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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/mfd/syscon.c | |
parent | Initial commit. (diff) | |
download | linux-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.c | 348 |
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", ®_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); |