summaryrefslogtreecommitdiffstats
path: root/drivers/mfd/syscon.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/mfd/syscon.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--drivers/mfd/syscon.c348
1 files changed, 348 insertions, 0 deletions
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
new file mode 100644
index 0000000000..c9550368d9
--- /dev/null
+++ b/drivers/mfd/syscon.c
@@ -0,0 +1,348 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * System Control Driver
+ *
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ * Copyright (C) 2012 Linaro Ltd.
+ *
+ * Author: Dong Aisheng <dong.aisheng@linaro.org>
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_data/syscon.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/mfd/syscon.h>
+#include <linux/slab.h>
+
+static struct platform_driver syscon_driver;
+
+static DEFINE_SPINLOCK(syscon_list_slock);
+static LIST_HEAD(syscon_list);
+
+struct syscon {
+ struct device_node *np;
+ struct regmap *regmap;
+ struct reset_control *reset;
+ struct list_head list;
+};
+
+static const struct regmap_config syscon_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+};
+
+static struct syscon *of_syscon_register(struct device_node *np, bool check_res)
+{
+ struct clk *clk;
+ struct syscon *syscon;
+ struct regmap *regmap;
+ void __iomem *base;
+ u32 reg_io_width;
+ int ret;
+ struct regmap_config syscon_config = syscon_regmap_config;
+ struct resource res;
+ struct reset_control *reset;
+
+ syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
+ if (!syscon)
+ return ERR_PTR(-ENOMEM);
+
+ if (of_address_to_resource(np, 0, &res)) {
+ ret = -ENOMEM;
+ goto err_map;
+ }
+
+ base = of_iomap(np, 0);
+ if (!base) {
+ ret = -ENOMEM;
+ goto err_map;
+ }
+
+ /* Parse the device's DT node for an endianness specification */
+ if (of_property_read_bool(np, "big-endian"))
+ syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
+ else if (of_property_read_bool(np, "little-endian"))
+ syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
+ else if (of_property_read_bool(np, "native-endian"))
+ syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
+
+ /*
+ * search for reg-io-width property in DT. If it is not provided,
+ * default to 4 bytes. regmap_init_mmio will return an error if values
+ * are invalid so there is no need to check them here.
+ */
+ ret = of_property_read_u32(np, "reg-io-width", &reg_io_width);
+ if (ret)
+ reg_io_width = 4;
+
+ ret = of_hwspin_lock_get_id(np, 0);
+ if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
+ syscon_config.use_hwlock = true;
+ syscon_config.hwlock_id = ret;
+ syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
+ } else if (ret < 0) {
+ switch (ret) {
+ case -ENOENT:
+ /* Ignore missing hwlock, it's optional. */
+ break;
+ default:
+ pr_err("Failed to retrieve valid hwlock: %d\n", ret);
+ fallthrough;
+ case -EPROBE_DEFER:
+ goto err_regmap;
+ }
+ }
+
+ syscon_config.name = kasprintf(GFP_KERNEL, "%pOFn@%pa", np, &res.start);
+ if (!syscon_config.name) {
+ ret = -ENOMEM;
+ goto err_regmap;
+ }
+ syscon_config.reg_stride = reg_io_width;
+ syscon_config.val_bits = reg_io_width * 8;
+ syscon_config.max_register = resource_size(&res) - reg_io_width;
+
+ regmap = regmap_init_mmio(NULL, base, &syscon_config);
+ kfree(syscon_config.name);
+ if (IS_ERR(regmap)) {
+ pr_err("regmap init failed\n");
+ ret = PTR_ERR(regmap);
+ goto err_regmap;
+ }
+
+ if (check_res) {
+ clk = of_clk_get(np, 0);
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
+ /* clock is optional */
+ if (ret != -ENOENT)
+ goto err_clk;
+ } else {
+ ret = regmap_mmio_attach_clk(regmap, clk);
+ if (ret)
+ goto err_attach_clk;
+ }
+
+ reset = of_reset_control_get_optional_exclusive(np, NULL);
+ if (IS_ERR(reset)) {
+ ret = PTR_ERR(reset);
+ goto err_attach_clk;
+ }
+
+ ret = reset_control_deassert(reset);
+ if (ret)
+ goto err_reset;
+ }
+
+ syscon->regmap = regmap;
+ syscon->np = np;
+
+ spin_lock(&syscon_list_slock);
+ list_add_tail(&syscon->list, &syscon_list);
+ spin_unlock(&syscon_list_slock);
+
+ return syscon;
+
+err_reset:
+ reset_control_put(reset);
+err_attach_clk:
+ if (!IS_ERR(clk))
+ clk_put(clk);
+err_clk:
+ regmap_exit(regmap);
+err_regmap:
+ iounmap(base);
+err_map:
+ kfree(syscon);
+ return ERR_PTR(ret);
+}
+
+static struct regmap *device_node_get_regmap(struct device_node *np,
+ bool check_res)
+{
+ struct syscon *entry, *syscon = NULL;
+
+ spin_lock(&syscon_list_slock);
+
+ list_for_each_entry(entry, &syscon_list, list)
+ if (entry->np == np) {
+ syscon = entry;
+ break;
+ }
+
+ spin_unlock(&syscon_list_slock);
+
+ if (!syscon)
+ syscon = of_syscon_register(np, check_res);
+
+ if (IS_ERR(syscon))
+ return ERR_CAST(syscon);
+
+ return syscon->regmap;
+}
+
+struct regmap *device_node_to_regmap(struct device_node *np)
+{
+ return device_node_get_regmap(np, false);
+}
+EXPORT_SYMBOL_GPL(device_node_to_regmap);
+
+struct regmap *syscon_node_to_regmap(struct device_node *np)
+{
+ if (!of_device_is_compatible(np, "syscon"))
+ return ERR_PTR(-EINVAL);
+
+ return device_node_get_regmap(np, true);
+}
+EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
+
+struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
+{
+ struct device_node *syscon_np;
+ struct regmap *regmap;
+
+ syscon_np = of_find_compatible_node(NULL, NULL, s);
+ if (!syscon_np)
+ return ERR_PTR(-ENODEV);
+
+ regmap = syscon_node_to_regmap(syscon_np);
+ of_node_put(syscon_np);
+
+ return regmap;
+}
+EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
+
+struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
+ const char *property)
+{
+ struct device_node *syscon_np;
+ struct regmap *regmap;
+
+ if (property)
+ syscon_np = of_parse_phandle(np, property, 0);
+ else
+ syscon_np = np;
+
+ if (!syscon_np)
+ return ERR_PTR(-ENODEV);
+
+ regmap = syscon_node_to_regmap(syscon_np);
+ of_node_put(syscon_np);
+
+ return regmap;
+}
+EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
+
+struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np,
+ const char *property,
+ int arg_count,
+ unsigned int *out_args)
+{
+ struct device_node *syscon_np;
+ struct of_phandle_args args;
+ struct regmap *regmap;
+ unsigned int index;
+ int rc;
+
+ rc = of_parse_phandle_with_fixed_args(np, property, arg_count,
+ 0, &args);
+ if (rc)
+ return ERR_PTR(rc);
+
+ syscon_np = args.np;
+ if (!syscon_np)
+ return ERR_PTR(-ENODEV);
+
+ regmap = syscon_node_to_regmap(syscon_np);
+ for (index = 0; index < arg_count; index++)
+ out_args[index] = args.args[index];
+ of_node_put(syscon_np);
+
+ return regmap;
+}
+EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args);
+
+/*
+ * It behaves the same as syscon_regmap_lookup_by_phandle() except where
+ * there is no regmap phandle. In this case, instead of returning -ENODEV,
+ * the function returns NULL.
+ */
+struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np,
+ const char *property)
+{
+ struct regmap *regmap;
+
+ regmap = syscon_regmap_lookup_by_phandle(np, property);
+ if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
+ return NULL;
+
+ return regmap;
+}
+EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional);
+
+static int syscon_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct syscon_platform_data *pdata = dev_get_platdata(dev);
+ struct syscon *syscon;
+ struct regmap_config syscon_config = syscon_regmap_config;
+ struct resource *res;
+ void __iomem *base;
+
+ syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
+ if (!syscon)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENOENT;
+
+ base = devm_ioremap(dev, res->start, resource_size(res));
+ if (!base)
+ return -ENOMEM;
+
+ syscon_config.max_register = resource_size(res) - 4;
+ if (pdata)
+ syscon_config.name = pdata->label;
+ syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
+ if (IS_ERR(syscon->regmap)) {
+ dev_err(dev, "regmap init failed\n");
+ return PTR_ERR(syscon->regmap);
+ }
+
+ platform_set_drvdata(pdev, syscon);
+
+ dev_dbg(dev, "regmap %pR registered\n", res);
+
+ return 0;
+}
+
+static const struct platform_device_id syscon_ids[] = {
+ { "syscon", },
+ { }
+};
+
+static struct platform_driver syscon_driver = {
+ .driver = {
+ .name = "syscon",
+ },
+ .probe = syscon_probe,
+ .id_table = syscon_ids,
+};
+
+static int __init syscon_init(void)
+{
+ return platform_driver_register(&syscon_driver);
+}
+postcore_initcall(syscon_init);