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Message-ID: <883584b6-ceab-b199-3118-e801e5109e10@st.com>
Date: Wed, 5 Feb 2020 16:40:00 +0100
From: Pierre Yves MORDRET <pierre-yves.mordret@...com>
To: Alain Volmat <alain.volmat@...com>, <wsa@...-dreams.de>
CC: <alexandre.torgue@...com>, <linux-i2c@...r.kernel.org>,
<linux-stm32@...md-mailman.stormreply.com>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <fabrice.gasnier@...com>
Subject: Re: [PATCHv2] i2c: i2c-stm32f7: allow controller to be wakeup-source
Hi all
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@...com>
Thanks
On 2/3/20 6:52 PM, Alain Volmat wrote:
> 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 <alain.volmat@...com>
> ---
> v2: - enclose _suspend and _resume functions (and related) with
> #ifdef CONFIG_PM_SLEEP
> - remove the __maybe_unused for functions enclosed with CONFIG_PM_SLEEP
> - move stm32f7_i2c_enable_wakeup function upper in the file to avoid
> having a prototype.
>
> 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 <linux/platform_device.h>
> #include <linux/pinctrl/consumer.h>
> #include <linux/pm_runtime.h>
> +#include <linux/pm_wakeirq.h>
> #include <linux/regmap.h>
> #include <linux/reset.h>
> #include <linux/slab.h>
> @@ -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 @@ static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
> 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 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
> 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,
>
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