Changes since v3
- the naming scheme has been fixed to remove double underscores and use
standard variable names
- the locking has been updated to protect the entire read/modify
operations.
Regarding the suggested use of the generic MMIO library, I noticed that
bgpio_init only allows for either dirin or dirout to be set, never both.
But since our controller has 2 separate registers, using bgpio_init
might not be possible here.
Shravan Kumar Ramani (1):
gpio: add driver for Mellanox BlueField GPIO controller
drivers/gpio/Kconfig | 6 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-mlxbf.c | 222 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 229 insertions(+)
create mode 100644 drivers/gpio/gpio-mlxbf.c
--
2.1.2
This patch adds support for the GPIO controller used by Mellanox
BlueField SOCs.
Reviewed-by: David Woods <[email protected]>
Signed-off-by: Shravan Kumar Ramani <[email protected]>
---
drivers/gpio/Kconfig | 6 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-mlxbf.c | 222 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 229 insertions(+)
create mode 100644 drivers/gpio/gpio-mlxbf.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b5a2845..c950fe8 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1292,6 +1292,12 @@ config GPIO_MERRIFIELD
help
Say Y here to support Intel Merrifield GPIO.
+config GPIO_MLXBF
+ tristate "Mellanox BlueField SoC GPIO"
+ depends on (MELLANOX_PLATFORM && ARM64 && ACPI) || COMPILE_TEST
+ help
+ Say Y here if you want GPIO support on Mellanox BlueField 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 37628f8..8d54279 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -83,6 +83,7 @@ obj-$(CONFIG_GPIO_MENZ127) += gpio-menz127.o
obj-$(CONFIG_GPIO_MERRIFIELD) += gpio-merrifield.o
obj-$(CONFIG_GPIO_MC33880) += gpio-mc33880.o
obj-$(CONFIG_GPIO_MC9S08DZ60) += gpio-mc9s08dz60.o
+obj-$(CONFIG_GPIO_MLXBF) += gpio-mlxbf.o
obj-$(CONFIG_GPIO_ML_IOH) += gpio-ml-ioh.o
obj-$(CONFIG_GPIO_MM_LANTIQ) += gpio-mm-lantiq.o
obj-$(CONFIG_GPIO_MOCKUP) += gpio-mockup.o
diff --git a/drivers/gpio/gpio-mlxbf.c b/drivers/gpio/gpio-mlxbf.c
new file mode 100644
index 0000000..e2d23c2
--- /dev/null
+++ b/drivers/gpio/gpio-mlxbf.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/acpi.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>
+
+/* Number of pins on BlueField */
+#define MLXBF_GPIO_NR 54
+
+/* Pad Electrical Controls. */
+#define MLXBF_GPIO_PAD_CONTROL_FIRST_WORD 0x0700
+#define MLXBF_GPIO_PAD_CONTROL_1_FIRST_WORD 0x0708
+#define MLXBF_GPIO_PAD_CONTROL_2_FIRST_WORD 0x0710
+#define MLXBF_GPIO_PAD_CONTROL_3_FIRST_WORD 0x0718
+
+#define MLXBF_GPIO_PIN_DIR_I 0x1040
+#define MLXBF_GPIO_PIN_DIR_O 0x1048
+#define MLXBF_GPIO_PIN_STATE 0x1000
+#define MLXBF_GPIO_SCRATCHPAD 0x20
+
+#ifdef CONFIG_PM
+struct mlxbf_gpio_context_save_regs {
+ u64 scratchpad;
+ u64 pad_control[MLXBF_GPIO_NR];
+ u64 pin_dir_i;
+ u64 pin_dir_o;
+};
+#endif
+
+/* Device state structure. */
+struct mlxbf_gpio_state {
+ struct gpio_chip gc;
+
+ /* Must hold this lock to modify shared data. */
+ spinlock_t lock;
+
+ /* Memory Address */
+ void __iomem *base;
+
+#ifdef CONFIG_PM
+ struct mlxbf_gpio_context_save_regs csave_regs;
+#endif
+};
+
+static int mlxbf_gpio_set_input(struct gpio_chip *chip, unsigned int offset)
+{
+ struct mlxbf_gpio_state *gs = gpiochip_get_data(chip);
+ u64 in;
+ u64 out;
+
+ spin_lock(&gs->lock);
+ out = readq(gs->base + MLXBF_GPIO_PIN_DIR_O);
+ in = readq(gs->base + MLXBF_GPIO_PIN_DIR_I);
+
+ writeq(out & ~BIT(offset), gs->base + MLXBF_GPIO_PIN_DIR_O);
+ writeq(in | BIT(offset), gs->base + MLXBF_GPIO_PIN_DIR_I);
+ spin_unlock(&gs->lock);
+
+ return 0;
+}
+
+static int mlxbf_gpio_set_output(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ struct mlxbf_gpio_state *gs = gpiochip_get_data(chip);
+ u64 in;
+ u64 out;
+
+ spin_lock(&gs->lock);
+ out = readq(gs->base + MLXBF_GPIO_PIN_DIR_O);
+ in = readq(gs->base + MLXBF_GPIO_PIN_DIR_I);
+
+ writeq(out | BIT(offset), gs->base + MLXBF_GPIO_PIN_DIR_O);
+ writeq(in & ~BIT(offset), gs->base + MLXBF_GPIO_PIN_DIR_I);
+ spin_unlock(&gs->lock);
+
+ return 0;
+}
+
+static int mlxbf_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ u64 value;
+ struct mlxbf_gpio_state *gs = gpiochip_get_data(chip);
+
+ spin_lock(&gs->lock);
+ value = readq(gs->base + MLXBF_GPIO_PIN_STATE);
+ spin_unlock(&gs->lock);
+
+ return (value >> offset) & 1;
+}
+
+static void mlxbf_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ u64 data;
+ struct mlxbf_gpio_state *gs = gpiochip_get_data(chip);
+
+ spin_lock(&gs->lock);
+ data = readq(gs->base + MLXBF_GPIO_PIN_STATE);
+
+ if (value)
+ data |= BIT(offset);
+ else
+ data &= ~BIT(offset);
+ writeq(data, gs->base + MLXBF_GPIO_PIN_STATE);
+ spin_unlock(&gs->lock);
+}
+
+static int mlxbf_gpio_probe(struct platform_device *pdev)
+{
+ struct mlxbf_gpio_state *gs;
+ struct device *dev = &pdev->dev;
+ struct gpio_chip *gc;
+ struct resource *res;
+ int ret;
+
+ gs = devm_kzalloc(&pdev->dev, sizeof(*gs), GFP_KERNEL);
+ if (!gs)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ gs->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(gs->base))
+ return PTR_ERR(gs->base);
+
+ gc = &gs->gc;
+ gc->direction_input = mlxbf_gpio_set_input;
+ gc->direction_output = mlxbf_gpio_set_output;
+ gc->get = mlxbf_gpio_get;
+ gc->set = mlxbf_gpio_set;
+ gc->label = dev_name(dev);
+ gc->parent = &pdev->dev;
+ gc->owner = THIS_MODULE;
+ gc->base = -1;
+ gc->ngpio = MLXBF_GPIO_NR;
+
+ ret = devm_gpiochip_add_data(dev, &gs->gc, gs);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed adding memory mapped gpiochip\n");
+ return ret;
+ }
+
+ spin_lock_init(&gs->lock);
+ platform_set_drvdata(pdev, gs);
+ dev_info(&pdev->dev, "registered Mellanox BlueField GPIO");
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int mlxbf_gpio_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct mlxbf_gpio_state *gs = platform_get_drvdata(pdev);
+
+ gs->csave_regs.scratchpad = readq(gs->base + MLXBF_GPIO_SCRATCHPAD);
+ gs->csave_regs.pad_control[0] =
+ readq(gs->base + MLXBF_GPIO_PAD_CONTROL_FIRST_WORD);
+ gs->csave_regs.pad_control[1] =
+ readq(gs->base + MLXBF_GPIO_PAD_CONTROL_1_FIRST_WORD);
+ gs->csave_regs.pad_control[2] =
+ readq(gs->base + MLXBF_GPIO_PAD_CONTROL_2_FIRST_WORD);
+ gs->csave_regs.pad_control[3] =
+ readq(gs->base + MLXBF_GPIO_PAD_CONTROL_3_FIRST_WORD);
+ gs->csave_regs.pin_dir_i = readq(gs->base + MLXBF_GPIO_PIN_DIR_I);
+ gs->csave_regs.pin_dir_o = readq(gs->base + MLXBF_GPIO_PIN_DIR_O);
+
+ return 0;
+}
+
+static int mlxbf_gpio_resume(struct platform_device *pdev)
+{
+ struct mlxbf_gpio_state *gs = platform_get_drvdata(pdev);
+
+ writeq(gs->csave_regs.scratchpad, gs->base + MLXBF_GPIO_SCRATCHPAD);
+ writeq(gs->csave_regs.pad_control[0],
+ gs->base + MLXBF_GPIO_PAD_CONTROL_FIRST_WORD);
+ writeq(gs->csave_regs.pad_control[1],
+ gs->base + MLXBF_GPIO_PAD_CONTROL_1_FIRST_WORD);
+ writeq(gs->csave_regs.pad_control[2],
+ gs->base + MLXBF_GPIO_PAD_CONTROL_2_FIRST_WORD);
+ writeq(gs->csave_regs.pad_control[3],
+ gs->base + MLXBF_GPIO_PAD_CONTROL_3_FIRST_WORD);
+ writeq(gs->csave_regs.pin_dir_i, gs->base + MLXBF_GPIO_PIN_DIR_I);
+ writeq(gs->csave_regs.pin_dir_o, gs->base + MLXBF_GPIO_PIN_DIR_O);
+
+ return 0;
+}
+#endif
+
+static const struct acpi_device_id mlxbf_gpio_acpi_match[] = {
+ { "MLNXBF02", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(acpi, mlxbf_gpio_acpi_match);
+
+static struct platform_driver mlxbf_gpio_driver = {
+ .driver = {
+ .name = "mlxbf_gpio",
+ .acpi_match_table = ACPI_PTR(mlxbf_gpio_acpi_match),
+ },
+ .probe = mlxbf_gpio_probe,
+#ifdef CONFIG_PM
+ .suspend = mlxbf_gpio_suspend,
+ .resume = mlxbf_gpio_resume,
+#endif
+};
+
+module_platform_driver(mlxbf_gpio_driver);
+
+MODULE_DESCRIPTION("Mellanox BlueField GPIO Driver");
+MODULE_AUTHOR("Mellanox Technologies");
+MODULE_LICENSE("GPL");
--
2.1.2
On Thu, Feb 21, 2019 at 10:33 PM Shravan Kumar Ramani
<[email protected]> wrote:
> Regarding the suggested use of the generic MMIO library, I noticed that
> bgpio_init only allows for either dirin or dirout to be set, never both.
> But since our controller has 2 separate registers, using bgpio_init
> might not be possible here.
OK let's just fix that instead of working around it, I will
send a patch.
Yours,
Linus Walleij