diff options
Diffstat (limited to 'drivers/gpio/gpio-graniterapids.c')
-rw-r--r-- | drivers/gpio/gpio-graniterapids.c | 383 |
1 files changed, 383 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-graniterapids.c b/drivers/gpio/gpio-graniterapids.c new file mode 100644 index 000000000000..c693fe05d50f --- /dev/null +++ b/drivers/gpio/gpio-graniterapids.c @@ -0,0 +1,383 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Intel Granite Rapids-D vGPIO driver + * + * Copyright (c) 2024, Intel Corporation. + * + * Author: Aapo Vienamo <aapo.vienamo@linux.intel.com> + */ + +#include <linux/array_size.h> +#include <linux/bitfield.h> +#include <linux/bitmap.h> +#include <linux/cleanup.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/gfp_types.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/math.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/overflow.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include <linux/gpio/driver.h> + +#define GNR_NUM_PINS 128 +#define GNR_PINS_PER_REG 32 +#define GNR_NUM_REGS DIV_ROUND_UP(GNR_NUM_PINS, GNR_PINS_PER_REG) + +#define GNR_CFG_BAR 0x00 +#define GNR_CFG_LOCK_OFFSET 0x04 +#define GNR_GPI_STATUS_OFFSET 0x20 +#define GNR_GPI_ENABLE_OFFSET 0x24 + +#define GNR_CFG_DW_RX_MASK GENMASK(25, 22) +#define GNR_CFG_DW_RX_DISABLE FIELD_PREP(GNR_CFG_DW_RX_MASK, 2) +#define GNR_CFG_DW_RX_EDGE FIELD_PREP(GNR_CFG_DW_RX_MASK, 1) +#define GNR_CFG_DW_RX_LEVEL FIELD_PREP(GNR_CFG_DW_RX_MASK, 0) +#define GNR_CFG_DW_RXDIS BIT(4) +#define GNR_CFG_DW_TXDIS BIT(3) +#define GNR_CFG_DW_RXSTATE BIT(1) +#define GNR_CFG_DW_TXSTATE BIT(0) + +/** + * struct gnr_gpio - Intel Granite Rapids-D vGPIO driver state + * @gc: GPIO controller interface + * @reg_base: base address of the GPIO registers + * @ro_bitmap: bitmap of read-only pins + * @lock: guard the registers + * @pad_backup: backup of the register state for suspend + */ +struct gnr_gpio { + struct gpio_chip gc; + void __iomem *reg_base; + DECLARE_BITMAP(ro_bitmap, GNR_NUM_PINS); + raw_spinlock_t lock; + u32 pad_backup[]; +}; + +static void __iomem *gnr_gpio_get_padcfg_addr(const struct gnr_gpio *priv, + unsigned int gpio) +{ + return priv->reg_base + gpio * sizeof(u32); +} + +static int gnr_gpio_configure_line(struct gpio_chip *gc, unsigned int gpio, + u32 clear_mask, u32 set_mask) +{ + struct gnr_gpio *priv = gpiochip_get_data(gc); + void __iomem *addr = gnr_gpio_get_padcfg_addr(priv, gpio); + u32 dw; + + if (test_bit(gpio, priv->ro_bitmap)) + return -EACCES; + + guard(raw_spinlock_irqsave)(&priv->lock); + + dw = readl(addr); + dw &= ~clear_mask; + dw |= set_mask; + writel(dw, addr); + + return 0; +} + +static int gnr_gpio_get(struct gpio_chip *gc, unsigned int gpio) +{ + const struct gnr_gpio *priv = gpiochip_get_data(gc); + u32 dw; + + dw = readl(gnr_gpio_get_padcfg_addr(priv, gpio)); + + return !!(dw & GNR_CFG_DW_RXSTATE); +} + +static void gnr_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value) +{ + u32 clear = 0; + u32 set = 0; + + if (value) + set = GNR_CFG_DW_TXSTATE; + else + clear = GNR_CFG_DW_TXSTATE; + + gnr_gpio_configure_line(gc, gpio, clear, set); +} + +static int gnr_gpio_get_direction(struct gpio_chip *gc, unsigned int gpio) +{ + struct gnr_gpio *priv = gpiochip_get_data(gc); + u32 dw; + + dw = readl(gnr_gpio_get_padcfg_addr(priv, gpio)); + + if (dw & GNR_CFG_DW_TXDIS) + return GPIO_LINE_DIRECTION_IN; + + return GPIO_LINE_DIRECTION_OUT; +} + +static int gnr_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio) +{ + return gnr_gpio_configure_line(gc, gpio, GNR_CFG_DW_RXDIS, 0); +} + +static int gnr_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio, int value) +{ + u32 clear = GNR_CFG_DW_TXDIS; + u32 set = value ? GNR_CFG_DW_TXSTATE : 0; + + return gnr_gpio_configure_line(gc, gpio, clear, set); +} + +static const struct gpio_chip gnr_gpio_chip = { + .owner = THIS_MODULE, + .get = gnr_gpio_get, + .set = gnr_gpio_set, + .get_direction = gnr_gpio_get_direction, + .direction_input = gnr_gpio_direction_input, + .direction_output = gnr_gpio_direction_output, +}; + +static void __iomem *gnr_gpio_get_reg_addr(const struct gnr_gpio *priv, + unsigned int base, + unsigned int gpio) +{ + return priv->reg_base + base + gpio * sizeof(u32); +} + +static void gnr_gpio_irq_ack(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct gnr_gpio *priv = gpiochip_get_data(gc); + irq_hw_number_t gpio = irqd_to_hwirq(d); + unsigned int reg_idx = gpio / GNR_PINS_PER_REG; + unsigned int bit_idx = gpio % GNR_PINS_PER_REG; + void __iomem *addr = gnr_gpio_get_reg_addr(priv, GNR_GPI_STATUS_OFFSET, reg_idx); + u32 reg; + + guard(raw_spinlock_irqsave)(&priv->lock); + + reg = readl(addr); + reg &= ~BIT(bit_idx); + writel(reg, addr); +} + +static void gnr_gpio_irq_mask_unmask(struct gpio_chip *gc, unsigned long gpio, bool mask) +{ + struct gnr_gpio *priv = gpiochip_get_data(gc); + unsigned int reg_idx = gpio / GNR_PINS_PER_REG; + unsigned int bit_idx = gpio % GNR_PINS_PER_REG; + void __iomem *addr = gnr_gpio_get_reg_addr(priv, GNR_GPI_ENABLE_OFFSET, reg_idx); + u32 reg; + + guard(raw_spinlock_irqsave)(&priv->lock); + + reg = readl(addr); + if (mask) + reg &= ~BIT(bit_idx); + else + reg |= BIT(bit_idx); + writel(reg, addr); +} + +static void gnr_gpio_irq_mask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + + gnr_gpio_irq_mask_unmask(gc, hwirq, true); + gpiochip_disable_irq(gc, hwirq); +} + +static void gnr_gpio_irq_unmask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + + gpiochip_enable_irq(gc, hwirq); + gnr_gpio_irq_mask_unmask(gc, hwirq, false); +} + +static int gnr_gpio_irq_set_type(struct irq_data *d, unsigned int type) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + irq_hw_number_t pin = irqd_to_hwirq(d); + u32 mask = GNR_CFG_DW_RX_MASK; + u32 set; + + /* Falling edge and level low triggers not supported by the GPIO controller */ + switch (type) { + case IRQ_TYPE_NONE: + set = GNR_CFG_DW_RX_DISABLE; + break; + case IRQ_TYPE_EDGE_RISING: + set = GNR_CFG_DW_RX_EDGE; + irq_set_handler_locked(d, handle_edge_irq); + break; + case IRQ_TYPE_LEVEL_HIGH: + set = GNR_CFG_DW_RX_LEVEL; + irq_set_handler_locked(d, handle_level_irq); + break; + default: + return -EINVAL; + } + + return gnr_gpio_configure_line(gc, pin, mask, set); +} + +static const struct irq_chip gnr_gpio_irq_chip = { + .irq_ack = gnr_gpio_irq_ack, + .irq_mask = gnr_gpio_irq_mask, + .irq_unmask = gnr_gpio_irq_unmask, + .irq_set_type = gnr_gpio_irq_set_type, + .flags = IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, +}; + +static void gnr_gpio_init_pin_ro_bits(struct device *dev, + const void __iomem *cfg_lock_base, + unsigned long *ro_bitmap) +{ + u32 tmp[GNR_NUM_REGS]; + + memcpy_fromio(tmp, cfg_lock_base, sizeof(tmp)); + bitmap_from_arr32(ro_bitmap, tmp, GNR_NUM_PINS); +} + +static irqreturn_t gnr_gpio_irq(int irq, void *data) +{ + struct gnr_gpio *priv = data; + unsigned int handled = 0; + + for (unsigned int i = 0; i < GNR_NUM_REGS; i++) { + const void __iomem *reg = priv->reg_base + i * sizeof(u32); + unsigned long pending; + unsigned long enabled; + unsigned int bit_idx; + + scoped_guard(raw_spinlock, &priv->lock) { + pending = readl(reg + GNR_GPI_STATUS_OFFSET); + enabled = readl(reg + GNR_GPI_ENABLE_OFFSET); + } + + /* Only enabled interrupts */ + pending &= enabled; + + for_each_set_bit(bit_idx, &pending, GNR_PINS_PER_REG) { + unsigned int hwirq = i * GNR_PINS_PER_REG + bit_idx; + + generic_handle_domain_irq(priv->gc.irq.domain, hwirq); + } + + handled += pending ? 1 : 0; + + } + return IRQ_RETVAL(handled); +} + +static int gnr_gpio_probe(struct platform_device *pdev) +{ + size_t num_backup_pins = IS_ENABLED(CONFIG_PM_SLEEP) ? GNR_NUM_PINS : 0; + struct device *dev = &pdev->dev; + struct gpio_irq_chip *girq; + struct gnr_gpio *priv; + void __iomem *regs; + int irq, ret; + + priv = devm_kzalloc(dev, struct_size(priv, pad_backup, num_backup_pins), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(regs)) + return PTR_ERR(regs); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + ret = devm_request_irq(dev, irq, gnr_gpio_irq, IRQF_SHARED | IRQF_NO_THREAD, + dev_name(dev), priv); + if (ret) + return dev_err_probe(dev, ret, "failed to request interrupt\n"); + + priv->reg_base = regs + readl(regs + GNR_CFG_BAR); + + gnr_gpio_init_pin_ro_bits(dev, priv->reg_base + GNR_CFG_LOCK_OFFSET, + priv->ro_bitmap); + + priv->gc = gnr_gpio_chip; + priv->gc.label = dev_name(dev); + priv->gc.parent = dev; + priv->gc.ngpio = GNR_NUM_PINS; + priv->gc.base = -1; + + girq = &priv->gc.irq; + gpio_irq_chip_set_chip(girq, &gnr_gpio_irq_chip); + girq->chip->name = dev_name(dev); + girq->parent_handler = NULL; + girq->num_parents = 0; + girq->parents = NULL; + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_bad_irq; + + platform_set_drvdata(pdev, priv); + + return devm_gpiochip_add_data(dev, &priv->gc, priv); +} + +static int gnr_gpio_suspend(struct device *dev) +{ + struct gnr_gpio *priv = dev_get_drvdata(dev); + unsigned int i; + + guard(raw_spinlock_irqsave)(&priv->lock); + + for_each_clear_bit(i, priv->ro_bitmap, priv->gc.ngpio) + priv->pad_backup[i] = readl(gnr_gpio_get_padcfg_addr(priv, i)); + + return 0; +} + +static int gnr_gpio_resume(struct device *dev) +{ + struct gnr_gpio *priv = dev_get_drvdata(dev); + unsigned int i; + + guard(raw_spinlock_irqsave)(&priv->lock); + + for_each_clear_bit(i, priv->ro_bitmap, priv->gc.ngpio) + writel(priv->pad_backup[i], gnr_gpio_get_padcfg_addr(priv, i)); + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(gnr_gpio_pm_ops, gnr_gpio_suspend, gnr_gpio_resume); + +static const struct acpi_device_id gnr_gpio_acpi_match[] = { + { "INTC1109" }, + {} +}; +MODULE_DEVICE_TABLE(acpi, gnr_gpio_acpi_match); + +static struct platform_driver gnr_gpio_driver = { + .driver = { + .name = "gpio-graniterapids", + .pm = pm_sleep_ptr(&gnr_gpio_pm_ops), + .acpi_match_table = gnr_gpio_acpi_match, + }, + .probe = gnr_gpio_probe, +}; +module_platform_driver(gnr_gpio_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Aapo Vienamo <aapo.vienamo@linux.intel.com>"); +MODULE_DESCRIPTION("Intel Granite Rapids-D vGPIO driver"); |