From 419be8e1dfed5afa497ca320e1b65954820b48c2 Mon Sep 17 00:00:00 2001 From: Alain Volmat Date: Mon, 3 Feb 2020 18:52:08 +0100 Subject: [PATCH] i2c: stm32f7: allow controller to be wakeup-source Allow the i2c-stm32f7 controller to become a wakeup-source of the system. In such case, when a slave is registered to the I2C controller, receiving a I2C message targeting that registered slave address wakes up the suspended system. In order to be able to wake-up, the I2C controller DT node must have the property wakeup-source defined and a slave must be registered. Signed-off-by: Alain Volmat Reviewed-by: Pierre-Yves MORDRET Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-stm32f7.c | 107 +++++++++++++++++++++++++------ 1 file changed, 86 insertions(+), 21 deletions(-) diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index 5c3e8ac6ad92..378956ac6d1d 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -49,6 +50,7 @@ /* STM32F7 I2C control 1 */ #define STM32F7_I2C_CR1_PECEN BIT(23) +#define STM32F7_I2C_CR1_WUPEN BIT(18) #define STM32F7_I2C_CR1_SBC BIT(16) #define STM32F7_I2C_CR1_RXDMAEN BIT(15) #define STM32F7_I2C_CR1_TXDMAEN BIT(14) @@ -301,6 +303,7 @@ struct stm32f7_i2c_msg { * @dma: dma data * @use_dma: boolean to know if dma is used in the current transfer * @regmap: holds SYSCFG phandle for Fast Mode Plus bits + * @wakeup_src: boolean to know if the device is a wakeup source */ struct stm32f7_i2c_dev { struct i2c_adapter adap; @@ -323,6 +326,7 @@ struct stm32f7_i2c_dev { struct stm32_i2c_dma *dma; bool use_dma; struct regmap *regmap; + bool wakeup_src; }; /* @@ -1691,6 +1695,24 @@ pm_free: return ret; } +static void stm32f7_i2c_enable_wakeup(struct stm32f7_i2c_dev *i2c_dev, + bool enable) +{ + void __iomem *base = i2c_dev->base; + u32 mask = STM32F7_I2C_CR1_WUPEN; + + if (!i2c_dev->wakeup_src) + return; + + if (enable) { + device_set_wakeup_enable(i2c_dev->dev, true); + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask); + } else { + device_set_wakeup_enable(i2c_dev->dev, false); + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask); + } +} + static int stm32f7_i2c_reg_slave(struct i2c_client *slave) { struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter); @@ -1717,6 +1739,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave) if (ret < 0) return ret; + if (!stm32f7_i2c_is_slave_registered(i2c_dev)) + stm32f7_i2c_enable_wakeup(i2c_dev, true); + if (id == 0) { /* Configure Own Address 1 */ oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1); @@ -1758,6 +1783,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave) ret = 0; pm_free: + if (!stm32f7_i2c_is_slave_registered(i2c_dev)) + stm32f7_i2c_enable_wakeup(i2c_dev, false); + pm_runtime_mark_last_busy(dev); pm_runtime_put_autosuspend(dev); @@ -1791,8 +1819,10 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave) i2c_dev->slave[id] = NULL; - if (!(stm32f7_i2c_is_slave_registered(i2c_dev))) + if (!stm32f7_i2c_is_slave_registered(i2c_dev)) { stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK); + stm32f7_i2c_enable_wakeup(i2c_dev, false); + } pm_runtime_mark_last_busy(i2c_dev->dev); pm_runtime_put_autosuspend(i2c_dev->dev); @@ -1879,6 +1909,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) return irq_error ? : -ENOENT; } + i2c_dev->wakeup_src = of_property_read_bool(pdev->dev.of_node, + "wakeup-source"); + i2c_dev->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(i2c_dev->clk)) { dev_err(&pdev->dev, "Error: Missing controller clock\n"); @@ -1985,6 +2018,16 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) goto clk_free; } + if (i2c_dev->wakeup_src) { + device_set_wakeup_capable(i2c_dev->dev, true); + + ret = dev_pm_set_wake_irq(i2c_dev->dev, irq_event); + if (ret) { + dev_err(i2c_dev->dev, "Failed to set wake up irq\n"); + goto clr_wakeup_capable; + } + } + platform_set_drvdata(pdev, i2c_dev); pm_runtime_set_autosuspend_delay(i2c_dev->dev, @@ -2014,6 +2057,13 @@ pm_disable: pm_runtime_set_suspended(i2c_dev->dev); pm_runtime_dont_use_autosuspend(i2c_dev->dev); + if (i2c_dev->wakeup_src) + dev_pm_clear_wake_irq(i2c_dev->dev); + +clr_wakeup_capable: + if (i2c_dev->wakeup_src) + device_set_wakeup_capable(i2c_dev->dev, false); + if (i2c_dev->dma) { stm32_i2c_dma_free(i2c_dev->dma); i2c_dev->dma = NULL; @@ -2032,6 +2082,15 @@ static int stm32f7_i2c_remove(struct platform_device *pdev) i2c_del_adapter(&i2c_dev->adap); pm_runtime_get_sync(i2c_dev->dev); + if (i2c_dev->wakeup_src) { + dev_pm_clear_wake_irq(i2c_dev->dev); + /* + * enforce that wakeup is disabled and that the device + * is marked as non wakeup capable + */ + device_init_wakeup(i2c_dev->dev, false); + } + pm_runtime_put_noidle(i2c_dev->dev); pm_runtime_disable(i2c_dev->dev); pm_runtime_set_suspended(i2c_dev->dev); @@ -2073,8 +2132,8 @@ static int __maybe_unused stm32f7_i2c_runtime_resume(struct device *dev) return 0; } -static int __maybe_unused -stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev) +#ifdef CONFIG_PM_SLEEP +static int stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev) { int ret; struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs; @@ -2095,8 +2154,7 @@ stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev) return ret; } -static int __maybe_unused -stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev) +static int stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev) { u32 cr1; int ret; @@ -2127,41 +2185,48 @@ stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev) return ret; } -static int __maybe_unused stm32f7_i2c_suspend(struct device *dev) +static int stm32f7_i2c_suspend(struct device *dev) { struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev); int ret; i2c_mark_adapter_suspended(&i2c_dev->adap); - ret = stm32f7_i2c_regs_backup(i2c_dev); - if (ret < 0) { - i2c_mark_adapter_resumed(&i2c_dev->adap); - return ret; - } - pinctrl_pm_select_sleep_state(dev); - pm_runtime_force_suspend(dev); + if (!device_may_wakeup(dev) && !dev->power.wakeup_path) { + ret = stm32f7_i2c_regs_backup(i2c_dev); + if (ret < 0) { + i2c_mark_adapter_resumed(&i2c_dev->adap); + return ret; + } + + pinctrl_pm_select_sleep_state(dev); + pm_runtime_force_suspend(dev); + } return 0; } -static int __maybe_unused stm32f7_i2c_resume(struct device *dev) +static int stm32f7_i2c_resume(struct device *dev) { struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev); int ret; - ret = pm_runtime_force_resume(dev); - if (ret < 0) - return ret; - pinctrl_pm_select_default_state(dev); + if (!device_may_wakeup(dev) && !dev->power.wakeup_path) { + ret = pm_runtime_force_resume(dev); + if (ret < 0) + return ret; + pinctrl_pm_select_default_state(dev); + + ret = stm32f7_i2c_regs_restore(i2c_dev); + if (ret < 0) + return ret; + } - ret = stm32f7_i2c_regs_restore(i2c_dev); - if (ret < 0) - return ret; i2c_mark_adapter_resumed(&i2c_dev->adap); return 0; } +#endif static const struct dev_pm_ops stm32f7_i2c_pm_ops = { SET_RUNTIME_PM_OPS(stm32f7_i2c_runtime_suspend, -- 2.20.1