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path: root/drivers/gpio/gpio-ixp4xx.c
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Diffstat (limited to 'drivers/gpio/gpio-ixp4xx.c')
-rw-r--r--drivers/gpio/gpio-ixp4xx.c474
1 files changed, 474 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-ixp4xx.c b/drivers/gpio/gpio-ixp4xx.c
new file mode 100644
index 000000000000..4b1cf7ea858d
--- /dev/null
+++ b/drivers/gpio/gpio-ixp4xx.c
@@ -0,0 +1,474 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// IXP4 GPIO driver
+// Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org>
+//
+// based on previous work and know-how from:
+// Deepak Saxena <dsaxena@plexity.net>
+
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/bitops.h>
+/* Include that go away with DT transition */
+#include <linux/irqchip/irq-ixp4xx.h>
+
+#include <asm/mach-types.h>
+
+#define IXP4XX_REG_GPOUT 0x00
+#define IXP4XX_REG_GPOE 0x04
+#define IXP4XX_REG_GPIN 0x08
+#define IXP4XX_REG_GPIS 0x0C
+#define IXP4XX_REG_GPIT1 0x10
+#define IXP4XX_REG_GPIT2 0x14
+#define IXP4XX_REG_GPCLK 0x18
+#define IXP4XX_REG_GPDBSEL 0x1C
+
+/*
+ * The hardware uses 3 bits to indicate interrupt "style".
+ * we clear and set these three bits accordingly. The lower 24
+ * bits in two registers (GPIT1 and GPIT2) are used to set up
+ * the style for 8 lines each for a total of 16 GPIO lines.
+ */
+#define IXP4XX_GPIO_STYLE_ACTIVE_HIGH 0x0
+#define IXP4XX_GPIO_STYLE_ACTIVE_LOW 0x1
+#define IXP4XX_GPIO_STYLE_RISING_EDGE 0x2
+#define IXP4XX_GPIO_STYLE_FALLING_EDGE 0x3
+#define IXP4XX_GPIO_STYLE_TRANSITIONAL 0x4
+#define IXP4XX_GPIO_STYLE_MASK GENMASK(2, 0)
+#define IXP4XX_GPIO_STYLE_SIZE 3
+
+/**
+ * struct ixp4xx_gpio - IXP4 GPIO state container
+ * @dev: containing device for this instance
+ * @fwnode: the fwnode for this GPIO chip
+ * @gc: gpiochip for this instance
+ * @domain: irqdomain for this chip instance
+ * @base: remapped I/O-memory base
+ * @irq_edge: Each bit represents an IRQ: 1: edge-triggered,
+ * 0: level triggered
+ */
+struct ixp4xx_gpio {
+ struct device *dev;
+ struct fwnode_handle *fwnode;
+ struct gpio_chip gc;
+ struct irq_domain *domain;
+ void __iomem *base;
+ unsigned long long irq_edge;
+};
+
+/**
+ * struct ixp4xx_gpio_map - IXP4 GPIO to parent IRQ map
+ * @gpio_offset: offset of the IXP4 GPIO line
+ * @parent_hwirq: hwirq on the parent IRQ controller
+ */
+struct ixp4xx_gpio_map {
+ int gpio_offset;
+ int parent_hwirq;
+};
+
+/* GPIO lines 0..12 have corresponding IRQs, GPIOs 13..15 have no IRQs */
+const struct ixp4xx_gpio_map ixp4xx_gpiomap[] = {
+ { .gpio_offset = 0, .parent_hwirq = 6 },
+ { .gpio_offset = 1, .parent_hwirq = 7 },
+ { .gpio_offset = 2, .parent_hwirq = 19 },
+ { .gpio_offset = 3, .parent_hwirq = 20 },
+ { .gpio_offset = 4, .parent_hwirq = 21 },
+ { .gpio_offset = 5, .parent_hwirq = 22 },
+ { .gpio_offset = 6, .parent_hwirq = 23 },
+ { .gpio_offset = 7, .parent_hwirq = 24 },
+ { .gpio_offset = 8, .parent_hwirq = 25 },
+ { .gpio_offset = 9, .parent_hwirq = 26 },
+ { .gpio_offset = 10, .parent_hwirq = 27 },
+ { .gpio_offset = 11, .parent_hwirq = 28 },
+ { .gpio_offset = 12, .parent_hwirq = 29 },
+};
+
+static void ixp4xx_gpio_irq_ack(struct irq_data *d)
+{
+ struct ixp4xx_gpio *g = irq_data_get_irq_chip_data(d);
+
+ __raw_writel(BIT(d->hwirq), g->base + IXP4XX_REG_GPIS);
+}
+
+static void ixp4xx_gpio_irq_unmask(struct irq_data *d)
+{
+ struct ixp4xx_gpio *g = irq_data_get_irq_chip_data(d);
+
+ /* ACK when unmasking if not edge-triggered */
+ if (!(g->irq_edge & BIT(d->hwirq)))
+ ixp4xx_gpio_irq_ack(d);
+
+ irq_chip_unmask_parent(d);
+}
+
+static int ixp4xx_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct ixp4xx_gpio *g = irq_data_get_irq_chip_data(d);
+ int line = d->hwirq;
+ unsigned long flags;
+ u32 int_style;
+ u32 int_reg;
+ u32 val;
+
+ switch (type) {
+ case IRQ_TYPE_EDGE_BOTH:
+ irq_set_handler_locked(d, handle_edge_irq);
+ int_style = IXP4XX_GPIO_STYLE_TRANSITIONAL;
+ g->irq_edge |= BIT(d->hwirq);
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ irq_set_handler_locked(d, handle_edge_irq);
+ int_style = IXP4XX_GPIO_STYLE_RISING_EDGE;
+ g->irq_edge |= BIT(d->hwirq);
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ irq_set_handler_locked(d, handle_edge_irq);
+ int_style = IXP4XX_GPIO_STYLE_FALLING_EDGE;
+ g->irq_edge |= BIT(d->hwirq);
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ irq_set_handler_locked(d, handle_level_irq);
+ int_style = IXP4XX_GPIO_STYLE_ACTIVE_HIGH;
+ g->irq_edge &= ~BIT(d->hwirq);
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ irq_set_handler_locked(d, handle_level_irq);
+ int_style = IXP4XX_GPIO_STYLE_ACTIVE_LOW;
+ g->irq_edge &= ~BIT(d->hwirq);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (line >= 8) {
+ /* pins 8-15 */
+ line -= 8;
+ int_reg = IXP4XX_REG_GPIT2;
+ } else {
+ /* pins 0-7 */
+ int_reg = IXP4XX_REG_GPIT1;
+ }
+
+ spin_lock_irqsave(&g->gc.bgpio_lock, flags);
+
+ /* Clear the style for the appropriate pin */
+ val = __raw_readl(g->base + int_reg);
+ val &= ~(IXP4XX_GPIO_STYLE_MASK << (line * IXP4XX_GPIO_STYLE_SIZE));
+ __raw_writel(val, g->base + int_reg);
+
+ __raw_writel(BIT(line), g->base + IXP4XX_REG_GPIS);
+
+ /* Set the new style */
+ val = __raw_readl(g->base + int_reg);
+ val |= (int_style << (line * IXP4XX_GPIO_STYLE_SIZE));
+ __raw_writel(val, g->base + int_reg);
+
+ /* Force-configure this line as an input */
+ val = __raw_readl(g->base + IXP4XX_REG_GPOE);
+ val |= BIT(d->hwirq);
+ __raw_writel(val, g->base + IXP4XX_REG_GPOE);
+
+ spin_unlock_irqrestore(&g->gc.bgpio_lock, flags);
+
+ /* This parent only accept level high (asserted) */
+ return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
+}
+
+static struct irq_chip ixp4xx_gpio_irqchip = {
+ .name = "IXP4GPIO",
+ .irq_ack = ixp4xx_gpio_irq_ack,
+ .irq_mask = irq_chip_mask_parent,
+ .irq_unmask = ixp4xx_gpio_irq_unmask,
+ .irq_set_type = ixp4xx_gpio_irq_set_type,
+};
+
+static int ixp4xx_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
+{
+ struct ixp4xx_gpio *g = gpiochip_get_data(gc);
+ struct irq_fwspec fwspec;
+
+ fwspec.fwnode = g->fwnode;
+ fwspec.param_count = 2;
+ fwspec.param[0] = offset;
+ fwspec.param[1] = IRQ_TYPE_NONE;
+
+ return irq_create_fwspec_mapping(&fwspec);
+}
+
+static int ixp4xx_gpio_irq_domain_translate(struct irq_domain *domain,
+ struct irq_fwspec *fwspec,
+ unsigned long *hwirq,
+ unsigned int *type)
+{
+
+ /* We support standard DT translation */
+ if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
+ *hwirq = fwspec->param[0];
+ *type = fwspec->param[1];
+ return 0;
+ }
+
+ /* This goes away when we transition to DT */
+ if (is_fwnode_irqchip(fwspec->fwnode)) {
+ if (fwspec->param_count != 2)
+ return -EINVAL;
+ *hwirq = fwspec->param[0];
+ *type = fwspec->param[1];
+ WARN_ON(*type == IRQ_TYPE_NONE);
+ return 0;
+ }
+ return -EINVAL;
+}
+
+static int ixp4xx_gpio_irq_domain_alloc(struct irq_domain *d,
+ unsigned int irq, unsigned int nr_irqs,
+ void *data)
+{
+ struct ixp4xx_gpio *g = d->host_data;
+ irq_hw_number_t hwirq;
+ unsigned int type = IRQ_TYPE_NONE;
+ struct irq_fwspec *fwspec = data;
+ int ret;
+ int i;
+
+ ret = ixp4xx_gpio_irq_domain_translate(d, fwspec, &hwirq, &type);
+ if (ret)
+ return ret;
+
+ dev_dbg(g->dev, "allocate IRQ %d..%d, hwirq %lu..%lu\n",
+ irq, irq + nr_irqs - 1,
+ hwirq, hwirq + nr_irqs - 1);
+
+ for (i = 0; i < nr_irqs; i++) {
+ struct irq_fwspec parent_fwspec;
+ const struct ixp4xx_gpio_map *map;
+ int j;
+
+ /* Not all lines support IRQs */
+ for (j = 0; j < ARRAY_SIZE(ixp4xx_gpiomap); j++) {
+ map = &ixp4xx_gpiomap[j];
+ if (map->gpio_offset == hwirq)
+ break;
+ }
+ if (j == ARRAY_SIZE(ixp4xx_gpiomap)) {
+ dev_err(g->dev, "can't look up hwirq %lu\n", hwirq);
+ return -EINVAL;
+ }
+ dev_dbg(g->dev, "found parent hwirq %u\n", map->parent_hwirq);
+
+ /*
+ * We set handle_bad_irq because the .set_type() should
+ * always be invoked and set the right type of handler.
+ */
+ irq_domain_set_info(d,
+ irq + i,
+ hwirq + i,
+ &ixp4xx_gpio_irqchip,
+ g,
+ handle_bad_irq,
+ NULL, NULL);
+ irq_set_probe(irq + i);
+
+ /*
+ * Create a IRQ fwspec to send up to the parent irqdomain:
+ * specify the hwirq we address on the parent and tie it
+ * all together up the chain.
+ */
+ parent_fwspec.fwnode = d->parent->fwnode;
+ parent_fwspec.param_count = 2;
+ parent_fwspec.param[0] = map->parent_hwirq;
+ /* This parent only handles asserted level IRQs */
+ parent_fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
+ dev_dbg(g->dev, "alloc_irqs_parent for %d parent hwirq %d\n",
+ irq + i, map->parent_hwirq);
+ ret = irq_domain_alloc_irqs_parent(d, irq + i, 1,
+ &parent_fwspec);
+ if (ret)
+ dev_err(g->dev,
+ "failed to allocate parent hwirq %d for hwirq %lu\n",
+ map->parent_hwirq, hwirq);
+ }
+
+ return 0;
+}
+
+static const struct irq_domain_ops ixp4xx_gpio_irqdomain_ops = {
+ .translate = ixp4xx_gpio_irq_domain_translate,
+ .alloc = ixp4xx_gpio_irq_domain_alloc,
+ .free = irq_domain_free_irqs_common,
+};
+
+static int ixp4xx_gpio_probe(struct platform_device *pdev)
+{
+ unsigned long flags;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct irq_domain *parent;
+ struct resource *res;
+ struct ixp4xx_gpio *g;
+ int ret;
+ int i;
+
+ 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)) {
+ dev_err(dev, "ioremap error\n");
+ return PTR_ERR(g->base);
+ }
+
+ /*
+ * Make sure GPIO 14 and 15 are NOT used as clocks but GPIO on
+ * specific machines.
+ */
+ if (machine_is_dsmg600() || machine_is_nas100d())
+ __raw_writel(0x0, g->base + IXP4XX_REG_GPCLK);
+
+ /*
+ * This is a very special big-endian ARM issue: when the IXP4xx is
+ * run in big endian mode, all registers in the machine are switched
+ * around to the CPU-native endianness. As you see mostly in the
+ * driver we use __raw_readl()/__raw_writel() to access the registers
+ * in the appropriate order. With the GPIO library we need to specify
+ * byte order explicitly, so this flag needs to be set when compiling
+ * for big endian.
+ */
+#if defined(CONFIG_CPU_BIG_ENDIAN)
+ flags = BGPIOF_BIG_ENDIAN_BYTE_ORDER;
+#else
+ flags = 0;
+#endif
+
+ /* Populate and register gpio chip */
+ ret = bgpio_init(&g->gc, dev, 4,
+ g->base + IXP4XX_REG_GPIN,
+ g->base + IXP4XX_REG_GPOUT,
+ NULL,
+ NULL,
+ g->base + IXP4XX_REG_GPOE,
+ flags);
+ if (ret) {
+ dev_err(dev, "unable to init generic GPIO\n");
+ return ret;
+ }
+ g->gc.to_irq = ixp4xx_gpio_to_irq;
+ g->gc.ngpio = 16;
+ g->gc.label = "IXP4XX_GPIO_CHIP";
+ /*
+ * TODO: when we have migrated to device tree and all GPIOs
+ * are fetched using phandles, set this to -1 to get rid of
+ * the fixed gpiochip base.
+ */
+ g->gc.base = 0;
+ g->gc.parent = &pdev->dev;
+ g->gc.owner = THIS_MODULE;
+
+ ret = devm_gpiochip_add_data(dev, &g->gc, g);
+ if (ret) {
+ dev_err(dev, "failed to add SoC gpiochip\n");
+ return ret;
+ }
+
+ /*
+ * When we convert to device tree we will simply look up the
+ * parent irqdomain using irq_find_host(parent) as parent comes
+ * from IRQCHIP_DECLARE(), then use of_node_to_fwnode() to get
+ * the fwnode. For now we need this boardfile style code.
+ */
+ if (np) {
+ struct device_node *irq_parent;
+
+ irq_parent = of_irq_find_parent(np);
+ if (!irq_parent) {
+ dev_err(dev, "no IRQ parent node\n");
+ return -ENODEV;
+ }
+ parent = irq_find_host(irq_parent);
+ if (!parent) {
+ dev_err(dev, "no IRQ parent domain\n");
+ return -ENODEV;
+ }
+ g->fwnode = of_node_to_fwnode(np);
+ } else {
+ parent = ixp4xx_get_irq_domain();
+ g->fwnode = irq_domain_alloc_fwnode(g->base);
+ if (!g->fwnode) {
+ dev_err(dev, "no domain base\n");
+ return -ENODEV;
+ }
+ }
+ g->domain = irq_domain_create_hierarchy(parent,
+ IRQ_DOMAIN_FLAG_HIERARCHY,
+ ARRAY_SIZE(ixp4xx_gpiomap),
+ g->fwnode,
+ &ixp4xx_gpio_irqdomain_ops,
+ g);
+ if (!g->domain) {
+ irq_domain_free_fwnode(g->fwnode);
+ dev_err(dev, "no hierarchical irq domain\n");
+ return ret;
+ }
+
+ /*
+ * After adding OF support, this is no longer needed: irqs
+ * will be allocated for the respective fwnodes.
+ */
+ if (!np) {
+ for (i = 0; i < ARRAY_SIZE(ixp4xx_gpiomap); i++) {
+ const struct ixp4xx_gpio_map *map = &ixp4xx_gpiomap[i];
+ struct irq_fwspec fwspec;
+
+ fwspec.fwnode = g->fwnode;
+ /* This is the hwirq for the GPIO line side of things */
+ fwspec.param[0] = map->gpio_offset;
+ fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
+ fwspec.param_count = 2;
+ ret = __irq_domain_alloc_irqs(g->domain,
+ -1, /* just pick something */
+ 1,
+ NUMA_NO_NODE,
+ &fwspec,
+ false,
+ NULL);
+ if (ret < 0) {
+ irq_domain_free_fwnode(g->fwnode);
+ dev_err(dev,
+ "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
+ map->gpio_offset, map->parent_hwirq,
+ ret);
+ return ret;
+ }
+ }
+ }
+
+ platform_set_drvdata(pdev, g);
+ dev_info(dev, "IXP4 GPIO @%p registered\n", g->base);
+
+ return 0;
+}
+
+static const struct of_device_id ixp4xx_gpio_of_match[] = {
+ {
+ .compatible = "intel,ixp4xx-gpio",
+ },
+ {},
+};
+
+
+static struct platform_driver ixp4xx_gpio_driver = {
+ .driver = {
+ .name = "ixp4xx-gpio",
+ .of_match_table = of_match_ptr(ixp4xx_gpio_of_match),
+ },
+ .probe = ixp4xx_gpio_probe,
+};
+builtin_platform_driver(ixp4xx_gpio_driver);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 11:38:53 +0100