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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/amba/bus.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/amba/bus.c')
-rw-r--r--drivers/amba/bus.c702
1 files changed, 702 insertions, 0 deletions
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
new file mode 100644
index 000000000..0aa2d3111
--- /dev/null
+++ b/drivers/amba/bus.c
@@ -0,0 +1,702 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/arch/arm/common/amba.c
+ *
+ * Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
+#include <linux/amba/bus.h>
+#include <linux/sizes.h>
+#include <linux/limits.h>
+#include <linux/clk/clk-conf.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/of_irq.h>
+#include <linux/of_device.h>
+#include <linux/acpi.h>
+#include <linux/iommu.h>
+#include <linux/dma-map-ops.h>
+
+#define to_amba_driver(d) container_of(d, struct amba_driver, drv)
+
+/* called on periphid match and class 0x9 coresight device. */
+static int
+amba_cs_uci_id_match(const struct amba_id *table, struct amba_device *dev)
+{
+ int ret = 0;
+ struct amba_cs_uci_id *uci;
+
+ uci = table->data;
+
+ /* no table data or zero mask - return match on periphid */
+ if (!uci || (uci->devarch_mask == 0))
+ return 1;
+
+ /* test against read devtype and masked devarch value */
+ ret = (dev->uci.devtype == uci->devtype) &&
+ ((dev->uci.devarch & uci->devarch_mask) == uci->devarch);
+ return ret;
+}
+
+static const struct amba_id *
+amba_lookup(const struct amba_id *table, struct amba_device *dev)
+{
+ while (table->mask) {
+ if (((dev->periphid & table->mask) == table->id) &&
+ ((dev->cid != CORESIGHT_CID) ||
+ (amba_cs_uci_id_match(table, dev))))
+ return table;
+ table++;
+ }
+ return NULL;
+}
+
+static int amba_get_enable_pclk(struct amba_device *pcdev)
+{
+ int ret;
+
+ pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
+ if (IS_ERR(pcdev->pclk))
+ return PTR_ERR(pcdev->pclk);
+
+ ret = clk_prepare_enable(pcdev->pclk);
+ if (ret)
+ clk_put(pcdev->pclk);
+
+ return ret;
+}
+
+static void amba_put_disable_pclk(struct amba_device *pcdev)
+{
+ clk_disable_unprepare(pcdev->pclk);
+ clk_put(pcdev->pclk);
+}
+
+
+static ssize_t driver_override_show(struct device *_dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct amba_device *dev = to_amba_device(_dev);
+ ssize_t len;
+
+ device_lock(_dev);
+ len = sprintf(buf, "%s\n", dev->driver_override);
+ device_unlock(_dev);
+ return len;
+}
+
+static ssize_t driver_override_store(struct device *_dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct amba_device *dev = to_amba_device(_dev);
+ int ret;
+
+ ret = driver_set_override(_dev, &dev->driver_override, buf, count);
+ if (ret)
+ return ret;
+
+ return count;
+}
+static DEVICE_ATTR_RW(driver_override);
+
+#define amba_attr_func(name,fmt,arg...) \
+static ssize_t name##_show(struct device *_dev, \
+ struct device_attribute *attr, char *buf) \
+{ \
+ struct amba_device *dev = to_amba_device(_dev); \
+ return sprintf(buf, fmt, arg); \
+} \
+static DEVICE_ATTR_RO(name)
+
+amba_attr_func(id, "%08x\n", dev->periphid);
+amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
+ (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
+ dev->res.flags);
+
+static struct attribute *amba_dev_attrs[] = {
+ &dev_attr_id.attr,
+ &dev_attr_resource.attr,
+ &dev_attr_driver_override.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(amba_dev);
+
+static int amba_read_periphid(struct amba_device *dev)
+{
+ struct reset_control *rstc;
+ u32 size, pid, cid;
+ void __iomem *tmp;
+ int i, ret;
+
+ ret = dev_pm_domain_attach(&dev->dev, true);
+ if (ret) {
+ dev_dbg(&dev->dev, "can't get PM domain: %d\n", ret);
+ goto err_out;
+ }
+
+ ret = amba_get_enable_pclk(dev);
+ if (ret) {
+ dev_dbg(&dev->dev, "can't get pclk: %d\n", ret);
+ goto err_pm;
+ }
+
+ /*
+ * Find reset control(s) of the amba bus and de-assert them.
+ */
+ rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node);
+ if (IS_ERR(rstc)) {
+ ret = PTR_ERR(rstc);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&dev->dev, "can't get reset: %d\n", ret);
+ goto err_clk;
+ }
+ reset_control_deassert(rstc);
+ reset_control_put(rstc);
+
+ size = resource_size(&dev->res);
+ tmp = ioremap(dev->res.start, size);
+ if (!tmp) {
+ ret = -ENOMEM;
+ goto err_clk;
+ }
+
+ /*
+ * Read pid and cid based on size of resource
+ * they are located at end of region
+ */
+ for (pid = 0, i = 0; i < 4; i++)
+ pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << (i * 8);
+ for (cid = 0, i = 0; i < 4; i++)
+ cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << (i * 8);
+
+ if (cid == CORESIGHT_CID) {
+ /* set the base to the start of the last 4k block */
+ void __iomem *csbase = tmp + size - 4096;
+
+ dev->uci.devarch = readl(csbase + UCI_REG_DEVARCH_OFFSET);
+ dev->uci.devtype = readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
+ }
+
+ if (cid == AMBA_CID || cid == CORESIGHT_CID) {
+ dev->periphid = pid;
+ dev->cid = cid;
+ }
+
+ if (!dev->periphid)
+ ret = -ENODEV;
+
+ iounmap(tmp);
+
+err_clk:
+ amba_put_disable_pclk(dev);
+err_pm:
+ dev_pm_domain_detach(&dev->dev, true);
+err_out:
+ return ret;
+}
+
+static int amba_match(struct device *dev, struct device_driver *drv)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+ struct amba_driver *pcdrv = to_amba_driver(drv);
+
+ mutex_lock(&pcdev->periphid_lock);
+ if (!pcdev->periphid) {
+ int ret = amba_read_periphid(pcdev);
+
+ /*
+ * Returning any error other than -EPROBE_DEFER from bus match
+ * can cause driver registration failure. So, if there's a
+ * permanent failure in reading pid and cid, simply map it to
+ * -EPROBE_DEFER.
+ */
+ if (ret) {
+ mutex_unlock(&pcdev->periphid_lock);
+ return -EPROBE_DEFER;
+ }
+ dev_set_uevent_suppress(dev, false);
+ kobject_uevent(&dev->kobj, KOBJ_ADD);
+ }
+ mutex_unlock(&pcdev->periphid_lock);
+
+ /* When driver_override is set, only bind to the matching driver */
+ if (pcdev->driver_override)
+ return !strcmp(pcdev->driver_override, drv->name);
+
+ return amba_lookup(pcdrv->id_table, pcdev) != NULL;
+}
+
+static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+ int retval = 0;
+
+ retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
+ if (retval)
+ return retval;
+
+ retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
+ return retval;
+}
+
+static int of_amba_device_decode_irq(struct amba_device *dev)
+{
+ struct device_node *node = dev->dev.of_node;
+ int i, irq = 0;
+
+ if (IS_ENABLED(CONFIG_OF_IRQ) && node) {
+ /* Decode the IRQs and address ranges */
+ for (i = 0; i < AMBA_NR_IRQS; i++) {
+ irq = of_irq_get(node, i);
+ if (irq < 0) {
+ if (irq == -EPROBE_DEFER)
+ return irq;
+ irq = 0;
+ }
+
+ dev->irq[i] = irq;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * These are the device model conversion veneers; they convert the
+ * device model structures to our more specific structures.
+ */
+static int amba_probe(struct device *dev)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+ struct amba_driver *pcdrv = to_amba_driver(dev->driver);
+ const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
+ int ret;
+
+ do {
+ ret = of_amba_device_decode_irq(pcdev);
+ if (ret)
+ break;
+
+ ret = of_clk_set_defaults(dev->of_node, false);
+ if (ret < 0)
+ break;
+
+ ret = dev_pm_domain_attach(dev, true);
+ if (ret)
+ break;
+
+ ret = amba_get_enable_pclk(pcdev);
+ if (ret) {
+ dev_pm_domain_detach(dev, true);
+ break;
+ }
+
+ pm_runtime_get_noresume(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
+ ret = pcdrv->probe(pcdev, id);
+ if (ret == 0)
+ break;
+
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);
+
+ amba_put_disable_pclk(pcdev);
+ dev_pm_domain_detach(dev, true);
+ } while (0);
+
+ return ret;
+}
+
+static void amba_remove(struct device *dev)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+ struct amba_driver *drv = to_amba_driver(dev->driver);
+
+ pm_runtime_get_sync(dev);
+ if (drv->remove)
+ drv->remove(pcdev);
+ pm_runtime_put_noidle(dev);
+
+ /* Undo the runtime PM settings in amba_probe() */
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);
+
+ amba_put_disable_pclk(pcdev);
+ dev_pm_domain_detach(dev, true);
+}
+
+static void amba_shutdown(struct device *dev)
+{
+ struct amba_driver *drv;
+
+ if (!dev->driver)
+ return;
+
+ drv = to_amba_driver(dev->driver);
+ if (drv->shutdown)
+ drv->shutdown(to_amba_device(dev));
+}
+
+static int amba_dma_configure(struct device *dev)
+{
+ struct amba_driver *drv = to_amba_driver(dev->driver);
+ enum dev_dma_attr attr;
+ int ret = 0;
+
+ if (dev->of_node) {
+ ret = of_dma_configure(dev, dev->of_node, true);
+ } else if (has_acpi_companion(dev)) {
+ attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
+ ret = acpi_dma_configure(dev, attr);
+ }
+
+ if (!ret && !drv->driver_managed_dma) {
+ ret = iommu_device_use_default_domain(dev);
+ if (ret)
+ arch_teardown_dma_ops(dev);
+ }
+
+ return ret;
+}
+
+static void amba_dma_cleanup(struct device *dev)
+{
+ struct amba_driver *drv = to_amba_driver(dev->driver);
+
+ if (!drv->driver_managed_dma)
+ iommu_device_unuse_default_domain(dev);
+}
+
+#ifdef CONFIG_PM
+/*
+ * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
+ * enable/disable the bus clock at runtime PM suspend/resume as this
+ * does not result in loss of context.
+ */
+static int amba_pm_runtime_suspend(struct device *dev)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+ int ret = pm_generic_runtime_suspend(dev);
+
+ if (ret == 0 && dev->driver) {
+ if (pm_runtime_is_irq_safe(dev))
+ clk_disable(pcdev->pclk);
+ else
+ clk_disable_unprepare(pcdev->pclk);
+ }
+
+ return ret;
+}
+
+static int amba_pm_runtime_resume(struct device *dev)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+ int ret;
+
+ if (dev->driver) {
+ if (pm_runtime_is_irq_safe(dev))
+ ret = clk_enable(pcdev->pclk);
+ else
+ ret = clk_prepare_enable(pcdev->pclk);
+ /* Failure is probably fatal to the system, but... */
+ if (ret)
+ return ret;
+ }
+
+ return pm_generic_runtime_resume(dev);
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops amba_pm = {
+ .suspend = pm_generic_suspend,
+ .resume = pm_generic_resume,
+ .freeze = pm_generic_freeze,
+ .thaw = pm_generic_thaw,
+ .poweroff = pm_generic_poweroff,
+ .restore = pm_generic_restore,
+ SET_RUNTIME_PM_OPS(
+ amba_pm_runtime_suspend,
+ amba_pm_runtime_resume,
+ NULL
+ )
+};
+
+/*
+ * Primecells are part of the Advanced Microcontroller Bus Architecture,
+ * so we call the bus "amba".
+ * DMA configuration for platform and AMBA bus is same. So here we reuse
+ * platform's DMA config routine.
+ */
+struct bus_type amba_bustype = {
+ .name = "amba",
+ .dev_groups = amba_dev_groups,
+ .match = amba_match,
+ .uevent = amba_uevent,
+ .probe = amba_probe,
+ .remove = amba_remove,
+ .shutdown = amba_shutdown,
+ .dma_configure = amba_dma_configure,
+ .dma_cleanup = amba_dma_cleanup,
+ .pm = &amba_pm,
+};
+EXPORT_SYMBOL_GPL(amba_bustype);
+
+static int __init amba_init(void)
+{
+ return bus_register(&amba_bustype);
+}
+
+postcore_initcall(amba_init);
+
+static int amba_proxy_probe(struct amba_device *adev,
+ const struct amba_id *id)
+{
+ WARN(1, "Stub driver should never match any device.\n");
+ return -ENODEV;
+}
+
+static const struct amba_id amba_stub_drv_ids[] = {
+ { 0, 0 },
+};
+
+static struct amba_driver amba_proxy_drv = {
+ .drv = {
+ .name = "amba-proxy",
+ },
+ .probe = amba_proxy_probe,
+ .id_table = amba_stub_drv_ids,
+};
+
+static int __init amba_stub_drv_init(void)
+{
+ if (!IS_ENABLED(CONFIG_MODULES))
+ return 0;
+
+ /*
+ * The amba_match() function will get called only if there is at least
+ * one amba driver registered. If all amba drivers are modules and are
+ * only loaded based on uevents, then we'll hit a chicken-and-egg
+ * situation where amba_match() is waiting on drivers and drivers are
+ * waiting on amba_match(). So, register a stub driver to make sure
+ * amba_match() is called even if no amba driver has been registered.
+ */
+ return amba_driver_register(&amba_proxy_drv);
+}
+late_initcall_sync(amba_stub_drv_init);
+
+/**
+ * amba_driver_register - register an AMBA device driver
+ * @drv: amba device driver structure
+ *
+ * Register an AMBA device driver with the Linux device model
+ * core. If devices pre-exist, the drivers probe function will
+ * be called.
+ */
+int amba_driver_register(struct amba_driver *drv)
+{
+ if (!drv->probe)
+ return -EINVAL;
+
+ drv->drv.bus = &amba_bustype;
+
+ return driver_register(&drv->drv);
+}
+EXPORT_SYMBOL(amba_driver_register);
+
+/**
+ * amba_driver_unregister - remove an AMBA device driver
+ * @drv: AMBA device driver structure to remove
+ *
+ * Unregister an AMBA device driver from the Linux device
+ * model. The device model will call the drivers remove function
+ * for each device the device driver is currently handling.
+ */
+void amba_driver_unregister(struct amba_driver *drv)
+{
+ driver_unregister(&drv->drv);
+}
+EXPORT_SYMBOL(amba_driver_unregister);
+
+static void amba_device_release(struct device *dev)
+{
+ struct amba_device *d = to_amba_device(dev);
+
+ of_node_put(d->dev.of_node);
+ if (d->res.parent)
+ release_resource(&d->res);
+ mutex_destroy(&d->periphid_lock);
+ kfree(d);
+}
+
+/**
+ * amba_device_add - add a previously allocated AMBA device structure
+ * @dev: AMBA device allocated by amba_device_alloc
+ * @parent: resource parent for this devices resources
+ *
+ * Claim the resource, and read the device cell ID if not already
+ * initialized. Register the AMBA device with the Linux device
+ * manager.
+ */
+int amba_device_add(struct amba_device *dev, struct resource *parent)
+{
+ int ret;
+
+ ret = request_resource(parent, &dev->res);
+ if (ret)
+ return ret;
+
+ /* If primecell ID isn't hard-coded, figure it out */
+ if (!dev->periphid) {
+ /*
+ * AMBA device uevents require reading its pid and cid
+ * registers. To do this, the device must be on, clocked and
+ * out of reset. However in some cases those resources might
+ * not yet be available. If that's the case, we suppress the
+ * generation of uevents until we can read the pid and cid
+ * registers. See also amba_match().
+ */
+ if (amba_read_periphid(dev))
+ dev_set_uevent_suppress(&dev->dev, true);
+ }
+
+ ret = device_add(&dev->dev);
+ if (ret)
+ release_resource(&dev->res);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(amba_device_add);
+
+static void amba_device_initialize(struct amba_device *dev, const char *name)
+{
+ device_initialize(&dev->dev);
+ if (name)
+ dev_set_name(&dev->dev, "%s", name);
+ dev->dev.release = amba_device_release;
+ dev->dev.bus = &amba_bustype;
+ dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+ dev->dev.dma_parms = &dev->dma_parms;
+ dev->res.name = dev_name(&dev->dev);
+ mutex_init(&dev->periphid_lock);
+}
+
+/**
+ * amba_device_alloc - allocate an AMBA device
+ * @name: sysfs name of the AMBA device
+ * @base: base of AMBA device
+ * @size: size of AMBA device
+ *
+ * Allocate and initialize an AMBA device structure. Returns %NULL
+ * on failure.
+ */
+struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
+ size_t size)
+{
+ struct amba_device *dev;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (dev) {
+ amba_device_initialize(dev, name);
+ dev->res.start = base;
+ dev->res.end = base + size - 1;
+ dev->res.flags = IORESOURCE_MEM;
+ }
+
+ return dev;
+}
+EXPORT_SYMBOL_GPL(amba_device_alloc);
+
+/**
+ * amba_device_register - register an AMBA device
+ * @dev: AMBA device to register
+ * @parent: parent memory resource
+ *
+ * Setup the AMBA device, reading the cell ID if present.
+ * Claim the resource, and register the AMBA device with
+ * the Linux device manager.
+ */
+int amba_device_register(struct amba_device *dev, struct resource *parent)
+{
+ amba_device_initialize(dev, dev->dev.init_name);
+ dev->dev.init_name = NULL;
+
+ return amba_device_add(dev, parent);
+}
+EXPORT_SYMBOL(amba_device_register);
+
+/**
+ * amba_device_put - put an AMBA device
+ * @dev: AMBA device to put
+ */
+void amba_device_put(struct amba_device *dev)
+{
+ put_device(&dev->dev);
+}
+EXPORT_SYMBOL_GPL(amba_device_put);
+
+/**
+ * amba_device_unregister - unregister an AMBA device
+ * @dev: AMBA device to remove
+ *
+ * Remove the specified AMBA device from the Linux device
+ * manager. All files associated with this object will be
+ * destroyed, and device drivers notified that the device has
+ * been removed. The AMBA device's resources including
+ * the amba_device structure will be freed once all
+ * references to it have been dropped.
+ */
+void amba_device_unregister(struct amba_device *dev)
+{
+ device_unregister(&dev->dev);
+}
+EXPORT_SYMBOL(amba_device_unregister);
+
+/**
+ * amba_request_regions - request all mem regions associated with device
+ * @dev: amba_device structure for device
+ * @name: name, or NULL to use driver name
+ */
+int amba_request_regions(struct amba_device *dev, const char *name)
+{
+ int ret = 0;
+ u32 size;
+
+ if (!name)
+ name = dev->dev.driver->name;
+
+ size = resource_size(&dev->res);
+
+ if (!request_mem_region(dev->res.start, size, name))
+ ret = -EBUSY;
+
+ return ret;
+}
+EXPORT_SYMBOL(amba_request_regions);
+
+/**
+ * amba_release_regions - release mem regions associated with device
+ * @dev: amba_device structure for device
+ *
+ * Release regions claimed by a successful call to amba_request_regions.
+ */
+void amba_release_regions(struct amba_device *dev)
+{
+ u32 size;
+
+ size = resource_size(&dev->res);
+ release_mem_region(dev->res.start, size);
+}
+EXPORT_SYMBOL(amba_release_regions);