power: reset: pwr-mlxbf: add BlueField SoC power control driver

This driver supports handling 2 BlueField power states controlled by
GPIO interrupts:

1) chip reset and
2) low power mode

Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 4b563db3ab3ec07bf3e6b59f8dde9664a572f64d..a8c46ba5878fefae873a0101f0f62610174b9a2f 100644 (file)
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -297,4 +297,10 @@ config NVMEM_REBOOT_MODE
          then the bootloader can read it and take different
          action according to the mode.
 
+config POWER_MLXBF
+       tristate "Mellanox BlueField power handling driver"
+       depends on (GPIO_MLXBF2 && ACPI)
+       help
+         This driver supports reset or low power mode handling for Mellanox BlueField.
+
 endif

diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index f606a2f60539583bd3e5b82bb816e75f02979996..0a39424fc558e66ff894a02b8359f0bedba86355 100644 (file)
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -35,3 +35,4 @@ obj-$(CONFIG_REBOOT_MODE) += reboot-mode.o
 obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o
 obj-$(CONFIG_POWER_RESET_SC27XX) += sc27xx-poweroff.o
 obj-$(CONFIG_NVMEM_REBOOT_MODE) += nvmem-reboot-mode.o
+obj-$(CONFIG_POWER_MLXBF) += pwr-mlxbf.o

diff --git a/drivers/power/reset/pwr-mlxbf.c b/drivers/power/reset/pwr-mlxbf.c
new file mode 100644 (file)
index 0000000..c1f9987
--- /dev/null
+++ b/drivers/power/reset/pwr-mlxbf.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0-only or BSD-3-Clause
+
+/*
+ *  Copyright (c) 2022 NVIDIA CORPORATION & AFFILIATES.
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/interrupt.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/reboot.h>
+#include <linux/types.h>
+
+const char *rst_pwr_hid = "MLNXBF24";
+const char *low_pwr_hid = "MLNXBF29";
+
+struct pwr_mlxbf {
+       struct work_struct send_work;
+       const char *hid;
+};
+
+static void pwr_mlxbf_send_work(struct work_struct *work)
+{
+       acpi_bus_generate_netlink_event("button/power.*", "Power Button", 0x80, 1);
+}
+
+static irqreturn_t pwr_mlxbf_irq(int irq, void *ptr)
+{
+       struct pwr_mlxbf *priv = ptr;
+
+       if (!strncmp(priv->hid, rst_pwr_hid, 8))
+               emergency_restart();
+
+       if (!strncmp(priv->hid, low_pwr_hid, 8))
+               schedule_work(&priv->send_work);
+
+       return IRQ_HANDLED;
+}
+
+static int pwr_mlxbf_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct acpi_device *adev;
+       struct pwr_mlxbf *priv;
+       const char *hid;
+       int irq, err;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       adev = ACPI_COMPANION(dev);
+       if (!adev)
+               return -ENXIO;
+
+       hid = acpi_device_hid(adev);
+       priv->hid = hid;
+
+       irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
+       if (irq < 0)
+               return dev_err_probe(dev, irq, "Error getting %s irq.\n", priv->hid);
+
+       err = devm_work_autocancel(dev, &priv->send_work, pwr_mlxbf_send_work);
+       if (err)
+               return err;
+
+       err = devm_request_irq(dev, irq, pwr_mlxbf_irq, 0, hid, priv);
+       if (err)
+               dev_err(dev, "Failed request of %s irq\n", priv->hid);
+
+       return err;
+}
+
+static const struct acpi_device_id __maybe_unused pwr_mlxbf_acpi_match[] = {
+       { "MLNXBF24", 0 },
+       { "MLNXBF29", 0 },
+       {},
+};
+MODULE_DEVICE_TABLE(acpi, pwr_mlxbf_acpi_match);
+
+static struct platform_driver pwr_mlxbf_driver = {
+       .driver = {
+               .name = "pwr_mlxbf",
+               .acpi_match_table = pwr_mlxbf_acpi_match,
+       },
+       .probe    = pwr_mlxbf_probe,
+};
+
+module_platform_driver(pwr_mlxbf_driver);
+
+MODULE_DESCRIPTION("Mellanox BlueField power driver");
+MODULE_AUTHOR("Asmaa Mnebhi <asmaa@nvidia.com>");
+MODULE_LICENSE("Dual BSD/GPL");