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path: root/drivers/gpio/gpio-ftgpio010.c
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Diffstat (limited to 'drivers/gpio/gpio-ftgpio010.c')
-rw-r--r--drivers/gpio/gpio-ftgpio010.c357
1 files changed, 357 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-ftgpio010.c b/drivers/gpio/gpio-ftgpio010.c
new file mode 100644
index 000000000..f77a965f5
--- /dev/null
+++ b/drivers/gpio/gpio-ftgpio010.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Faraday Technolog FTGPIO010 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/bitops.h>
+#include <linux/clk.h>
+
+/* GPIO registers definition */
+#define GPIO_DATA_OUT 0x00
+#define GPIO_DATA_IN 0x04
+#define GPIO_DIR 0x08
+#define GPIO_BYPASS_IN 0x0C
+#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_RAW 0x24
+#define GPIO_INT_STAT_MASKED 0x28
+#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 ftgpio_gpio - Gemini GPIO state container
+ * @dev: containing device for this instance
+ * @gc: gpiochip for this instance
+ * @base: remapped I/O-memory base
+ * @clk: silicon clock
+ */
+struct ftgpio_gpio {
+ struct device *dev;
+ struct gpio_chip gc;
+ void __iomem *base;
+ struct clk *clk;
+};
+
+static void ftgpio_gpio_ack_irq(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct ftgpio_gpio *g = gpiochip_get_data(gc);
+
+ writel(BIT(irqd_to_hwirq(d)), g->base + GPIO_INT_CLR);
+}
+
+static void ftgpio_gpio_mask_irq(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct ftgpio_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);
+ gpiochip_disable_irq(gc, irqd_to_hwirq(d));
+}
+
+static void ftgpio_gpio_unmask_irq(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct ftgpio_gpio *g = gpiochip_get_data(gc);
+ u32 val;
+
+ gpiochip_enable_irq(gc, irqd_to_hwirq(d));
+ val = readl(g->base + GPIO_INT_EN);
+ val |= BIT(irqd_to_hwirq(d));
+ writel(val, g->base + GPIO_INT_EN);
+}
+
+static int ftgpio_gpio_set_irq_type(struct irq_data *d, unsigned int type)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct ftgpio_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);
+
+ ftgpio_gpio_ack_irq(d);
+
+ return 0;
+}
+
+static void ftgpio_gpio_irq_handler(struct irq_desc *desc)
+{
+ struct gpio_chip *gc = irq_desc_get_handler_data(desc);
+ struct ftgpio_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_RAW);
+ if (stat)
+ for_each_set_bit(offset, &stat, gc->ngpio)
+ generic_handle_domain_irq(gc->irq.domain, offset);
+
+ chained_irq_exit(irqchip, desc);
+}
+
+static int ftgpio_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
+ unsigned long config)
+{
+ enum pin_config_param param = pinconf_to_config_param(config);
+ u32 arg = pinconf_to_config_argument(config);
+ struct ftgpio_gpio *g = gpiochip_get_data(gc);
+ unsigned long pclk_freq;
+ u32 deb_div;
+ u32 val;
+
+ if (param != PIN_CONFIG_INPUT_DEBOUNCE)
+ return -ENOTSUPP;
+
+ /*
+ * Debounce only works if interrupts are enabled. The manual
+ * states that if PCLK is 66 MHz, and this is set to 0x7D0, then
+ * PCLK is divided down to 33 kHz for the debounce timer. 0x7D0 is
+ * 2000 decimal, so what they mean is simply that the PCLK is
+ * divided by this value.
+ *
+ * As we get a debounce setting in microseconds, we calculate the
+ * desired period time and see if we can get a suitable debounce
+ * time.
+ */
+ pclk_freq = clk_get_rate(g->clk);
+ deb_div = DIV_ROUND_CLOSEST(pclk_freq, arg);
+
+ /* This register is only 24 bits wide */
+ if (deb_div > (1 << 24))
+ return -ENOTSUPP;
+
+ dev_dbg(g->dev, "prescale divisor: %08x, resulting frequency %lu Hz\n",
+ deb_div, (pclk_freq/deb_div));
+
+ val = readl(g->base + GPIO_DEBOUNCE_PRESCALE);
+ if (val == deb_div) {
+ /*
+ * The debounce timer happens to already be set to the
+ * desirable value, what a coincidence! We can just enable
+ * debounce on this GPIO line and return. This happens more
+ * often than you think, for example when all GPIO keys
+ * on a system are requesting the same debounce interval.
+ */
+ val = readl(g->base + GPIO_DEBOUNCE_EN);
+ val |= BIT(offset);
+ writel(val, g->base + GPIO_DEBOUNCE_EN);
+ return 0;
+ }
+
+ val = readl(g->base + GPIO_DEBOUNCE_EN);
+ if (val) {
+ /*
+ * Oh no! Someone is already using the debounce with
+ * another setting than what we need. Bummer.
+ */
+ return -ENOTSUPP;
+ }
+
+ /* First come, first serve */
+ writel(deb_div, g->base + GPIO_DEBOUNCE_PRESCALE);
+ /* Enable debounce */
+ val |= BIT(offset);
+ writel(val, g->base + GPIO_DEBOUNCE_EN);
+
+ return 0;
+}
+
+static const struct irq_chip ftgpio_irq_chip = {
+ .name = "FTGPIO010",
+ .irq_ack = ftgpio_gpio_ack_irq,
+ .irq_mask = ftgpio_gpio_mask_irq,
+ .irq_unmask = ftgpio_gpio_unmask_irq,
+ .irq_set_type = ftgpio_gpio_set_irq_type,
+ .flags = IRQCHIP_IMMUTABLE,
+ GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static int ftgpio_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ftgpio_gpio *g;
+ struct gpio_irq_chip *girq;
+ int irq;
+ int ret;
+
+ g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
+ if (!g)
+ return -ENOMEM;
+
+ g->dev = dev;
+
+ g->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(g->base))
+ return PTR_ERR(g->base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq <= 0)
+ return irq ? irq : -EINVAL;
+
+ g->clk = devm_clk_get(dev, NULL);
+ if (!IS_ERR(g->clk)) {
+ ret = clk_prepare_enable(g->clk);
+ if (ret)
+ return ret;
+ } else if (PTR_ERR(g->clk) == -EPROBE_DEFER) {
+ /*
+ * Percolate deferrals, for anything else,
+ * just live without the clocking.
+ */
+ return PTR_ERR(g->clk);
+ }
+
+ 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");
+ goto dis_clk;
+ }
+ g->gc.label = "FTGPIO010";
+ g->gc.base = -1;
+ g->gc.parent = dev;
+ g->gc.owner = THIS_MODULE;
+ /* ngpio is set by bgpio_init() */
+
+ /* We need a silicon clock to do debounce */
+ if (!IS_ERR(g->clk))
+ g->gc.set_config = ftgpio_gpio_set_config;
+
+ girq = &g->gc.irq;
+ gpio_irq_chip_set_chip(girq, &ftgpio_irq_chip);
+ girq->parent_handler = ftgpio_gpio_irq_handler;
+ girq->num_parents = 1;
+ girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
+ GFP_KERNEL);
+ if (!girq->parents) {
+ ret = -ENOMEM;
+ goto dis_clk;
+ }
+ girq->default_type = IRQ_TYPE_NONE;
+ girq->handler = handle_bad_irq;
+ girq->parents[0] = irq;
+
+ /* 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);
+
+ /* Clear any use of debounce */
+ writel(0x0, g->base + GPIO_DEBOUNCE_EN);
+
+ ret = devm_gpiochip_add_data(dev, &g->gc, g);
+ if (ret)
+ goto dis_clk;
+
+ platform_set_drvdata(pdev, g);
+ dev_info(dev, "FTGPIO010 @%p registered\n", g->base);
+
+ return 0;
+
+dis_clk:
+ clk_disable_unprepare(g->clk);
+
+ return ret;
+}
+
+static int ftgpio_gpio_remove(struct platform_device *pdev)
+{
+ struct ftgpio_gpio *g = platform_get_drvdata(pdev);
+
+ clk_disable_unprepare(g->clk);
+
+ return 0;
+}
+
+static const struct of_device_id ftgpio_gpio_of_match[] = {
+ {
+ .compatible = "cortina,gemini-gpio",
+ },
+ {
+ .compatible = "moxa,moxart-gpio",
+ },
+ {
+ .compatible = "faraday,ftgpio010",
+ },
+ {},
+};
+
+static struct platform_driver ftgpio_gpio_driver = {
+ .driver = {
+ .name = "ftgpio010-gpio",
+ .of_match_table = of_match_ptr(ftgpio_gpio_of_match),
+ },
+ .probe = ftgpio_gpio_probe,
+ .remove = ftgpio_gpio_remove,
+};
+builtin_platform_driver(ftgpio_gpio_driver);