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authorLinus Walleij <linus.walleij@linaro.org>2017-01-22 15:18:44 +0300
committerLinus Walleij <linus.walleij@linaro.org>2017-01-26 12:00:24 +0300
commit49cec4d8326b27e64779f888c680466d7863558f (patch)
treeea78741c8fb34c61d47e8d2b6cfeea84f8187c91 /drivers/gpio
parent284864f990ac3e186fb5beb4b0d5b3188fe8f225 (diff)
downloadlinux-49cec4d8326b27e64779f888c680466d7863558f.tar.xz
gpio: Add a driver for Cortina Systems Gemini GPIO
This is a heavy edit/rewrite of the GPIO driver for the Gemini SoC from arch/arm/mach-gemini/gpio.c. This rewrite uses all the best-in-class helper like generic GPIO and GPIOLIB_IRQCHIP and has been tested on ITian Square One Gemini-based NAS/router. Cc: Janos Laube <janos.dev@gmail.com> Cc: Paulius Zaleckas <paulius.zaleckas@gmail.com> Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/Kconfig9
-rw-r--r--drivers/gpio/Makefile1
-rw-r--r--drivers/gpio/gpio-gemini.c236
3 files changed, 246 insertions, 0 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d5d36549ecc1..701809b1a105 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -197,6 +197,15 @@ config GPIO_GE_FPGA
and write pin state) for GPIO implemented in a number of GE single
board computers.
+config GPIO_GEMINI
+ bool "Gemini GPIO"
+ depends on ARCH_GEMINI
+ depends on OF_GPIO
+ select GPIO_GENERIC
+ select GPIOLIB_IRQCHIP
+ help
+ Support for common GPIOs found in Cortina systems Gemini platforms.
+
config GPIO_GENERIC_PLATFORM
tristate "Generic memory-mapped GPIO controller support (MMIO platform device)"
select GPIO_GENERIC
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index a7676b82de6f..de45957b9b62 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o
obj-$(CONFIG_GPIO_ETRAXFS) += gpio-etraxfs.o
obj-$(CONFIG_GPIO_F7188X) += gpio-f7188x.o
obj-$(CONFIG_GPIO_GE_FPGA) += gpio-ge.o
+obj-$(CONFIG_GPIO_GEMINI) += gpio-gemini.o
obj-$(CONFIG_GPIO_GPIO_MM) += gpio-gpio-mm.o
obj-$(CONFIG_GPIO_GRGPIO) += gpio-grgpio.o
obj-$(CONFIG_HTC_EGPIO) += gpio-htc-egpio.o
diff --git a/drivers/gpio/gpio-gemini.c b/drivers/gpio/gpio-gemini.c
new file mode 100644
index 000000000000..962485163b7f
--- /dev/null
+++ b/drivers/gpio/gpio-gemini.c
@@ -0,0 +1,236 @@
+/*
+ * Gemini gpiochip and interrupt routines
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Based on arch/arm/mach-gemini/gpio.c:
+ * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ *
+ * Based on plat-mxc/gpio.c:
+ * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
+ * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
+ */
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/of_gpio.h>
+#include <linux/bitops.h>
+
+/* GPIO registers definition */
+#define GPIO_DATA_OUT 0x00
+#define GPIO_DATA_IN 0x04
+#define GPIO_DIR 0x08
+#define GPIO_DATA_SET 0x10
+#define GPIO_DATA_CLR 0x14
+#define GPIO_PULL_EN 0x18
+#define GPIO_PULL_TYPE 0x1C
+#define GPIO_INT_EN 0x20
+#define GPIO_INT_STAT 0x24
+#define GPIO_INT_MASK 0x2C
+#define GPIO_INT_CLR 0x30
+#define GPIO_INT_TYPE 0x34
+#define GPIO_INT_BOTH_EDGE 0x38
+#define GPIO_INT_LEVEL 0x3C
+#define GPIO_DEBOUNCE_EN 0x40
+#define GPIO_DEBOUNCE_PRESCALE 0x44
+
+/**
+ * struct gemini_gpio - Gemini GPIO state container
+ * @dev: containing device for this instance
+ * @gc: gpiochip for this instance
+ */
+struct gemini_gpio {
+ struct device *dev;
+ struct gpio_chip gc;
+ void __iomem *base;
+};
+
+static void gemini_gpio_ack_irq(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct gemini_gpio *g = gpiochip_get_data(gc);
+
+ writel(BIT(irqd_to_hwirq(d)), g->base + GPIO_INT_CLR);
+}
+
+static void gemini_gpio_mask_irq(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct gemini_gpio *g = gpiochip_get_data(gc);
+ u32 val;
+
+ val = readl(g->base + GPIO_INT_EN);
+ val &= ~BIT(irqd_to_hwirq(d));
+ writel(val, g->base + GPIO_INT_EN);
+}
+
+static void gemini_gpio_unmask_irq(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct gemini_gpio *g = gpiochip_get_data(gc);
+ u32 val;
+
+ val = readl(g->base + GPIO_INT_EN);
+ val |= BIT(irqd_to_hwirq(d));
+ writel(val, g->base + GPIO_INT_EN);
+}
+
+static int gemini_gpio_set_irq_type(struct irq_data *d, unsigned int type)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct gemini_gpio *g = gpiochip_get_data(gc);
+ u32 mask = BIT(irqd_to_hwirq(d));
+ u32 reg_both, reg_level, reg_type;
+
+ reg_type = readl(g->base + GPIO_INT_TYPE);
+ reg_level = readl(g->base + GPIO_INT_LEVEL);
+ reg_both = readl(g->base + GPIO_INT_BOTH_EDGE);
+
+ switch (type) {
+ case IRQ_TYPE_EDGE_BOTH:
+ irq_set_handler_locked(d, handle_edge_irq);
+ reg_type &= ~mask;
+ reg_both |= mask;
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ irq_set_handler_locked(d, handle_edge_irq);
+ reg_type &= ~mask;
+ reg_both &= ~mask;
+ reg_level &= ~mask;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ irq_set_handler_locked(d, handle_edge_irq);
+ reg_type &= ~mask;
+ reg_both &= ~mask;
+ reg_level |= mask;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ irq_set_handler_locked(d, handle_level_irq);
+ reg_type |= mask;
+ reg_level &= ~mask;
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ irq_set_handler_locked(d, handle_level_irq);
+ reg_type |= mask;
+ reg_level |= mask;
+ break;
+ default:
+ irq_set_handler_locked(d, handle_bad_irq);
+ return -EINVAL;
+ }
+
+ writel(reg_type, g->base + GPIO_INT_TYPE);
+ writel(reg_level, g->base + GPIO_INT_LEVEL);
+ writel(reg_both, g->base + GPIO_INT_BOTH_EDGE);
+
+ gemini_gpio_ack_irq(d);
+
+ return 0;
+}
+
+static struct irq_chip gemini_gpio_irqchip = {
+ .name = "GPIO",
+ .irq_ack = gemini_gpio_ack_irq,
+ .irq_mask = gemini_gpio_mask_irq,
+ .irq_unmask = gemini_gpio_unmask_irq,
+ .irq_set_type = gemini_gpio_set_irq_type,
+};
+
+static void gemini_gpio_irq_handler(struct irq_desc *desc)
+{
+ struct gpio_chip *gc = irq_desc_get_handler_data(desc);
+ struct gemini_gpio *g = gpiochip_get_data(gc);
+ struct irq_chip *irqchip = irq_desc_get_chip(desc);
+ int offset;
+ unsigned long stat;
+
+ chained_irq_enter(irqchip, desc);
+
+ stat = readl(g->base + GPIO_INT_STAT);
+ if (stat)
+ for_each_set_bit(offset, &stat, gc->ngpio)
+ generic_handle_irq(irq_find_mapping(gc->irqdomain,
+ offset));
+
+ chained_irq_exit(irqchip, desc);
+}
+
+static int gemini_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ struct gemini_gpio *g;
+ int irq;
+ int ret;
+
+ g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
+ if (!g)
+ return -ENOMEM;
+
+ g->dev = dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ g->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(g->base))
+ return PTR_ERR(g->base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (!irq)
+ return -EINVAL;
+
+ ret = bgpio_init(&g->gc, dev, 4,
+ g->base + GPIO_DATA_IN,
+ g->base + GPIO_DATA_SET,
+ g->base + GPIO_DATA_CLR,
+ g->base + GPIO_DIR,
+ NULL,
+ 0);
+ if (ret) {
+ dev_err(dev, "unable to init generic GPIO\n");
+ return ret;
+ }
+ g->gc.label = "Gemini";
+ g->gc.base = -1;
+ g->gc.parent = dev;
+ g->gc.owner = THIS_MODULE;
+ /* ngpio is set by bgpio_init() */
+
+ ret = devm_gpiochip_add_data(dev, &g->gc, g);
+ if (ret)
+ return ret;
+
+ /* Disable, unmask and clear all interrupts */
+ writel(0x0, g->base + GPIO_INT_EN);
+ writel(0x0, g->base + GPIO_INT_MASK);
+ writel(~0x0, g->base + GPIO_INT_CLR);
+
+ ret = gpiochip_irqchip_add(&g->gc, &gemini_gpio_irqchip,
+ 0, handle_bad_irq,
+ IRQ_TYPE_NONE);
+ if (ret) {
+ dev_info(dev, "could not add irqchip\n");
+ return ret;
+ }
+ gpiochip_set_chained_irqchip(&g->gc, &gemini_gpio_irqchip,
+ irq, gemini_gpio_irq_handler);
+
+ dev_info(dev, "Gemini GPIO @%p registered\n", g->base);
+
+ return 0;
+}
+
+static const struct of_device_id gemini_gpio_of_match[] = {
+ {
+ .compatible = "cortina,gemini-gpio",
+ },
+ {},
+};
+
+static struct platform_driver gemini_gpio_driver = {
+ .driver = {
+ .name = "gemini-gpio",
+ .of_match_table = of_match_ptr(gemini_gpio_of_match),
+ },
+ .probe = gemini_gpio_probe,
+};
+builtin_platform_driver(gemini_gpio_driver);