diff options
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_gpio.c')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_gpio.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_gpio.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_gpio.c new file mode 100644 index 000000000000..a8d966db5715 --- /dev/null +++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_gpio.c @@ -0,0 +1,212 @@ +// SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause + +/* Initialize and handle GPIO interrupt triggered by INT_N PHY signal. + * This GPIO interrupt triggers the PHY state machine to bring the link + * up/down. + * + * Copyright (C) 2021 NVIDIA CORPORATION & AFFILIATES + */ + +#include <linux/acpi.h> +#include <linux/bitfield.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/gpio/driver.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/irqreturn.h> +#include <linux/platform_device.h> +#include <linux/property.h> + +#include "mlxbf_gige.h" +#include "mlxbf_gige_regs.h" + +#define MLXBF_GIGE_GPIO_CAUSE_FALL_EN 0x48 +#define MLXBF_GIGE_GPIO_CAUSE_OR_CAUSE_EVTEN0 0x80 +#define MLXBF_GIGE_GPIO_CAUSE_OR_EVTEN0 0x94 +#define MLXBF_GIGE_GPIO_CAUSE_OR_CLRCAUSE 0x98 + +static void mlxbf_gige_gpio_enable(struct mlxbf_gige *priv) +{ + unsigned long flags; + u32 val; + + spin_lock_irqsave(&priv->gpio_lock, flags); + val = readl(priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_OR_CLRCAUSE); + val |= priv->phy_int_gpio_mask; + writel(val, priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_OR_CLRCAUSE); + + /* The INT_N interrupt level is active low. + * So enable cause fall bit to detect when GPIO + * state goes low. + */ + val = readl(priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_FALL_EN); + val |= priv->phy_int_gpio_mask; + writel(val, priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_FALL_EN); + + /* Enable PHY interrupt by setting the priority level */ + val = readl(priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_OR_EVTEN0); + val |= priv->phy_int_gpio_mask; + writel(val, priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_OR_EVTEN0); + spin_unlock_irqrestore(&priv->gpio_lock, flags); +} + +static void mlxbf_gige_gpio_disable(struct mlxbf_gige *priv) +{ + unsigned long flags; + u32 val; + + spin_lock_irqsave(&priv->gpio_lock, flags); + val = readl(priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_OR_EVTEN0); + val &= ~priv->phy_int_gpio_mask; + writel(val, priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_OR_EVTEN0); + spin_unlock_irqrestore(&priv->gpio_lock, flags); +} + +static irqreturn_t mlxbf_gige_gpio_handler(int irq, void *ptr) +{ + struct mlxbf_gige *priv; + u32 val; + + priv = ptr; + + /* Check if this interrupt is from PHY device. + * Return if it is not. + */ + val = readl(priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_OR_CAUSE_EVTEN0); + if (!(val & priv->phy_int_gpio_mask)) + return IRQ_NONE; + + /* Clear interrupt when done, otherwise, no further interrupt + * will be triggered. + */ + val = readl(priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_OR_CLRCAUSE); + val |= priv->phy_int_gpio_mask; + writel(val, priv->gpio_io + MLXBF_GIGE_GPIO_CAUSE_OR_CLRCAUSE); + + generic_handle_irq(priv->phy_irq); + + return IRQ_HANDLED; +} + +static void mlxbf_gige_gpio_mask(struct irq_data *irqd) +{ + struct mlxbf_gige *priv = irq_data_get_irq_chip_data(irqd); + + mlxbf_gige_gpio_disable(priv); +} + +static void mlxbf_gige_gpio_unmask(struct irq_data *irqd) +{ + struct mlxbf_gige *priv = irq_data_get_irq_chip_data(irqd); + + mlxbf_gige_gpio_enable(priv); +} + +static struct irq_chip mlxbf_gige_gpio_chip = { + .name = "mlxbf_gige_phy", + .irq_mask = mlxbf_gige_gpio_mask, + .irq_unmask = mlxbf_gige_gpio_unmask, +}; + +static int mlxbf_gige_gpio_domain_map(struct irq_domain *d, + unsigned int irq, + irq_hw_number_t hwirq) +{ + irq_set_chip_data(irq, d->host_data); + irq_set_chip_and_handler(irq, &mlxbf_gige_gpio_chip, handle_simple_irq); + irq_set_noprobe(irq); + + return 0; +} + +static const struct irq_domain_ops mlxbf_gige_gpio_domain_ops = { + .map = mlxbf_gige_gpio_domain_map, + .xlate = irq_domain_xlate_twocell, +}; + +#ifdef CONFIG_ACPI +static int mlxbf_gige_gpio_resources(struct acpi_resource *ares, + void *data) +{ + struct acpi_resource_gpio *gpio; + u32 *phy_int_gpio = data; + + if (ares->type == ACPI_RESOURCE_TYPE_GPIO) { + gpio = &ares->data.gpio; + *phy_int_gpio = gpio->pin_table[0]; + } + + return 1; +} +#endif + +void mlxbf_gige_gpio_free(struct mlxbf_gige *priv) +{ + irq_dispose_mapping(priv->phy_irq); + irq_domain_remove(priv->irqdomain); +} + +int mlxbf_gige_gpio_init(struct platform_device *pdev, + struct mlxbf_gige *priv) +{ + struct device *dev = &pdev->dev; + struct resource *res; + u32 phy_int_gpio = 0; + int ret; + + LIST_HEAD(resources); + + res = platform_get_resource(pdev, IORESOURCE_MEM, MLXBF_GIGE_RES_GPIO0); + if (!res) + return -ENODEV; + + priv->gpio_io = devm_ioremap(dev, res->start, resource_size(res)); + if (!priv->gpio_io) + return -ENOMEM; + +#ifdef CONFIG_ACPI + ret = acpi_dev_get_resources(ACPI_COMPANION(dev), + &resources, mlxbf_gige_gpio_resources, + &phy_int_gpio); + acpi_dev_free_resource_list(&resources); + if (ret < 0 || !phy_int_gpio) { + dev_err(dev, "Error retrieving the gpio phy pin"); + return -EINVAL; + } +#endif + + priv->phy_int_gpio_mask = BIT(phy_int_gpio); + + mlxbf_gige_gpio_disable(priv); + + priv->hw_phy_irq = platform_get_irq(pdev, MLXBF_GIGE_PHY_INT_N); + + priv->irqdomain = irq_domain_add_simple(NULL, 1, 0, + &mlxbf_gige_gpio_domain_ops, + priv); + if (!priv->irqdomain) { + dev_err(dev, "Failed to add IRQ domain\n"); + return -ENOMEM; + } + + priv->phy_irq = irq_create_mapping(priv->irqdomain, 0); + if (!priv->phy_irq) { + irq_domain_remove(priv->irqdomain); + priv->irqdomain = NULL; + dev_err(dev, "Error mapping PHY IRQ\n"); + return -EINVAL; + } + + ret = devm_request_irq(dev, priv->hw_phy_irq, mlxbf_gige_gpio_handler, + IRQF_ONESHOT | IRQF_SHARED, "mlxbf_gige_phy", priv); + if (ret) { + dev_err(dev, "Failed to request PHY IRQ"); + mlxbf_gige_gpio_free(priv); + return ret; + } + + return ret; +} |