| Message ID | 1596431876-24115-2-git-send-email-alain.volmat@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | i2c: stm32: add host-notify support via i2c slave | expand |
Hi Alain Look good for me Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com> Best Regards On 8/3/20 7:17 AM, Alain Volmat wrote: > SMBus Host-Notify protocol, from the adapter point of view > consist of receiving a message from a client, including the > client address and some other data. > > It can be simply handled by creating a new slave device > and registering a callback performing the parsing of the > message received from the client. > > This commit introduces two new core functions > * i2c_new_slave_host_notify_device > * i2c_free_slave_host_notify_device > that take care of registration of the new slave device and > callback and will call i2c_handle_smbus_host_notify once a > Host-Notify event is received. > > Signed-off-by: Alain Volmat <alain.volmat@st.com> > --- > v3: move smbus host-notify slave code into i2c-smbus.c file > rework slave callback index handling > add sanity check in slave free function > v2: identical to v1 > drivers/i2c/i2c-smbus.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/i2c-smbus.h | 12 ++++++ > 2 files changed, 119 insertions(+) > > diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c > index dc0108287ccf..d3d06e3b4f3b 100644 > --- a/drivers/i2c/i2c-smbus.c > +++ b/drivers/i2c/i2c-smbus.c > @@ -197,6 +197,113 @@ EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert); > > module_i2c_driver(smbalert_driver); > > +#if IS_ENABLED(CONFIG_I2C_SLAVE) > +#define SMBUS_HOST_NOTIFY_LEN 3 > +struct i2c_slave_host_notify_status { > + u8 index; > + u8 addr; > +}; > + > +static int i2c_slave_host_notify_cb(struct i2c_client *client, > + enum i2c_slave_event event, u8 *val) > +{ > + struct i2c_slave_host_notify_status *status = client->dev.platform_data; > + > + switch (event) { > + case I2C_SLAVE_WRITE_RECEIVED: > + /* We only retrieve the first byte received (addr) > + * since there is currently no support to retrieve the data > + * parameter from the client. > + */ > + if (status->index == 0) > + status->addr = *val; > + if (status->index < U8_MAX) > + status->index++; > + break; > + case I2C_SLAVE_STOP: > + if (status->index == SMBUS_HOST_NOTIFY_LEN) > + i2c_handle_smbus_host_notify(client->adapter, > + status->addr); > + fallthrough; > + case I2C_SLAVE_WRITE_REQUESTED: > + status->index = 0; > + break; > + case I2C_SLAVE_READ_REQUESTED: > + case I2C_SLAVE_READ_PROCESSED: > + *val = 0xff; > + break; > + } > + > + return 0; > +} > + > +/** > + * i2c_new_slave_host_notify_device - get a client for SMBus host-notify support > + * @adapter: the target adapter > + * Context: can sleep > + * > + * Setup handling of the SMBus host-notify protocol on a given I2C bus segment. > + * > + * Handling is done by creating a device and its callback and handling data > + * received via the SMBus host-notify address (0x8) > + * > + * This returns the client, which should be ultimately freed using > + * i2c_free_slave_host_notify_device(); or an ERRPTR to indicate an error. > + */ > +struct i2c_client *i2c_new_slave_host_notify_device(struct i2c_adapter *adapter) > +{ > + struct i2c_board_info host_notify_board_info = { > + I2C_BOARD_INFO("smbus_host_notify", 0x08), > + .flags = I2C_CLIENT_SLAVE, > + }; > + struct i2c_slave_host_notify_status *status; > + struct i2c_client *client; > + int ret; > + > + status = kzalloc(sizeof(struct i2c_slave_host_notify_status), > + GFP_KERNEL); > + if (!status) > + return ERR_PTR(-ENOMEM); > + > + host_notify_board_info.platform_data = status; > + > + client = i2c_new_client_device(adapter, &host_notify_board_info); > + if (IS_ERR(client)) { > + kfree(status); > + return client; > + } > + > + ret = i2c_slave_register(client, i2c_slave_host_notify_cb); > + if (ret) { > + i2c_unregister_device(client); > + kfree(status); > + return ERR_PTR(ret); > + } > + > + return client; > +} > +EXPORT_SYMBOL_GPL(i2c_new_slave_host_notify_device); > + > +/** > + * i2c_free_slave_host_notify_device - free the client for SMBus host-notify > + * support > + * @client: the client to free > + * Context: can sleep > + * > + * Free the i2c_client allocated via i2c_new_slave_host_notify_device > + */ > +void i2c_free_slave_host_notify_device(struct i2c_client *client) > +{ > + if (IS_ERR_OR_NULL(client)) > + return; > + > + i2c_slave_unregister(client); > + kfree(client->dev.platform_data); > + i2c_unregister_device(client); > +} > +EXPORT_SYMBOL_GPL(i2c_free_slave_host_notify_device); > +#endif > + > /* > * SPD is not part of SMBus but we include it here for convenience as the > * target systems are the same. > diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h > index 1e4e0de4ef8b..1ef421818d3a 100644 > --- a/include/linux/i2c-smbus.h > +++ b/include/linux/i2c-smbus.h > @@ -38,6 +38,18 @@ static inline int of_i2c_setup_smbus_alert(struct i2c_adapter *adap) > return 0; > } > #endif > +#if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_I2C_SLAVE) > +struct i2c_client *i2c_new_slave_host_notify_device(struct i2c_adapter *adapter); > +void i2c_free_slave_host_notify_device(struct i2c_client *client); > +#else > +static inline struct i2c_client *i2c_new_slave_host_notify_device(struct i2c_adapter *adapter) > +{ > + return ERR_PTR(-ENOSYS); > +} > +static inline void i2c_free_slave_host_notify_device(struct i2c_client *client) > +{ > +} > +#endif > > #if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_DMI) > void i2c_register_spd(struct i2c_adapter *adap); >
On Mon, Aug 03, 2020 at 07:17:55AM +0200, Alain Volmat wrote: > SMBus Host-Notify protocol, from the adapter point of view > consist of receiving a message from a client, including the > client address and some other data. > > It can be simply handled by creating a new slave device > and registering a callback performing the parsing of the > message received from the client. > > This commit introduces two new core functions > * i2c_new_slave_host_notify_device > * i2c_free_slave_host_notify_device > that take care of registration of the new slave device and > callback and will call i2c_handle_smbus_host_notify once a > Host-Notify event is received. > > Signed-off-by: Alain Volmat <alain.volmat@st.com> Applied to for-next, thanks!
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c index dc0108287ccf..d3d06e3b4f3b 100644 --- a/drivers/i2c/i2c-smbus.c +++ b/drivers/i2c/i2c-smbus.c @@ -197,6 +197,113 @@ EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert); module_i2c_driver(smbalert_driver); +#if IS_ENABLED(CONFIG_I2C_SLAVE) +#define SMBUS_HOST_NOTIFY_LEN 3 +struct i2c_slave_host_notify_status { + u8 index; + u8 addr; +}; + +static int i2c_slave_host_notify_cb(struct i2c_client *client, + enum i2c_slave_event event, u8 *val) +{ + struct i2c_slave_host_notify_status *status = client->dev.platform_data; + + switch (event) { + case I2C_SLAVE_WRITE_RECEIVED: + /* We only retrieve the first byte received (addr) + * since there is currently no support to retrieve the data + * parameter from the client. + */ + if (status->index == 0) + status->addr = *val; + if (status->index < U8_MAX) + status->index++; + break; + case I2C_SLAVE_STOP: + if (status->index == SMBUS_HOST_NOTIFY_LEN) + i2c_handle_smbus_host_notify(client->adapter, + status->addr); + fallthrough; + case I2C_SLAVE_WRITE_REQUESTED: + status->index = 0; + break; + case I2C_SLAVE_READ_REQUESTED: + case I2C_SLAVE_READ_PROCESSED: + *val = 0xff; + break; + } + + return 0; +} + +/** + * i2c_new_slave_host_notify_device - get a client for SMBus host-notify support + * @adapter: the target adapter + * Context: can sleep + * + * Setup handling of the SMBus host-notify protocol on a given I2C bus segment. + * + * Handling is done by creating a device and its callback and handling data + * received via the SMBus host-notify address (0x8) + * + * This returns the client, which should be ultimately freed using + * i2c_free_slave_host_notify_device(); or an ERRPTR to indicate an error. + */ +struct i2c_client *i2c_new_slave_host_notify_device(struct i2c_adapter *adapter) +{ + struct i2c_board_info host_notify_board_info = { + I2C_BOARD_INFO("smbus_host_notify", 0x08), + .flags = I2C_CLIENT_SLAVE, + }; + struct i2c_slave_host_notify_status *status; + struct i2c_client *client; + int ret; + + status = kzalloc(sizeof(struct i2c_slave_host_notify_status), + GFP_KERNEL); + if (!status) + return ERR_PTR(-ENOMEM); + + host_notify_board_info.platform_data = status; + + client = i2c_new_client_device(adapter, &host_notify_board_info); + if (IS_ERR(client)) { + kfree(status); + return client; + } + + ret = i2c_slave_register(client, i2c_slave_host_notify_cb); + if (ret) { + i2c_unregister_device(client); + kfree(status); + return ERR_PTR(ret); + } + + return client; +} +EXPORT_SYMBOL_GPL(i2c_new_slave_host_notify_device); + +/** + * i2c_free_slave_host_notify_device - free the client for SMBus host-notify + * support + * @client: the client to free + * Context: can sleep + * + * Free the i2c_client allocated via i2c_new_slave_host_notify_device + */ +void i2c_free_slave_host_notify_device(struct i2c_client *client) +{ + if (IS_ERR_OR_NULL(client)) + return; + + i2c_slave_unregister(client); + kfree(client->dev.platform_data); + i2c_unregister_device(client); +} +EXPORT_SYMBOL_GPL(i2c_free_slave_host_notify_device); +#endif + /* * SPD is not part of SMBus but we include it here for convenience as the * target systems are the same. diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h index 1e4e0de4ef8b..1ef421818d3a 100644 --- a/include/linux/i2c-smbus.h +++ b/include/linux/i2c-smbus.h @@ -38,6 +38,18 @@ static inline int of_i2c_setup_smbus_alert(struct i2c_adapter *adap) return 0; } #endif +#if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_I2C_SLAVE) +struct i2c_client *i2c_new_slave_host_notify_device(struct i2c_adapter *adapter); +void i2c_free_slave_host_notify_device(struct i2c_client *client); +#else +static inline struct i2c_client *i2c_new_slave_host_notify_device(struct i2c_adapter *adapter) +{ + return ERR_PTR(-ENOSYS); +} +static inline void i2c_free_slave_host_notify_device(struct i2c_client *client) +{ +} +#endif #if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_DMI) void i2c_register_spd(struct i2c_adapter *adap);
SMBus Host-Notify protocol, from the adapter point of view consist of receiving a message from a client, including the client address and some other data. It can be simply handled by creating a new slave device and registering a callback performing the parsing of the message received from the client. This commit introduces two new core functions * i2c_new_slave_host_notify_device * i2c_free_slave_host_notify_device that take care of registration of the new slave device and callback and will call i2c_handle_smbus_host_notify once a Host-Notify event is received. Signed-off-by: Alain Volmat <alain.volmat@st.com> --- v3: move smbus host-notify slave code into i2c-smbus.c file rework slave callback index handling add sanity check in slave free function v2: identical to v1 drivers/i2c/i2c-smbus.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/i2c-smbus.h | 12 ++++++ 2 files changed, 119 insertions(+)