[PATCH v3 0/2] i2c: stm32: add host-notify support via i2c slave

[PATCH v3 0/2] i2c: stm32: add host-notify support via i2c slave

[Alain Volmat]

This serie replaces the previous 'stm32-f7: Addition of SMBus Alert /
Host-notify features' serie to only focus on the SMBus Host-Notify feature.
It should be applied with "[PATCH] i2c: add binding to mark a bus as SMBus"
from Wolfram which defines the newly introduced "smbus" binding.

Alain Volmat (2):
  i2c: smbus: add core function handling SMBus host-notify
  i2c: stm32f7: Add SMBus Host-Notify protocol support

 drivers/i2c/busses/Kconfig       |   1 +
 drivers/i2c/busses/i2c-stm32f7.c | 110 +++++++++++++++++++++++++++++++++------
 drivers/i2c/i2c-smbus.c          | 107 +++++++++++++++++++++++++++++++++++++
 include/linux/i2c-smbus.h        |  12 +++++
 4 files changed, 215 insertions(+), 15 deletions(-)

-- 
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: fix a bad test within the i2c-stm32f7 driver leading to decrease of
    available slave slot

[PATCH v3 0/2] i2c: stm32: add host-notify support via i2c slave

[Alain Volmat]

This serie replaces the previous 'stm32-f7: Addition of SMBus Alert /
Host-notify features' serie to only focus on the SMBus Host-Notify feature.
It should be applied with "[PATCH] i2c: add binding to mark a bus as SMBus"
from Wolfram which defines the newly introduced "smbus" binding.

Alain Volmat (2):
  i2c: smbus: add core function handling SMBus host-notify
  i2c: stm32f7: Add SMBus Host-Notify protocol support

 drivers/i2c/busses/Kconfig       |   1 +
 drivers/i2c/busses/i2c-stm32f7.c | 110 +++++++++++++++++++++++++++++++++------
 drivers/i2c/i2c-smbus.c          | 107 +++++++++++++++++++++++++++++++++++++
 include/linux/i2c-smbus.h        |  12 +++++
 4 files changed, 215 insertions(+), 15 deletions(-)

-- 
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: fix a bad test within the i2c-stm32f7 driver leading to decrease of
    available slave slot


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[PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify

[Alain Volmat]

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);
-- 
2.7.4

[PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify

[Alain Volmat]

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);
-- 
2.7.4


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[PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support

[Alain Volmat]

Rely on the core functions to implement the host-notify
protocol via the a I2C slave device.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
---
 v3: identical to v2
 v2: fix slot #0 usage condition within stm32f7_i2c_get_free_slave_id

 drivers/i2c/busses/Kconfig       |   1 +
 drivers/i2c/busses/i2c-stm32f7.c | 110 +++++++++++++++++++++++++++++++++------
 2 files changed, 96 insertions(+), 15 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 735bf31a3fdf..ae8671727a4c 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1036,6 +1036,7 @@ config I2C_STM32F7
 	tristate "STMicroelectronics STM32F7 I2C support"
 	depends on ARCH_STM32 || COMPILE_TEST
 	select I2C_SLAVE
+	select I2C_SMBUS
 	help
 	  Enable this option to add support for STM32 I2C controller embedded
 	  in STM32F7 SoCs.
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index bff3479fe122..223c238c3c09 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -18,6 +18,7 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -50,6 +51,7 @@
 
 /* STM32F7 I2C control 1 */
 #define STM32F7_I2C_CR1_PECEN			BIT(23)
+#define STM32F7_I2C_CR1_SMBHEN			BIT(20)
 #define STM32F7_I2C_CR1_WUPEN			BIT(18)
 #define STM32F7_I2C_CR1_SBC			BIT(16)
 #define STM32F7_I2C_CR1_RXDMAEN			BIT(15)
@@ -150,7 +152,7 @@
 
 #define STM32F7_I2C_MAX_LEN			0xff
 #define STM32F7_I2C_DMA_LEN_MIN			0x16
-#define STM32F7_I2C_MAX_SLAVE			0x2
+#define STM32F7_I2C_MAX_SLAVE			0x3
 
 #define STM32F7_I2C_DNF_DEFAULT			0
 #define STM32F7_I2C_DNF_MAX			16
@@ -301,6 +303,8 @@ struct stm32f7_i2c_msg {
  * @fmp_creg: register address for clearing Fast Mode Plus bits
  * @fmp_mask: mask for Fast Mode Plus bits in set register
  * @wakeup_src: boolean to know if the device is a wakeup source
+ * @smbus_mode: states that the controller is configured in SMBus mode
+ * @host_notify_client: SMBus host-notify client
  */
 struct stm32f7_i2c_dev {
 	struct i2c_adapter adap;
@@ -327,6 +331,8 @@ struct stm32f7_i2c_dev {
 	u32 fmp_creg;
 	u32 fmp_mask;
 	bool wakeup_src;
+	bool smbus_mode;
+	struct i2c_client *host_notify_client;
 };
 
 /*
@@ -1321,10 +1327,18 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
 	int i;
 
 	/*
-	 * slave[0] supports 7-bit and 10-bit slave address
-	 * slave[1] supports 7-bit slave address only
+	 * slave[0] support only SMBus Host address (0x8)
+	 * slave[1] supports 7-bit and 10-bit slave address
+	 * slave[2] supports 7-bit slave address only
 	 */
-	for (i = STM32F7_I2C_MAX_SLAVE - 1; i >= 0; i--) {
+	if (i2c_dev->smbus_mode && (slave->addr == 0x08)) {
+		if (i2c_dev->slave[0])
+			goto fail;
+		*id = 0;
+		return 0;
+	}
+
+	for (i = STM32F7_I2C_MAX_SLAVE - 1; i > 0; i--) {
 		if (i == 1 && (slave->flags & I2C_CLIENT_TEN))
 			continue;
 		if (!i2c_dev->slave[i]) {
@@ -1333,6 +1347,7 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
 		}
 	}
 
+fail:
 	dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);
 
 	return -EINVAL;
@@ -1776,7 +1791,13 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
 		stm32f7_i2c_enable_wakeup(i2c_dev, true);
 
-	if (id == 0) {
+	switch (id) {
+	case 0:
+		/* Slave SMBus Host */
+		i2c_dev->slave[id] = slave;
+		break;
+
+	case 1:
 		/* Configure Own Address 1 */
 		oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
 		oar1 &= ~STM32F7_I2C_OAR1_MASK;
@@ -1789,7 +1810,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 		oar1 |= STM32F7_I2C_OAR1_OA1EN;
 		i2c_dev->slave[id] = slave;
 		writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
-	} else if (id == 1) {
+		break;
+
+	case 2:
 		/* Configure Own Address 2 */
 		oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
 		oar2 &= ~STM32F7_I2C_OAR2_MASK;
@@ -1802,7 +1825,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 		oar2 |= STM32F7_I2C_OAR2_OA2EN;
 		i2c_dev->slave[id] = slave;
 		writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
-	} else {
+		break;
+
+	default:
+		dev_err(dev, "I2C slave id not supported\n");
 		ret = -ENODEV;
 		goto pm_free;
 	}
@@ -1843,10 +1869,10 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
 	if (ret < 0)
 		return ret;
 
-	if (id == 0) {
+	if (id == 1) {
 		mask = STM32F7_I2C_OAR1_OA1EN;
 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
-	} else {
+	} else if (id == 2) {
 		mask = STM32F7_I2C_OAR2_OA2EN;
 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
 	}
@@ -1911,14 +1937,51 @@ static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
 					  &i2c_dev->fmp_mask);
 }
 
+static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
+{
+	struct i2c_adapter *adap = &i2c_dev->adap;
+	void __iomem *base = i2c_dev->base;
+	struct i2c_client *client;
+
+	client = i2c_new_slave_host_notify_device(adap);
+	if (IS_ERR(client))
+		return PTR_ERR(client);
+
+	i2c_dev->host_notify_client = client;
+
+	/* Enable SMBus Host address */
+	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN);
+
+	return 0;
+}
+
+static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
+{
+	void __iomem *base = i2c_dev->base;
+
+	if (i2c_dev->host_notify_client) {
+		/* Disable SMBus Host address */
+		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
+				     STM32F7_I2C_CR1_SMBHEN);
+		i2c_free_slave_host_notify_device(i2c_dev->host_notify_client);
+	}
+}
+
 static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
-		I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
-		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
-		I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
-		I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
-		I2C_FUNC_SMBUS_I2C_BLOCK;
+	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+
+	u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
+		   I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+		   I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+		   I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
+		   I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
+		   I2C_FUNC_SMBUS_I2C_BLOCK;
+
+	if (i2c_dev->smbus_mode)
+		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
+
+	return func;
 }
 
 static const struct i2c_algorithm stm32f7_i2c_algo = {
@@ -2084,10 +2147,22 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
 
 	stm32f7_i2c_hw_config(i2c_dev);
 
+	i2c_dev->smbus_mode = of_property_read_bool(pdev->dev.of_node, "smbus");
+
 	ret = i2c_add_adapter(adap);
 	if (ret)
 		goto pm_disable;
 
+	if (i2c_dev->smbus_mode) {
+		ret = stm32f7_i2c_enable_smbus_host(i2c_dev);
+		if (ret) {
+			dev_err(i2c_dev->dev,
+				"failed to enable SMBus Host-Notify protocol (%d)\n",
+				ret);
+			goto i2c_adapter_remove;
+		}
+	}
+
 	dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
 
 	pm_runtime_mark_last_busy(i2c_dev->dev);
@@ -2095,6 +2170,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
 
 	return 0;
 
+i2c_adapter_remove:
+	i2c_del_adapter(adap);
+
 pm_disable:
 	pm_runtime_put_noidle(i2c_dev->dev);
 	pm_runtime_disable(i2c_dev->dev);
@@ -2126,6 +2204,8 @@ static int stm32f7_i2c_remove(struct platform_device *pdev)
 {
 	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
 
+	stm32f7_i2c_disable_smbus_host(i2c_dev);
+
 	i2c_del_adapter(&i2c_dev->adap);
 	pm_runtime_get_sync(i2c_dev->dev);
 
-- 
2.7.4

[PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support

[Alain Volmat]

Rely on the core functions to implement the host-notify
protocol via the a I2C slave device.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
---
 v3: identical to v2
 v2: fix slot #0 usage condition within stm32f7_i2c_get_free_slave_id

 drivers/i2c/busses/Kconfig       |   1 +
 drivers/i2c/busses/i2c-stm32f7.c | 110 +++++++++++++++++++++++++++++++++------
 2 files changed, 96 insertions(+), 15 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 735bf31a3fdf..ae8671727a4c 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1036,6 +1036,7 @@ config I2C_STM32F7
 	tristate "STMicroelectronics STM32F7 I2C support"
 	depends on ARCH_STM32 || COMPILE_TEST
 	select I2C_SLAVE
+	select I2C_SMBUS
 	help
 	  Enable this option to add support for STM32 I2C controller embedded
 	  in STM32F7 SoCs.
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index bff3479fe122..223c238c3c09 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -18,6 +18,7 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
@@ -50,6 +51,7 @@
 
 /* STM32F7 I2C control 1 */
 #define STM32F7_I2C_CR1_PECEN			BIT(23)
+#define STM32F7_I2C_CR1_SMBHEN			BIT(20)
 #define STM32F7_I2C_CR1_WUPEN			BIT(18)
 #define STM32F7_I2C_CR1_SBC			BIT(16)
 #define STM32F7_I2C_CR1_RXDMAEN			BIT(15)
@@ -150,7 +152,7 @@
 
 #define STM32F7_I2C_MAX_LEN			0xff
 #define STM32F7_I2C_DMA_LEN_MIN			0x16
-#define STM32F7_I2C_MAX_SLAVE			0x2
+#define STM32F7_I2C_MAX_SLAVE			0x3
 
 #define STM32F7_I2C_DNF_DEFAULT			0
 #define STM32F7_I2C_DNF_MAX			16
@@ -301,6 +303,8 @@ struct stm32f7_i2c_msg {
  * @fmp_creg: register address for clearing Fast Mode Plus bits
  * @fmp_mask: mask for Fast Mode Plus bits in set register
  * @wakeup_src: boolean to know if the device is a wakeup source
+ * @smbus_mode: states that the controller is configured in SMBus mode
+ * @host_notify_client: SMBus host-notify client
  */
 struct stm32f7_i2c_dev {
 	struct i2c_adapter adap;
@@ -327,6 +331,8 @@ struct stm32f7_i2c_dev {
 	u32 fmp_creg;
 	u32 fmp_mask;
 	bool wakeup_src;
+	bool smbus_mode;
+	struct i2c_client *host_notify_client;
 };
 
 /*
@@ -1321,10 +1327,18 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
 	int i;
 
 	/*
-	 * slave[0] supports 7-bit and 10-bit slave address
-	 * slave[1] supports 7-bit slave address only
+	 * slave[0] support only SMBus Host address (0x8)
+	 * slave[1] supports 7-bit and 10-bit slave address
+	 * slave[2] supports 7-bit slave address only
 	 */
-	for (i = STM32F7_I2C_MAX_SLAVE - 1; i >= 0; i--) {
+	if (i2c_dev->smbus_mode && (slave->addr == 0x08)) {
+		if (i2c_dev->slave[0])
+			goto fail;
+		*id = 0;
+		return 0;
+	}
+
+	for (i = STM32F7_I2C_MAX_SLAVE - 1; i > 0; i--) {
 		if (i == 1 && (slave->flags & I2C_CLIENT_TEN))
 			continue;
 		if (!i2c_dev->slave[i]) {
@@ -1333,6 +1347,7 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
 		}
 	}
 
+fail:
 	dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);
 
 	return -EINVAL;
@@ -1776,7 +1791,13 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
 		stm32f7_i2c_enable_wakeup(i2c_dev, true);
 
-	if (id == 0) {
+	switch (id) {
+	case 0:
+		/* Slave SMBus Host */
+		i2c_dev->slave[id] = slave;
+		break;
+
+	case 1:
 		/* Configure Own Address 1 */
 		oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
 		oar1 &= ~STM32F7_I2C_OAR1_MASK;
@@ -1789,7 +1810,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 		oar1 |= STM32F7_I2C_OAR1_OA1EN;
 		i2c_dev->slave[id] = slave;
 		writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
-	} else if (id == 1) {
+		break;
+
+	case 2:
 		/* Configure Own Address 2 */
 		oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
 		oar2 &= ~STM32F7_I2C_OAR2_MASK;
@@ -1802,7 +1825,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 		oar2 |= STM32F7_I2C_OAR2_OA2EN;
 		i2c_dev->slave[id] = slave;
 		writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
-	} else {
+		break;
+
+	default:
+		dev_err(dev, "I2C slave id not supported\n");
 		ret = -ENODEV;
 		goto pm_free;
 	}
@@ -1843,10 +1869,10 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
 	if (ret < 0)
 		return ret;
 
-	if (id == 0) {
+	if (id == 1) {
 		mask = STM32F7_I2C_OAR1_OA1EN;
 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
-	} else {
+	} else if (id == 2) {
 		mask = STM32F7_I2C_OAR2_OA2EN;
 		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
 	}
@@ -1911,14 +1937,51 @@ static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
 					  &i2c_dev->fmp_mask);
 }
 
+static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
+{
+	struct i2c_adapter *adap = &i2c_dev->adap;
+	void __iomem *base = i2c_dev->base;
+	struct i2c_client *client;
+
+	client = i2c_new_slave_host_notify_device(adap);
+	if (IS_ERR(client))
+		return PTR_ERR(client);
+
+	i2c_dev->host_notify_client = client;
+
+	/* Enable SMBus Host address */
+	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN);
+
+	return 0;
+}
+
+static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
+{
+	void __iomem *base = i2c_dev->base;
+
+	if (i2c_dev->host_notify_client) {
+		/* Disable SMBus Host address */
+		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
+				     STM32F7_I2C_CR1_SMBHEN);
+		i2c_free_slave_host_notify_device(i2c_dev->host_notify_client);
+	}
+}
+
 static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
-		I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
-		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
-		I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
-		I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
-		I2C_FUNC_SMBUS_I2C_BLOCK;
+	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+
+	u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
+		   I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+		   I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+		   I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
+		   I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
+		   I2C_FUNC_SMBUS_I2C_BLOCK;
+
+	if (i2c_dev->smbus_mode)
+		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
+
+	return func;
 }
 
 static const struct i2c_algorithm stm32f7_i2c_algo = {
@@ -2084,10 +2147,22 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
 
 	stm32f7_i2c_hw_config(i2c_dev);
 
+	i2c_dev->smbus_mode = of_property_read_bool(pdev->dev.of_node, "smbus");
+
 	ret = i2c_add_adapter(adap);
 	if (ret)
 		goto pm_disable;
 
+	if (i2c_dev->smbus_mode) {
+		ret = stm32f7_i2c_enable_smbus_host(i2c_dev);
+		if (ret) {
+			dev_err(i2c_dev->dev,
+				"failed to enable SMBus Host-Notify protocol (%d)\n",
+				ret);
+			goto i2c_adapter_remove;
+		}
+	}
+
 	dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
 
 	pm_runtime_mark_last_busy(i2c_dev->dev);
@@ -2095,6 +2170,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
 
 	return 0;
 
+i2c_adapter_remove:
+	i2c_del_adapter(adap);
+
 pm_disable:
 	pm_runtime_put_noidle(i2c_dev->dev);
 	pm_runtime_disable(i2c_dev->dev);
@@ -2126,6 +2204,8 @@ static int stm32f7_i2c_remove(struct platform_device *pdev)
 {
 	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
 
+	stm32f7_i2c_disable_smbus_host(i2c_dev);
+
 	i2c_del_adapter(&i2c_dev->adap);
 	pm_runtime_get_sync(i2c_dev->dev);
 
-- 
2.7.4


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify

[Pierre Yves MORDRET]

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);
> 

Re: [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify

[Pierre Yves MORDRET]

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);
> 

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Re: [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support

[Pierre Yves MORDRET]

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:
> Rely on the core functions to implement the host-notify
> protocol via the a I2C slave device.
> 
> Signed-off-by: Alain Volmat <alain.volmat@st.com>
> ---
>  v3: identical to v2
>  v2: fix slot #0 usage condition within stm32f7_i2c_get_free_slave_id
> 
>  drivers/i2c/busses/Kconfig       |   1 +
>  drivers/i2c/busses/i2c-stm32f7.c | 110 +++++++++++++++++++++++++++++++++------
>  2 files changed, 96 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 735bf31a3fdf..ae8671727a4c 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -1036,6 +1036,7 @@ config I2C_STM32F7
>  	tristate "STMicroelectronics STM32F7 I2C support"
>  	depends on ARCH_STM32 || COMPILE_TEST
>  	select I2C_SLAVE
> +	select I2C_SMBUS
>  	help
>  	  Enable this option to add support for STM32 I2C controller embedded
>  	  in STM32F7 SoCs.
> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> index bff3479fe122..223c238c3c09 100644
> --- a/drivers/i2c/busses/i2c-stm32f7.c
> +++ b/drivers/i2c/busses/i2c-stm32f7.c
> @@ -18,6 +18,7 @@
>  #include <linux/delay.h>
>  #include <linux/err.h>
>  #include <linux/i2c.h>
> +#include <linux/i2c-smbus.h>
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
> @@ -50,6 +51,7 @@
>  
>  /* STM32F7 I2C control 1 */
>  #define STM32F7_I2C_CR1_PECEN			BIT(23)
> +#define STM32F7_I2C_CR1_SMBHEN			BIT(20)
>  #define STM32F7_I2C_CR1_WUPEN			BIT(18)
>  #define STM32F7_I2C_CR1_SBC			BIT(16)
>  #define STM32F7_I2C_CR1_RXDMAEN			BIT(15)
> @@ -150,7 +152,7 @@
>  
>  #define STM32F7_I2C_MAX_LEN			0xff
>  #define STM32F7_I2C_DMA_LEN_MIN			0x16
> -#define STM32F7_I2C_MAX_SLAVE			0x2
> +#define STM32F7_I2C_MAX_SLAVE			0x3
>  
>  #define STM32F7_I2C_DNF_DEFAULT			0
>  #define STM32F7_I2C_DNF_MAX			16
> @@ -301,6 +303,8 @@ struct stm32f7_i2c_msg {
>   * @fmp_creg: register address for clearing Fast Mode Plus bits
>   * @fmp_mask: mask for Fast Mode Plus bits in set register
>   * @wakeup_src: boolean to know if the device is a wakeup source
> + * @smbus_mode: states that the controller is configured in SMBus mode
> + * @host_notify_client: SMBus host-notify client
>   */
>  struct stm32f7_i2c_dev {
>  	struct i2c_adapter adap;
> @@ -327,6 +331,8 @@ struct stm32f7_i2c_dev {
>  	u32 fmp_creg;
>  	u32 fmp_mask;
>  	bool wakeup_src;
> +	bool smbus_mode;
> +	struct i2c_client *host_notify_client;
>  };
>  
>  /*
> @@ -1321,10 +1327,18 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
>  	int i;
>  
>  	/*
> -	 * slave[0] supports 7-bit and 10-bit slave address
> -	 * slave[1] supports 7-bit slave address only
> +	 * slave[0] support only SMBus Host address (0x8)
> +	 * slave[1] supports 7-bit and 10-bit slave address
> +	 * slave[2] supports 7-bit slave address only
>  	 */
> -	for (i = STM32F7_I2C_MAX_SLAVE - 1; i >= 0; i--) {
> +	if (i2c_dev->smbus_mode && (slave->addr == 0x08)) {
> +		if (i2c_dev->slave[0])
> +			goto fail;
> +		*id = 0;
> +		return 0;
> +	}
> +
> +	for (i = STM32F7_I2C_MAX_SLAVE - 1; i > 0; i--) {
>  		if (i == 1 && (slave->flags & I2C_CLIENT_TEN))
>  			continue;
>  		if (!i2c_dev->slave[i]) {
> @@ -1333,6 +1347,7 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
>  		}
>  	}
>  
> +fail:
>  	dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);
>  
>  	return -EINVAL;
> @@ -1776,7 +1791,13 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
>  	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
>  		stm32f7_i2c_enable_wakeup(i2c_dev, true);
>  
> -	if (id == 0) {
> +	switch (id) {
> +	case 0:
> +		/* Slave SMBus Host */
> +		i2c_dev->slave[id] = slave;
> +		break;
> +
> +	case 1:
>  		/* Configure Own Address 1 */
>  		oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
>  		oar1 &= ~STM32F7_I2C_OAR1_MASK;
> @@ -1789,7 +1810,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
>  		oar1 |= STM32F7_I2C_OAR1_OA1EN;
>  		i2c_dev->slave[id] = slave;
>  		writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
> -	} else if (id == 1) {
> +		break;
> +
> +	case 2:
>  		/* Configure Own Address 2 */
>  		oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
>  		oar2 &= ~STM32F7_I2C_OAR2_MASK;
> @@ -1802,7 +1825,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
>  		oar2 |= STM32F7_I2C_OAR2_OA2EN;
>  		i2c_dev->slave[id] = slave;
>  		writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
> -	} else {
> +		break;
> +
> +	default:
> +		dev_err(dev, "I2C slave id not supported\n");
>  		ret = -ENODEV;
>  		goto pm_free;
>  	}
> @@ -1843,10 +1869,10 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
>  	if (ret < 0)
>  		return ret;
>  
> -	if (id == 0) {
> +	if (id == 1) {
>  		mask = STM32F7_I2C_OAR1_OA1EN;
>  		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
> -	} else {
> +	} else if (id == 2) {
>  		mask = STM32F7_I2C_OAR2_OA2EN;
>  		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
>  	}
> @@ -1911,14 +1937,51 @@ static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
>  					  &i2c_dev->fmp_mask);
>  }
>  
> +static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
> +{
> +	struct i2c_adapter *adap = &i2c_dev->adap;
> +	void __iomem *base = i2c_dev->base;
> +	struct i2c_client *client;
> +
> +	client = i2c_new_slave_host_notify_device(adap);
> +	if (IS_ERR(client))
> +		return PTR_ERR(client);
> +
> +	i2c_dev->host_notify_client = client;
> +
> +	/* Enable SMBus Host address */
> +	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN);
> +
> +	return 0;
> +}
> +
> +static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
> +{
> +	void __iomem *base = i2c_dev->base;
> +
> +	if (i2c_dev->host_notify_client) {
> +		/* Disable SMBus Host address */
> +		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
> +				     STM32F7_I2C_CR1_SMBHEN);
> +		i2c_free_slave_host_notify_device(i2c_dev->host_notify_client);
> +	}
> +}
> +
>  static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
>  {
> -	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
> -		I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
> -		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
> -		I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
> -		I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
> -		I2C_FUNC_SMBUS_I2C_BLOCK;
> +	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
> +
> +	u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
> +		   I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
> +		   I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
> +		   I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
> +		   I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
> +		   I2C_FUNC_SMBUS_I2C_BLOCK;
> +
> +	if (i2c_dev->smbus_mode)
> +		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
> +
> +	return func;
>  }
>  
>  static const struct i2c_algorithm stm32f7_i2c_algo = {
> @@ -2084,10 +2147,22 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
>  
>  	stm32f7_i2c_hw_config(i2c_dev);
>  
> +	i2c_dev->smbus_mode = of_property_read_bool(pdev->dev.of_node, "smbus");
> +
>  	ret = i2c_add_adapter(adap);
>  	if (ret)
>  		goto pm_disable;
>  
> +	if (i2c_dev->smbus_mode) {
> +		ret = stm32f7_i2c_enable_smbus_host(i2c_dev);
> +		if (ret) {
> +			dev_err(i2c_dev->dev,
> +				"failed to enable SMBus Host-Notify protocol (%d)\n",
> +				ret);
> +			goto i2c_adapter_remove;
> +		}
> +	}
> +
>  	dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
>  
>  	pm_runtime_mark_last_busy(i2c_dev->dev);
> @@ -2095,6 +2170,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> +i2c_adapter_remove:
> +	i2c_del_adapter(adap);
> +
>  pm_disable:
>  	pm_runtime_put_noidle(i2c_dev->dev);
>  	pm_runtime_disable(i2c_dev->dev);
> @@ -2126,6 +2204,8 @@ static int stm32f7_i2c_remove(struct platform_device *pdev)
>  {
>  	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
>  
> +	stm32f7_i2c_disable_smbus_host(i2c_dev);
> +
>  	i2c_del_adapter(&i2c_dev->adap);
>  	pm_runtime_get_sync(i2c_dev->dev);
>  
> 

Re: [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support

[Pierre Yves MORDRET]

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:
> Rely on the core functions to implement the host-notify
> protocol via the a I2C slave device.
> 
> Signed-off-by: Alain Volmat <alain.volmat@st.com>
> ---
>  v3: identical to v2
>  v2: fix slot #0 usage condition within stm32f7_i2c_get_free_slave_id
> 
>  drivers/i2c/busses/Kconfig       |   1 +
>  drivers/i2c/busses/i2c-stm32f7.c | 110 +++++++++++++++++++++++++++++++++------
>  2 files changed, 96 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 735bf31a3fdf..ae8671727a4c 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -1036,6 +1036,7 @@ config I2C_STM32F7
>  	tristate "STMicroelectronics STM32F7 I2C support"
>  	depends on ARCH_STM32 || COMPILE_TEST
>  	select I2C_SLAVE
> +	select I2C_SMBUS
>  	help
>  	  Enable this option to add support for STM32 I2C controller embedded
>  	  in STM32F7 SoCs.
> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> index bff3479fe122..223c238c3c09 100644
> --- a/drivers/i2c/busses/i2c-stm32f7.c
> +++ b/drivers/i2c/busses/i2c-stm32f7.c
> @@ -18,6 +18,7 @@
>  #include <linux/delay.h>
>  #include <linux/err.h>
>  #include <linux/i2c.h>
> +#include <linux/i2c-smbus.h>
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
>  #include <linux/iopoll.h>
> @@ -50,6 +51,7 @@
>  
>  /* STM32F7 I2C control 1 */
>  #define STM32F7_I2C_CR1_PECEN			BIT(23)
> +#define STM32F7_I2C_CR1_SMBHEN			BIT(20)
>  #define STM32F7_I2C_CR1_WUPEN			BIT(18)
>  #define STM32F7_I2C_CR1_SBC			BIT(16)
>  #define STM32F7_I2C_CR1_RXDMAEN			BIT(15)
> @@ -150,7 +152,7 @@
>  
>  #define STM32F7_I2C_MAX_LEN			0xff
>  #define STM32F7_I2C_DMA_LEN_MIN			0x16
> -#define STM32F7_I2C_MAX_SLAVE			0x2
> +#define STM32F7_I2C_MAX_SLAVE			0x3
>  
>  #define STM32F7_I2C_DNF_DEFAULT			0
>  #define STM32F7_I2C_DNF_MAX			16
> @@ -301,6 +303,8 @@ struct stm32f7_i2c_msg {
>   * @fmp_creg: register address for clearing Fast Mode Plus bits
>   * @fmp_mask: mask for Fast Mode Plus bits in set register
>   * @wakeup_src: boolean to know if the device is a wakeup source
> + * @smbus_mode: states that the controller is configured in SMBus mode
> + * @host_notify_client: SMBus host-notify client
>   */
>  struct stm32f7_i2c_dev {
>  	struct i2c_adapter adap;
> @@ -327,6 +331,8 @@ struct stm32f7_i2c_dev {
>  	u32 fmp_creg;
>  	u32 fmp_mask;
>  	bool wakeup_src;
> +	bool smbus_mode;
> +	struct i2c_client *host_notify_client;
>  };
>  
>  /*
> @@ -1321,10 +1327,18 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
>  	int i;
>  
>  	/*
> -	 * slave[0] supports 7-bit and 10-bit slave address
> -	 * slave[1] supports 7-bit slave address only
> +	 * slave[0] support only SMBus Host address (0x8)
> +	 * slave[1] supports 7-bit and 10-bit slave address
> +	 * slave[2] supports 7-bit slave address only
>  	 */
> -	for (i = STM32F7_I2C_MAX_SLAVE - 1; i >= 0; i--) {
> +	if (i2c_dev->smbus_mode && (slave->addr == 0x08)) {
> +		if (i2c_dev->slave[0])
> +			goto fail;
> +		*id = 0;
> +		return 0;
> +	}
> +
> +	for (i = STM32F7_I2C_MAX_SLAVE - 1; i > 0; i--) {
>  		if (i == 1 && (slave->flags & I2C_CLIENT_TEN))
>  			continue;
>  		if (!i2c_dev->slave[i]) {
> @@ -1333,6 +1347,7 @@ static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
>  		}
>  	}
>  
> +fail:
>  	dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);
>  
>  	return -EINVAL;
> @@ -1776,7 +1791,13 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
>  	if (!stm32f7_i2c_is_slave_registered(i2c_dev))
>  		stm32f7_i2c_enable_wakeup(i2c_dev, true);
>  
> -	if (id == 0) {
> +	switch (id) {
> +	case 0:
> +		/* Slave SMBus Host */
> +		i2c_dev->slave[id] = slave;
> +		break;
> +
> +	case 1:
>  		/* Configure Own Address 1 */
>  		oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
>  		oar1 &= ~STM32F7_I2C_OAR1_MASK;
> @@ -1789,7 +1810,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
>  		oar1 |= STM32F7_I2C_OAR1_OA1EN;
>  		i2c_dev->slave[id] = slave;
>  		writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
> -	} else if (id == 1) {
> +		break;
> +
> +	case 2:
>  		/* Configure Own Address 2 */
>  		oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
>  		oar2 &= ~STM32F7_I2C_OAR2_MASK;
> @@ -1802,7 +1825,10 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
>  		oar2 |= STM32F7_I2C_OAR2_OA2EN;
>  		i2c_dev->slave[id] = slave;
>  		writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
> -	} else {
> +		break;
> +
> +	default:
> +		dev_err(dev, "I2C slave id not supported\n");
>  		ret = -ENODEV;
>  		goto pm_free;
>  	}
> @@ -1843,10 +1869,10 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
>  	if (ret < 0)
>  		return ret;
>  
> -	if (id == 0) {
> +	if (id == 1) {
>  		mask = STM32F7_I2C_OAR1_OA1EN;
>  		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
> -	} else {
> +	} else if (id == 2) {
>  		mask = STM32F7_I2C_OAR2_OA2EN;
>  		stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
>  	}
> @@ -1911,14 +1937,51 @@ static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
>  					  &i2c_dev->fmp_mask);
>  }
>  
> +static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
> +{
> +	struct i2c_adapter *adap = &i2c_dev->adap;
> +	void __iomem *base = i2c_dev->base;
> +	struct i2c_client *client;
> +
> +	client = i2c_new_slave_host_notify_device(adap);
> +	if (IS_ERR(client))
> +		return PTR_ERR(client);
> +
> +	i2c_dev->host_notify_client = client;
> +
> +	/* Enable SMBus Host address */
> +	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN);
> +
> +	return 0;
> +}
> +
> +static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
> +{
> +	void __iomem *base = i2c_dev->base;
> +
> +	if (i2c_dev->host_notify_client) {
> +		/* Disable SMBus Host address */
> +		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
> +				     STM32F7_I2C_CR1_SMBHEN);
> +		i2c_free_slave_host_notify_device(i2c_dev->host_notify_client);
> +	}
> +}
> +
>  static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
>  {
> -	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
> -		I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
> -		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
> -		I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
> -		I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
> -		I2C_FUNC_SMBUS_I2C_BLOCK;
> +	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
> +
> +	u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
> +		   I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
> +		   I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
> +		   I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
> +		   I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
> +		   I2C_FUNC_SMBUS_I2C_BLOCK;
> +
> +	if (i2c_dev->smbus_mode)
> +		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
> +
> +	return func;
>  }
>  
>  static const struct i2c_algorithm stm32f7_i2c_algo = {
> @@ -2084,10 +2147,22 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
>  
>  	stm32f7_i2c_hw_config(i2c_dev);
>  
> +	i2c_dev->smbus_mode = of_property_read_bool(pdev->dev.of_node, "smbus");
> +
>  	ret = i2c_add_adapter(adap);
>  	if (ret)
>  		goto pm_disable;
>  
> +	if (i2c_dev->smbus_mode) {
> +		ret = stm32f7_i2c_enable_smbus_host(i2c_dev);
> +		if (ret) {
> +			dev_err(i2c_dev->dev,
> +				"failed to enable SMBus Host-Notify protocol (%d)\n",
> +				ret);
> +			goto i2c_adapter_remove;
> +		}
> +	}
> +
>  	dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
>  
>  	pm_runtime_mark_last_busy(i2c_dev->dev);
> @@ -2095,6 +2170,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> +i2c_adapter_remove:
> +	i2c_del_adapter(adap);
> +
>  pm_disable:
>  	pm_runtime_put_noidle(i2c_dev->dev);
>  	pm_runtime_disable(i2c_dev->dev);
> @@ -2126,6 +2204,8 @@ static int stm32f7_i2c_remove(struct platform_device *pdev)
>  {
>  	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
>  
> +	stm32f7_i2c_disable_smbus_host(i2c_dev);
> +
>  	i2c_del_adapter(&i2c_dev->adap);
>  	pm_runtime_get_sync(i2c_dev->dev);
>  
> 

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Re: [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify

[Wolfram Sang]

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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!


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Re: [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify

[Wolfram Sang]

[-- Attachment #1.1: Type: text/plain, Size: 770 bytes --]

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!


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Re: [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support

[Wolfram Sang]

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On Mon, Aug 03, 2020 at 07:17:56AM +0200, Alain Volmat wrote:
> Rely on the core functions to implement the host-notify
> protocol via the a I2C slave device.
> 
> Signed-off-by: Alain Volmat <alain.volmat@st.com>

Applied to for-next, thanks!


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Re: [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support

[Wolfram Sang]

[-- Attachment #1.1: Type: text/plain, Size: 253 bytes --]

On Mon, Aug 03, 2020 at 07:17:56AM +0200, Alain Volmat wrote:
> Rely on the core functions to implement the host-notify
> protocol via the a I2C slave device.
> 
> Signed-off-by: Alain Volmat <alain.volmat@st.com>

Applied to for-next, thanks!


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