--- /dev/null
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Intel Xe I2C attached Microcontroller Units (MCU)
+ *
+ * Copyright (C) 2025 Intel Corporation.
+ */
+
+#include <linux/array_size.h>
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/notifier.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/sprintf.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include "regs/xe_i2c_regs.h"
+#include "regs/xe_irq_regs.h"
+
+#include "xe_device.h"
+#include "xe_device_types.h"
+#include "xe_i2c.h"
+#include "xe_mmio.h"
+#include "xe_platform_types.h"
+
+/**
+ * DOC: Xe I2C devices
+ *
+ * Register a platform device for the I2C host controller (Synpsys DesignWare
+ * I2C) if the registers of that controller are mapped to the MMIO, and also the
+ * I2C client device for the Add-In Management Controller (the MCU) attached to
+ * the host controller.
+ *
+ * See drivers/i2c/busses/i2c-designware-* for more information on the I2C host
+ * controller.
+ */
+
+static const char adapter_name[] = "i2c_designware";
+
+static const struct property_entry xe_i2c_adapter_properties[] = {
+ PROPERTY_ENTRY_STRING("compatible", "intel,xe-i2c"),
+ PROPERTY_ENTRY_U32("clock-frequency", I2C_MAX_FAST_MODE_PLUS_FREQ),
+ { }
+};
+
+static inline void xe_i2c_read_endpoint(struct xe_mmio *mmio, void *ep)
+{
+ u32 *val = ep;
+
+ val[0] = xe_mmio_read32(mmio, REG_SG_REMAP_ADDR_PREFIX);
+ val[1] = xe_mmio_read32(mmio, REG_SG_REMAP_ADDR_POSTFIX);
+}
+
+static void xe_i2c_client_work(struct work_struct *work)
+{
+ struct xe_i2c *i2c = container_of(work, struct xe_i2c, work);
+ struct i2c_board_info info = {
+ .type = "amc",
+ .flags = I2C_CLIENT_HOST_NOTIFY,
+ .addr = i2c->ep.addr[1],
+ };
+
+ i2c->client[0] = i2c_new_client_device(i2c->adapter, &info);
+}
+
+static int xe_i2c_notifier(struct notifier_block *nb, unsigned long action, void *data)
+{
+ struct xe_i2c *i2c = container_of(nb, struct xe_i2c, bus_notifier);
+ struct i2c_adapter *adapter = i2c_verify_adapter(data);
+ struct device *dev = data;
+
+ if (action == BUS_NOTIFY_ADD_DEVICE &&
+ adapter && dev->parent == &i2c->pdev->dev) {
+ i2c->adapter = adapter;
+ schedule_work(&i2c->work);
+ return NOTIFY_OK;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int xe_i2c_register_adapter(struct xe_i2c *i2c)
+{
+ struct pci_dev *pci = to_pci_dev(i2c->drm_dev);
+ struct platform_device *pdev;
+ struct fwnode_handle *fwnode;
+ int ret;
+
+ fwnode = fwnode_create_software_node(xe_i2c_adapter_properties, NULL);
+ if (!fwnode)
+ return -ENOMEM;
+
+ /*
+ * Not using platform_device_register_full() here because we don't have
+ * a handle to the platform_device before it returns. xe_i2c_notifier()
+ * uses that handle, but it may be called before
+ * platform_device_register_full() is done.
+ */
+ pdev = platform_device_alloc(adapter_name, pci_dev_id(pci));
+ if (!pdev) {
+ ret = -ENOMEM;
+ goto err_fwnode_remove;
+ }
+
+ if (i2c->adapter_irq) {
+ struct resource res;
+
+ res = DEFINE_RES_IRQ_NAMED(i2c->adapter_irq, "xe_i2c");
+
+ ret = platform_device_add_resources(pdev, &res, 1);
+ if (ret)
+ goto err_pdev_put;
+ }
+
+ pdev->dev.parent = i2c->drm_dev;
+ pdev->dev.fwnode = fwnode;
+ i2c->adapter_node = fwnode;
+ i2c->pdev = pdev;
+
+ ret = platform_device_add(pdev);
+ if (ret)
+ goto err_pdev_put;
+
+ return 0;
+
+err_pdev_put:
+ platform_device_put(pdev);
+err_fwnode_remove:
+ fwnode_remove_software_node(fwnode);
+
+ return ret;
+}
+
+static void xe_i2c_unregister_adapter(struct xe_i2c *i2c)
+{
+ platform_device_unregister(i2c->pdev);
+ fwnode_remove_software_node(i2c->adapter_node);
+}
+
+/**
+ * xe_i2c_irq_handler: Handler for I2C interrupts
+ * @xe: xe device instance
+ * @master_ctl: interrupt register
+ *
+ * Forward interrupts generated by the I2C host adapter to the I2C host adapter
+ * driver.
+ */
+void xe_i2c_irq_handler(struct xe_device *xe, u32 master_ctl)
+{
+ if (!xe->i2c || !xe->i2c->adapter_irq)
+ return;
+
+ if (master_ctl & I2C_IRQ)
+ generic_handle_irq_safe(xe->i2c->adapter_irq);
+}
+
+static int xe_i2c_irq_map(struct irq_domain *h, unsigned int virq,
+ irq_hw_number_t hw_irq_num)
+{
+ irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
+ return 0;
+}
+
+static const struct irq_domain_ops xe_i2c_irq_ops = {
+ .map = xe_i2c_irq_map,
+};
+
+static int xe_i2c_create_irq(struct xe_i2c *i2c)
+{
+ struct irq_domain *domain;
+
+ if (!(i2c->ep.capabilities & XE_I2C_EP_CAP_IRQ))
+ return 0;
+
+ domain = irq_domain_create_linear(dev_fwnode(i2c->drm_dev), 1, &xe_i2c_irq_ops, NULL);
+ if (!domain)
+ return -ENOMEM;
+
+ i2c->adapter_irq = irq_create_mapping(domain, 0);
+ i2c->irqdomain = domain;
+
+ return 0;
+}
+
+static void xe_i2c_remove_irq(struct xe_i2c *i2c)
+{
+ if (!i2c->irqdomain)
+ return;
+
+ irq_dispose_mapping(i2c->adapter_irq);
+ irq_domain_remove(i2c->irqdomain);
+}
+
+static int xe_i2c_read(void *context, unsigned int reg, unsigned int *val)
+{
+ struct xe_i2c *i2c = context;
+
+ *val = xe_mmio_read32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET));
+
+ return 0;
+}
+
+static int xe_i2c_write(void *context, unsigned int reg, unsigned int val)
+{
+ struct xe_i2c *i2c = context;
+
+ xe_mmio_write32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET), val);
+
+ return 0;
+}
+
+static const struct regmap_config i2c_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_read = xe_i2c_read,
+ .reg_write = xe_i2c_write,
+ .fast_io = true,
+};
+
+static void xe_i2c_remove(void *data)
+{
+ struct xe_i2c *i2c = data;
+ unsigned int i;
+
+ for (i = 0; i < XE_I2C_MAX_CLIENTS; i++)
+ i2c_unregister_device(i2c->client[i]);
+
+ bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier);
+ xe_i2c_unregister_adapter(i2c);
+ xe_i2c_remove_irq(i2c);
+}
+
+/**
+ * xe_i2c_probe: Probe the I2C host adapter and the I2C clients attached to it
+ * @xe: xe device instance
+ *
+ * Register all the I2C devices described in the I2C Endpoint data structure.
+ *
+ * Return: 0 on success, error code on failure
+ */
+int xe_i2c_probe(struct xe_device *xe)
+{
+ struct device *drm_dev = xe->drm.dev;
+ struct xe_i2c_endpoint ep;
+ struct regmap *regmap;
+ struct xe_i2c *i2c;
+ int ret;
+
+ if (xe->info.platform != XE_BATTLEMAGE)
+ return 0;
+
+ xe_i2c_read_endpoint(xe_root_tile_mmio(xe), &ep);
+ if (ep.cookie != XE_I2C_EP_COOKIE_DEVICE)
+ return 0;
+
+ i2c = devm_kzalloc(drm_dev, sizeof(*i2c), GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ INIT_WORK(&i2c->work, xe_i2c_client_work);
+ i2c->mmio = xe_root_tile_mmio(xe);
+ i2c->drm_dev = drm_dev;
+ i2c->ep = ep;
+
+ regmap = devm_regmap_init(drm_dev, NULL, i2c, &i2c_regmap_config);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ i2c->bus_notifier.notifier_call = xe_i2c_notifier;
+ ret = bus_register_notifier(&i2c_bus_type, &i2c->bus_notifier);
+ if (ret)
+ return ret;
+
+ ret = xe_i2c_create_irq(i2c);
+ if (ret)
+ goto err_unregister_notifier;
+
+ ret = xe_i2c_register_adapter(i2c);
+ if (ret)
+ goto err_remove_irq;
+
+ return devm_add_action_or_reset(drm_dev, xe_i2c_remove, i2c);
+
+err_remove_irq:
+ xe_i2c_remove_irq(i2c);
+
+err_unregister_notifier:
+ bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier);
+
+ return ret;
+}
projects / thirdparty / kernel / linux.git / commitdiff
