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authorBartosz Golaszewski <bgolaszewski@baylibre.com>2019-10-03 11:29:12 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-07 13:50:47 +0200
commit507fd01d5333338753a1cc26322dfc9f856c109f (patch)
tree1c15e4d8e2be9ae306d0c72f165357eace49df9e /arch/sh/drivers
parentd4387cd117414ba80230f27a514be5ca4a09cfcc (diff)
drivers: move the early platform device support to arch/sh
SuperH is the only user of the current implementation of early platform device support. We want to introduce a more robust approach to early probing. As the first step - move all the current early platform code to arch/sh. In order not to export internal drivers/base functions to arch code for this temporary solution - copy the two needed routines for driver matching from drivers/base/platform.c to arch/sh/drivers/platform_early.c. Also: call early_platform_cleanup() from subsys_initcall() so that it's called after all early devices are probed. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Rich Felker <dalias@libc.org> Link: https://lore.kernel.org/r/20191003092913.10731-2-brgl@bgdev.pl Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/sh/drivers')
-rw-r--r--arch/sh/drivers/Makefile2
-rw-r--r--arch/sh/drivers/platform_early.c347
2 files changed, 348 insertions, 1 deletions
diff --git a/arch/sh/drivers/Makefile b/arch/sh/drivers/Makefile
index 3e93b434e604..56b0acace6e7 100644
--- a/arch/sh/drivers/Makefile
+++ b/arch/sh/drivers/Makefile
@@ -3,7 +3,7 @@
# Makefile for the Linux SuperH-specific device drivers.
#
-obj-y += dma/
+obj-y += dma/ platform_early.o
obj-$(CONFIG_PCI) += pci/
obj-$(CONFIG_SUPERHYWAY) += superhyway/
diff --git a/arch/sh/drivers/platform_early.c b/arch/sh/drivers/platform_early.c
new file mode 100644
index 000000000000..3dfe9f3541bb
--- /dev/null
+++ b/arch/sh/drivers/platform_early.c
@@ -0,0 +1,347 @@
+// SPDX--License-Identifier: GPL-2.0
+
+#include <asm/platform_early.h>
+#include <linux/mod_devicetable.h>
+#include <linux/pm.h>
+
+static __initdata LIST_HEAD(early_platform_driver_list);
+static __initdata LIST_HEAD(early_platform_device_list);
+
+static const struct platform_device_id *
+platform_match_id(const struct platform_device_id *id,
+ struct platform_device *pdev)
+{
+ while (id->name[0]) {
+ if (strcmp(pdev->name, id->name) == 0) {
+ pdev->id_entry = id;
+ return id;
+ }
+ id++;
+ }
+ return NULL;
+}
+
+static int platform_match(struct device *dev, struct device_driver *drv)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct platform_driver *pdrv = to_platform_driver(drv);
+
+ /* When driver_override is set, only bind to the matching driver */
+ if (pdev->driver_override)
+ return !strcmp(pdev->driver_override, drv->name);
+
+ /* Then try to match against the id table */
+ if (pdrv->id_table)
+ return platform_match_id(pdrv->id_table, pdev) != NULL;
+
+ /* fall-back to driver name match */
+ return (strcmp(pdev->name, drv->name) == 0);
+}
+
+#ifdef CONFIG_PM
+static void device_pm_init_common(struct device *dev)
+{
+ if (!dev->power.early_init) {
+ spin_lock_init(&dev->power.lock);
+ dev->power.qos = NULL;
+ dev->power.early_init = true;
+ }
+}
+
+static void pm_runtime_early_init(struct device *dev)
+{
+ dev->power.disable_depth = 1;
+ device_pm_init_common(dev);
+}
+#else
+static void pm_runtime_early_init(struct device *dev) {}
+#endif
+
+/**
+ * early_platform_driver_register - register early platform driver
+ * @epdrv: early_platform driver structure
+ * @buf: string passed from early_param()
+ *
+ * Helper function for early_platform_init() / early_platform_init_buffer()
+ */
+int __init early_platform_driver_register(struct early_platform_driver *epdrv,
+ char *buf)
+{
+ char *tmp;
+ int n;
+
+ /* Simply add the driver to the end of the global list.
+ * Drivers will by default be put on the list in compiled-in order.
+ */
+ if (!epdrv->list.next) {
+ INIT_LIST_HEAD(&epdrv->list);
+ list_add_tail(&epdrv->list, &early_platform_driver_list);
+ }
+
+ /* If the user has specified device then make sure the driver
+ * gets prioritized. The driver of the last device specified on
+ * command line will be put first on the list.
+ */
+ n = strlen(epdrv->pdrv->driver.name);
+ if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
+ list_move(&epdrv->list, &early_platform_driver_list);
+
+ /* Allow passing parameters after device name */
+ if (buf[n] == '\0' || buf[n] == ',')
+ epdrv->requested_id = -1;
+ else {
+ epdrv->requested_id = simple_strtoul(&buf[n + 1],
+ &tmp, 10);
+
+ if (buf[n] != '.' || (tmp == &buf[n + 1])) {
+ epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
+ n = 0;
+ } else
+ n += strcspn(&buf[n + 1], ",") + 1;
+ }
+
+ if (buf[n] == ',')
+ n++;
+
+ if (epdrv->bufsize) {
+ memcpy(epdrv->buffer, &buf[n],
+ min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
+ epdrv->buffer[epdrv->bufsize - 1] = '\0';
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * early_platform_add_devices - adds a number of early platform devices
+ * @devs: array of early platform devices to add
+ * @num: number of early platform devices in array
+ *
+ * Used by early architecture code to register early platform devices and
+ * their platform data.
+ */
+void __init early_platform_add_devices(struct platform_device **devs, int num)
+{
+ struct device *dev;
+ int i;
+
+ /* simply add the devices to list */
+ for (i = 0; i < num; i++) {
+ dev = &devs[i]->dev;
+
+ if (!dev->devres_head.next) {
+ pm_runtime_early_init(dev);
+ INIT_LIST_HEAD(&dev->devres_head);
+ list_add_tail(&dev->devres_head,
+ &early_platform_device_list);
+ }
+ }
+}
+
+/**
+ * early_platform_driver_register_all - register early platform drivers
+ * @class_str: string to identify early platform driver class
+ *
+ * Used by architecture code to register all early platform drivers
+ * for a certain class. If omitted then only early platform drivers
+ * with matching kernel command line class parameters will be registered.
+ */
+void __init early_platform_driver_register_all(char *class_str)
+{
+ /* The "class_str" parameter may or may not be present on the kernel
+ * command line. If it is present then there may be more than one
+ * matching parameter.
+ *
+ * Since we register our early platform drivers using early_param()
+ * we need to make sure that they also get registered in the case
+ * when the parameter is missing from the kernel command line.
+ *
+ * We use parse_early_options() to make sure the early_param() gets
+ * called at least once. The early_param() may be called more than
+ * once since the name of the preferred device may be specified on
+ * the kernel command line. early_platform_driver_register() handles
+ * this case for us.
+ */
+ parse_early_options(class_str);
+}
+
+/**
+ * early_platform_match - find early platform device matching driver
+ * @epdrv: early platform driver structure
+ * @id: id to match against
+ */
+static struct platform_device * __init
+early_platform_match(struct early_platform_driver *epdrv, int id)
+{
+ struct platform_device *pd;
+
+ list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
+ if (platform_match(&pd->dev, &epdrv->pdrv->driver))
+ if (pd->id == id)
+ return pd;
+
+ return NULL;
+}
+
+/**
+ * early_platform_left - check if early platform driver has matching devices
+ * @epdrv: early platform driver structure
+ * @id: return true if id or above exists
+ */
+static int __init early_platform_left(struct early_platform_driver *epdrv,
+ int id)
+{
+ struct platform_device *pd;
+
+ list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
+ if (platform_match(&pd->dev, &epdrv->pdrv->driver))
+ if (pd->id >= id)
+ return 1;
+
+ return 0;
+}
+
+/**
+ * early_platform_driver_probe_id - probe drivers matching class_str and id
+ * @class_str: string to identify early platform driver class
+ * @id: id to match against
+ * @nr_probe: number of platform devices to successfully probe before exiting
+ */
+static int __init early_platform_driver_probe_id(char *class_str,
+ int id,
+ int nr_probe)
+{
+ struct early_platform_driver *epdrv;
+ struct platform_device *match;
+ int match_id;
+ int n = 0;
+ int left = 0;
+
+ list_for_each_entry(epdrv, &early_platform_driver_list, list) {
+ /* only use drivers matching our class_str */
+ if (strcmp(class_str, epdrv->class_str))
+ continue;
+
+ if (id == -2) {
+ match_id = epdrv->requested_id;
+ left = 1;
+
+ } else {
+ match_id = id;
+ left += early_platform_left(epdrv, id);
+
+ /* skip requested id */
+ switch (epdrv->requested_id) {
+ case EARLY_PLATFORM_ID_ERROR:
+ case EARLY_PLATFORM_ID_UNSET:
+ break;
+ default:
+ if (epdrv->requested_id == id)
+ match_id = EARLY_PLATFORM_ID_UNSET;
+ }
+ }
+
+ switch (match_id) {
+ case EARLY_PLATFORM_ID_ERROR:
+ pr_warn("%s: unable to parse %s parameter\n",
+ class_str, epdrv->pdrv->driver.name);
+ /* fall-through */
+ case EARLY_PLATFORM_ID_UNSET:
+ match = NULL;
+ break;
+ default:
+ match = early_platform_match(epdrv, match_id);
+ }
+
+ if (match) {
+ /*
+ * Set up a sensible init_name to enable
+ * dev_name() and others to be used before the
+ * rest of the driver core is initialized.
+ */
+ if (!match->dev.init_name && slab_is_available()) {
+ if (match->id != -1)
+ match->dev.init_name =
+ kasprintf(GFP_KERNEL, "%s.%d",
+ match->name,
+ match->id);
+ else
+ match->dev.init_name =
+ kasprintf(GFP_KERNEL, "%s",
+ match->name);
+
+ if (!match->dev.init_name)
+ return -ENOMEM;
+ }
+
+ if (epdrv->pdrv->probe(match))
+ pr_warn("%s: unable to probe %s early.\n",
+ class_str, match->name);
+ else
+ n++;
+ }
+
+ if (n >= nr_probe)
+ break;
+ }
+
+ if (left)
+ return n;
+ else
+ return -ENODEV;
+}
+
+/**
+ * early_platform_driver_probe - probe a class of registered drivers
+ * @class_str: string to identify early platform driver class
+ * @nr_probe: number of platform devices to successfully probe before exiting
+ * @user_only: only probe user specified early platform devices
+ *
+ * Used by architecture code to probe registered early platform drivers
+ * within a certain class. For probe to happen a registered early platform
+ * device matching a registered early platform driver is needed.
+ */
+int __init early_platform_driver_probe(char *class_str,
+ int nr_probe,
+ int user_only)
+{
+ int k, n, i;
+
+ n = 0;
+ for (i = -2; n < nr_probe; i++) {
+ k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
+
+ if (k < 0)
+ break;
+
+ n += k;
+
+ if (user_only)
+ break;
+ }
+
+ return n;
+}
+
+/**
+ * early_platform_cleanup - clean up early platform code
+ */
+static int __init early_platform_cleanup(void)
+{
+ struct platform_device *pd, *pd2;
+
+ /* clean up the devres list used to chain devices */
+ list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
+ dev.devres_head) {
+ list_del(&pd->dev.devres_head);
+ memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
+ }
+
+ return 0;
+}
+/*
+ * This must happen once after all early devices are probed but before probing
+ * real platform devices.
+ */
+subsys_initcall(early_platform_cleanup);