u32(pdev->dev.of_node, "lantiq,shadow", &shadow))
+		chip->shadow = shadow;
+
+	return of_mm_gpiochip_add(pdev->dev.of_node, &chip->mmchip);
+}
+
+static int ltq_mm_remove(struct platform_device *pdev)
+{
+	struct ltq_mm *chip = platform_get_drvdata(pdev);
+
+	of_mm_gpiochip_remove(&chip->mmchip);
+
+	return 0;
+}
+
+static const struct of_device_id ltq_mm_match[] = {
+	{ .compatible = "lantiq,gpio-mm" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ltq_mm_match);
+
+static struct platform_driver ltq_mm_driver = {
+	.probe = ltq_mm_probe,
+	.remove = ltq_mm_remove,
+	.driver = {
+		.name = "gpio-mm-ltq",
+		.of_match_table = ltq_mm_match,
+	},
+};
+
+static int __init ltq_mm_init(void)
+{
+	return platform_driver_register(&ltq_mm_driver);
+}
+
+subsys_initcall(ltq_mm_init);
+
+static void __exit ltq_mm_exit(void)
+{
+	platform_driver_unregister(&ltq_mm_driver);
+}
+module_exit(ltq_mm_exit);