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Subject[PATCH v4 1/1] gpio: add driver for Mellanox BlueField 2 GPIO controller
Date
This patch adds support for the GPIO controller used by
Mellanox BlueField 2 SOCs.

Signed-off-by: Asmaa Mnebhi <Asmaa@mellanox.com>
---
drivers/gpio/Kconfig | 7 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-mlxbf2.c | 335 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 343 insertions(+)
create mode 100644 drivers/gpio/gpio-mlxbf2.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b8013cf..6234ccc 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1399,6 +1399,13 @@ config GPIO_MLXBF
help
Say Y here if you want GPIO support on Mellanox BlueField SoC.

+config GPIO_MLXBF2
+ tristate "Mellanox BlueField 2 SoC GPIO"
+ depends on (MELLANOX_PLATFORM && ARM64 && ACPI) || (64BIT && COMPILE_TEST)
+ select GPIO_GENERIC
+ help
+ Say Y here if you want GPIO support on Mellanox BlueField 2 SoC.
+
config GPIO_ML_IOH
tristate "OKI SEMICONDUCTOR ML7213 IOH GPIO support"
depends on X86 || COMPILE_TEST
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 0b57126..b2cfc21 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_GPIO_MENZ127) += gpio-menz127.o
obj-$(CONFIG_GPIO_MERRIFIELD) += gpio-merrifield.o
obj-$(CONFIG_GPIO_ML_IOH) += gpio-ml-ioh.o
obj-$(CONFIG_GPIO_MLXBF) += gpio-mlxbf.o
+obj-$(CONFIG_GPIO_MLXBF2) += gpio-mlxbf2.o
obj-$(CONFIG_GPIO_MM_LANTIQ) += gpio-mm-lantiq.o
obj-$(CONFIG_GPIO_MOCKUP) += gpio-mockup.o
obj-$(CONFIG_GPIO_MOXTET) += gpio-moxtet.o
diff --git a/drivers/gpio/gpio-mlxbf2.c b/drivers/gpio/gpio-mlxbf2.c
new file mode 100644
index 0000000..7b70850
--- /dev/null
+++ b/drivers/gpio/gpio-mlxbf2.c
@@ -0,0 +1,335 @@
+// 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>
+#include <linux/version.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 (IS_ERR(yu_arm_gpio_lock_param.io))
+ ret = PTR_ERR(yu_arm_gpio_lock_param.io);
+
+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;
+
+ spin_lock(&gs->gc.bgpio_lock);
+ mutex_lock(yu_arm_gpio_lock_param.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)) {
+ mutex_unlock(yu_arm_gpio_lock_param.lock);
+ spin_unlock(&gs->gc.bgpio_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)
+{
+ writel(YU_ARM_GPIO_LOCK_RELEASE, yu_arm_gpio_lock_param.io);
+ mutex_unlock(yu_arm_gpio_lock_param.lock);
+ spin_unlock(&gs->gc.bgpio_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 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");
--
2.1.2
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