* [PATCH v3 0/2] i2c: stm32: add host-notify support via i2c slave
@ 2020-08-03 5:17 Alain Volmat
2020-08-03 5:17 ` [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify Alain Volmat
2020-08-03 5:17 ` [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support Alain Volmat
0 siblings, 2 replies; 7+ messages in thread
From: Alain Volmat @ 2020-08-03 5:17 UTC (permalink / raw)
To: wsa, pierre-yves.mordret
Cc: alexandre.torgue, linux-kernel, alain.volmat, linux-i2c,
fabrice.gasnier, linux-stm32, linux-arm-kernel
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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^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify
2020-08-03 5:17 [PATCH v3 0/2] i2c: stm32: add host-notify support via i2c slave Alain Volmat
@ 2020-08-03 5:17 ` Alain Volmat
2020-08-04 14:03 ` Pierre Yves MORDRET
2020-09-09 8:39 ` Wolfram Sang
2020-08-03 5:17 ` [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support Alain Volmat
1 sibling, 2 replies; 7+ messages in thread
From: Alain Volmat @ 2020-08-03 5:17 UTC (permalink / raw)
To: wsa, pierre-yves.mordret
Cc: alexandre.torgue, linux-kernel, alain.volmat, linux-i2c,
fabrice.gasnier, linux-stm32, linux-arm-kernel
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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^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support
2020-08-03 5:17 [PATCH v3 0/2] i2c: stm32: add host-notify support via i2c slave Alain Volmat
2020-08-03 5:17 ` [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify Alain Volmat
@ 2020-08-03 5:17 ` Alain Volmat
2020-08-04 14:04 ` Pierre Yves MORDRET
2020-09-09 8:39 ` Wolfram Sang
1 sibling, 2 replies; 7+ messages in thread
From: Alain Volmat @ 2020-08-03 5:17 UTC (permalink / raw)
To: wsa, pierre-yves.mordret
Cc: alexandre.torgue, linux-kernel, alain.volmat, linux-i2c,
fabrice.gasnier, linux-stm32, linux-arm-kernel
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
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify
2020-08-03 5:17 ` [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify Alain Volmat
@ 2020-08-04 14:03 ` Pierre Yves MORDRET
2020-09-09 8:39 ` Wolfram Sang
1 sibling, 0 replies; 7+ messages in thread
From: Pierre Yves MORDRET @ 2020-08-04 14:03 UTC (permalink / raw)
To: Alain Volmat, wsa
Cc: alexandre.torgue, linux-kernel, linux-i2c, fabrice.gasnier,
linux-stm32, linux-arm-kernel
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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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support
2020-08-03 5:17 ` [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support Alain Volmat
@ 2020-08-04 14:04 ` Pierre Yves MORDRET
2020-09-09 8:39 ` Wolfram Sang
1 sibling, 0 replies; 7+ messages in thread
From: Pierre Yves MORDRET @ 2020-08-04 14:04 UTC (permalink / raw)
To: Alain Volmat, wsa
Cc: alexandre.torgue, linux-kernel, linux-i2c, fabrice.gasnier,
linux-stm32, linux-arm-kernel
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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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify
2020-08-03 5:17 ` [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify Alain Volmat
2020-08-04 14:03 ` Pierre Yves MORDRET
@ 2020-09-09 8:39 ` Wolfram Sang
1 sibling, 0 replies; 7+ messages in thread
From: Wolfram Sang @ 2020-09-09 8:39 UTC (permalink / raw)
To: Alain Volmat
Cc: alexandre.torgue, linux-kernel, pierre-yves.mordret, linux-i2c,
fabrice.gasnier, linux-stm32, linux-arm-kernel
[-- 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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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support
2020-08-03 5:17 ` [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support Alain Volmat
2020-08-04 14:04 ` Pierre Yves MORDRET
@ 2020-09-09 8:39 ` Wolfram Sang
1 sibling, 0 replies; 7+ messages in thread
From: Wolfram Sang @ 2020-09-09 8:39 UTC (permalink / raw)
To: Alain Volmat
Cc: alexandre.torgue, linux-kernel, pierre-yves.mordret, linux-i2c,
fabrice.gasnier, linux-stm32, linux-arm-kernel
[-- 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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^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2020-09-09 8:41 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-03 5:17 [PATCH v3 0/2] i2c: stm32: add host-notify support via i2c slave Alain Volmat
2020-08-03 5:17 ` [PATCH v3 1/2] i2c: smbus: add core function handling SMBus host-notify Alain Volmat
2020-08-04 14:03 ` Pierre Yves MORDRET
2020-09-09 8:39 ` Wolfram Sang
2020-08-03 5:17 ` [PATCH v3 2/2] i2c: stm32f7: Add SMBus Host-Notify protocol support Alain Volmat
2020-08-04 14:04 ` Pierre Yves MORDRET
2020-09-09 8:39 ` Wolfram Sang
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