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linux-sg2042/drivers/gpio/gpio-mlxbf2.c

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// SPDX-License-Identifier: GPL-2.0
#include <linux/acpi.h>
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.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_MODE1_CLEAR 0x50
#define YU_GPIO_MODE0_SET 0x54
#define YU_GPIO_MODE0_CLEAR 0x58
#ifdef CONFIG_PM
struct mlxbf2_gpio_context_save_regs {
u32 gpio_mode0;
u32 gpio_mode1;
};
#endif
/* BlueField-2 gpio block context structure. */
struct mlxbf2_gpio_context {
struct gpio_chip gc;
/* YU GPIO blocks address */
void __iomem *gpio_io;
#ifdef CONFIG_PM
struct mlxbf2_gpio_context_save_regs *csave_regs;
#endif
};
/* 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 = {
.start = YU_ARM_GPIO_LOCK_ADDR,
.end = YU_ARM_GPIO_LOCK_ADDR + YU_ARM_GPIO_LOCK_SIZE - 1,
.name = "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);
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)) {
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);
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;
}
/* 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_chip *gc;
struct resource *res;
unsigned int npins;
int ret;
gs = devm_kzalloc(dev, sizeof(*gs), GFP_KERNEL);
if (!gs)
return -ENOMEM;
/* YU GPIO block address */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
gs->gpio_io = devm_ioremap(dev, res->start, resource_size(res));
if (!gs->gpio_io)
return -ENOMEM;
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);
gc->direction_input = mlxbf2_gpio_direction_input;
gc->direction_output = mlxbf2_gpio_direction_output;
gc->ngpio = npins;
gc->owner = THIS_MODULE;
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;
}
#ifdef CONFIG_PM
static int mlxbf2_gpio_suspend(struct platform_device *pdev,
pm_message_t state)
{
struct mlxbf2_gpio_context *gs = platform_get_drvdata(pdev);
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 mlxbf2_gpio_resume(struct platform_device *pdev)
{
struct mlxbf2_gpio_context *gs = platform_get_drvdata(pdev);
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;
}
#endif
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 = ACPI_PTR(mlxbf2_gpio_acpi_match),
},
.probe = mlxbf2_gpio_probe,
#ifdef CONFIG_PM
.suspend = mlxbf2_gpio_suspend,
.resume = mlxbf2_gpio_resume,
#endif
};
module_platform_driver(mlxbf2_gpio_driver);
MODULE_DESCRIPTION("Mellanox BlueField-2 GPIO Driver");
MODULE_AUTHOR("Mellanox Technologies");
MODULE_LICENSE("GPL v2");
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