diff options
Diffstat (limited to 'drivers/gpio/gpio-mlxbf2.c')
| -rw-r--r-- | drivers/gpio/gpio-mlxbf2.c | 460 |
1 files changed, 460 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-mlxbf2.c b/drivers/gpio/gpio-mlxbf2.c new file mode 100644 index 000000000..77a41151c --- /dev/null +++ b/drivers/gpio/gpio-mlxbf2.c @@ -0,0 +1,460 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2020-2021 NVIDIA CORPORATION & AFFILIATES + */ + +#include <linux/bitfield.h> +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/gpio/driver.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/kernel.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/resource.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +/* + * There are 3 YU GPIO blocks: + * gpio[0]: HOST_GPIO0->HOST_GPIO31 + * gpio[1]: HOST_GPIO32->HOST_GPIO63 + * gpio[2]: HOST_GPIO64->HOST_GPIO69 + */ +#define MLXBF2_GPIO_MAX_PINS_PER_BLOCK 32 + +/* + * arm_gpio_lock register: + * bit[31] lock status: active if set + * bit[15:0] set lock + * The lock is enabled only if 0xd42f is written to this field + */ +#define YU_ARM_GPIO_LOCK_ADDR 0x2801088 +#define YU_ARM_GPIO_LOCK_SIZE 0x8 +#define YU_LOCK_ACTIVE_BIT(val) (val >> 31) +#define YU_ARM_GPIO_LOCK_ACQUIRE 0xd42f +#define YU_ARM_GPIO_LOCK_RELEASE 0x0 + +/* + * gpio[x] block registers and their offset + */ +#define YU_GPIO_DATAIN 0x04 +#define YU_GPIO_MODE1 0x08 +#define YU_GPIO_MODE0 0x0c +#define YU_GPIO_DATASET 0x14 +#define YU_GPIO_DATACLEAR 0x18 +#define YU_GPIO_CAUSE_RISE_EN 0x44 +#define YU_GPIO_CAUSE_FALL_EN 0x48 +#define YU_GPIO_MODE1_CLEAR 0x50 +#define YU_GPIO_MODE0_SET 0x54 +#define YU_GPIO_MODE0_CLEAR 0x58 +#define YU_GPIO_CAUSE_OR_CAUSE_EVTEN0 0x80 +#define YU_GPIO_CAUSE_OR_EVTEN0 0x94 +#define YU_GPIO_CAUSE_OR_CLRCAUSE 0x98 + +struct mlxbf2_gpio_context_save_regs { + u32 gpio_mode0; + u32 gpio_mode1; +}; + +/* BlueField-2 gpio block context structure. */ +struct mlxbf2_gpio_context { + struct gpio_chip gc; + struct irq_chip irq_chip; + + /* YU GPIO blocks address */ + void __iomem *gpio_io; + + struct mlxbf2_gpio_context_save_regs *csave_regs; +}; + +/* BlueField-2 gpio shared structure. */ +struct mlxbf2_gpio_param { + void __iomem *io; + struct resource *res; + struct mutex *lock; +}; + +static struct resource yu_arm_gpio_lock_res = + DEFINE_RES_MEM_NAMED(YU_ARM_GPIO_LOCK_ADDR, YU_ARM_GPIO_LOCK_SIZE, "YU_ARM_GPIO_LOCK"); + +static DEFINE_MUTEX(yu_arm_gpio_lock_mutex); + +static struct mlxbf2_gpio_param yu_arm_gpio_lock_param = { + .res = &yu_arm_gpio_lock_res, + .lock = &yu_arm_gpio_lock_mutex, +}; + +/* Request memory region and map yu_arm_gpio_lock resource */ +static int mlxbf2_gpio_get_lock_res(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct resource *res; + resource_size_t size; + int ret = 0; + + mutex_lock(yu_arm_gpio_lock_param.lock); + + /* Check if the memory map already exists */ + if (yu_arm_gpio_lock_param.io) + goto exit; + + res = yu_arm_gpio_lock_param.res; + size = resource_size(res); + + if (!devm_request_mem_region(dev, res->start, size, res->name)) { + ret = -EFAULT; + goto exit; + } + + yu_arm_gpio_lock_param.io = devm_ioremap(dev, res->start, size); + if (!yu_arm_gpio_lock_param.io) + ret = -ENOMEM; + +exit: + mutex_unlock(yu_arm_gpio_lock_param.lock); + + return ret; +} + +/* + * Acquire the YU arm_gpio_lock to be able to change the direction + * mode. If the lock_active bit is already set, return an error. + */ +static int mlxbf2_gpio_lock_acquire(struct mlxbf2_gpio_context *gs) +{ + u32 arm_gpio_lock_val; + + mutex_lock(yu_arm_gpio_lock_param.lock); + raw_spin_lock(&gs->gc.bgpio_lock); + + arm_gpio_lock_val = readl(yu_arm_gpio_lock_param.io); + + /* + * When lock active bit[31] is set, ModeX is write enabled + */ + if (YU_LOCK_ACTIVE_BIT(arm_gpio_lock_val)) { + raw_spin_unlock(&gs->gc.bgpio_lock); + mutex_unlock(yu_arm_gpio_lock_param.lock); + return -EINVAL; + } + + writel(YU_ARM_GPIO_LOCK_ACQUIRE, yu_arm_gpio_lock_param.io); + + return 0; +} + +/* + * Release the YU arm_gpio_lock after changing the direction mode. + */ +static void mlxbf2_gpio_lock_release(struct mlxbf2_gpio_context *gs) + __releases(&gs->gc.bgpio_lock) + __releases(yu_arm_gpio_lock_param.lock) +{ + writel(YU_ARM_GPIO_LOCK_RELEASE, yu_arm_gpio_lock_param.io); + raw_spin_unlock(&gs->gc.bgpio_lock); + mutex_unlock(yu_arm_gpio_lock_param.lock); +} + +/* + * mode0 and mode1 are both locked by the gpio_lock field. + * + * Together, mode0 and mode1 define the gpio Mode dependeing also + * on Reg_DataOut. + * + * {mode1,mode0}:{Reg_DataOut=0,Reg_DataOut=1}->{DataOut=0,DataOut=1} + * + * {0,0}:Reg_DataOut{0,1}->{Z,Z} Input PAD + * {0,1}:Reg_DataOut{0,1}->{0,1} Full drive Output PAD + * {1,0}:Reg_DataOut{0,1}->{0,Z} 0-set PAD to low, 1-float + * {1,1}:Reg_DataOut{0,1}->{Z,1} 0-float, 1-set PAD to high + */ + +/* + * Set input direction: + * {mode1,mode0} = {0,0} + */ +static int mlxbf2_gpio_direction_input(struct gpio_chip *chip, + unsigned int offset) +{ + struct mlxbf2_gpio_context *gs = gpiochip_get_data(chip); + int ret; + + /* + * Although the arm_gpio_lock was set in the probe function, check again + * if it is still enabled to be able to write to the ModeX registers. + */ + ret = mlxbf2_gpio_lock_acquire(gs); + if (ret < 0) + return ret; + + writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE0_CLEAR); + writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE1_CLEAR); + + mlxbf2_gpio_lock_release(gs); + + return ret; +} + +/* + * Set output direction: + * {mode1,mode0} = {0,1} + */ +static int mlxbf2_gpio_direction_output(struct gpio_chip *chip, + unsigned int offset, + int value) +{ + struct mlxbf2_gpio_context *gs = gpiochip_get_data(chip); + int ret = 0; + + /* + * Although the arm_gpio_lock was set in the probe function, + * check again it is still enabled to be able to write to the + * ModeX registers. + */ + ret = mlxbf2_gpio_lock_acquire(gs); + if (ret < 0) + return ret; + + writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE1_CLEAR); + writel(BIT(offset), gs->gpio_io + YU_GPIO_MODE0_SET); + + mlxbf2_gpio_lock_release(gs); + + return ret; +} + +static void mlxbf2_gpio_irq_enable(struct irq_data *irqd) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); + struct mlxbf2_gpio_context *gs = gpiochip_get_data(gc); + int offset = irqd_to_hwirq(irqd); + unsigned long flags; + u32 val; + + raw_spin_lock_irqsave(&gs->gc.bgpio_lock, flags); + val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE); + val |= BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE); + + val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0); + val |= BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0); + raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags); +} + +static void mlxbf2_gpio_irq_disable(struct irq_data *irqd) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); + struct mlxbf2_gpio_context *gs = gpiochip_get_data(gc); + int offset = irqd_to_hwirq(irqd); + unsigned long flags; + u32 val; + + raw_spin_lock_irqsave(&gs->gc.bgpio_lock, flags); + val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0); + val &= ~BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0); + raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags); +} + +static irqreturn_t mlxbf2_gpio_irq_handler(int irq, void *ptr) +{ + struct mlxbf2_gpio_context *gs = ptr; + struct gpio_chip *gc = &gs->gc; + unsigned long pending; + u32 level; + + pending = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_CAUSE_EVTEN0); + writel(pending, gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE); + + for_each_set_bit(level, &pending, gc->ngpio) + generic_handle_domain_irq_safe(gc->irq.domain, level); + + return IRQ_RETVAL(pending); +} + +static int +mlxbf2_gpio_irq_set_type(struct irq_data *irqd, unsigned int type) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); + struct mlxbf2_gpio_context *gs = gpiochip_get_data(gc); + int offset = irqd_to_hwirq(irqd); + unsigned long flags; + bool fall = false; + bool rise = false; + u32 val; + + switch (type & IRQ_TYPE_SENSE_MASK) { + case IRQ_TYPE_EDGE_BOTH: + fall = true; + rise = true; + break; + case IRQ_TYPE_EDGE_RISING: + rise = true; + break; + case IRQ_TYPE_EDGE_FALLING: + fall = true; + break; + default: + return -EINVAL; + } + + raw_spin_lock_irqsave(&gs->gc.bgpio_lock, flags); + if (fall) { + val = readl(gs->gpio_io + YU_GPIO_CAUSE_FALL_EN); + val |= BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_FALL_EN); + } + + if (rise) { + val = readl(gs->gpio_io + YU_GPIO_CAUSE_RISE_EN); + val |= BIT(offset); + writel(val, gs->gpio_io + YU_GPIO_CAUSE_RISE_EN); + } + raw_spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags); + + return 0; +} + +/* BlueField-2 GPIO driver initialization routine. */ +static int +mlxbf2_gpio_probe(struct platform_device *pdev) +{ + struct mlxbf2_gpio_context *gs; + struct device *dev = &pdev->dev; + struct gpio_irq_chip *girq; + struct gpio_chip *gc; + unsigned int npins; + const char *name; + int ret, irq; + + name = dev_name(dev); + + gs = devm_kzalloc(dev, sizeof(*gs), GFP_KERNEL); + if (!gs) + return -ENOMEM; + + /* YU GPIO block address */ + gs->gpio_io = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(gs->gpio_io)) + return PTR_ERR(gs->gpio_io); + + ret = mlxbf2_gpio_get_lock_res(pdev); + if (ret) { + dev_err(dev, "Failed to get yu_arm_gpio_lock resource\n"); + return ret; + } + + if (device_property_read_u32(dev, "npins", &npins)) + npins = MLXBF2_GPIO_MAX_PINS_PER_BLOCK; + + gc = &gs->gc; + + ret = bgpio_init(gc, dev, 4, + gs->gpio_io + YU_GPIO_DATAIN, + gs->gpio_io + YU_GPIO_DATASET, + gs->gpio_io + YU_GPIO_DATACLEAR, + NULL, + NULL, + 0); + + if (ret) { + dev_err(dev, "bgpio_init failed\n"); + return ret; + } + + gc->direction_input = mlxbf2_gpio_direction_input; + gc->direction_output = mlxbf2_gpio_direction_output; + gc->ngpio = npins; + gc->owner = THIS_MODULE; + + irq = platform_get_irq(pdev, 0); + if (irq >= 0) { + gs->irq_chip.name = name; + gs->irq_chip.irq_set_type = mlxbf2_gpio_irq_set_type; + gs->irq_chip.irq_enable = mlxbf2_gpio_irq_enable; + gs->irq_chip.irq_disable = mlxbf2_gpio_irq_disable; + + girq = &gs->gc.irq; + girq->chip = &gs->irq_chip; + girq->handler = handle_simple_irq; + girq->default_type = IRQ_TYPE_NONE; + /* This will let us handle the parent IRQ in the driver */ + girq->num_parents = 0; + girq->parents = NULL; + girq->parent_handler = NULL; + + /* + * Directly request the irq here instead of passing + * a flow-handler because the irq is shared. + */ + ret = devm_request_irq(dev, irq, mlxbf2_gpio_irq_handler, + IRQF_SHARED, name, gs); + if (ret) { + dev_err(dev, "failed to request IRQ"); + return ret; + } + } + + platform_set_drvdata(pdev, gs); + + ret = devm_gpiochip_add_data(dev, &gs->gc, gs); + if (ret) { + dev_err(dev, "Failed adding memory mapped gpiochip\n"); + return ret; + } + + return 0; +} + +static int __maybe_unused mlxbf2_gpio_suspend(struct device *dev) +{ + struct mlxbf2_gpio_context *gs = dev_get_drvdata(dev); + + gs->csave_regs->gpio_mode0 = readl(gs->gpio_io + + YU_GPIO_MODE0); + gs->csave_regs->gpio_mode1 = readl(gs->gpio_io + + YU_GPIO_MODE1); + + return 0; +} + +static int __maybe_unused mlxbf2_gpio_resume(struct device *dev) +{ + struct mlxbf2_gpio_context *gs = dev_get_drvdata(dev); + + writel(gs->csave_regs->gpio_mode0, gs->gpio_io + + YU_GPIO_MODE0); + writel(gs->csave_regs->gpio_mode1, gs->gpio_io + + YU_GPIO_MODE1); + + return 0; +} +static SIMPLE_DEV_PM_OPS(mlxbf2_pm_ops, mlxbf2_gpio_suspend, mlxbf2_gpio_resume); + +static const struct acpi_device_id __maybe_unused mlxbf2_gpio_acpi_match[] = { + { "MLNXBF22", 0 }, + {}, +}; +MODULE_DEVICE_TABLE(acpi, mlxbf2_gpio_acpi_match); + +static struct platform_driver mlxbf2_gpio_driver = { + .driver = { + .name = "mlxbf2_gpio", + .acpi_match_table = mlxbf2_gpio_acpi_match, + .pm = &mlxbf2_pm_ops, + }, + .probe = mlxbf2_gpio_probe, +}; + +module_platform_driver(mlxbf2_gpio_driver); + +MODULE_DESCRIPTION("Mellanox BlueField-2 GPIO Driver"); +MODULE_AUTHOR("Asmaa Mnebhi <asmaa@nvidia.com>"); +MODULE_LICENSE("GPL v2"); |