diff options
Diffstat (limited to 'drivers/gpu/drm/xe/xe_i2c.c')
| -rw-r--r-- | drivers/gpu/drm/xe/xe_i2c.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_i2c.c b/drivers/gpu/drm/xe/xe_i2c.c new file mode 100644 index 000000000000..db9c0340be5c --- /dev/null +++ b/drivers/gpu/drm/xe/xe_i2c.c @@ -0,0 +1,329 @@ +// 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, +}; + +void xe_i2c_pm_suspend(struct xe_device *xe) +{ + struct xe_mmio *mmio = xe_root_tile_mmio(xe); + + if (!xe->i2c || xe->i2c->ep.cookie != XE_I2C_EP_COOKIE_DEVICE) + return; + + xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D3hot); + drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); +} + +void xe_i2c_pm_resume(struct xe_device *xe, bool d3cold) +{ + struct xe_mmio *mmio = xe_root_tile_mmio(xe); + + if (!xe->i2c || xe->i2c->ep.cookie != XE_I2C_EP_COOKIE_DEVICE) + return; + + if (d3cold) + xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_MEMORY); + + xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D0); + drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); +} + +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; + xe->i2c = i2c; + + /* PCI PM isn't aware of this device, bring it up and match it with SGUnit state. */ + xe_i2c_pm_resume(xe, true); + + 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; +} |