Some platforms need to get system controller ready as soon as possible. The patch provides early_syscon_initialization which create early mapping for all syscon compatible devices in early_syscon_probe. Regmap is get via syscon_early_regmap_lookup_by_phandle()
Regular device probes attach device to regmap via regmap_attach_dev(). For early syscon initialization is necessary to extend struct syscon and provide remove function which unmap all early init structures. Signed-off-by: Michal Simek <[email protected]> --- drivers/mfd/syscon.c | 126 +++++++++++++++++++++++++++++++++++++++------ include/linux/mfd/syscon.h | 11 ++++ 2 files changed, 120 insertions(+), 17 deletions(-) diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index 71841f9..5935f02 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -20,12 +20,15 @@ #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/regmap.h> +#include <linux/slab.h> #include <linux/mfd/syscon.h> static struct platform_driver syscon_driver; struct syscon { + void __iomem *base; struct regmap *regmap; + struct resource res; }; static int syscon_match_node(struct device *dev, void *data) @@ -95,6 +98,24 @@ struct regmap *syscon_regmap_lookup_by_pdevname(const char *s) } EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname); +struct regmap *syscon_early_regmap_lookup_by_phandle(struct device_node *np, + const char *property) +{ + struct device_node *syscon_np; + struct syscon *syscon; + + syscon_np = of_parse_phandle(np, property, 0); + if (!syscon_np) + return ERR_PTR(-ENODEV); + + syscon = syscon_np->data; + + of_node_put(syscon_np); + + return syscon->regmap; +} +EXPORT_SYMBOL_GPL(syscon_early_regmap_lookup_by_phandle); + struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np, const char *property) { @@ -128,40 +149,110 @@ static int syscon_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct syscon *syscon; struct resource *res; - void __iomem *base; - syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL); + /* Early syscon init */ + if (pdev->dev.of_node && pdev->dev.of_node->data) { + syscon = pdev->dev.of_node->data; + res = &syscon->res; + regmap_attach_dev(dev, syscon->regmap, &syscon_regmap_config); + } else { + + syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL); + if (!syscon) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENOENT; + + syscon->base = devm_ioremap(dev, res->start, + resource_size(res)); + if (!syscon->base) + return -ENOMEM; + + syscon_regmap_config.max_register = res->end - res->start - 3; + syscon->regmap = devm_regmap_init_mmio(dev, syscon->base, + &syscon_regmap_config); + if (IS_ERR(syscon->regmap)) { + dev_err(dev, "regmap init failed\n"); + return PTR_ERR(syscon->regmap); + } + } + + platform_set_drvdata(pdev, syscon); + + dev_info(dev, "regmap %pR registered\n", res); + + return 0; +} + +static const struct platform_device_id syscon_ids[] = { + { "syscon", }, + { } +}; + +static int syscon_remove(struct platform_device *pdev) +{ + struct syscon *syscon = platform_get_drvdata(pdev); + + if (pdev->dev.of_node && pdev->dev.of_node->data) { + iounmap(syscon->base); + kfree(syscon); + } + + return 0; +} + +static int early_syscon_probe(struct device_node *np) +{ + struct syscon *syscon; + + syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); if (!syscon) return -ENOMEM; - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) - return -ENOENT; + if (of_address_to_resource(np, 0, &syscon->res)) + return -EINVAL; - base = devm_ioremap(dev, res->start, resource_size(res)); - if (!base) - return -ENOMEM; + syscon->base = ioremap(syscon->res.start, resource_size(&syscon->res)); + if (!syscon->base) { + pr_err("%s: Unable to map I/O memory\n", __func__); + return PTR_ERR(syscon->base); + } - syscon_regmap_config.max_register = res->end - res->start - 3; - syscon->regmap = devm_regmap_init_mmio(dev, base, - &syscon_regmap_config); + syscon_regmap_config.max_register = syscon->res.end - + syscon->res.start - 3; + syscon->regmap = regmap_init_mmio(NULL, syscon->base, + &syscon_regmap_config); if (IS_ERR(syscon->regmap)) { - dev_err(dev, "regmap init failed\n"); + pr_err("regmap init failed\n"); return PTR_ERR(syscon->regmap); } - platform_set_drvdata(pdev, syscon); + np->data = syscon; - dev_info(dev, "regmap %pR registered\n", res); + of_node_put(np); + + pr_info("%s: regmap %pR registered\n", np->full_name, &syscon->res); return 0; } -static const struct platform_device_id syscon_ids[] = { - { "syscon", }, - { } +static struct of_device_id of_syscon_ids[] = { + { .compatible = "syscon" }, + {}, }; +void __init early_syscon_init(void) +{ + struct device_node *np; + + for_each_matching_node_and_match(np, of_syscon_ids, NULL) { + if (!early_syscon_probe(np)) + BUG(); + } +} + static struct platform_driver syscon_driver = { .driver = { .name = "syscon", @@ -169,6 +260,7 @@ static struct platform_driver syscon_driver = { .of_match_table = of_syscon_match, }, .probe = syscon_probe, + .remove = syscon_remove, .id_table = syscon_ids, }; diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h index 8789fa3..465c092 100644 --- a/include/linux/mfd/syscon.h +++ b/include/linux/mfd/syscon.h @@ -24,6 +24,10 @@ extern struct regmap *syscon_regmap_lookup_by_pdevname(const char *s); extern struct regmap *syscon_regmap_lookup_by_phandle( struct device_node *np, const char *property); +extern struct regmap *syscon_early_regmap_lookup_by_phandle( + struct device_node *np, + const char *property); +extern void early_syscon_init(void); #else static inline struct regmap *syscon_node_to_regmap(struct device_node *np) { @@ -46,6 +50,13 @@ static inline struct regmap *syscon_regmap_lookup_by_phandle( { return ERR_PTR(-ENOSYS); } + +static struct regmap *syscon_early_regmap_lookup_by_phandle( + struct device_node *np, + const char *property) +{ + return ERR_PTR(-ENOSYS); +} #endif #endif /* __LINUX_MFD_SYSCON_H__ */ -- 1.8.2.3
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