gpio: add driver for Mellanox BlueField GPIO

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      |   7 +++
 drivers/gpio/Makefile     |   1 +
 drivers/gpio/gpio-mlxbf.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 162 insertions(+)
 create mode 100644 drivers/gpio/gpio-mlxbf.c

drivers/gpio/Kconfig +7 -0

index 3f50526..0d9ddff 100644
@@ -1316,6 +1316,13 @@ 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
+       select GPIO_GENERIC
+       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

drivers/gpio/Makefile +1 -0

index 54d5527..db8d854 100644
@@ -85,6 +85,7 @@ 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

drivers/gpio/gpio-mlxbf.c new file +54 -0

new file mode 100644
index 0000000..42087c6
@@ -0,0 +1,154 @@
+// 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/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/resource.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;
+
+       /* Memory Address */
+       void __iomem *base;
+
+#ifdef CONFIG_PM
+       struct mlxbf_gpio_context_save_regs csave_regs;
+#endif
+};
+
+static int mlxbf_gpio_probe(struct platform_device *pdev)
+{
+       struct mlxbf_gpio_state *gs;
+       struct device *dev = &pdev->dev;

drivers/gpio/gpio-mlxbf.c new file +77 -1

+       gc->owner = THIS_MODULE;
+       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;
+       }
+
+       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