| Message ID | 20240614140421.3172674-2-peter.griffin@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add syscon of_syscon_register_regmap api | expand |
On Fri, 2024-06-14 at 15:04 +0100, Peter Griffin wrote: > The of_syscon_register_regmap() API allows an externally created regmap > to be registered with syscon. This regmap can then be returned to client > drivers using the syscon_regmap_lookup_by_phandle() APIs. > > The API is used by platforms where mmio access to the syscon registers is > not possible, and a underlying soc driver like exynos-pmu provides a SoC > specific regmap that can issue a SMC or hypervisor call to write the > register. > > This approach keeps the SoC complexities out of syscon, but allows common > drivers such as syscon-poweroff, syscon-reboot and friends that are used > by many SoCs already to be re-used. > > Signed-off-by: Peter Griffin <peter.griffin@linaro.org> With this series, the exynos5 usb phy driver works on gs101 without having to patch it to use exynos_get_pmu_regmap_by_phandle() instead of the standard syscon_regmap_lookup_by_phandle(): Tested-by: André Draszik <andre.draszik@linaro.org>
On Fri, Jun 14, 2024, at 16:04, Peter Griffin wrote: > The of_syscon_register_regmap() API allows an externally created regmap > to be registered with syscon. This regmap can then be returned to client > drivers using the syscon_regmap_lookup_by_phandle() APIs. > > The API is used by platforms where mmio access to the syscon registers is > not possible, and a underlying soc driver like exynos-pmu provides a SoC > specific regmap that can issue a SMC or hypervisor call to write the > register. > > This approach keeps the SoC complexities out of syscon, but allows common > drivers such as syscon-poweroff, syscon-reboot and friends that are used > by many SoCs already to be re-used. > > Signed-off-by: Peter Griffin <peter.griffin@linaro.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
On Fri, Jun 14, 2024 at 9:04 AM Peter Griffin <peter.griffin@linaro.org> wrote: > > The of_syscon_register_regmap() API allows an externally created regmap > to be registered with syscon. This regmap can then be returned to client > drivers using the syscon_regmap_lookup_by_phandle() APIs. > > The API is used by platforms where mmio access to the syscon registers is > not possible, and a underlying soc driver like exynos-pmu provides a SoC > specific regmap that can issue a SMC or hypervisor call to write the > register. > > This approach keeps the SoC complexities out of syscon, but allows common > drivers such as syscon-poweroff, syscon-reboot and friends that are used > by many SoCs already to be re-used. > > Signed-off-by: Peter Griffin <peter.griffin@linaro.org> > --- Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org> > drivers/mfd/syscon.c | 48 ++++++++++++++++++++++++++++++++++++++ > include/linux/mfd/syscon.h | 8 +++++++ > 2 files changed, 56 insertions(+) > > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c > index 7d0e91164cba..44991da3ea23 100644 > --- a/drivers/mfd/syscon.c > +++ b/drivers/mfd/syscon.c > @@ -192,6 +192,54 @@ static struct regmap *device_node_get_regmap(struct device_node *np, > return syscon->regmap; > } > > +/** > + * of_syscon_register_regmap() - Register regmap for specified device node > + * @np: Device tree node > + * @regmap: Pointer to regmap object > + * > + * Register an externally created regmap object with syscon for the specified > + * device tree node. This regmap can then be returned to client drivers using > + * the syscon_regmap_lookup_by_phandle() API. > + * > + * Return: 0 on success, negative error code on failure. > + */ > +int of_syscon_register_regmap(struct device_node *np, struct regmap *regmap) > +{ > + struct syscon *entry, *syscon = NULL; > + > + if (!np || !regmap) > + return -EINVAL; > + > + /* check if syscon entry already exists */ > + 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) > + return -EEXIST; > + > + syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); > + if (!syscon) > + return -ENOMEM; > + > + syscon->regmap = regmap; > + syscon->np = np; > + > + /* register the regmap in syscon list */ > + spin_lock(&syscon_list_slock); > + list_add_tail(&syscon->list, &syscon_list); > + spin_unlock(&syscon_list_slock); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(of_syscon_register_regmap); > + > struct regmap *device_node_to_regmap(struct device_node *np) > { > return device_node_get_regmap(np, false); > diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h > index c315903f6dab..aad9c6b50463 100644 > --- a/include/linux/mfd/syscon.h > +++ b/include/linux/mfd/syscon.h > @@ -28,6 +28,8 @@ struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np, > unsigned int *out_args); > struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np, > const char *property); > +int of_syscon_register_regmap(struct device_node *np, > + struct regmap *regmap); > #else > static inline struct regmap *device_node_to_regmap(struct device_node *np) > { > @@ -67,6 +69,12 @@ static inline struct regmap *syscon_regmap_lookup_by_phandle_optional( > return NULL; > } > > +static inline int of_syscon_register_regmap(struct device_node *np, > + struct regmap *regmap) > +{ > + return -EOPNOTSUPP; > +} > + > #endif > > #endif /* __LINUX_MFD_SYSCON_H__ */ > -- > 2.45.2.627.g7a2c4fd464-goog >
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index 7d0e91164cba..44991da3ea23 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -192,6 +192,54 @@ static struct regmap *device_node_get_regmap(struct device_node *np, return syscon->regmap; } +/** + * of_syscon_register_regmap() - Register regmap for specified device node + * @np: Device tree node + * @regmap: Pointer to regmap object + * + * Register an externally created regmap object with syscon for the specified + * device tree node. This regmap can then be returned to client drivers using + * the syscon_regmap_lookup_by_phandle() API. + * + * Return: 0 on success, negative error code on failure. + */ +int of_syscon_register_regmap(struct device_node *np, struct regmap *regmap) +{ + struct syscon *entry, *syscon = NULL; + + if (!np || !regmap) + return -EINVAL; + + /* check if syscon entry already exists */ + 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) + return -EEXIST; + + syscon = kzalloc(sizeof(*syscon), GFP_KERNEL); + if (!syscon) + return -ENOMEM; + + syscon->regmap = regmap; + syscon->np = np; + + /* register the regmap in syscon list */ + spin_lock(&syscon_list_slock); + list_add_tail(&syscon->list, &syscon_list); + spin_unlock(&syscon_list_slock); + + return 0; +} +EXPORT_SYMBOL_GPL(of_syscon_register_regmap); + struct regmap *device_node_to_regmap(struct device_node *np) { return device_node_get_regmap(np, false); diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h index c315903f6dab..aad9c6b50463 100644 --- a/include/linux/mfd/syscon.h +++ b/include/linux/mfd/syscon.h @@ -28,6 +28,8 @@ struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np, unsigned int *out_args); struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np, const char *property); +int of_syscon_register_regmap(struct device_node *np, + struct regmap *regmap); #else static inline struct regmap *device_node_to_regmap(struct device_node *np) { @@ -67,6 +69,12 @@ static inline struct regmap *syscon_regmap_lookup_by_phandle_optional( return NULL; } +static inline int of_syscon_register_regmap(struct device_node *np, + struct regmap *regmap) +{ + return -EOPNOTSUPP; +} + #endif #endif /* __LINUX_MFD_SYSCON_H__ */
The of_syscon_register_regmap() API allows an externally created regmap to be registered with syscon. This regmap can then be returned to client drivers using the syscon_regmap_lookup_by_phandle() APIs. The API is used by platforms where mmio access to the syscon registers is not possible, and a underlying soc driver like exynos-pmu provides a SoC specific regmap that can issue a SMC or hypervisor call to write the register. This approach keeps the SoC complexities out of syscon, but allows common drivers such as syscon-poweroff, syscon-reboot and friends that are used by many SoCs already to be re-used. Signed-off-by: Peter Griffin <peter.griffin@linaro.org> --- drivers/mfd/syscon.c | 48 ++++++++++++++++++++++++++++++++++++++ include/linux/mfd/syscon.h | 8 +++++++ 2 files changed, 56 insertions(+)