| Message ID | 1616075089-28115-3-git-send-email-alain.volmat@foss.st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | i2c: stm32f7: add SMBus-Alert support | expand |
Hi All On 3/18/21 2:44 PM, Alain Volmat wrote: > Add support for the SMBus-Alert protocol to the STM32F7 that has > dedicated control and status logic. > > If SMBus-Alert is used, the SMBALERT# pin must be configured as alternate > function for I2C Alert. > > Signed-off-by: Alain Volmat <alain.volmat@foss.st.com> > > --- > v2: - rely on st,smbus-alert binding instead of smbus > --- > drivers/i2c/busses/i2c-stm32f7.c | 73 ++++++++++++++++++++++++++++++++ > 1 file changed, 73 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c > index c62c815b88eb..bd840cd2b9e4 100644 > --- a/drivers/i2c/busses/i2c-stm32f7.c > +++ b/drivers/i2c/busses/i2c-stm32f7.c > @@ -51,6 +51,7 @@ > > /* STM32F7 I2C control 1 */ > #define STM32F7_I2C_CR1_PECEN BIT(23) > +#define STM32F7_I2C_CR1_ALERTEN BIT(22) > #define STM32F7_I2C_CR1_SMBHEN BIT(20) > #define STM32F7_I2C_CR1_WUPEN BIT(18) > #define STM32F7_I2C_CR1_SBC BIT(16) > @@ -125,6 +126,7 @@ > (((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17) > #define STM32F7_I2C_ISR_DIR BIT(16) > #define STM32F7_I2C_ISR_BUSY BIT(15) > +#define STM32F7_I2C_ISR_ALERT BIT(13) > #define STM32F7_I2C_ISR_PECERR BIT(11) > #define STM32F7_I2C_ISR_ARLO BIT(9) > #define STM32F7_I2C_ISR_BERR BIT(8) > @@ -138,6 +140,7 @@ > #define STM32F7_I2C_ISR_TXE BIT(0) > > /* STM32F7 I2C Interrupt Clear */ > +#define STM32F7_I2C_ICR_ALERTCF BIT(13) > #define STM32F7_I2C_ICR_PECCF BIT(11) > #define STM32F7_I2C_ICR_ARLOCF BIT(9) > #define STM32F7_I2C_ICR_BERRCF BIT(8) > @@ -283,6 +286,17 @@ struct stm32f7_i2c_msg { > u8 smbus_buf[I2C_SMBUS_BLOCK_MAX + 3] __aligned(4); > }; > > +/** > + * struct stm32f7_i2c_alert - SMBus alert specific data > + * @setup: platform data for the smbus_alert i2c client > + * @ara: I2C slave device used to respond to the SMBus Alert with Alert > + * Response Address > + */ > +struct stm32f7_i2c_alert { > + struct i2c_smbus_alert_setup setup; > + struct i2c_client *ara; > +}; > + > /** > * struct stm32f7_i2c_dev - private data of the controller > * @adap: I2C adapter for this controller > @@ -312,6 +326,7 @@ struct stm32f7_i2c_msg { > * @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 > + * @alert: SMBus alert specific data > */ > struct stm32f7_i2c_dev { > struct i2c_adapter adap; > @@ -340,6 +355,7 @@ struct stm32f7_i2c_dev { > bool wakeup_src; > bool smbus_mode; > struct i2c_client *host_notify_client; > + struct stm32f7_i2c_alert *alert; > }; > > /* > @@ -1616,6 +1632,13 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) > f7_msg->result = -EINVAL; > } > > + if (status & STM32F7_I2C_ISR_ALERT) { > + dev_dbg(dev, "<%s>: SMBus alert received\n", __func__); > + writel_relaxed(STM32F7_I2C_ICR_ALERTCF, base + STM32F7_I2C_ICR); > + i2c_handle_smbus_alert(i2c_dev->alert->ara); > + return IRQ_HANDLED; > + } > + > if (!i2c_dev->slave_running) { > u32 mask; > /* Disable interrupts */ > @@ -1982,6 +2005,42 @@ static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev) > } > } > > +static int stm32f7_i2c_enable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev) > +{ > + struct stm32f7_i2c_alert *alert; > + struct i2c_adapter *adap = &i2c_dev->adap; > + struct device *dev = i2c_dev->dev; > + void __iomem *base = i2c_dev->base; > + > + alert = devm_kzalloc(dev, sizeof(*alert), GFP_KERNEL); > + if (!alert) > + return -ENOMEM; > + > + alert->ara = i2c_new_smbus_alert_device(adap, &alert->setup); > + if (IS_ERR(alert->ara)) > + return PTR_ERR(alert->ara); > + > + i2c_dev->alert = alert; > + > + /* Enable SMBus Alert */ > + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_ALERTEN); > + > + return 0; > +} > + > +static void stm32f7_i2c_disable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev) > +{ > + struct stm32f7_i2c_alert *alert = i2c_dev->alert; > + void __iomem *base = i2c_dev->base; > + > + if (alert) { > + /* Disable SMBus Alert */ > + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, > + STM32F7_I2C_CR1_ALERTEN); > + i2c_unregister_device(alert->ara); > + } > +} > + > static u32 stm32f7_i2c_func(struct i2c_adapter *adap) > { > struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap); > @@ -2169,6 +2228,16 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) > } > } > > + if (of_property_read_bool(pdev->dev.of_node, "st,smbus-alert")) { > + ret = stm32f7_i2c_enable_smbus_alert(i2c_dev); > + if (ret) { > + dev_err(i2c_dev->dev, > + "failed to enable SMBus alert protocol (%d)\n", > + ret); > + goto i2c_disable_smbus_host; > + } > + } > + > dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr); > > pm_runtime_mark_last_busy(i2c_dev->dev); > @@ -2176,6 +2245,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) > > return 0; > > +i2c_disable_smbus_host: > + stm32f7_i2c_disable_smbus_host(i2c_dev); > + > i2c_adapter_remove: > i2c_del_adapter(adap); > > @@ -2210,6 +2282,7 @@ static int stm32f7_i2c_remove(struct platform_device *pdev) > { > struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev); > > + stm32f7_i2c_disable_smbus_alert(i2c_dev); > stm32f7_i2c_disable_smbus_host(i2c_dev); > > i2c_del_adapter(&i2c_dev->adap); > Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com> Regards
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index c62c815b88eb..bd840cd2b9e4 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -51,6 +51,7 @@ /* STM32F7 I2C control 1 */ #define STM32F7_I2C_CR1_PECEN BIT(23) +#define STM32F7_I2C_CR1_ALERTEN BIT(22) #define STM32F7_I2C_CR1_SMBHEN BIT(20) #define STM32F7_I2C_CR1_WUPEN BIT(18) #define STM32F7_I2C_CR1_SBC BIT(16) @@ -125,6 +126,7 @@ (((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17) #define STM32F7_I2C_ISR_DIR BIT(16) #define STM32F7_I2C_ISR_BUSY BIT(15) +#define STM32F7_I2C_ISR_ALERT BIT(13) #define STM32F7_I2C_ISR_PECERR BIT(11) #define STM32F7_I2C_ISR_ARLO BIT(9) #define STM32F7_I2C_ISR_BERR BIT(8) @@ -138,6 +140,7 @@ #define STM32F7_I2C_ISR_TXE BIT(0) /* STM32F7 I2C Interrupt Clear */ +#define STM32F7_I2C_ICR_ALERTCF BIT(13) #define STM32F7_I2C_ICR_PECCF BIT(11) #define STM32F7_I2C_ICR_ARLOCF BIT(9) #define STM32F7_I2C_ICR_BERRCF BIT(8) @@ -283,6 +286,17 @@ struct stm32f7_i2c_msg { u8 smbus_buf[I2C_SMBUS_BLOCK_MAX + 3] __aligned(4); }; +/** + * struct stm32f7_i2c_alert - SMBus alert specific data + * @setup: platform data for the smbus_alert i2c client + * @ara: I2C slave device used to respond to the SMBus Alert with Alert + * Response Address + */ +struct stm32f7_i2c_alert { + struct i2c_smbus_alert_setup setup; + struct i2c_client *ara; +}; + /** * struct stm32f7_i2c_dev - private data of the controller * @adap: I2C adapter for this controller @@ -312,6 +326,7 @@ struct stm32f7_i2c_msg { * @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 + * @alert: SMBus alert specific data */ struct stm32f7_i2c_dev { struct i2c_adapter adap; @@ -340,6 +355,7 @@ struct stm32f7_i2c_dev { bool wakeup_src; bool smbus_mode; struct i2c_client *host_notify_client; + struct stm32f7_i2c_alert *alert; }; /* @@ -1616,6 +1632,13 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) f7_msg->result = -EINVAL; } + if (status & STM32F7_I2C_ISR_ALERT) { + dev_dbg(dev, "<%s>: SMBus alert received\n", __func__); + writel_relaxed(STM32F7_I2C_ICR_ALERTCF, base + STM32F7_I2C_ICR); + i2c_handle_smbus_alert(i2c_dev->alert->ara); + return IRQ_HANDLED; + } + if (!i2c_dev->slave_running) { u32 mask; /* Disable interrupts */ @@ -1982,6 +2005,42 @@ static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev) } } +static int stm32f7_i2c_enable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_alert *alert; + struct i2c_adapter *adap = &i2c_dev->adap; + struct device *dev = i2c_dev->dev; + void __iomem *base = i2c_dev->base; + + alert = devm_kzalloc(dev, sizeof(*alert), GFP_KERNEL); + if (!alert) + return -ENOMEM; + + alert->ara = i2c_new_smbus_alert_device(adap, &alert->setup); + if (IS_ERR(alert->ara)) + return PTR_ERR(alert->ara); + + i2c_dev->alert = alert; + + /* Enable SMBus Alert */ + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_ALERTEN); + + return 0; +} + +static void stm32f7_i2c_disable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_alert *alert = i2c_dev->alert; + void __iomem *base = i2c_dev->base; + + if (alert) { + /* Disable SMBus Alert */ + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_ALERTEN); + i2c_unregister_device(alert->ara); + } +} + static u32 stm32f7_i2c_func(struct i2c_adapter *adap) { struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap); @@ -2169,6 +2228,16 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) } } + if (of_property_read_bool(pdev->dev.of_node, "st,smbus-alert")) { + ret = stm32f7_i2c_enable_smbus_alert(i2c_dev); + if (ret) { + dev_err(i2c_dev->dev, + "failed to enable SMBus alert protocol (%d)\n", + ret); + goto i2c_disable_smbus_host; + } + } + dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr); pm_runtime_mark_last_busy(i2c_dev->dev); @@ -2176,6 +2245,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) return 0; +i2c_disable_smbus_host: + stm32f7_i2c_disable_smbus_host(i2c_dev); + i2c_adapter_remove: i2c_del_adapter(adap); @@ -2210,6 +2282,7 @@ static int stm32f7_i2c_remove(struct platform_device *pdev) { struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev); + stm32f7_i2c_disable_smbus_alert(i2c_dev); stm32f7_i2c_disable_smbus_host(i2c_dev); i2c_del_adapter(&i2c_dev->adap);
Add support for the SMBus-Alert protocol to the STM32F7 that has dedicated control and status logic. If SMBus-Alert is used, the SMBALERT# pin must be configured as alternate function for I2C Alert. Signed-off-by: Alain Volmat <alain.volmat@foss.st.com> --- v2: - rely on st,smbus-alert binding instead of smbus --- drivers/i2c/busses/i2c-stm32f7.c | 73 ++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+)