I think leaving Arnd and Mark off of CC was a mistake. Correcting now.
> 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]> > --- > > Changes in v3: > - Keep backward compatibility for platform drivers and test it > - Use only one probe method which is early_syscon_probe > suggested by Lee Jones. Do not force anybody to call early_syscon_init > - Add kernel-doc description > > Changes in v2: > - Fix bad logic in early_syscon_probe > - Fix compilation failure for x86_64 reported by zero day testing system > - Regmap change available here > git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git tags/nodev > > drivers/mfd/syscon.c | 159 > ++++++++++++++++++++++++++++++++++++++++----- > include/linux/mfd/syscon.h | 11 ++++ > 2 files changed, 153 insertions(+), 17 deletions(-) > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c > index 71841f9..8e2ff88 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 +98,30 @@ struct regmap *syscon_regmap_lookup_by_pdevname(const char > *s) > } > EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname); > > +/** > + * syscon_early_regmap_lookup_by_phandle - Early phandle lookup function > + * @np: device_node pointer > + * @property: property name which handle system controller phandle > + * Return: regmap pointer, an error pointer otherwise > + */ > +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) > { > @@ -123,36 +150,118 @@ static struct regmap_config syscon_regmap_config = { > .reg_stride = 4, > }; > > -static int syscon_probe(struct platform_device *pdev) > +/** > + * early_syscon_probe - Early system controller probe method > + * @np: device_node pointer > + * @syscon_p: syscon pointer > + * @res: device IO resource > + * Return: 0 if successful, a negative error code otherwise > + */ > +static int early_syscon_probe(struct device_node *np, struct syscon > **syscon_p, > + struct resource *res) > { > - struct device *dev = &pdev->dev; > struct syscon *syscon; > - struct resource *res; > - void __iomem *base; > + int ret; > + > + if (np && np->data) { > + pr_debug("Early syscon was called\n"); > + *syscon_p = (struct syscon *)&np->data; > + return 0; > + } > > - syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL); > + syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); > if (!syscon) > return -ENOMEM; > > - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > - if (!res) > - return -ENOENT; > + *syscon_p = (struct syscon *)&syscon; > > - base = devm_ioremap(dev, res->start, resource_size(res)); > - if (!base) > - return -ENOMEM; > + if (!res && np) { > + if (of_address_to_resource(np, 0, &syscon->res)) { > + ret = -EINVAL; > + goto alloc; > + } > + > + np->data = syscon; > + of_node_put(np); > + } else { > + syscon->res = *res; > + } > > - syscon_regmap_config.max_register = res->end - res->start - 3; > - syscon->regmap = devm_regmap_init_mmio(dev, base, > - &syscon_regmap_config); > + syscon->base = ioremap(syscon->res.start, resource_size(&syscon->res)); > + if (!syscon->base) { > + pr_err("%s: Unable to map I/O memory\n", __func__); > + ret = PTR_ERR(syscon->base); > + goto alloc; > + } > + > + 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"); > - return PTR_ERR(syscon->regmap); > + pr_err("regmap init failed\n"); > + ret = PTR_ERR(syscon->regmap); > + goto iomap; > } > + if (np) > + pr_info("syscon: %s regmap %pR registered\n", np->name, > + &syscon->res); > + > + return 0; > + > +iomap: > + iounmap(syscon->base); > +alloc: > + kfree(syscon); > + > + return ret; > +} > + > +/** > + * early_syscon_init - Early system controller initialization > + */ > +void __init early_syscon_init(void) > +{ > + struct device_node *np; > + struct syscon *syscon = NULL; > + > + for_each_matching_node_and_match(np, of_syscon_match, NULL) { > + if (early_syscon_probe(np, &syscon, NULL)) > + BUG(); > + } > +} > + > +/** > + * syscon_probe - System controller probe method > + * @pdev: Platform device > + * Return: 0 if successful, a negative error code otherwise > + */ > +static int syscon_probe(struct platform_device *pdev) > +{ > + struct syscon *syscon, *syscon_p; > + struct resource *res = NULL; > + struct device *dev = &pdev->dev; > + struct device_node *np = pdev->dev.of_node; > + int ret; > + > + if (!np) { > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res) > + return -ENOENT; > + } > + ret = early_syscon_probe(np, &syscon_p, res); > + if (ret) { > + dev_err(dev, "Syscon probe failed\n"); > + return ret; > + } > + > + syscon = *(struct syscon **)syscon_p; > + > + regmap_attach_dev(dev, syscon->regmap, &syscon_regmap_config); > > platform_set_drvdata(pdev, syscon); > > - dev_info(dev, "regmap %pR registered\n", res); > + dev_info(dev, "regmap attach device to %pR\n", &syscon->res); > > return 0; > } > @@ -162,6 +271,21 @@ static const struct platform_device_id syscon_ids[] = { > { } > }; > > +/** > + * syscon_remove - System controller cleanup function > + * @pdev: Platform device > + * Return: 0 always > + */ > +static int syscon_remove(struct platform_device *pdev) > +{ > + struct syscon *syscon = platform_get_drvdata(pdev); > + > + iounmap(syscon->base); > + kfree(syscon); > + > + return 0; > +} > + > static struct platform_driver syscon_driver = { > .driver = { > .name = "syscon", > @@ -169,6 +293,7 @@ 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__ */ -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
