MIPS: Lantiq: add SoC specific code for XWAY family

Add support for the Lantiq XWAY family of Mips24KEc SoCs.

* Danube (PSB50702)
* Twinpass (PSB4000)
* AR9 (PSB50802)
* Amazon SE (PSB5061)

The Amazon SE is a lightweight SoC and has no PCI as well as a different
clock. We split the code out into seperate files to handle this.

The GPIO pins on the SoCs are multi function and there are several bits
we can use to configure the pins. To be as compatible as possible to
GPIOLIB we add a function

int lq_gpio_request(unsigned int pin, unsigned int alt0,
        unsigned int alt1, unsigned int dir, const char *name);

which lets you configure the 2 "alternate function" bits. This way drivers like
PCI can make use of GPIOLIB without a cubersome wrapper.

The PLL code inside arch/mips/lantiq/xway/clk-xway.c is voodoo to me. It was
taken from a 2.4.20 source tree and was never really changed by me since then.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2249/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 195 insertions, 0 deletions

diff --git a/arch/mips/lantiq/xway/gpio.c b/arch/mips/lantiq/xway/gpio.c
new file mode 100644
index 0000000..a321451
--- /dev/null
+++ b/arch/mips/lantiq/xway/gpio.c
@@ -0,0 +1,195 @@
+/*
+ *  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) 2010 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+
+#include <lantiq_soc.h>
+
+#define LTQ_GPIO_OUT		0x00
+#define LTQ_GPIO_IN		0x04
+#define LTQ_GPIO_DIR		0x08
+#define LTQ_GPIO_ALTSEL0	0x0C
+#define LTQ_GPIO_ALTSEL1	0x10
+#define LTQ_GPIO_OD		0x14
+
+#define PINS_PER_PORT		16
+#define MAX_PORTS		3
+
+#define ltq_gpio_getbit(m, r, p)	(!!(ltq_r32(m + r) & (1 << p)))
+#define ltq_gpio_setbit(m, r, p)	ltq_w32_mask(0, (1 << p), m + r)
+#define ltq_gpio_clearbit(m, r, p)	ltq_w32_mask((1 << p), 0, m + r)
+
+struct ltq_gpio {
+	void __iomem *membase;
+	struct gpio_chip chip;
+};
+
+static struct ltq_gpio ltq_gpio_port[MAX_PORTS];
+
+int gpio_to_irq(unsigned int gpio)
+{
+	return -EINVAL;
+}
+EXPORT_SYMBOL(gpio_to_irq);
+
+int irq_to_gpio(unsigned int gpio)
+{
+	return -EINVAL;
+}
+EXPORT_SYMBOL(irq_to_gpio);
+
+int ltq_gpio_request(unsigned int pin, unsigned int alt0,
+	unsigned int alt1, unsigned int dir, const char *name)
+{
+	int id = 0;
+
+	if (pin >= (MAX_PORTS * PINS_PER_PORT))
+		return -EINVAL;
+	if (gpio_request(pin, name)) {
+		pr_err("failed to setup lantiq gpio: %s\n", name);
+		return -EBUSY;
+	}
+	if (dir)
+		gpio_direction_output(pin, 1);
+	else
+		gpio_direction_input(pin);
+	while (pin >= PINS_PER_PORT) {
+		pin -= PINS_PER_PORT;
+		id++;
+	}
+	if (alt0)
+		ltq_gpio_setbit(ltq_gpio_port[id].membase,
+			LTQ_GPIO_ALTSEL0, pin);
+	else
+		ltq_gpio_clearbit(ltq_gpio_port[id].membase,
+			LTQ_GPIO_ALTSEL0, pin);
+	if (alt1)
+		ltq_gpio_setbit(ltq_gpio_port[id].membase,
+			LTQ_GPIO_ALTSEL1, pin);
+	else
+		ltq_gpio_clearbit(ltq_gpio_port[id].membase,
+			LTQ_GPIO_ALTSEL1, pin);
+	return 0;
+}
+EXPORT_SYMBOL(ltq_gpio_request);
+
+static void ltq_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
+{
+	struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
+
+	if (value)
+		ltq_gpio_setbit(ltq_gpio->membase, LTQ_GPIO_OUT, offset);
+	else
+		ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_OUT, offset);
+}
+
+static int ltq_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
+
+	return ltq_gpio_getbit(ltq_gpio->membase, LTQ_GPIO_IN, offset);
+}
+
+static int ltq_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
+{
+	struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
+
+	ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_OD, offset);
+	ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_DIR, offset);
+
+	return 0;
+}
+
+static int ltq_gpio_direction_output(struct gpio_chip *chip,
+	unsigned int offset, int value)
+{
+	struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
+
+	ltq_gpio_setbit(ltq_gpio->membase, LTQ_GPIO_OD, offset);
+	ltq_gpio_setbit(ltq_gpio->membase, LTQ_GPIO_DIR, offset);
+	ltq_gpio_set(chip, offset, value);
+
+	return 0;
+}
+
+static int ltq_gpio_req(struct gpio_chip *chip, unsigned offset)
+{
+	struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
+
+	ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_ALTSEL0, offset);
+	ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_ALTSEL1, offset);
+	return 0;
+}
+
+static int ltq_gpio_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+
+	if (pdev->id >= MAX_PORTS) {
+		dev_err(&pdev->dev, "invalid gpio port %d\n",
+			pdev->id);
+		return -EINVAL;
+	}
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "failed to get memory for gpio port %d\n",
+			pdev->id);
+		return -ENOENT;
+	}
+	res = devm_request_mem_region(&pdev->dev, res->start,
+		resource_size(res), dev_name(&pdev->dev));
+	if (!res) {
+		dev_err(&pdev->dev,
+			"failed to request memory for gpio port %d\n",
+			pdev->id);
+		return -EBUSY;
+	}
+	ltq_gpio_port[pdev->id].membase = devm_ioremap_nocache(&pdev->dev,
+		res->start, resource_size(res));
+	if (!ltq_gpio_port[pdev->id].membase) {
+		dev_err(&pdev->dev, "failed to remap memory for gpio port %d\n",
+			pdev->id);
+		return -ENOMEM;
+	}
+	ltq_gpio_port[pdev->id].chip.label = "ltq_gpio";
+	ltq_gpio_port[pdev->id].chip.direction_input = ltq_gpio_direction_input;
+	ltq_gpio_port[pdev->id].chip.direction_output =
+		ltq_gpio_direction_output;
+	ltq_gpio_port[pdev->id].chip.get = ltq_gpio_get;
+	ltq_gpio_port[pdev->id].chip.set = ltq_gpio_set;
+	ltq_gpio_port[pdev->id].chip.request = ltq_gpio_req;
+	ltq_gpio_port[pdev->id].chip.base = PINS_PER_PORT * pdev->id;
+	ltq_gpio_port[pdev->id].chip.ngpio = PINS_PER_PORT;
+	platform_set_drvdata(pdev, &ltq_gpio_port[pdev->id]);
+	return gpiochip_add(&ltq_gpio_port[pdev->id].chip);
+}
+
+static struct platform_driver
+ltq_gpio_driver = {
+	.probe = ltq_gpio_probe,
+	.driver = {
+		.name = "ltq_gpio",
+		.owner = THIS_MODULE,
+	},
+};
+
+int __init ltq_gpio_init(void)
+{
+	int ret = platform_driver_register(&ltq_gpio_driver);
+
+	if (ret)
+		pr_info("ltq_gpio : Error registering platfom driver!");
+	return ret;
+}
+
+postcore_initcall(ltq_gpio_init);